Researcher basic information

• Doctor of Fisheries Sciences, Hokkaido University, Hokkaido University

• https://researchmap.jp/1175_SalMon?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200901028361363949

• 200901028361363949

• cosmetics
• chondroitin sulfate
• collagen peptide
• collagenous scaffold
• ECM
• collagen
• 魚類生理学
• Fish Physiology

• Life Science, Aquatic life science, collagen peptide hydrolysate chondroitin sulfate
• Life Science, Aquatic bioproduction science, sturgeon aquaculture caviar regional activation industry-academia-government collaboration
• Life Science, Cell biology, extracellular matrix regulation of cellular activity
• Nanotechnology/Materials, Organic functional materials, Collagen cell scaffold tissue engineering regenerative medicine

• Bachelor's degree program, School of Fisheries Sciences
• Master's degree program, Graduate School of Fisheries Sciences
• Doctoral (PhD) degree program, Graduate School of Fisheries Sciences

Research activity information

• 1998, 1998: Best Oral Presentation Award, 2nd International Symposium on Fish Otolith Research and Application

• Potential role of COUP-TF in regulating major yolk protein gene expression in sea urchin.
  Ichiro Higuchi; Shiori Tsue; Yudai Kitano; Osamu Nishimiya; Masashi Hosokawa; Fumiaki Beppu; Kazuhiro Ura; Yasuaki Takagi
  General and comparative endocrinology, 376, 114867, 114867, Jan. 2026, [International Magazine]
  English, Scientific journal, Major yolk protein (MYP) serves as a critical nutrient reservoir for gonadal development in sea urchins, but the transcriptional regulation of its encoding gene remains largely uncharacterized. Here, we cloned and analyzed the MYP promoter from Mesocentrotus nudus and found two conserved elements with putative binding sites for the orphan nuclear receptor COUP-TF (chicken ovalbumin upstream promoter-transcription factor). We cloned the full-length cDNA encoding COUP-TF from M. nudus (MnCOUP-TF). The cDNA encoded a 472-amino acid protein highly homologous to other COUP-TF/SVP subfamily members. RT-PCR and qPCR analyses revealed that transcripts of both MnCOUP-TF and MYP were present in several tissues, including gonads, and their levels exhibited a significant positive correlation during gonadal maturation (R2 = 0.6764, p < 0.01). Electrophoretic mobility shift assays demonstrated specific binding of MnCOUP-TF to the MYP promoter, and transactivation assays showed that MnCOUP-TF activates transcription through these sites. Furthermore, total lipids extracted from gonadal tissue enhanced MnCOUP-TF-dependent reporter activity in a dose-dependent manner. This enhancement was comparable to the effect of 9-cis-retinoic acid, a compound known to activate COUP-TF at high concentrations, although it is not considered to be a physiological COUP-TF ligand. These results suggest that MnCOUP-TF regulates MYP expression in a ligand-dependent manner and that endogenous activators may be present in gonadal lipids. To our knowledge, this is the first molecular evidence implicating COUP-TF in yolk protein gene regulation in sea urchins, providing new insights into nuclear receptor-mediated control of reproduction in marine invertebrates.
• Comparative Study of the Gel-Forming Ability of Type I Collagens Extracted from Different Organs and Fish Species
  Abdul Ghani; Mantaro Okada; Beini Sun; Xi Zhang; Ichiro Higuchi; Yasuaki Takagi
  Gels, 11, 7, 533, 533, MDPI AG, 09 Jul. 2025, [Peer-reviewed], [Last author, Corresponding author]
  English, Scientific journal, The gel-forming ability of collagens is vital for their application in cell scaffolds, yet very few comparative studies on fish collagen sources are available. This study isolated and characterized type I collagens from carp skin (CSK), scales (CSC), and swim bladders (CSB) and sturgeon skin (SSK) and swim bladders (SSB). The carp collagens exhibited higher thermal stability (34.75–34.78 °C) and formed more transparent, stronger gels than the sturgeon collagens. Additionally, as demonstrated by scanning electron microscopy, the sturgeon collagens exhibited faster fibril formation, with visible fibrils after 3 h which grew thicker but did not form bundles. The carp collagens, in contrast, initially displayed fewer, thinner, and longer fibrils, with their formation accelerating over time and fibril bundles emerging after 24 h. All collagen solutions of 4% (w/v) exhibited shear-thinning flow behavior, with the carp-derived solutions showing higher viscosities (103–104 Pa·s) than those demonstrated by the sturgeon-derived solutions (102–103 Pa·s). The CSBs and SSBs demonstrated the highest storage (G′) and loss (G″) moduli, with the former exhibiting the lowest loss tangent (tan δ), indicative of a stronger gel structure. The gels at 24 h showed slightly poorer mechanical properties than those at 3 h. The CSC and SSB gels had the highest thermal stability. These findings highlight the distinctiveness of the characteristics of collagens and their gels, emphasizing their potential in biomaterial applications. The present study also provides a foundational framework for assessing cellular responses in a comparative context that may help in identifying the most suitable collagen types for biomedical applications.
• Identification and expression of nuclear receptor genes during nutritive phagocyte development in sea urchin Mesocentrotus nudus gonads
  Kazuhiro Ura; Shiori Tsue; Takushi Sato; Seishi Hagihara; Mizuha Satoh; Ichiro Higuchi; Heng Wang; Osamu Nishimiya; Shigeho Ijiri; Yasuaki Takagi
  General and Comparative Endocrinology, 366, 114715, 114715, Elsevier BV, Apr. 2025, [Peer-reviewed], [Last author]
  English, Scientific journal
• Properties of Skin Collagen from Southern Catfish (Silurus meridionalis) Fed with Raw and Cooked Food
  Qi Zhang; Shufang Hou; Yanmei Liu; Jia Du; Yongkang Jia; Qiushi Yang; Tingting Xu; Yasuaki Takagi; Dapeng Li; Xi Zhang
  Foods, 13, 18, 2901, 2901, MDPI AG, 13 Sep. 2024, [Peer-reviewed]
  English, Scientific journal, The southern catfish (Silurus meridionalis) is an economically important carnivorous freshwater fish in China. In this study, we compared the properties of skin collagen from southern catfish fed with raw food (RF) and cooked food (CF). The skin collagen yield in the RF group (8.66 ± 0.11%) was significantly higher than that of the CF group (8.00 ± 0.27%). SDS-PAGE, circular dichroism spectroscopy, and FTIR analyses revealed that the collagen extracted from southern catfish skin in both groups was type I collagen, with a unique triple helix structure and high purity. The thermal denaturation temperature of collagen in the RF group (35.20 ± 0.11 °C) was significantly higher than that of the CF group (34.51 ± 0.25 °C). The DPPH free radical scavenging rates were 68.30 ± 2.41% in the RF collagen and 61.78 ± 3.91% in the CF collagen, which was higher than that found in most fish collagen. Both the RF and CF groups had high ability to form fibrils in vitro. Under the same conditions, the CF group exhibited faster fibril formation and a thicker fibril diameter (p < 0.05). In addition, the RF group exhibited significantly higher expression of col1a1 compared to the CF group. These results indicated that feeding southern catfish raw food contributed to collagen production, and the collagen from these fish may have potential in biomaterial applications.
• Nuclear receptor gene expression during early gametogenesis in sea urchin Mesocentrotus nudus gonads
  Shuichiro Watanabe; Ken Matsuzaki; Utano Shimizu; Ichiro Higuchi; Takashi Todo; Yasuaki Takagi; Kazuhiro Ura
  Fisheries Science, 90, 6, 907, 924, Springer Science and Business Media LLC, 10 Jun. 2024, [Peer-reviewed]
  English, Scientific journal
• Valorization of sturgeon skin to produce biomedical-grade gelatin
  Md Rashidul Islam; Shunji Yunoki; Kazuhiro Ura; Yasuaki Takagi
  Sustainable Chemistry and Pharmacy, 39, 101612, Elsevier BV, Jun. 2024, [Peer-reviewed], [Last author]
  English, Scientific journal
• Effects of self-assembled type II collagen fibrils on the morphology and growth of pre-chondrogenic ATDC5 cells
  Linyan Shi; Kazuhiro Ura; Yasuaki Takagi
  Osteoarthritis and Cartilage Open, 6, 2, 100450, 100450, Elsevier BV, Jun. 2024, [Peer-reviewed], [Last author]
  English, Scientific journal, 45267556
• Effects of different culture salinities on the growth and muscle quality of grass carp (Ctenopharyngodon idellus)
  Yongkang Jia; Jia Du; Rujuan Xi; Qi Zhang; Li Li; Dapeng Li; Yasuaki Takagi; Xi Zhang
  Journal of Animal Science, 102, Oxford University Press (OUP), 03 Jan. 2024, [Peer-reviewed]
  English, Scientific journal, Abstract
  
  Grass carp (Ctenopharyngodon idellus) is an economically important farmed fish. This experiment was conducted to study the effects of different culture salinities on the growth and muscle quality of grass carp. We found that salinity of 0 to 5 had no significant effect on the growth of grass carp, but it significantly decreased at salinities above 5. Compared to salinity 0, the protein content of serum was significantly higher at salinities of 3 and 5. However, all serum biochemical compound measured, except glucose and total protein, decreased significantly at salinity 9. Muscle textural properties of grass carp were significantly higher at salinities of 3 and 5 than at 0, 7, and 9. Salinities of 0 to 3 had no significant effect on muscle nutrition of grass carp, but this parameter tended to decrease at salinities above 7. Salinities of 3 and 5 significantly favored muscle growth and expression of collagen-related genes, whereas the opposite was true for salinities of 7 and 9. These results indicated that grass carp grew normally at salinities of 3 and 5, with some improvement in muscle quality, whereas salinities of 7 and 9 had a negative effect on growth and quality. Therefore, appropriate salinity levels can help to improve the muscle quality of grass carp without affecting their growth.
• Valorization of sturgeon notochord to obtain antioxidant non-collagenous peptides from the purification process of chondroitin sulfate
  Dawei Meng; Yasuaki Takagi
  Sustainable Chemistry and Pharmacy, 36, 101299, 101299, Elsevier BV, Dec. 2023, [Peer-reviewed], [Last author]
  English, Scientific journal
• Fibroblast-activating potency of a hydrolysate of purified collagen and a tissue hydrolysate from sturgeon skin
  Naoya Terauchi; Dawei Meng; Wen Li; Haruto Inada; Kazuhiro Ura; Yasuaki Takagi
  Fisheries Science, 89, 4, 527, 535, Springer Science and Business Media LLC, 12 May 2023, [Peer-reviewed], [Corresponding author]
  English, Scientific journal, 14203650
• Production and antioxidant activity of peptides from sturgeon head
  Md Rashidul Islam; Wen Li; Yumi Ogata; Takeya Yoshioka; Kazuhiro Ura; Takagi Yasuaki
  Sustainable Chemistry and Pharmacy, 31, 100944, 100944, Elsevier BV, Apr. 2023, [Peer-reviewed], [Last author]
  English, Scientific journal
• Advanced Utilization of By-Product from the Sturgeon Aquaculture Industry: Optimum Preparation of Notochord-Derived Multifunctional Peptides by Glycation using the Maillard Reaction
  Boxue Yang; Wenzhao Li; Asuka Ishii; Ga-hyun Joe; Yutaka Shimizu; Yasuaki Takagi; Hiroki Saeki
  Waste and Biomass Valorization, Springer Science and Business Media LLC, 24 Mar. 2023
  Scientific journal
• Extraction of chondroitin sulfate and type II collagen from sturgeon (Acipenser gueldenstaedti) notochord and characterization of their hybrid fibrils
  Dawei Meng; Wen Li; Xiaoqian Leng; Yasuaki Takagi; Zhiyuan Dai; Hao Du; Qiwei Wei
  Process Biochemistry, 124, 180, 188, Elsevier BV, Jan. 2023, [Peer-reviewed]
  English, Scientific journal
• Comparation of the structural characteristics and biological activities of chondroitin sulfates extracted from notochord and backbone of Chinese sturgeon (Acipenser sinensis)
  Dawei Meng; Xiaoqian Leng; Yan Zhang; Jiang Luo; Hao Du; Yasuaki Takagi; Zhiyuan Dai; Qiwei Wei
  Carbohydrate Research, 522, 108685, 108685, Elsevier BV, Dec. 2022, [Peer-reviewed]
  English, Scientific journal
• Industrial application of fish cartilaginous tissues
  Wen Li; Kazuhiro Ura; Yasuaki Takagi
  Current Research in Food Science, 5, 698, 709, Elsevier BV, Apr. 2022, [Peer-reviewed], [Last author]
  English, Scientific journal
• Cloning of cDNA encoding a newly recognized apolipoprotein-like protein and its expression in the northern sea urchin Mesocentrotus nudus
  Tomoharu Yuhi; Osamu Nishimiya; Kaoru Ohno; Asami Takita; Takako Inoguchi; Kazuhiro Ura; Yasuaki Takagi
  Fisheries Science, 88, 2, 259, 273, Mar. 2022, [Peer-reviewed], [Last author]
  English, Scientific journal
• Preparation of collagen nanofibril-scaffold from the skin of catfish (Pangasianodon hypophthalmus) farmed in the Mekong Delta.
  Ho QP; Thi MTL; Huynh LH; Tran MP; Thi BTN; Takagi Y
  AACL Bioflux, 124, 180, 188, 2022, [Peer-reviewed], [Last author]
  English, Scientific journal
• Antioxidant and fibroblast-activating activities of the by-product of skate chondroitin extractive production
  Wen Li; Naoya Terauchi; Dawei Meng; Nobuyuki Miyamoto; Naonobu Tsutsumi; Kazuhiro Ura; Yasuaki Takagi
  Sustainable Chemistry and Pharmacy, 23, 100499, 100499, Elsevier BV, Oct. 2021, [Peer-reviewed], [Last author]
  English, Scientific journal
• Incorporation of amine functional group on surface of hydroxyapatite prepared fromstriped catfish (Pagasianodon hypophthalmus) bone
  Quoc Phong Ho; Takagi Yasuaki; Lien Huong Huynh; Thanh Tuyen Nguyen; Minh Phu Tran; Thi Minh Thuy Le; Luu Ngoc Hanh Cao
  Can Tho University Journal of Science, 13, Aquaculture, 64, 72, Can Tho University, 30 Jun. 2021, [Peer-reviewed]
  Scientific journal, This study was conducted to incorporate amine functional groups on the surface of hydroxyapatite to enhance its potential application in biomedical materials. Hydroxyapatite particles (HA) were synthesized from striped catfish (Pagasianodon hypophthalmus) bone and surface modified by grafting with (3-aminopropyl)triethoxysilane (APTES). Important factors affected grafting efficiency such as concentration of APTES, water content, reaction temperature and reaction time were studied. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) were used to confirm the grafting reaction on HA surfaces. Grafting efficiency was evaluated based on intensity of characteristic absorption peaks of APTES. The experimental results showed that amine functional groups were successfully introduced on HA surface at optimal condition of 0.2 M APTES, 0.75 wt.% water content, at 60°C and 12-hour reaction time.
• Effects of temperature on growth performance, survival rate, digestive enzyme activities and physiological parameters of striped snakehead (Channa striata) at fry stage
  Thi Thanh Huong Do; Thi Kim Ha Nguyen; Tinh Em Nguyen; Minh Ky Tang; Takagi Yasuaki; Thanh Phuong Nguyen
  Can Tho University Journal of Science, 13, Aquaculture, 10, 20, Can Tho University, 30 Jun. 2021, [Peer-reviewed]
  English, Scientific journal, The effects of temperature on growth performance, survival rate, digestive enzymatic activities, and physiological responses of striped snakehead (Channa striata) at fry stage were evaluated. The study consisted of two trials including (1) determination of temperature threshold and (2) effects of different temperatures (24°C, 27°C (control), 30°C, 33°C and 36°C) on growth performance, survival rate, digestive enzyme activities and physiological parameters of striped snakehead fry stage for 90 days. The growth experiment was conducted in 500-L tank (250-L water) with triplicates. The stocking density was 300 individuals per tank. Striped snakehead at fry stage showed a high tolerance to temperature ranging from 10 to 40ºC. After 90 days, fish reared in 30°C performed the greatest weight and survival rate (13.1±3.12 g/fish and 15.5±4.63%, respectively). The number of red blood cells and hemoglobin concentrations increased with the increase in temperature. It was discovered that different temperatures (from 27 to 36°C) did not significantly influence the number of white blood cells, osmolality, and ion concentration of fish. Glucose and cortisol concentrations increased with temperature rises and peaked in fish reared at 36°C, while temperatures of 30oC and 33oC showed higher digestive enzyme activities. It proves that 30°C is the optimal level for striped snakehead fry rearing.
• Nghiên cứu gắn kết collagen da cá tra lên bề mặt hydroxyapatite từ xương cá tra
  Hồ Quốc Phong; Ngọc Gia Ngân Võ; Huỳnh Liên Hương; Takagi Yasuaki; Lê Thị Minh Thủy; Nguyễn Việt Bách
  Can Tho University Journal of Science, 57, 3, 1, 9, Can Tho University, 30 Jun. 2021, [Peer-reviewed]
  Vietnamese, Scientific journal, Nghiên cứu được tiến hành nhằm gắn kết collagen trích ly từ da cá tra (Pangasiidae) lên bề mặt hydroxyapatite (HA) tổng hợp từ xương cá tra làm tăng khả năng ứng dụng trong lĩnh vực y sinh. Sau khi trích ly, collagen được gắn kết lên bề mặt HA thông qua cầu nối glutaraldehyde. Các hạt HA trước tiên gắn kết với 3 – amino propyl triethoxysilane (APTES) tạo nhóm chức amine trên bề mặt. Glutaraldehyde là cầu nối gắn kết HA và collagen thông qua phản ứng giữa nhóm chức amine và aldehyde. Các yếu tố ảnh đến sự gắn kết như nồng độ collagen, pH dung dịch phản ứng, thời gian và nhiệt độ của phản ứng được tiến hành khảo sát. Kết quả thí nghiệm cho thấy nồng độ collagen 1 mg/mL, dung dịch acetic acid hòa tan collagen có pH 3, thời gian phản ứng 3 giờ và nhiệt độ phản ứng 37C là điều kiện thích hợp để tiến hành gắn kết. Ngoài ra, kết quả chụp SEM cho thấy rằng các hạt HA được chế tạo có kích thước khoảng 1.000 nm và bị phủ một lớp collagen sau khi gắn kết.
• Free radical scavenging activity of type II collagen peptides and chondroitin sulfate oligosaccharides from by-products of mottled skate processing
  Wen Li; Taishi Kobayashi; DaWei Meng; Nobuyuki Miyamoto; Naonobu Tsutsumi; Kazuhiro Ura; Yasuaki Takagi
  Food Bioscience, 41, 100991, 100991, Elsevier BV, Jun. 2021, [Peer-reviewed], [Last author]
  English, Scientific journal
• Purity and properties of gelatins extracted from the head tissue of the hybrid kalamtra sturgeon
  Md. Rashidul Islam; Tomoharu Yuhi; Dawei Meng; Takeya Yoshioka; Yumi Ogata; Kazuhiro Ura; Yasuaki Takagi
  LWT-Food Science and Technology, 142, 110944, 110944, Elsevier BV, May 2021, [Peer-reviewed], [Last author]
  English, Scientific journal, 14203650
• Feasibility of collagens obtained from bester sturgeon Huso huso × Acipenser ruthenus for industrial use
  Xi Zhang; Huiyan Zhang; Shigeru Toriumi; Kazuhiro Ura; Yasuaki Takagi
  Aquaculture, 529, 735641, 735641, Elsevier BV, Dec. 2020, [Peer-reviewed], [Last author]
  English, Scientific journal
• Optimization of Extraction of Gelatin from the Head of Kalamtra Sturgeon (Huso dauricus × Acipenser scherenkii × Acipenser transmontanus)
  Md. Rashidul Islam; Tomoharu Yuhi; Kazuhiro Ura; Yasuaki Takagi
  Applied Sciences, 10, 19, 6660, 6660, MDPI AG, 23 Sep. 2020, [Peer-reviewed], [Last author]
  English, Scientific journal, To develop a new method for extracting gelatin from the sturgeon head, the conditions for pretreatment and extraction were optimized. Treatment at 65 °C (3–3.5 h) was enough to separate the head into mixed tissues (skin, scales, pectoral fins, muscle, bones, gills, and small cartilage pieces), skull cartilage, and liquid. From the intensities of α-, β- and γ-bands and yields, the optimized pretreatment conditions for type A and type B gelatin were 0.05 M HCl (1 h) and 0.1 M NaOH (1 h), respectively. The best extraction conditions were: (1) for type A gelatin: with distilled water (DW) (w/v 1:5) at 35 °C, pH 7 when stirring at 200 rpm for 3 h, and (2) for type B gelatin: with DW (w/v 1:5) at 50 °C, pH 8 when stirring at 200 rpm for 1 h. After the decalcification of extracted residues with 0.05 M HCl for 3 h, re-extraction of gelatin was possible. Under the best extraction conditions, yields of type A and B gelatins were 5.01 and 7.25% (dry gelatin weight/wet sample weight), respectively. Thus, it is possible to extract an industrial amount of gelatin from sturgeon heads, making them valuable by-products., 14203650
• Effects of phosphate ion concentration on in-vitro fibrillogenesis of sturgeon type I collagen
  Dawei Meng; Wen Li; Kazuhiro Ura; Yasuaki Takagi
  International Journal of Biological Macromolecules, 148, 182, 191, Elsevier BV, Apr. 2020, [Peer-reviewed], [Last author]
  English, Scientific journal, 14203659
• Nghiên cứu trích ly hydroxyapatite từ xương cá tra (Pangasianodon hypophthalmus)
  Hồ Quốc Phong; Phan Đình Khôi; Huỳnh Liên Hương; Nguyễn Văn Nhã; Nguyễn Thị Bích Thuyền; Yasuaki Takagi; Lê Thị Minh Thủy; Trần Minh Phú
  Can Tho University Journal of Science, 56, 199, 211, Can Tho University, 2020, [Peer-reviewed]
  Vietnamese, Scientific journal
• Ảnh hưởng của độ mặn lên chỉ tiêu sinh lý, tăng trưởng và hoạt tính men tiêu hóa của cá lóc (Channa striata) giai đoạn cá bột lên cá hương
  Đỗ Thị Thanh Hương; Tăng Minh Kỳ; Nguyễn Thị Kim Hà; Nguyễn Tính Em; Takagi Yasuaki; Nguyễn Thanh Phương
  Can Tho University Journal of Science, 56, 11, 19, Can Tho University, 2020, [Peer-reviewed]
  Vietnamese, Scientific journal
• Major yolk protein binds folic acid in sea urchin
  Ura K; Goto T; Kitano Y; Nishimiya O; Takagi Y
  Aquaculture Science, 68, 309, 316, 2020, [Peer-reviewed], [Last author]
  English, Scientific journal
• Quantitative changes of major yolk protein in the coelomic fluid and gonads of the sea urchin, Mesocentrotus nudus, during the reproductive cycle.
  Ura K; Suzuki N; Numata H; Tsue S; Satoh M; Takei N; Higuchi I; Yuhi T; Nishimiya O; Takagi Y
  Bull. Fish. Sci. Hokkaido Univ., 69, 29, 36, 2019, [Peer-reviewed], [Last author]
  English, Research institution
• Properties of collagen extracted from Amur sturgeon Acipenser schrenckii and assessment of collagen fibrils in vitro
  Zhang X; Adachi S; Ura K; Takagi Y
  Int. J. Biol. Macromol., 137, 809, 820, 2019, [Peer-reviewed], [Last author]
  English, Scientific journal
• Self-assembled collagen fibrils from the swim bladder of Bester sturgeon enable alignment of MC3T3-E1 cells and enhance osteogenic differentiation.
  Moroi S; MiuraT; Tamura T; Zhang X; Ura K; Takagi Y
  Mater. Sci. Engineer. C, 104, 109925, 2019, [Peer-reviewed], [Last author]
  English, Scientific journal
• The effect of alkaline pretreatment on the biochemical characteristics and fibril-forming abilities of types I and II collagen extracted from bester sturgeon by-products.
  Meng D; Tanaka H; Kobayashi T; Hatayama H; Zhang X; Ura K; Yunoki S; Takagi Y
  Int. J. Biol. Macromol., 131, 572, 580, 2019, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal, Non-mammalian collagens have attracted increasing attention for industrial and biomedical use. We have therefore evaluated extraction conditions and the biochemical properties of collagens from aquacultured sturgeon. Pepsin-soluble type I and type II collagen were respectively extracted from the skin and notochord of bester sturgeon by-products, with yields of 63.9 ± 0.19% and 35.5 ± 0.68%. Collagen extraction efficiency was improved by an alkaline pretreatment of the skin and notochord (fewer extraction cycles were required), but the final yields decreased to 56.2 ± 0.84% for type I and 31.8 ± 1.13% for type II. Alkaline pretreatment did not affect the thermal stability or triple-helical structure of both types of collagen. Types I and II collagen formed re-assembled fibril structures in vitro, under different conditions. Alkaline pretreatment slowed down the formation of type I collagen fibrils and specifically inhibited the formation of thick fibril-bundle structures. In contrast, alkaline pretreatment did not change type II collagen fibril formation. In conclusion, alkaline pretreatment of sturgeon skin and notochord is an effective method to accelerate collagen extraction process of types I and II collagen without changing their biochemical properties. However, it decreases the yield of both collagens and specifically changes the fibril-forming ability of type I collagen.
• Improvement of muscle quality of grass carp (Ctenopharyngodon idellus) with a bio-floating bed in culture ponds.
  Zhang X; Wang J; Tang R; He X; Li L; Takagi Y; Li D
  Front. Physiol., 10, 683, 2019, [Peer-reviewed]
  English, Scientific journal
• Anti-obesity effects of chondroitin sulfate oligosaccharides from the skate Raja pulchra.
  Li W; Kobayashi T; Moroi S; Kotake H; Ikoma T; Saeki H; Ura K; Takagi Y
  Carbohydr. Polym., 214, 303, 310, 2019, [Peer-reviewed], [Last author]
  English, Scientific journal
• Purification and biochemical characterization of a vitellogenin-like protein from sea urchin.
  Nishimiya O; Teraoka Y; Gotoh T; Yuhi T; Higuchi I; Ura K; Takagi Y
  Fish. Sci., 85, 1, 127, 135, 2019, [Peer-reviewed], [Last author]
  English, Scientific journal
• Collagen peptides derived from the triple helical region of sturgeon collagen improve glucose tolerance in normal mice
  Yukiho Sasaoka; Hideki Kishimura; Shinji Adachi; Yasuaki Takagi
  Journal of Food Biochemistry, 42, 2, e12478, Blackwell Publishing Ltd, 01 Apr. 2018, [Peer-reviewed], [Last author]
  English, Scientific journal
• Characterization of biochemical and functional properties of water-soluble tempe flour.
  Puteri NE; Astawan M; Pulpi NS; Wresdiyati T; Takagi Y
  Food Sci. Tech. (Campinas), 31, suppl 1, 147, 153, 2018, [Peer-reviewed], [Last author]
  English, Scientific journal
• Morphology and anatomy of corallimorpharian Metarhodactis aff. boninensis from Thailand
  Dokkadew S; Kaewsuralikhit C; Takagi Y; Taparhudee W
  Journal of Fisheries and Environment, 42, 1, 13, 2018, [Peer-reviewed]
  English, Scientific journal
• Antioxidant activity of proteins extracted from red alga dulse harvested in Japan
  Sato N; Furuta T; Takeda T; Miyabe Y; Ura K; Takagi Y; Yasui H; Kumagai Y; Kishimura H
  Journal of Food Biochemistry, 43, 2, e12709, e12709, Wiley, 2018, [Peer-reviewed]
  English, Scientific journal
• Localization of major yolk protein in the digestive tract of the sea urchin Strongylocentrotus intermedius
  Yuki Okashita; Heng Wang; Shiori Tsue; Osamu Nishimiya; Kazuhiro Ura; Yasuaki Takagi
  FISHERIES SCIENCE, 83, 5, 803, 810, Sep. 2017, [Peer-reviewed], [Last author]
  English, Scientific journal
• Anisotropic tough double network hydrogel from fish collagen and its spontaneous in vivo bonding to bone
  Md. Tariful Islam Mredha; Nobuto Kitamura; Takayuki Nonoyama; Susumu Wada; Keiko Goto; Xi Zhang; Tasuku Nakajima; Takayuki Kurokawa; Yasuaki Takagi; Kazunori Yasuda; Jian Ping Gong
  BIOMATERIALS, 132, 85, 95, Jul. 2017, [Peer-reviewed]
  English, Scientific journal
• The reproductive cycle and transcription-level changes in the major yolk protein of wild northern sea urchin, Mesocentrotus nudus, in southern Hokkaido
  Ura K; Wang H; Hori T; Aizawa S; Tsue S; Satoh M; Takei N; Hoshino K; Higuchi I; Sanuki S; Yuhi T; Nishimiya O; Takagi Y
  Aquaculture Science, 65, 3, 231, 237, 日本水産増殖学会, 2017, [Peer-reviewed], [Last author]
  English, Scientific journal
• Genetic characterization of Amur sturgeon Acipenser schrenckii and its hybrid caught around Hokkaido
  Noriko Azuma; Seishi Hagihara; Masaki Ichimura; Yasuaki Takagi; Kazuhiro Ura; Shinji Adachi
  ICHTHYOLOGICAL RESEARCH, 64, 1, 139, 144, Jan. 2017, [Peer-reviewed]
  English, Scientific journal
• Double-Network Hydrogels Strongly Bondable to Bones by Spontaneous Osteogenesis Penetration
  Takayuki Nonoyama; Susumu Wada; Ryuji Kiyama; Nobuto Kitamura; Md. Tariful Islam Mredha; Xi Zhang; Takayuki Kurokawa; Tasuku Nakajima; Yasuaki Takagi; Kazunori Yasuda; Jian Ping Gong
  ADVANCED MATERIALS, 28, 31, 6740, +, Aug. 2016, [Peer-reviewed]
  English, Scientific journal
• Characterization of type I and II procollagen alpha 1chain in Amur sturgeon (Acipenser schrenckii) and comparison of their gene expression
  Xi Zhang; Noriko Azuma; Seishi Hagihara; Shinji Adachi; Kazuhiro Ura; Yasuaki Takagi
  GENE, 579, 1, 8, 16, Mar. 2016, [Peer-reviewed], [Last author]
  English, Scientific journal
• Embryonic and larval development of hatchery-reared silver therapon Leiopotherapon plumbeus (Perciformes: Terapontidae)
  Frolan A. Aya; Vicar Stella N. Nillasca; Luis Maria B. Garcia; Yasuaki Takagi
  ICHTHYOLOGICAL RESEARCH, 63, 1, 121, 131, Jan. 2016, [Peer-reviewed], [Last author]
  English, Scientific journal
• The major yolk protein in sea urchin egg yolk granules is a glycoprotein complex
  Heng Wang; Kazuhiro Ura; Yasuaki Takagi
  FISHERIES SCIENCE, 81, 6, 1127, 1134, Nov. 2015, [Peer-reviewed], [Last author]
  English, Scientific journal
• Swim bladder collagen forms hydrogel with macroscopic superstructure by diffusion induced fast gelation
  Md. Tariful Islam Mredha; Xi Zhang; Takayuki Nonoyama; Tasuku Nakajima; Takayuki Kurokawa; Yasuaki Takagi; Jian Ping Gong
  JOURNAL OF MATERIALS CHEMISTRY B, 3, 39, 7658, 7666, 2015, [Peer-reviewed]
  English, Scientific journal
• Physical-chemical identifier prepared by scallop shell
  Isao Shimono; Shiro Takahashi; Sentaro Mori; Katsuyuki Sato; Junya Kobayashi; Yasuaki Takagi
  Report of the Hokkaido Industrial Technology Center, 13, 18, 25, Dec. 2014, [Last author]
  Japanese, Research institution
• Identification, cDNA cloning, and expression analysis of dermatopontin in the goldfish Carassius auratus
  Norihiko Komatsu; Nobuhiro Ogawa; Kurin Iimura; Kazuhiro Ura; Yasuaki Takagi
  FISHERIES SCIENCE, 80, 6, 1249, 1256, Nov. 2014, [Peer-reviewed], [Last author]
  English, Scientific journal
• Biochemical characterisation and assessment of fibril-forming ability of collagens extracted from Bester sturgeon Huso huso x Acipenser ruthenus
  Xi Zhang; Mika Ookawa; Yongkai Tan; Kazuhiro Ura; Shinji Adachi; Yasuaki Takagi
  FOOD CHEMISTRY, 160, 305, 312, Oct. 2014, [Peer-reviewed], [Last author]
  English, Scientific journal
• Dorsal Hump Morphology in Pink Salmon (Oncorhynchus gorbuscha)
  Kenta Susuki; Masaki Ichimura; Yosuke Koshino; Masahide Kaeriyama; Yasuaki Takagi; Shinji Adachi; Hideaki Kudo
  JOURNAL OF MORPHOLOGY, 275, 5, 514, 527, May 2014, [Peer-reviewed]
  English, Scientific journal
• Spatiotemporal expression of the dermatopontin gene in zebrafish Danio rerio
  Yongkai Tan; Kurin Iimura; Tetsuro Sato; Kazuhiro Ura; Yasuaki Takagi
  Gene, 516, 2, 277, 284, 10 Mar. 2013, [Peer-reviewed], [Last author]
  English, Scientific journal
• Developmental structure of the vertebral column, fins, scutes and scales in bester sturgeon, a hybrid of beluga Huso huso and sterlet Acipenser ruthenus
  X. Zhang; K. Shimoda; K. Ura; S. Adachi; Y. Takagi
  JOURNAL OF FISH BIOLOGY, 81, 6, 1985, 2004, Nov. 2012, [Peer-reviewed], [Last author]
  English, Scientific journal
• Purification and biochemical characterization of a cellulase from the digestive organs of the short-spined sea urchin Strongylocentrotus intermedius
  Syuto Hasegawa; Kazuhiro Ura; Hiroyuki Tanaka; Takao Ojima; Yasuaki Takagi
  FISHERIES SCIENCE, 78, 5, 1107, 1115, Sep. 2012, [Peer-reviewed], [Last author]
  English, Scientific journal
• The effect of ions and cryoprotectants upon sperm motility and fertilization success in the loach Misgurnus anguillicaudatus
  George Shigueki Yasui; Takafumi Fujimoto; Lenin Arias-Rodriguez; Yasuaki Takagi; Katsutoshi Arai
  AQUACULTURE, 344, 147, 152, May 2012, [Peer-reviewed]
  English, Scientific journal
• Expression Patterns of runx2, sparc, and bgp During Scale Regeneration in the Goldfish Carassius auratus
  Kurin Iimura; Hidekazu Tohse; Kazuhiro Ura; Yasuaki Takagi
  JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION, 318B, 3, 190, 198, May 2012, [Peer-reviewed], [Last author]
  English, Scientific journal
• Immunohistochemical Analysis of the Proteolytic Enzyme Subtilase in the Digestive Organs of the Sea Urchin Strongylocentrotus intermedius
  Kazuhiro Ura; Syuto Hasegawa; Eri Tanaka; Takahiro Gotoh; Takao Ojima; Yasuaki Takagi
  ANATOMICAL RECORD-ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, 295, 1, 73, 77, Jan. 2012, [Peer-reviewed], [Last author]
  English, Scientific journal
• Proposal for the application method utilizing the phosphor prepared by a scallop shell (II)
  Shimono Isao; Shiro Takahashi; Sentaro Mori; Katsuyuki Sato; Junya Kobayashi; Yasuaki Takagi
  Report of the Hokkaido Industrial Technology Center, 12, 31, 37, テクノポリス函館技術振興協会, 2012, [Last author]
  Japanese, Research institution, ホタテガイ貝殻の利活用は、大量使用の見込める製品(土壌改良材等)の低コスト化と、少量でも付加価値の高い製品の創製というように、目的別に取組むことが望ましい。本研究では、ホタテガイ貝殻から高機能材料を創製することを目的とし、ホタテガイ貝殻が持つ蛍光機能を活かした応用研究を行った。本研究の結果、貝殻製蛍光体の4つの発光帯の強度比は、食品の灰化処理を目的として行なった熱処理に対し、高い安定性を示した。この結果に基づき、ホタテガイ貝殻から創製した貝殻製蛍光体の、発光帯の強度比を識別番号と見なし、これを食品やサプリメントのロット番号や製造年月日等の情報と対応させることで、包装容器と中身との同一性を証明するための目印となる食品用標識剤を提案した。
• Scale calcification in the goldfish in vitro: histological and quantitative analysis
  Nobuhiro Ogawa; Kazuhiro Ura; Yasuaki Takagi
  FISHERIES SCIENCE, 76, 2, 189, 198, Mar. 2010, [Peer-reviewed], [Last author]
  English, Scientific journal
• Control of Polymorphism and Morphology of Calcium Carbonate Crystals by a Matrix Protein Aggregate in Fish Otoliths
  Hidekazu Tohse; Kazuko Saruwatari; Toshihiro Kogure; Hiromichi Nagasawa; Yasuaki Takagi
  CRYSTAL GROWTH & DESIGN, 9, 11, 4897, 4901, Nov. 2009, [Peer-reviewed], [Last author]
  English, Scientific journal
• Discrimination of Origins of Aquacultured Scallops and Rainbow Trout Using Trace Elemental Fingerprints of Shells and Otoliths
  KOBAYASHI Yutaka; TAKAMURA Takumi; SHIMONO Isao; URA Kazuhiro; TAKAGI Yasuaki
  Aquaculture Science, 57, 2, 271, 278, Japanese Society for Aquaculture Science, Jun. 2009, [Peer-reviewed], [Last author]
  Japanese, Compositions of the trace elements in bivalve shells and fish otoliths, both of which are made of calcium carbonate crystals, largely reflect those of elements in the environment, and thus, may be "foot prints" of the individuals' environmental life histories. In the present study, the trace elemental compositions of these tissues were applied to the discrimination of production places of the aquacultured scallop Patinopecten yessoensis and rainbow trout Oncorhynchus mykiss. Concentrations of lithium, manganese, strontium and barium in the aquacultured, 2⁺-year old scallop shells, which were from Otsuchi and Yamada in Iwate prefecture and Shikabe and Shiriuchi in Hokkaido, were measured by inductively coupled plasma mass spectrometry. By MANOVA analysis, the discrimination accuracy was 81.3%; 9 individuals, mostly from Otsuchi, out of 48 ones were mis-discriminated. Similarly, elemental concentrations of the otoliths from Hachimantai in Iwate and Nanae in Hokkaido were quantified. The discrimination accuracy by MANOVA was 95.5%; two individuals out of 44 ones were mis-discriminated. These data suggest that elemental compositions of bivalve shells and fish otoliths are useful keys to estimate their origins in the aquacultured species, although variations of the compositions by the production year should be carefully studied further.
• Post-molt processes of cuticle formation and calcification in the Japanese mitten crab Eriocheir japonicus
  Konomi Sakamoto; Wataru Honto; Masaharu Iguchi; Nobuhiro Ogawa; Kazuhiro Ura; Yasuaki Takagi
  Fisheries Science, 75, 1, 91, 98, Feb. 2009, [Peer-reviewed], [Corresponding author]
  English, Scientific journal
• Purification of subtilase from short-spined sea urchin Strongylocentrotus intermedius
  浦 和寛; 田中 恵梨; 東藤 孝; 後藤 孝弘; 清水 幹博; 尾島 孝男; 都木 靖彰
  Bulletin of fisheries sciences, Hokkaido University, 58, 3, 21, 28, 北海道大学大学院水産科学研究院 = Research Faculty of Fisheries Sciences, Hokkaido University, Feb. 2009, [Last author]
  Japanese, We purified a subtilase from digestive system of short spined sea urchin Strongylocentortus intermedius by a combination of ion-exchange chromatography and gel filtration. The molecular weight of purified subtilase on SDS-PAGE under both reducing and nonreducing conditions was 35,000. Antiserum against subtilase specifically immunostained its antigen. By Western blot analysis, immunoreactive with this antibody were observed in stomach and intestine.
• Identification of a novel matrix protein contained in a protein aggregate associated with collagen in fish otoliths
  Hidekazu Tohse; Yasuaki Takagi; Hiromichi Nagasawa
  FEBS JOURNAL, 275, 10, 2512, 2523, May 2008, [Peer-reviewed]
  English, Scientific journal
• Lack of circadian regulation of in vitro melatonin release from the pineal organ of salmonid teleosts
  Masayuki Iigo; Tomotaka Abe; Saori Kambayashi; Kaoru Oikawa; Tomohiro Masuda; Kanta Mizusawa; Shoji Kitamura; Teruo Azuma; Yasuaki Takagi; Katsumi Aida; Tadashi Yanagisawa
  GENERAL AND COMPARATIVE ENDOCRINOLOGY, 154, 1-3, 91, 97, Oct. 2007, [Peer-reviewed]
  English, Scientific journal
• Teleost Fish Scales: A Unique Biological Model for the Fabrication of Materials for Corneal Stroma Regeneration
  Yasuaki Takagi; Kazuhiro Ura
  Journal of Nanoscience and Nanotechnology, 7, 3, 757, 762, 01 Mar. 2007, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Application of laser ablation ICPMS to trace the environmental history of chum salmon Oncorhynchus keta
  Takaomi Arai; Takafumi Hirata; Yasuaki Takagi
  MARINE ENVIRONMENTAL RESEARCH, 63, 1, 55, 66, Feb. 2007, [Peer-reviewed], [Last author]
  English, Scientific journal
• Scale regeneration and calcification in goldfish Carassius auratus: quantitative and morphological processes
  Yasuharu Ohira; Motohiro Shimizu; Kazuhiro Ura; Yasuaki Takagi
  FISHERIES SCIENCE, 73, 1, 46, 54, Feb. 2007, [Peer-reviewed], [Last author]
  English, Scientific journal
• Localization and diurnal variations of carbonic anhydrase rnRNA expression in the inner ear of the rainbow trout Oncorhynchus mykiss
  Hidekazu Tohse; Emi Murayama; Tsuyoshi Ohira; Yasuaki Takagi; Hiromichi Nagasawa
  COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY, 145, 3-4, 257, 264, Nov. 2006, [Peer-reviewed]
  English, Scientific journal
• Hypoxic conditions induce centrum defects in red sea bream Pagrus major (Temminck and Schlegel)
  Yoshifumi Sawada; Manabu Hattori; Naoko Sudo; Keitaro Kato; Yasuaki Takagi; Kazuhiro Ura; Michio Kurata; Tokihiko Okada; Hidemi Kumai
  Aquaculture Research, 37, 8, 805, 812, Wiley, Jun. 2006, [Peer-reviewed]
  English, Scientific journal
• Induction of centrum defects in amberjack, Seriola dumerili, by exposure of embryos to hypoxia.
  Sawada Y; Hattori M; Iteya M; Takagi Y; Ura K; Seoka M; Kato K; Kurata M; Miyatake H; Katayama A; Kumai H
  Fisheries Science, 72, 364, 372, Mar. 2006, [Peer-reviewed]
  English, Scientific journal
• Fluorescence properties of scallop shells fired in a carbon dioxide atmosphere
  Isao Shimono; Takumi Takamura; Chiyoko Hosaka; Junya Kobayashi; Yasuaki Takagi; Hajime Yamamoto
  Journal of the Ceramic Society of Japan, 114, 1328, 341, 346, Ceramic Society of Japan, 2006
  Japanese, Scientific journal
• Osteoblastic activity and estrogenic response in the regenerating scale of goldfish, a good model of osteogenesis
  Hiroaki Yoshikubo; Nobuo Suzuki; Keiju Takemura; Masahiro Hoso; Sayaka Yashima; Shawichi Iwamuro; Yasuaki Takagi; Makoto J. Tabata; Atsuhiko Hattori
  Life Sciences, 76, 23, 2699, 2709, Elsevier Inc., 22 Apr. 2005, [Peer-reviewed]
  English, Scientific journal
• Diel changes in endolymph aragonite saturation rate and mRNA expression of otolith matrix proteins in the trout otolith organ
  Y Takagi; H Tohse; E Murayama; T Ohira; H Nagasawa
  MARINE ECOLOGY PROGRESS SERIES, 294, 249, 256, 2005, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• A crustacean Ca2+-binding protein with a glutamate-rich sequence promotes CaCO3 crystallization
  Hirotoshi ENDO; Yasuaki TAKAGI; Noriaki OZAKI; Toshihiro KOGURE; Toshiki WATANABE
  Biochemical Journal, 384, 1, 159, 167, 15 Nov. 2004, [Peer-reviewed]
  English, Scientific journal
• Immunohistochemical localization of two otolith matrix proteins in the otolith and inner ear of the rainbow trout, Oncorhynchus mykiss: comparative aspects between the adult inner ear and embryonic otocysts
  E Murayama; Y Takagi; H Nagasawa
  HISTOCHEMISTRY AND CELL BIOLOGY, 121, 2, 155, 166, Feb. 2004, [Peer-reviewed]
  English, Scientific journal
• Vertebral deformities in cultured red sea bream, Pagrus major, Temminck and Schlegel.
  Hattori, M; Y. Sawada; Y. Takagi; R. Suzuki; T. Okada; H. Kumai
  Aquaculture Research, 34, 1129, 1137, 10 Oct. 2003, [Peer-reviewed]
  English, Scientific journal
• Fine structure of soft and hard tissues involved in eye migration in metamorphosing Japanese flounder (Paralichthys olivaceus).
  Okada N; Takagi Y; Tanaka M; Tagawa M
  The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology, 273, 1, 663, 668, 1, Jul. 2003, [Peer-reviewed]
  Scientific journal
• Behavior of chum salmon as revealed by micro data loggers off the Sanriku coast, Japan: A review
  Takagi Yasuaki; Tanaka Hideji; Naito Yasuhiko
  Otsuchi Marine Science, 28, 6, 13, Otsuchi Marine Research Center, Ocean Research Institute, the University of Tokyo, 28 Mar. 2003, [Peer-reviewed], [Lead author, Corresponding author]
  English, The homing season of chum salmon in the Sanriku coastal area is generally late September to January. The surface water temperature is 20℃ at the beginning of the season and decreases to 12℃ at the end. This temperature condition is very tough for the homing migration of chum salmon, since they are typical cold-water species. How do they behave in the waters where temperatures can be close to their upper lethal limit? We monitored swimming behavior of salmon using micro data-loggers to study the relationship between homing behavior and ambient temperature. Seasonal changes in seawater temperature transformed the salmon behavior from deep diving to surface swimming. The deep diving is a type of behavioral thermoregulation in thermally stratified water with high surface temperature, whereas surface swimming helps the salmon to locate their natal rivers. Sexual maturation induced the salmon to seek their natal river in the surface water, even if their temperature was high. An analysis of the vertical movements of the salmon indicated that salmon are negatively buoyant throughout the dive, and thus, the energy cost for deep diving cannot be negligible. Our data indicate the high behavioral adaptability of salmon to such thermally stratified water with high surface temperature.
• Otolith formation and endolymph chemistry: A strong correlation between the aragonite saturation state and pH in the endolymph of the trout otolith organ
  Yasuaki Takagi
  Marine Ecology Progress Series, 231, 237, 245, Inter-Research, 22 Apr. 2002, [Peer-reviewed], [Lead author, Last author, Corresponding author]
  English, Scientific journal
• Fish otolith contains a unique structural protein, otolin-1
  E Murayama; Y Takagi; T Ohira; JG Davis; MI Greene; H Nagasawa
  EUROPEAN JOURNAL OF BIOCHEMISTRY, 269, 2, 688, 696, Jan. 2002, [Peer-reviewed]
  English, Scientific journal
• Effects of starvation and subsequent refeeding on formation and resorption of acellular bone in tilapia, Oreochromis niloticus
  Yasuaki Takagi
  Zoological Science, 18, 5, 623, 629, Jul. 2001, [Peer-reviewed], [Lead author, Last author, Corresponding author]
  English, Scientific journal
• 三陸から世界への発信をめざして--沿岸海洋研究の新しい試み (特集 沿岸海洋環境)
  都木 靖彰; 宮崎 信之
  地球環境, 6, 1, 87, 91, 国際環境研究協会, 2001, [Lead author, Corresponding author]
  Japanese, Scientific journal
• 三陸沿岸域に回帰したサケの行動 (特集 沿岸海洋環境)
  都木 靖彰; 乙部 弘隆; 田中 秀二
  地球環境, 6, 1, 69, 77, 国際環境研究協会, 2001, [Lead author, Corresponding author]
  Japanese, Scientific journal
• Distinct seawater and freshwater types of chloride cells in killifish, Fundulus heteroclitus
  F. Katoh; S. Hasegawa; J. Kita; Y. Takagi; T. Kaneko
  Canadian Journal of Zoology, 79, 5, 822, 829, Canadian Science Publishing, 2001, [Peer-reviewed]
  English, Scientific journal
• Swimming speeds and buoyancy compensation of migrating adult chum salmon Oncorhynchus keta revealed by speed/depth/acceleration data logger
  Hideji Tanaka; Yasuaki Takagi; Yasuhiko Naito
  Journal of Experimental Biology, 204, 22, 3895, 3904, 2001, [Peer-reviewed]
  English, Scientific journal
• Asymmetrical development of bones and soft tissues during eye migration of metamorphosing Japanese flounder, Paralichthys olivaceus
  Nozomi Okada; Yasuaki Takagi; Tadahisa Seikai; Masaru Tanaka; Masatomo Tagawa
  Cell and Tissue Research, 304, 1, 59, 66, Springer Science and Business Media LLC, 2001, [Peer-reviewed]
  English, Scientific journal
• Stimulation of non-specific immune functions in seawater-acclimated rainbow trout, Oncorhynchus mykiss, with reference to the role of growth hormone
  T. Yada; T. Azuma; Y. Takagi
  Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology, 129, 2-3, 695, 701, 2001, [Peer-reviewed], [Last author]
  English, Scientific journal
• Molecular cloning and expression of an otolith matrix protein cDNA from the rainbow trout, Oncorhynchus mykiss
  Emi Murayama; Atsuro Okuno; Tsuyoshi Ohira; Yasuaki Takagi; Hiromichi Nagasawa
  Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 126, 4, 511, 520, Elsevier BV, Aug. 2000, [Peer-reviewed]
  English, Scientific journal
• Relationship between homing behavior of chum salmon Oncorhynchus keta returning to the Sanriku Coast and sea and weather conditions
  H Otobe; Y Takagi; A Anbo
  NIPPON SUISAN GAKKAISHI, 66, 4, 705, 712, Jul. 2000, [Peer-reviewed]
  Japanese, Scientific journal
• Behavioural thermoregulation of chum salmon during homing migration in coastal waters
  Hideji Tanaka; Yasuaki Takagi; Yasuhiko Naito
  Journal of Experimental Biology, 203, 12, 1825, 1833, Jun. 2000, [Peer-reviewed]
  English, Scientific journal
• Immunolocalization of gastrolith matrix protein (GAMP) in the gastroliths and exoskeleton of crayfish, Procambarus clarkii
  Y Takagi; K Ishii; N Ozaki; H Nagasawa
  ZOOLOGICAL SCIENCE, 17, 2, 179, 184, Mar. 2000, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Cellular contributions to the otolith formation in teleosts : A review
  Takagi Yasuaki
  Otsuchi marine science, 25, 1, 6, The University of Tokyo, Mar. 2000, [Peer-reviewed], [Lead author, Last author, Corresponding author]
  English
• Carbohydrates of the otolith organ in the rainbow trout Oncorhynchus mykiss detected by lectins
  Yasuaki Takagi; Kou Ishida; Yasuo Mugiya
  Fisheries Science, 66, 5, 933, 939, Blackwell Publishing, 2000, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Ultrastructural immunolocalization of the otolith water-soluble-matrix in the inner ear of rainbow trout just-hatched fry
  Yasuaki Takagi
  Fisheries Science, 66, 1, 71, 77, Blackwell Publishing, 2000, [Peer-reviewed], [Lead author, Last author, Corresponding author]
  English, Scientific journal
• Cloning and Expression of a cDNA Encoding an Insoluble Matrix Protein in the Gastroliths of a Crayfish, Procambarus clarkii
  TSUTSUI Naoaki; ISHII Katsuaki; TAKAGI Yasuaki; WATANABE Toshiki; NAGASAWA Hiromichi
  ZOOLOGICAL SCIENCE, 16, 4, 619, 628, Zoological Society of Japan, 15 Aug. 1999, [Peer-reviewed]
  English, Scientific journal, In the crayfish Procambarus clarkii, the gastroliths are formed as a paired structure in the stomach during the premolt period, and contain calcium carbonate and a small amount of an organic matrix. In this investigation, a cDNA encoding an insoluble matrix protein was isolated from P. clarkii. The open reading frame encoded 505 amino acid residues including two unique repeated sequences. The N-terminal half of the amino acid sequence, which included 10-amino-acid repeats, exhibited a high degree of similarity to that of involucrin, a protein synthesized in human keratinocytes. Northern blot analysis revealed that mRNA encoding the matrix protein is specifically expressed in the gastrolith discs during the premolt period in which the gastroliths formed. In the gastrolith discs, levels of expression of this mRNA correlated increases in weights of the gastroliths concomitant with their formation. Organ culture of the gastrolith discs suggested that expression of mRNA in the discs is induced by molting hormone, 20-hydroxyecdysone. These results reinforced the relationship between the matrix protein and formation of the gastroliths. Functional analysis showed that the protein inhibits calcium carbonate crystallization in a solution system, suggesting that the protein plays a role in the calcification of the gastroliths.
• Characterization of morphology and physiological actions of scale osteoclasts in the rainbow trout
  P. Persson; B. Th. Bjornsson; Y. Takagi
  Journal of Fish Biology, 54, 3, 669, 684, Wiley, Mar. 1999, [Peer-reviewed], [Last author]
  English, Scientific journal
• Characterization of ootolith soluble-matrix producing cells in the saccular epithelium of rainbow trout (Oncorhynchus mykiss) inner ear
  Yasuaki Takagi; Akiyoshi Takahashi
  The Anatomical Record, 254, 3, 322, 329, Wiley, 01 Mar. 1999, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Effects of Calcitonin on Calcium Balance and Bone Resorption in Rainbow Trout, Oncorhynchus mykiss
  SIGURDUR H. JOHANNSSON; PETRA PERSSON; YASUAKI TAKAGI; BJORN TH. BJORNSSON
  Annals of the New York Academy of Sciences, 839, 1 TRENDS IN COM, 434, 436, Wiley, May 1998, [Peer-reviewed]
  English, Scientific journal
• Cortisol Inhibits Glycosaminoglycan Synthesis in Cultured Rainbow Trout Cartilage
  Yasuaki Takagi; Björn Thrandur Björnsson
  General and Comparative Endocrinology, 108, 1, 80, 86, Elsevier BV, Oct. 1997, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Meshwork arrangement of mitochondria-rich, Na+,K+-ATPase-rich cells in the saccular epithelium of rainbow trout (Oncorhynchus mykiss) inner ear
  Yasuaki Takagi
  The Anatomical Record, 248, 4, 483, 489, Wiley, Aug. 1997, [Peer-reviewed], [Lead author, Last author, Corresponding author]
  English, Scientific journal
• Estradiol-17b and nutritional status affect calcium balance, scale and bone resorption, and bone formation in rainbow trout, Oncorhynchus mykiss
  PERSSON P.
  Journal of Comparative Pgysiology, 167, 473, 468, 473, 1997, [Peer-reviewed]
  English, Scientific journal
• Regulation of cartilage glycosaminoglycan synthesis in the rainbow trout, Oncorhynchus mykiss, by 3,3′,5-tri-iodo-l-thyronine and IGF-I
  Y Takagi; B Th Björnsson
  Journal of Endocrinology, 149, 2, 357, 365, Bioscientifica, May 1996, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal,
  The actions of 3,3′,5-tri-iodo-l-thyronine (T₃) and recombinant human IGF-I (rhIGF-I) as well as their interaction on cartilage growth in rainbow trout (Oncorhynchus mykiss) were examined. Uptake of ³H-methyl thymidine and ³⁵S-sulfate by isolated branchial cartilage was measured as a marker for chondrocyte proliferation and sulfated glycosaminoglycan synthesis respectively. When T₃ (1·0 μg/g) was injected intraperitoneally, plasma T₃ levels reached a transient peak after 1 day and decreased rapidly thereafter. Sulfate and thymidine uptake were not affected by T₃ at 1 and 3 days post-injection, but at 6 days post-injection both were significantly higher in T₃injected fish than those in controls. The stimulatory effects of a T₃ injection on sulfate and thymidine uptake were dose-dependent over the range of 0·01, 0·1 and 1·0 μg/g. In vitro exposure of cartilage to T₃ (0·075, 0·75, 7·5, 75 and 750 nm) for 6 days resulted in dose-dependent stimulation of sulfate uptake, with a maximum response at 7·5 nm and higher. T₃ exposure (7·5 nm) for 2 or 3 days also increased sulfate uptake, but only slightly. Thymidine uptake was not clearly affected by T₃. In vitro addition of rhIGF-I (0·075, 0·75 and 7·5 nm) increased sulfate uptake, but not thymidine uptake, dose-dependently. Compared with T₃, rhIGF-I induced a greater maximum level of sulfate uptake: at 7·5 nm rhIGF-I increased the uptake 17-fold whereas T₃ increased the uptake fourfold. When T₃ (0·075, 0·75 or 7·5 nm) and rhIGF-I (0·1 or 1·0 nm) were added together, stimulative actions of T₃ on sulfate uptake were largely additive to those of rhIGF-I. The results indicate that T₃ as well as IGF-I are important modulators of sulfated glycosaminoglycan synthesis in rainbow trout cartilage.
  
  
  Journal of Endocrinology (1996) 149, 357–365
• Developmental sequence of bone-resorbing cells induced by intramuscular implantation of mineral-containing bone particles into rainbow trout, Oncorhynchus mykiss
  Yasuaki Takagi; Toyoji Kaneko
  Cell and Tissue Research, 280, 1, 153, 158, Springer-Verlag, Apr. 1995, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Hypoosmoregulatory ability of eyed-stage embryos of chum salmon
  T. Kaneko; S. Hasegawa; Y. Takagi; M. Tagawa; T. Hirano
  Marine Biology, 122, 1, 165, 170, Springer Science and Business Media LLC, Mar. 1995, [Peer-reviewed]
  English, Scientific journal
• Tartrate resistant acid phosphatase as a marker for scale resorption in rainbow trout, Oncorhynchus mykiss: effects of estradiol-17? treatment and refeeding
  Petra Persson; Yasuaki Takagi; Bjorn Thrandur Bjornssonl
  Fish Physiology and Biochemistry, 14, 329, 339, 1995, [Peer-reviewed]
  English, Scientific journal
• Stimulation of skeletal growth by thyroid hormone administrations in the rainbow trout,Oncorhynchus mykiss
  Yasuaki Takagi; Joe Hirano; Hiroshi Tanabe; Juro Yamada
  Journal of Experimental Zoology, 268, 3, 229, 238, Wiley, 01 Mar. 1994, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Osmoregulatory Ability and Growth in Seawater of Landlocked Sockeye Salmon, Oncorhynchus nerka.
  YAMANOME Takeshi; SHIDA Osamu; MITSUBOSHI Toru; TOKUSHIMA Masanori; OMURA Reiji; TAKAGI Yasuaki
  Aquaculture Science, 42, 3, 389, 396, Japanese Society for Aquaculture Science, 1994, [Peer-reviewed], [Last author]
  Japanese, Scientific journal, Landlocked sockeye salmon (Oncorhynchus nerka) were transferred into seawater (SW) directly or after pre-acclimation to 50% seawater (50% SW) . The time course changes of their serum sodium level and weight increase were measured. Two similar experiments were conducted in November 1991 (0+year) and April 1992 (1+year), when osmoregulatory ability of the fish was low and high, respectively. In November 1991, serum sodium level of the fish pre-acclimated to 50% SW for 4 months was lower compared with that of directly transferred fish. Almost all of the directly transferred fish stopped growing in SW, whereas some of the pre-acclimated fish increased their weight. In April 1992, even in directly transferred fish, serum sodium level was lower compared with that of pre-acclimated fish in November. Pre-acclimation to 50% SW for 2 weeks did not enhance osmoregulatory ability further in spring. All individuals of both group increased their weight in SW. These data suggest that growth of landlocked sockeye salmon in SW may closely relate to the osmoregulatory ability of the fish at the time of transfer to SW.
• Changes in metabolism of acellular bone in tilapia, Oreochromis niloticus, during deficiency and subsequent repletion of calcium
  Yasuaki Takagi; Juro Yamada
  Comparative Biochemistry and Physiology Part A: Physiology, 105, 3, 459, 462, Elsevier BV, Jul. 1993, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Effects of calcium deprivation on the metabolism of acellular bone in tilapia, Oreochromis niloticus
  Yasuaki Takagi; Juro Yamada
  Comparative Biochemistry and Physiology Part A: Physiology, 102, 3, 481, 485, Elsevier BV, Jul. 1992, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Effects of growth hormones on bone formation and resorption in rainbow trout (Oncorhynchus mykiss), as examined by histomorphometry of the pharyngeal bone
  Yasuaki Takagi; Shunsuke Moriyama; Tetsuya Hirano; Juro Yamada
  General and Comparative Endocrinology, 86, 1, 90, 95, Elsevier BV, Apr. 1992, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• In vitro measurements of calcium influx into isolated goldfish scales in reference to the effects of putative calcemic hormones.
  Takagi Yasuaki; Hirano Tetsuya; Yamada Juro
  Zoological Science, 6, 1, 83, 89, 日本動物学会, 1989, [Peer-reviewed], [Lead author, Corresponding author]
  English
• Scale regeneration of tilapia (Oreochromis niloticus) under various ambient and dietary calcium concentrations
  Takagi Yasuaki; Hirano Tetsuya; Yamada Juro
  Comparative Biochemistry and Physiology Part A: Physiology, 92, 4, 605, 608, Elsevier BV, Jan. 1989, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Effects of the removal of corpuscles of Stannius on the transport of calcium across the intestine of rainbow trout.
  Takagi, Y; Y. Nakamura; J. Yamada
  Zoological science, 2, 4, 523, 530, Zoological Society of Japan, 1985, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal, Effects of stanniectomy (CSX) on the absorption of Ca in the intestine of rainbow trout were examined by incubating the everted gut sac in Ringer solution. The serum Ca concentration increased by CSX in fish adapted to 1/3 SW but not in those adapted to FW. Ca moved from mucosa to serosa in the anterior intestine from FW-shams and the movement was not affected by CSX. The absorptive movement of Ca was not evident in 1/3 SW-shams but became apparent following CSX. Transports of water and other electrolytes (Na, Cl, K, Mg and Pi) showed no significant changes by CSX. The results indicated that the intestine is a target organ for an active principle of the CS, which are activated in a high-Ca environment to prevent Ca entry from the ambient water.

• ウニ殻を原料とした施肥材から溶出する栄養塩の定量とマコンブSaccharina japonica配偶体への影響評価
  丸山恒哉; 工藤勲; 樋口一郎; 水田浩之; 都木靖彰; 浦和寛, 日本水産学会大会講演要旨集(CD-ROM), 2025, 2025
• ウニ用配合飼料に用いる海藻代替材料の探索
  山本梨乃; 井戸篤史; 井戸篤史; 樋口一郎; 都木靖彰; 浦和寛, 日本水産学会大会講演要旨集(CD-ROM), 2024, 2024
• マナマコの新規卵黄タンパク質の同定
  西川奈歩; 樋口一郎; 渡邊周一郎; 都木靖彰; 浦和寛, 日本水産学会大会講演要旨集(CD-ROM), 2023, 2023
• ウニ殻から溶出する栄養塩の測定
  丸山恒哉; 工藤勲; 樋口一郎; 水田浩之; 都木靖彰; 浦和寛, 日本水産学会大会講演要旨集(CD-ROM), 2023, 2023
• キタムラサキウニMYP遺伝子プロモーター領域における核内受容体COUP-TF結合能の解析
  北野雄大; 樋口一郎; 細川雅史; 浦和寛; 都木靖彰, 日本水産学会大会講演要旨集, 2020, 2020
• キタムラサキウニMYP遺伝子プロモーター領域における核内受容体COUP-TFの機能解析
  北野雄大; 樋口一郎; 細川雅史; 浦和寛; 都木靖彰, 日本水産学会北海道支部大会講演要旨集(CD-ROM), 2020 (CD-ROM), 2020
• キタムラサキウニMYP遺伝子プロモーター領域における核内受容体COUP-TF結合能の解析
  樋口一郎; 津江志緒莉; 西宮攻; 浦和寛; 都木靖彰, 日本水産学会北海道支部大会講演要旨集, 2017, 2017
• 北海道産チョウザメ類の養殖産業化のための生産・加工体制整備
  足立伸次; 都木靖彰; 井尻成保; 萩原聖士; 三坂尚行; 古市明文; 市村政樹, ノーステック財団 研究開発助成事業2017 成果報告書, 2017
  Japanese, Others
• メガネカスベ軟骨コラーゲンの性状解析―機能性食品への応用を目指して―
  小林大志; 張曦; 宮本宜之; 東典子; 浦和寛; 都木靖彰, 日本水産学会大会講演要旨集, 2016, 175, 26 Mar. 2016
  Japanese
• 魚類コラーゲンの線維化制御に関与する分子の研究―9 キンギョにおけるルミカンの発現解析
  石川弘希; 原島あずさ; 日下哲佑; 道辰麻生; 東典子; 浦和寛; 都木靖彰, 日本水産学会大会講演要旨集, 2016, 20, 26 Mar. 2016
  Japanese
• 魚類コラーゲンの線維化制御に関与する分子の研究―8 キンギョにおけるデコリンの局在解析
  道辰麻生; 石本伸; 太田遼祐; 東典子; 浦和寛; 都木靖彰, 日本水産学会大会講演要旨集, 2015, 213, 27 Mar. 2015
  Japanese
• 魚類コラーゲンの再生医療用材料としての適性―2 軟骨細胞の増殖・分化におよぼすベステルコラーゲンの効果
  重本梓; 張曦; 土生雅哉; 三浦隆之; 東典子; 浦和寛; 都木靖彰, 日本水産学会大会講演要旨集, 2015, 25, 27 Mar. 2015
  Japanese
• 魚類コラーゲンの線維化制御に関与する分子の研究―7 キンギョにおけるコンドロアドヘリンの発現解析
  原島あずさ; 日下哲佑; 道辰麻生; 吉岡純矢; 東典子; 浦和寛; 都木靖彰, 日本水産学会大会講演要旨集, 2015, 25, 27 Mar. 2015
  Japanese
• 魚類コラーゲンの再生医療用材料としての適性―1 脂肪細胞の増殖・分化におよぼすベステルコラーゲンの抑制効果
  三浦隆之; 張曦; 土生雅哉; 重本梓; 東典子; 浦和寛; 都木靖彰, 日本水産学会大会講演要旨集, 2015, 25, 27 Mar. 2015
  Japanese
• 1P132 Broadband dielectric relaxation of the aqueous solution of tilapia and sturgeon collagen(07. Water & Hydration & Electrolyte,Poster,The 52nd Annual Meeting of the Biophysical Society of Japan(BSJ2014))
  Hiroshi Kawamata; Shunsuke Kuwaki; Masanori Mizuno; Kazunari Urasawa; Tomobumi Mishina; Toshiyuki Ikoma; Junzo Tanaka; Xi Zhang; Shinji Adachi; Kazuhiro Ura; Noriko Azuma; Yasuaki Takagi; Ryusuke Nozaki, Seibutsu Butsuri, 54, supplement1-2, S162, S162, 2014
  Biophysical Society of Japan
• チョウザメ・コラーゲン由来血糖値上昇抑制作用ペプチドの調製とその構造特性
  富田友季穂; 岸村栄毅; 小柳佳子; CHUN Byung-soo; 安藤靖浩; 都木靖彰; 足立伸次; 佐伯宏樹, 日本栄養・食糧学会大会講演要旨集, 66th, 2012
• JSPS Asia-Africa Science Platform Program: Brief summaryu of first year activities
  Katsutoshi Arai; Junichiro Okamoto; Nobuo Kimura; Yasuaki Takagi; Kunihiko Konno; John Bower; Virgilia Sulit, Fish for the People, 10, 2, 42, 47, 2012
  English, Others
• ウロコから眼 : さかなのウロコのコラーゲンを利用して人工角膜をつくる
  都木 靖彰, 化学と生物, 49, 3, 156, 158, 01 Mar. 2011
  公益社団法人 日本農芸化学会, Japanese
• Fish collagen: molecular comparison to mammalian collagen and perspectives to its industrial use
  都木 靖彰, Bio industry, 28, 11, 10, 15, 2011
  シーエムシー出版, Japanese
• ウロコから眼：さかなのウロコのコラーゲンを利用して人工角膜を造る
  都木 靖彰, 化学と生物, 49, 3, 156, 158, 2011
• ホタテガイ貝殻蛍光体を利用した標識方法の提案
  下野 功; 高橋 志郎; 森 千太郎; 佐藤 克行; 小林 淳哉; 都木 靖彰, 北海道立工業技術センター研究報告, 11, 57, 59, Dec. 2010
  ホタテガイ貝殻から作られた蛍光体の発光スペクトルは複数の発光帯からなり、その強度比は製造条件等により変化する。この特徴を利用し、ホタテガイ貝殻蛍光体を利用した標識方法を提案する。食品加工段階で商品に標識剤を添加し、添加した標識剤の番号を品質保証書に記載しておくことで、商品と品質保証書の同一性を保証することが可能となる。この標識剤は、焼成したホタテガイ貝殻という、これまでに食経験のある素材を用いていることから、食品中に直接添加することができ、さらに添加後は番号の書き換えが出来ないという特徴を持つ。, テクノポリス函館技術振興協会, Japanese
• 硬骨魚類における耳石の形成メカニズム
  生物の科学 遺伝, 7, 42, 47, 2010
• 魚のうろこのコラーゲンの特徴―分子生物学―
  マテリアルインテグレーション, 23, 2, 12, 16, 2010
• はじめに―なぜ，今，さかなコラーゲンか―
  マテリアルインテグレーション, 23, 2, 1, 5, 2010
• Characteristics of fish scale collagen: a molecular biological point of view
  Materials Integration, 23, 2, 12, 16, 2010
• Investigation of the luminescence center in the phosphor by utilizing a scallop shell
  SHIMONO Isao; TAKAHASHI Shiro; SHIMIZU Takeshi; TAKAMURA Takumi; KOBAYASHI Junya; TAKAGI Yasuaki, Journal of the Ceramic Society of Japan, suppl 117, S5-S10, S10, 2009
  In this study of the phosphor utilizing a scallop shell, it was researched that the luminescence center was estimated from the chemical composition of the shell for the final purpose of the improvement of the luminescence property. The luminescence centers were estimated to be Cu and Mn from the experiment result and literature investigation. Furthermore, these concentrations were small by more than two orders in comparison with the commercially available phosphors. Therefore, improvement of the luminescence property can be expected by doping Cu and Mn to the shell and to investigate the relationship between these concentrations and the luminescence property to find the optimum concentration., The Ceramic Society of Japan, Japanese
• The Study on the emmision center of the fluorescent material synthesized from scallop shells
  suppl 117, S5-S10, 2009
• ホタテガイ貝殻を用いた蛍光体材料の開発（2）
  下野 功; 高橋 志郎; 清水 健志; 高村 巧; 小林 淳哉; 都木 靖彰, 北海道立工業技術センター研究報告, 10, 26, 32, Dec. 2008
  本研究は、ホタテガイ貝殻を用いた蛍光体材料の開発において、貝殻の化学組成から発光中心を探索し、それについて研究を積み重ね、蛍光特性の向上を目的として行った。貝殻から作られた蛍光体の発光中心は、CuおよびMnと考えられ、それらの濃度はこれまでに報告されているCaS系やZnS系蛍光体と比較して二桁以上も低いことが知られた。蛍光特性の向上には、CaCO3にCuおよびMnをドープし、それらの濃度と蛍光特性との関係を調査することが重要であり、CuおよびMn濃度の最適化を図ることにより蛍光特性の向上が期待される。現在のところ、CaCO3へのCuおよびMnドープは、貝殻を除いて成功しておらず、その原因として、貝殻の有機基質とナノ構造が重要な役割を果していると考えられる。, テクノポリス函館技術振興協会, Japanese
• Mineralogical charactaristics of otolith in rainbow trout(O ncorhynchus mykiss)
  Arai Isao; Takagi Yasuaki; Nagasawa Hiromichi; Kogure Toshihiro, Abstracts for Annual Meeting of Japan Association of Mineralogical Sciences, 2008, 0, 173, 173, 2008
  Fish otolith is calcium carbonate polycrystalline body containing organic matter including protein. It was reported that teleost sagitta and lapillus are made by aragonite, and astriscus is made by vaterite. Sagitta , lapisus and astaricus are ones of fish otolith. But other studies about teleost fish proved that many factors cause generation of differ crystal polymoph in sagitta.In this study, characteristics of aragonite and vaterite in sagitta were studied by thermogravimetry and differential thermal analysis. In the result, sagitta aragonite show 710K exothermic peak without variation in weight. In other hand, sagitta and synthesis vaterite show 740K exothermic peak in common. Those results suggest that there are some characteristics that specific to sagitta., Japan Association of Mineralogical Sciences, Japanese
• Toward the understanding on the mechanism of biomineralization in teleost fish scales
  小川 展弘; 都木 靖彰, Bio industry, 24, 12, 47, 55,3, Dec. 2007, [Invited], [Last author, Corresponding author]
  シーエムシー出版, Japanese
• 魚類のウロコに認められる角膜様のコラーゲン配列とその形成メカニズムの解明 (特集 生命機能と材料--生命機能マテリアル/生命現象マテリアル) -- (生体の中にある材料の成因・メカニズム)
  都木 靖彰, マテリアルインテグレ-ション, 20, 11, 20, 26, Nov. 2007
  ティー・アイ・シィー, Japanese
• Crystal grains of otolith in rainbow trout (Oncorhynchus mykiss)
  ARAI I.; RAIMBOURG H.; SARUWATARI K.; TAKAGI Y.; NAGASAWA H.; KOGURE T., 日本鉱物学会・学術講演会,日本岩石鉱物鉱床学会学術講演会講演要旨集, 2007, 180, 180, 22 Sep. 2007
  Japanese
• 魚類のウロコに認められる角膜様のコラーゲン配列とその形成メカニズムの解明
  マテリアルインテグレーション, 20, 11, 20, 26, 2007
• Calcification mechanism of scales in teleosts
  Bioindustry, 24, 12, 47, 55, 2007
• MECHANISM OF OSTEOGENESIS IN TELEOSTS : ANALYSIS BY REGENERATING SCALE OF GOLDFISH(Endocrinology,Abstracts of papers presented at the 75^ Annual Meeting of the Zoological Society of Japan) :
  Suzuki Nobuo; Yoshikubo Hiroaki; Takemura Keiju; Hoso Masahiro; Yashima Sayaka; Iwamuro Shawichi; Takagi Yasuaki; Hattori Atsuhiko, Zoological science, 21, 12, 1339, 1339, 2004
  Zoological Society of Japan, English
• 魚類の耳石はいかにして形成されるか? : 結晶成長を制御する基質タンパク質, OMP-1と otolin-1
  村山 英未; 都木 靖彰; 長澤 寛道, 化学と生物, 41, 1, 11, 12, 25 Jan. 2003
  Japanese
• 耳石が語るバイオミネラリゼーションのメカニズム
  都木 靖彰, 日本比較内分泌学会ニュース = Newsletter of Japan Society for Comparative Endocrinology, 104, 22, 23, Feb. 2002
  日本比較内分泌学会, Japanese
• バイオミネラリゼーション (総特集 海洋生命系のダイナミクス) -- (2章 機能系のダイナミクス--多様な海洋環境に生命はどのように適応しているか?)
  長澤 寛道; 都木 靖彰, 号外海洋, 29, 76, 82, 2002
  海洋出版, Japanese
• CRUSTOCALCIN : A STUDY ON POTENTIAL FUNCTION OF A SKELETAL CA^<2+>-BINDING PROTEIN OF KURUMA PRAWN PENAEUS JAPONICUS(Biochemistry)(Proceedings of the Seventy-Third Annual Meeting of the Zoological Society of Japan) :
  Endo Hirotoshi; Takagi Yasuaki; Watanabe Toshiki, Zoological science, 19, 12, 1480, 1480, 2002
  Zoological Society of Japan, English
• Localization of a Ca^<2+> binding protein DD4 in the calcified exoskeleton of kuruma prawn Penaeus japonicus.(Biochemistry)(Proceeding of the Seventy-Third Annual Meeting of the Zoological Society of Japan) :
  Endo Hirotoshi; Takagi Yasuaki; Watanabe Toshiki, Zoological science, 18, 51, 51, 2001
  Zoological Society of Japan, English
• 魚類における耳石形成の分子機構 (総特集 生物がつくる鉱物--バイオミネラリゼーション研究の新展開)
  村山 英未; 都木 靖彰; 長澤 寛道, 海洋, 32, 6, 391, 397, Jun. 2000
  海洋出版, Japanese
• Ca^<2+> binding capacity of DD4 protein which is expressed during calcification of the exoskeleton of the kuruma-prawn Penaeus japonicus(Biochemistry)Proceedings of the Seventy-First Annual Meeting of the Zoological Society of Japan :
  Endo Hirotoshi; Takagi Yasuaki; Watanabe Toshiki, Zoological science, 17, 47, 47, 2000
  Zoological Society of Japan, English
• A STUDY OF THE MATRIX PROTEIN IN THE FISH OTOLITH(Biochemistry)Proceedings of the Seventy-First Annual Meeting of the Zoological Society of Japan :
  Murayama Emi; Takagi Yasuaki; Nagasawa Hiromichi, Zoological science, 17, 52, 52, 2000
  Zoological Society of Japan, English
• THE BEHAVIOR AND AMBIENT TEMPERATURE OF HOMING CHUM SALMON MONITORED BY A DATA LOGGER (19th Symposium on Polar Biology)
  TANAKA Hideji; TAKAGI Yasuaki; IWATA Munehiko; NAITO Yasuhiko, Proceedings of the NIPR Symposium on Polar Biology, 11, 62, 73, Feb. 1998
  We studied the behavior of homing chum salmon in coastal waters using a data logger tagging method that will increase the duration of study and sample size without tracking effort We used data loggers, which can record the depth data and the temperature data simultaneously for 19.3 days at 5 and 10 s intervals, respectively. In late November 1994 off the coast of Sannku, northern Honshu, we released eight homing adults with data loggers, three loggers were retrieved near the release site after 0.8-1 3 days. A possible reason for missing loggers is the accidental detachment of instruments General feature of vertical behavior of salmon was similar to previous results obtained by a transmitter-tracking system; salmon made a series of ascents and descents, whose vertical speed was about 0 1-0.3m/s, and returned frequently to the surface water. As a result, salmon made large amplitude zigzag motions starting from the surface water The median thickness of the water column where salmon traveled through in two minutes was 3 2-6 5 m The vertical thermal structure was well mixed. There was no consistent tendency of behavior in relation to the ambient water temperature The observed large amplitude of vertical zigzag motion could be typical behavior of homing chum salmon in our study area in the isothermal water column. We conclude that use of a data logger holds promise for behavior studies of homing adult salmon, which facilitate recovery of the instruments by returning to natal rivers., National Institute of Polar Research, English
• ニジマス内耳小嚢におけるMitochondria-rich cell(MRC)の網目状分布 (総特集 バイオミネラリゼ-ション)
  都木 靖彰, 海洋, 28, 11, 675, 678, Nov. 1996
  海洋出版, Japanese

• ウナギの科学
  塚本勝巳, 第3章 3.2 骨格
  朝倉書店, 2019, [Joint work]
• 魚類学の百科事典
  骨組織の形成と代謝
  丸善出版, 2018, [Joint work]
• 魚類学
  矢部 衞; 桑村 哲生; 都木 靖彰
  恒星社厚生閣, 2017, 377, Japanese, Scholarly book, [Editor]
• マリンバイオテクノロジーの新潮流
  シーエムシー出版, 2011

• 増殖生物学特論Ⅰ, 2024年, 修士課程, 水産科学院
• 増殖生物学特論Ⅱ, 2024年, 修士課程, 水産科学院
• 水産科学英語Ⅰ, 2024年, 学士課程, 水産学部
• 水産科学英語Ⅱ, 2024年, 学士課程, 水産学部
• 水族生理学, 2024年, 学士課程, 水産学部

• （社）日本動物学会
• 日本水産学会
• 日本水産増殖学会
• Zoological Society of Japan

• Biomedical application of fish collagen: Development of the bone-mimetic collagen-fibril coating on the titan-made bone implant
  Grants-in-Aid for Scientific Research
  05 Apr. 2021 - 31 Mar. 2025
  都木 靖彰; 浦 和寛; 東藤 正浩
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 21H04731
• Development of scaffolds for cartilage tissue engineering using marine collagen: beyond the paradigm
  Grants-in-Aid for Scientific Research
  09 Jul. 2021 - 31 Mar. 2023
  都木 靖彰; 浦 和寛
  小課題1．チョウザメ脊索Ⅱ型コラーゲン（NC）を用いたⅡ型コラーゲン線維コート技術の開発： 本研究室で開発されたチョウザメ浮袋コラーゲン（SBC）を用いた線維コート技術 (Moroi et al., DOI: 10.1016/j.msec.2019.109925) を基盤としてNCの線維コート技術を開発した（線維コートとは、コラーゲン原線維を培養容器底面に一様にコーティングする技術で、生体組織のコラーゲン性基質と細胞とのインタラクションの研究を可能にする新技術である）。Ⅱ型コラーゲン溶液の濃度、線維化バッファー（リン酸バッファー）の濃度、ｐH、インキュベーション温度などを最適化することで、世界で初めてⅡ型コラーゲンの線維コートに成功した。また、マウス軟骨前駆細胞ATDC5を用いた培養試験を実施し、Ⅱ型コラーゲン分子コートと比較して線維コート上では細胞増殖速度が低下する一方で軟骨基質産生を示すアルシアンブルー染色が強陽性となる（＝前軟骨細胞から成熟軟骨細胞への分化が促進される）ことを確認した。今後軟骨細胞遺伝子発現量を定量する。
  小課題2．NCを用いた3次元足場ゲルの開発： 市販のブタⅠ型コラーゲンのゲル化法を参考に、細胞毒性の低い架橋剤ゲニピンを添加することで、NCを用いてNC原線維から成るゲルとNC分子からなるゲルの合成に成功した。今後ゲルの粘弾性や細胞培養への応用技術を開発する。
  小課題3．SBCもしくはNCを用いた軟骨細胞spheroid作成技術の開発： SBCを用いてマウス由来前骨芽細胞MC3T3-E1をスフェロイド化する技術を応用し、ATDC5細胞のスフェロイド化に挑戦した。しかし、MC3T3-E1がスフェロイド化する条件ではATDC5細胞はスフェロイド化しなかった。本技術開発には別のアイディアが必要であると思われる。
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Exploratory), Hokkaido University, 21K19130
• Formation of collagen bandles with micron-order diameter in sturgeon collagen: the mechanism of formation and bioactivity
  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)
  Jun. 2019 - Mar. 2021
  Takagi Yasuaki
  The micron-order bundles are the morphology of collagen observed in animal bodies and give stiffness to the tissue. Thus, clarifying the bundle formation mechanism will support the development of cellular scaffolds that have the mechanical strength required for tissue engineering. Since mammalian collagens do not form such bundles in vitro, we use the sturgeon collagen, that can form bundles, and developed key technologies, such as high-speed AFM and digital microscopies, which enable us to directly observe the process of micron-order bundle formation in vitro. In addition, the technology to regulate the diameter of collagen fibrils and bundles by changing NaCl and phosphate buffer concentrations, coating collagen bundles or fine fibrils on cell-culture wells, and culturing the cells on the surface were developed. These technologies are powerful tools to further clarify the bundle formation mechanism and the effects of bundles on cellular functions in the future.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Exploratory), Hokkaido University, Principal investigator, 19K22322
• Studies on the medical application of fish collagen peptides
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  Apr. 2018 - Mar. 2021
  Takagi Yasuaki
  Aiming to percutaneously apply collagen peptides (CPs) as the acute and chronic wound-healing accelerator, new collagen-purification and gelatin-extraction technologies that show excellent yield and collagen content were developed. Then, the effects of subcritical water treatment on antioxidant activity and fibroblast-activating activity of enzymatically hydrolyzed CPs were examined. The subcritical-water treatment further hydrolyzed enzymatically hydrolyzed CPs into smaller peptides and increased CPs' antioxidant activity. However, it did not change fibroblast (L929) migration and proliferation activities of enzymatically hydrolyzed CPs. The more extended treatment inhibited fibroblast migration and decreased CPs' proliferation-promoting activity. These data strongly suggest that the appropriate treatment with subcritical water makes enzymatically hydrolyzed CPs higher antioxidant activity, which is suitable for acute and chronic wound-healing accelerators.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Principal investigator, 18H02273
• Development of novel anti-infmallatory fish peptides by introducing glycosyl units
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
  Apr. 2017 - Mar. 2020
  SAEKI HIROKI
  Modification of fish meat-derived digestive peptides conjugated with alginate oligosaccharide (AO) using the Maillard reaction significantly enhanced anti-inflammatory function. Isoelectric focusing without amphoteric electrolytes (Autofocusing) was an effective means for concentrating and separating only AO-bound anti-inflammatory peptides from the digested fish meat. The negative charge of carboxyl groups of uronic acids in AO was involved in the concentration of anti-inflammatory peptides. It was also clarified that this uronic acid would be an important factor for the enhancement of anti-inflammatory function. Furthermore, collagen peptide also enhanced anti-inflammatory function by AO-modification. These finding suggest the practical versatility of the AO-modification using the Maillard reaction as a manner for production of anti-inflammatory edible peptides.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Coinvestigator, 17K07932
• Studies to find a mechanism of gonadal growth stimulation in sea urchin
  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
  Apr. 2014 - Mar. 2017
  Takagi Yasuaki; URA Kazuhiro; TODO Takashi
  We developed organ culture system using the sea urchin gonads for analysis of endocrine system during the gonadal growth. To date, it is well known that growth of gonad by synthesis and stored of MYP. The aim of this present study is identification of hormonal chemicals to induce the gonadal growth in sea urchin. We performed organ culture using the sea urchin gonads in the coelomic fluids of sea urchin, we measured MYP mRNA levels in the gonads by qPCR after incubation for 3days. The levels of MYP mRNA were no changing after incubation. It is suggested that MYP synthesis by nuclear receptor in gonads. Moreover, we extracted total lipids fraction form the gonads of sea urchin, and then gonads were incubated in the medium containing total lipids. However, NYP mRNA was no induced in this experiment. In the present study, we can’t identify the gonadal stimulation hormone in sea urchin. In future, we will try the comparison of colemic fluids compounds during gonadl growth.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, Principal investigator, 26660167
• Sea urchin has steroid hormone metabolism ?
  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
  Apr. 2013 - Mar. 2016
  Ura Kazuhiro; TAKAGI Yasuaki; IJIRI Shigeho
  It is still unclear that the endocrine system such as synthesize and/or embolism of steroid hormones during the period of gonadal growth in sea urchin. This study aimed to identify genes involved in gonadal growth and to investigate gene expression in the period of gonadal growth in sea urchin. RNA-seq analysis using next-generation sequencer was carried out on growing gonads of the Northern sea urchin, Mesocentrotus nudus. BLASTn analysis identified 22 transcripts potentially involved endocrine factors such as nuclear receptor (NR) and 21 transcripts of P450 in the growing gonad. However, the homologous genes as ER, AR, P450scc, P450c17, P450arom were not observed in sea urchin. In these analysis, it is suggested that sea urchin has no sex steroid hormones as same as vertebrate. These results suggested that sea urchin synthesized steroid hormones as same as other insects.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, Coinvestigator, 25660159
• Analyses of molecular mechanisms of gonadal sex differentiation, oocyte growth and maturation for the development of techniques on artificial control of reproduction in sturgeons
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
  Apr. 2012 - Mar. 2016
  Adachi Shinji; ARAI Katsutoshi; TAKAGI Yasuaki; HIRAMATSU Naoshi; YAMAHA Etsuro; IJIRI Shigeho
  Identification of genes that express by stage specific manner and quantification of their mRNA levels in gonads were conducted throughout the periods of molecular sex differentiation, morphological sex differentiation, oocyte growth and maturation in Russian and Amur sturgeons using a next-generation sequencer. The information obtained from this study was utilized in the application for the development of techniques on sexing in the early developmental stage, induction of sexual maturation in the earlier gonadal developmental stage, production of good quality eggs and production of all female population.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, Coinvestigator, 24248033
• Studies on the function of non-collagenous proteins contained in the goldfish scales on the regulation of collagen fibril diameter and alignment.
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  Apr. 2012 - Mar. 2016
  Takagi Yasuaki
  I conducted comprehensive cDNA cloning of SLRPs in zebrafish and goldfish, and 10 new sequences were deposited to the database (DDBJ). Then, spatiotemporal expressions of mRNAs of decorin (dcn), biglycan (bgn), chondroadherin (chad), lumican (lum), osteoglycin (ogn) and dermatopontin (dpt) were clarified. In addition, recombinant proteins of Dcn, Bgn and Dpt and their specific antibodies were produced, and immunohistochemical localizations of these proteins were clarified. Hybrid gel made of recombinant Dpt and type I collagen was developed. Moreover, dpt-knock down experiment revealed that Dpt regulated m RNA expressions, fibril diameter and alignment of both type I and type II collagens in zebrafish. All these data are new to science, and the present results opened the possibility of new hybrid scaffolds consisted of collagen fibrils and SLRPs/Dpt.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Principal investigator, 24380101
• Is there gonadal stimulation hormone in sea urchins?
  Grants-in-Aid for Scientific Research
  2011 - 2013
  TAKAGI Yasuaki; URA Kazuhiro; TODO Takashi
  Sea urchin gonadal growth is characterized by intragonadal nutrient storage and the use of the stored nutrient for gametogenesis. Before gametogenesis initiation, gonads increase in size by accumulating nutrients such as proteins, lipids and carbohydrates in nutritive phagocytes that fill the gonadal lumina of both sexes. The major protein is termed major yolk glycoprotein or major yolk protein (MYP), which is a glycoprotein having molecular weight of 160-180 kDa, and has significant roles in gametogenesis. However, we have no information about gonadal development mechanisms, as well as the regulation mechanism on the synthesis of MYP in gonads. Therefore, to understand the mechanisms of gonadal development, we developed quantitative PCR system of MYP mRNA expression as well as an organ culture systems using sea urchin gonads. These techniques will enable a endocrinological research on gonadal developments in the sea urchin.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 23658152
• Digestive physiology to development the artificial diet for sea urchin.
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
  2010 - 2012
  URA Kazuhiro; TAKAGI Yasuaki
  Subtilase and cellulase exhibited hydrolytic activity toward carboxymethyl cellulose with optimum temperature and pH at 30 °C and pH 8.0, respectively. The thermal stability was characterized and temperature at which activity decreased to50% by the 30 min treatment at pH 7.0 was 32 °C. The isolated cellulase activity was remained at high level at 5-20 °C which is growth temperature of the short-spined sea urchin. Thus, we confirmed that a cellulase of the short-spined sea urchin is adaptiveenzyme around low water temperature.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Coinvestigator, 22580194
• Studies on the mechanism of collagen fibril assembly in fish scales
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2009 - 2012
  TAKAGI Yasuaki; IKOMA Toshiyuki; URA Kazuhiro
  Using MS analysis, scale SLRPs, which were possible regulators of 3-dimensinal architecture of teleost fish collagen, were identified. After the cDNA cloning of SLRPs, localization of their mRNAs were clarified. We also revealed a negative correlation between collagen denaturation temperature (DT) and contents of α3-subunit, as well as positive correlation between DT and hydroxylation ratio of proline residues in the collagen. Thus, these two factors seem to be the major regulators of DT of fish collagen. Artificial fibrillogenesis of collagen under magnetic field enabled a synthesis of a material having relatively aligned collagen fibrils, whose viscoelasticity and tensile strength were highest under 4 T and 12 T, respectively. High-density meso-porous new material was also synthesized using fish collagen.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Principal investigator, 21380116
• Regulation mechanism of biomineralization based on interaction between organic matrices and inorganic crystals
  Grants-in-Aid for Scientific Research Grant-in-Aid for Creative Scientific Research
  2005 - 2009
  NAGASAWA Hiromichi; KOGURE Toshihiro; TAKAGI Yasuaki; SAKUDA Shohei
  It has been hypothesized that biomineralization, an action of mineral formation by organisms, is regulated by a small amount of organic materials included in biominerals. Using calcified tissues of some aquatic organisms we searched for calcification-regulating organic compounds, and purified them for structural and functional identification. We also clarified the crystallographic properties of each calcified tissue by electron microscopic analyses and verified the hypothesis by discovering many high- and low-molecular-weight organic compounds, which regulate calcification.
  Japan Society for the Promotion of Science, Grant-in-Aid for Creative Scientific Research, The University of Tokyo, Coinvestigator, 17GS0311
• Studies on the cellular mechanism of collagen fibril alignment in the regenerating scales of goldfish : toward the bioinspired fabrication of artificial cornea
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2006 - 2008
  TAKAGI Yasuaki; URA Kazuhiro; IKOMA Toshiyuki
  ウロコのコラーゲンを用いて再生医療用人工基質の合成をめざして、生物学と材料科学の両面から研究を推進した。生物学的アプローチにより鱗形成細胞分化の分子機構、コラーゲン配向を制御する候補分子、組織ごとのコラーゲンα鎖組成を明らかにした。また、材料科学的アプローチにより、ブタ及びティラピアコラーゲン線維配向ゲルを高磁場内で実現するとともに、湿潤環境下による乾燥により10~20wt%の高密度化に成功した。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Principal investigator, 18380109
• ウニにインスリンはあるのか?
  Grants-in-Aid for Scientific Research Grant-in-Aid for Exploratory Research
  2006 - 2007
  都木 靖彰; 浦 和寛
  我が国の水産業において、水産無脊椎動物は重要な増養殖対象動物としての位置を占めており、種苗生産・放流や養殖が盛んに行われている種も多い。近年、日本沿岸域における水産生物資源、特に無脊椎動物の資源量は減少傾向にあることから、今後は優良品種の育種や高度で効率的な増養殖技術の開発が必要になると考えられるが、水産無脊椎動物においてそのような試みは著しく立ち遅れている。その大きな理由として、水産無脊椎動物の成長や成熟を制御する内分泌系に関する基礎的知見が極めて少ないといえる。比較的研究されているウニでも、糖質・脂質・タンパク質の代謝を制御する内的因子(ホルモンなど)の存在の有無や、それらの作用機序について正確に把握されていないのが現状である。本研究は、ウニをモデル生物として選定し、無脊椎動物の内分泌機構の解明に着手するものである。
  今年度は、エゾバフンウニ消化器官において、モルモット抗ブタインスリン抗血清を用いて免疫組織化学的解析を行った。その結果、胃において消化管内腔側の上皮細胞の小さな顆粒に陽性反応が認められた。また、卵巣、精巣、放射神経にも免疫陽性反応が認められた。このことからエゾバフンウニにインスリン様物質が局在している可能性が示された。
  Japan Society for the Promotion of Science, Grant-in-Aid for Exploratory Research, Hokkaido University, Principal investigator, 18658075
• Analysis of sea urchin digestive system for the development artifical feed
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
  2004 - 2005
  SHIMIZU Motohiro; TAKAGI Yasuaki; OJIMA Takao; URA Kazuhiro
  The sea urchin is an important coastal fisheries resource in Hokkaido. Unfortunately, they have been decrease in natural stocks, and therefore aquaculture techniques are required. In order to develop possible culture methods, physiological roles of digestive canal under artificial conditions should be revealed. However, there is little information on the fine structure and physiological roles of the digestive canal of the sea urchin. Following results were obtained.
  1.The digestive canal of the sea urchin has following five parts, pharynx, esophagus, stomach, intestine and rectum. In the epithelium layer of the pharynx and esophagus, two types of granular cells stained with PAS and/or alcian blue were observed. Some granules observed in pharynx and esophagus were also stained with Hematoxylin. In epithelium layer of stomach, one type of granules were found. These granules were secreted in apical region of cytoplasm.
  2.In order to obtain information about carnivorous actions of sea urchin, we investigated the occurrence of proteases in the sea urchin viscera and purified a major protease. N-terminal and internal amino acid sequences of the protease showed 37.9-55.2% identity to those of subtilisin-like alkaline serine protease, i.e. a subtilase. We determined the entire amino acid sequence of the protease using cDNAs amplified by PCR from cDNA library using degenerated primers. The mature sea urchin subtilase was considered to consist of 311 residues with calculated molecular mas of 32,270 Da. Primary structure of catalytic domain of the sea urchin subtilase showed 33-46% identity with those of bacterial subtilases such as subtilisin, proteinase K, and aqualysin.
  3.In this study, we attempted to isolate and characterize a cellulose from sea urchin. A cDNA library from sea urchin digestive tracts was constructed and cDNA encoding SnEG54 were amplified by the PCR using degenerate primers designed from the partial amino acid sequences of SnEG54. By overlapping the amino acid sequence of 444 residues was deduced from the coding region. The amino acid sequence of mature SnEG54 showed 57, 55 and 51% identity with the corresponding regions of termite, sea squirt, and abalone cellulases, respectively.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Coinvestigator, 16580140
• 魚類の再生鱗をモデルとした脊椎動物の骨再生機構研究の新展開
  Grants-in-Aid for Scientific Research Grant-in-Aid for Exploratory Research
  2004 - 2005
  都木 靖彰; 浦 和寛
  1.昨年にひきつづき、キンギョの鱗再生にともない発現するRunx2(Cbfa1)およびBMP2,4遺伝子の塩基配列決定をおこなった。Runx2は4種のアイソフォームの全塩基配列を決定した。BMP2はほぼ70%程度の配列の決定を終えた。キンギョRunx2遺伝子はこれまでに報告されたゼブラフィッシュRunx2bと最も高い相同性(約90%)を示した。BMP2および4のcDNA断片はゼブラフィッシュBMP2および4と高い相同性を示した。
  2.鱗有機基質の主成分であるキンギョI型コラーゲンα鎖cDNA塩基配列を決定した。3種のα1(I)cDNA(α1(I)-A,B,C)を得、α1(I)-Aはその全塩基配列を、α1(I)-B,Cはその70%を決定した。α2(I)も3種のcDNAを得、それらの全塩基配列を決定した。α3(I)は1種類の全塩基配列を決定した。キンギョα鎖は、ゼブラフィッシュα鎖と約90%、哺乳類のα鎖と約70%の相同性を示した。また、分子系統樹ではα3(I)がα1(I)から分岐していることが確認された。さらに、既報の脊椎動物I型コラーゲンα鎖のPro残基数とコラーゲン変性温度の関係を近似式で表し、Y=0.3853X-44.712(r=0.9916)を得た。ここで、Y:変成温度(℃)、X:アミノ酸1000残基あたりのPro残基数である。この式を用いてキンギョのコラーゲンの変成温度を推定したところ、変成温度は三量体を構成するα鎖の組成で異なり、α3(I)鎖を多く含むと変成温度が高くなることが示された。
  3.低リン・低カルシウム条件下におかれたキンギョの再生鱗の有機基質の微細構造解析をおこなった。リン酸カルシウム結晶は、非コラーゲン性有機基質の電子密度の高い物質中で形成され、成長することを明らかにした。
  Japan Society for the Promotion of Science, Grant-in-Aid for Exploratory Research, Hokkaido University, Principal investigator, 16658077
• Stock identification of cultured fish and shellfish by composition of trace elements in the hard tissues : a new technology for identification of product origin.
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2003 - 2005
  TAKAGI Yasuaki; ARAI Takaomi; ABE Syuiti; YAMAHA Etsuro
  For trace-elemental fingerprint studies in fish otoliths, industry-coupled plasma mass spectrography (ICPMS) has not used in Japan. The present study was undertaken to develop ICPMS-based trace-elemental fingerprint studies in the hard tissues of cultured fish and shellfish in Japan. Following results were obtained.
  1. We developed standard methods to determine trace-elemental composition of fish otoliths and shells of shellfish using solution-based and laser abration ICPMS. Trace-elemental compositions were useful fingerprints that could identify product origin of cultured species.
  2. We clarified migratory patterns of some salmonid and eel species using Sr contents and Sr/Ca ratio of otoliths determined by EPMA and revealed that the method is a powerful tool to study migration patterns of anadromous, catadromous or diadromous fishes.
  3. We developed a DNA microarray to identify stocks of chum salmon. The array was accurate and time effective, and required no special equipments such as DNA sequencer. Therefore, the method is especially a powerful tool to identify chum salmon stocks in the field study and on board.
  4. We immunohistochemically localized otolith matrix proteins, OMP-1 and otolin-1, and suggested important rolls of these proteins in calcification and formation of otolith micro structures. We also revealed that the aragonite saturation ratio of endolymph was maintained over 1.0 through the day-night cycle, suggesting aragonite crystal growth could be continued through a day. On the other hand, mRNA expression of otolin-1 showed clear daily rhythm with significantly higher expressions during night-time, suggesting a key fuction of otolin-1 to construct daily rings. In masu salmon, increases in Sr concentrations and Sr/Ca ratios in the serum occurred 7 days after the seawater transfer. Such a time-lag must be taken into account to reconstruct migration patterns in the anadromous fishes.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Principal investigator, 15380125
• Life history of marine mammals and their environunental condition
  Grants-in-Aid for Scientific Research
  2001 - 2004
  MIYAZAKI Nobuyuki; OTOBE Hirotaka; AMANO Masao; ARAI Takaomi; TANABE Shinsuke
  We investigate distribution, migration, growth, reproduction, feeding habit, population identification of dolphins and seals in the various areas of the world. And we also enforce monitoring study on marine pollution of organochlorine compounds (OCs), organotin cimpounds (BTs), heavy metals, and radionuclides, using samples of marine mammals. We published 93 scientific papers (88 in English and 4 in Japanese) with the peered referees, 23 articles (4 in English, 19 in Japanese) and one English proceedings. In the international and national academic conference, we made 77 presentations (38 in English and 39 in Japanese).
  Accumulation study of hazardous chemicals such as OCs, BTs and heavy metals survey provided the interesting scientific evidence of Dall's porpoises. Since 1991 when the former USSR was collapsed, Caspian Sea faced severe environmental condition. Main reason of the mass die-off of several thousands Caspian seals occurred in 1997, 1998 and 2000, might be due to the lowered immune system of the species. We found the A-type influenza virus (A/Bangkok/1/79/HsN2) in the serum samples of Caspian seals. This influenza virus has been active in the Caspian seals for more than 20 years. In the near future, humans might be infected with this virus all over the world. Thus, we need to establish the well-organized research system for this matter.
  We investigated evaluation of mitogen-induced responses in marine mammals and human lymphocytes by in-vitro exposure of BTs. Significant suppression was observed when the cells were exposed at normal level in the nature, suggesting BTs are strong toxic chemical. And we also found significant effect of plural hazardous chemicals. This study suggests that we need to establish the long-term monitoring system in marine ecosystem.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), The University of Tokyo, 13460082
• Molecular mechanism of otolith microstructure formation : immunohistochemical localization of two matrix proteins and expressions of tneir mRNAs
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
  2001 - 2002
  TAKAGI Yasuaki
  1. Identification of otolith-matrix-producing cells and localization of matrix proteins in the otolith : Specific antibodies against the major proteins of otolith matrix, OMP-1 and otolin-1, were raised and immunohistochemistry was conducted. The squamous epithelial cells and the transitional epithelial cells of the inner ear sacculus were identified as OMP-1-producing cells, whereas the cells located at the most periferal region of the sensory epithelium were identified as otolin-1-producing cells. The OMP-1 was contained in the otolith only, whereas the otolin-1 was included in both the otolith and the otolith membrane (gelatinous layer). The electron microscopy revealed that the otolith was composed of two types of the organic matrices, a dense sheet-like matrix and a fine meshwork matrix. Both OMP-1 and otolin-1 were detected in the meshwork. Differences in the density of the meshwork matrix makes daily rings, thus it is possible that the daily changes in the rate of production and/or deposition of OMP-1 and otolin-1 closely relate to the formation of the daily rings.
  2. Development of real-time quantitative PCR system for OMP-1 and otolin-1 mRNA expression : We have developed the real-time PCR system to quantify OMP-1 and otolin-1 mRNA expression levels from the left and right sacculi of the individual rainbow trout. The daily changes of the expression levels of OMP-1 and otolin-1 mRNA were now under the investigation.
  3. Determination of the supersaturation ratio of the inner ear endolymph : Otolith is composed of calcium carbonate poly crystals crystallized from the endolymph. Therefore, the growth rate of the otolith calcium carbonate must be highly dependent on the supersaturation ratio (S_a) of the endolymph. We have measured individually the ionic composition of the endolymph and calculated the S_a. The endolymph S_a was 2.027-4.303, clearly indicating that the endolymph is supersaturated with respect to the aragonite. The S_a was closely related to the pH of the endolymph, thus, pH-regulation of the endolymph is crucial for the otolith growth.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Principal investigator, 13660178
• Salmon migaration and their behavioral and physiological adaptation to fluctuation of ambient temperature
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B).
  1999 - 2000
  NAITO Yasuhiko; TAKAGI Yasuaki; UEDA Hiroshi; TANAKA Hideji; KATO Akiko; IIGO Masayuki
  We could obtain continuous data of swimming body axis, tail beat activity for two days from two coastal-migrating chum salmon in Otsuchi coast, Iwate in 1999 using micro-data loggers, which have never been successfully obtained in the past. Analysis of these data showed that salmon consumed more energy for ascent than descent and never control the air volume in the air bladder.
  We also succeeded to obtain 51days continuous data of swim speed, swim depth and ambient temperature from a offshore-migrating chum salmon in July, 2000. We attached a micro-data logger to a salmon at mid south of Bering Sea and recovered at coast of Nemuro city of Hokkaido. Preliminary analysis suggested that salmon swam at a mean speed of 36.2km/day. This means 2427km of swim distance in total during 51days, which occupied 80% of total 2760km of horizontal distance from release point to recaptured point.
  We also conducted data-logger experiment on 30 trout, Oncorhynchus nerka, at Chuzenji Lake in 1999 and 2000 and successfully obtained data of swim depth and ambient temperature from 23 fish. From experiments we expected behavioral and temperature-physiological difference in their performance between condition of gonads of both sex. Data are under analysis.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B)., National Institute of Polar Research, Coinvestigator, 11460093
• 魚類耳石の微細輪紋形成機構-耳石有機基質合成と内リンパ液イオン組成からの解析
  Grants-in-Aid for Scientific Research Grant-in-Aid for Encouragement of Young Scientists (A)
  1999 - 2000
  都木 靖彰
  耳石に刻まれる日周輪やチェックリング読みとりの正確性を増し、さらなる情報を解読するためには、内耳内リンパ液の微量採取法、イオン組成測定法、耳石有機基質産生活性測定法を確立し、それらが日周輪・チェックリング形成に果す役割を解明することが必要である。
  昨年度に確立した方法を用いて、ニジマスの内リンパ液のイオン組成と炭酸カルシウムアラゴナイトに対する過飽和度を求め、内リンパ液の過飽和度とpH、二酸化炭素分圧、炭酸イオン濃度、Caイオン濃度との関係を解析した。その結果、過飽和度は内リンパ液のpHに比例していることを明らかにした。このことは、内リンパ液のpHの調節により耳石成長量が調節されていることを示す。現在この成果について学術論文を執筆中である。
  次に、ストレスとチェックリング形成との関係を明らかにする目的で、追い回しストレスが内リンパ液イオン組成に与える影響を調べた。短時間の追い回しストレスは血液の酸性化を引き起こしたが、内リンパ液のイオン組成、過飽和度には大きな変化がなかった。このことから、短時間のストレスはチェックリング形成の原因とならないものと結論できた。現在、繰り返しストレス、長時間のストレスの影響を調べている。
  OMP-1は、我々のグループが世界に先駆けてその構造を明らかにした、耳石の可溶性有機基質であり、その成果を学術雑誌に論文として発表した(裏面参照)。また、現在OMP-1遺伝子発現量を競合PCR法を用いて調べている。
  さらに、耳石有機基質の性質とその産生機構を明らかにする目的で、OMP-1の電顕的分布を調べるとともに、耳石に含まれる糖成分の解析を行った。これらの成果も学術雑誌に論文として発表した(裏面参照)。
  以上の成果をまとめる目的で、耳石形成機構に関する二つの総説を学術雑誌に発表した(裏面参照)。
  Japan Society for the Promotion of Science, Grant-in-Aid for Encouragement of Young Scientists (A), The University of Tokyo, Principal investigator, 11760131
• POPULATION MANAGEMENT OF MARINE MAMMALS AND ENVIRONMENTAL STUDY ON THEIR HABITATS
  Grants-in-Aid for Scientific Research
  1997 - 2000
  MIYAZAKI Nobuyuki; AMANO Masao; OTOBE Hirotaka; TAKAGI Yasuaki; TANABE Shinsuke
  We investigated taxonomy, reproduction, growth, behavior, feeding habitat of marine mammals, and environmental condition of their habitats polluted by hazardous chemicals (organochlorine compounds, organtin conpounds, and heavy metals, etc). Concerning this project, we published 37 scientific papers, and 36 articles of book and report. We also made 49 presentations in the international and domestic scientific society, and also 28 lectures to public people. Based on these scientific results, we recommended actual management of marine mammals, which involved not only information on life history parameters but also information on marine pollution. We disseminated these scientific information to the public people in the worlds by home page (http : //wakame.ori.u-tokyo.ac.jp).
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B)., OCEAN RESEARCH INSTITUTE, THE UNIVIVERSITY OF TOKYO, 09460086
• 電顕組織化学法による耳石基質の合成・次着経路とその日周輪形勢に果たす機能の解明
  Grants-in-Aid for Scientific Research Grant-in-Aid for Encouragement of Young Scientists (A)
  1997 - 1998
  都木 靖彰
  硬骨魚類の耳石は、年齢、日齢査定形質として水産学研究に必要不可欠な硬組織である。にもかかわらず、年輪・日周輪形成メカニズムはいまだに解明されていない。本研究は,耳石日周輪形成メカニズムを、主に耳石有機基質の産生メカニズムから解明しようとするものである。本年度は昨年度に引き続き、以下の諸点を明らかにした。
  1. 抗耳石可溶性基質抗体を用いた透過型電顕組織化学を昨年に引き続き行い、移行上皮細胞・扁平上皮細胞における耳石可溶性基質産生機構およびその耳石への取り込み機構を明らかにした。可溶性基質は産生後、移行上皮細胞では小型の、扁平上皮細胞ではより大型の分泌小胞中に保存された後、エクソサイトーシスにより内リンパ液中へと分泌される。分泌された可溶性基質が内リンパ液中から耳石へと取り込まれていく様子も観察された。
  2. 小嚢上皮・耳石のレクチン組織化学法および、耳石可溶性基質・内リンパ液のドットプロット法により、小麦胚芽、コンカナバリンAおよびインゲンマメレクチンに反応するN一結合型糖鎖を含む物質が感覚細胞および支持細胞から耳石膜を介して、あるいは移行上皮細胞および支持細胞から内リンパ液を介して耳石に取り込まれることを明らかにした。
  3. ニジマス耳石割断面を走査型電子顕微鏡で詳細に観察したところ、小石状、平板状、球状など様々な結晶構造が観察された。現在、これらの構造がすべてあらゴアナイトからできているのか、他の結晶系(カルサイトなど)が混在しているのか、X線回折を行うべくサンプルを準備中である。それと平行して耳石可溶性基質抗体を用いた免疫組織化学を走査型電顕上で行うべく技術開発中である。
  以上の結果は、タンパク質に加えて糖質、たぶん糖タンパク質が耳石形成に重要な機能を果たしていることを示唆する。今後耳石基質タンパク質や糖鎖の構造を明らかにし、その機能を解明する必要がある。
  Japan Society for the Promotion of Science, Grant-in-Aid for Encouragement of Young Scientists (A), The University of Tokyo, Principal investigator, 09760172
• レクチン組織化学法を用いた魚類耳石有機基盤の糖構造およびその合成・沈着経路の解明
  Grants-in-Aid for Scientific Research Grant-in-Aid for Encouragement of Young Scientists (A)
  1996 - 1996
  都木 靖彰
  耳石は耳石特有の有機基質に炭酸カルシウムが沈着して生長するとされる。本研究は、糖と特異的に結合するレクチンを用いて耳石有機基質の糖構造の決定、その産生細胞の特定および産生機構の解明を目的として行われた。材料としてニジマスの最も大きい耳石(扁平石)を包む内耳膜迷路である小嚢を用いた。研究結果の概要は以下の通りである。
  1.透過型電子顕微鏡観察により、小嚢上皮細胞を感覚細胞、支持細胞、移行上皮細胞、Mitochondria-rich cell(MRC)、扁平上皮細胞に分類した。MRCを除くすべての細胞が分泌活性を有するタンパク合成細胞であり、耳石形成に関与することを示唆した。
  2.MRCは、その微細構造はイオン輸送生細胞の特徴を有し、代表的なイオンポンプであるNa^+,K^+-ATPaseを高濃度に持つことを証明した。このことから、MRCは小嚢内リンパ液の特殊なイオン組成の形成にあずかるイオン輸送性細胞であると断定した。
  3.アルシアンブルー。PAS染色により、耳石には主として産生多糖類が、耳石膜には酸性多糖と中性多糖両方が含まれることを明らかとした。小嚢上皮のレクチン組織化学染色により、感覚上皮・移行上皮・扁平上皮細胞にはマンノース・N-アセチルグルコサミンが、支持細胞にはマンノースが含まれることを証明した。一方、ガラクトースやN-アセチルガラクトサミンが小嚢上皮に含まれる可能性は低いことを解明した。耳石抽出物を電気泳動・ウェスタンブロッティング後、レクチン(ConA)染色したところ、耳石基質タンパクの主要な成分はマンノースを含む糖タンパクであった。同様の成分は内リンパ液中にも存在した。これらのことから、小嚢上皮に含まれるマンノースの少なくとも一部は耳石基質タンパクと結合した後内リンパ液中に分泌され、耳石中に取り込まれることを示唆した。
  Japan Society for the Promotion of Science, Grant-in-Aid for Encouragement of Young Scientists (A), The University of Tokyo, Principal investigator, 08760174
• Marine Pollution of chemicals and Biological Impact
  Grants-in-Aid for Scientific Research
  1994 - 1996
  MIYAZAKI Nobuyuki; TANABE Shinsuke; AMANO Masao; TAKAGI Yasuaki; TAKEUCHI Ichiro; OTOBE Hirotaka
  We examined hazardous chemicals deposited in marine animals collected from the tropical waters to the Antarctic and the Arctic ocean. Research results have been published by 10 scientific papers, 6 books and 14 documentations, and reported by 13 oral presentations in scientific meetings. These scientific contents are summarized by the following 5 items ; (1) concentration of organochlorine compounds (PCB,DDT,BHC etc.) in dolphins collected from the worldwide areas and their biological impact, (2) concentration of organochlorine compounds (PCB,DDT,BHC etc.) in Baikal seals and their biological impact, (3) concentration of organotin compounds in dolphins collected from Japanese waters and their biological impact, (4) concentration of heavy metals (Hg, Cd, Pb etc.) in Aderie penguins collected from the Antarctic Ocean, and (5) future plan of international research organization on marine pollution.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Ocean Research Institute, Tokyo Unuv., 06454097
• 魚類のカルシウム代謝調節と硬組織の形成機構に関する研究
  Grants-in-Aid for Scientific Research Grant-in-Aid for Encouragement of Young Scientists (Research Fellowship)
  1989 - 1990
  都木 靖彰
  Japan Society for the Promotion of Science, Grant-in-Aid for Encouragement of Young Scientists (Research Fellowship), Hokkaido University, Principal investigator, 01790464

• コラーゲンを含む組成物
  Patent right, 田中順三; 生駒俊之; 吉岡朋彦; 許哲峰; 都木靖彰; 浦和寛
  特許6132299
  2017
• ウニ用畜養飼料
  Patent right, 浦和寛; 都木靖彰; 今村聖祐; 村上雅之; 堤尚信
  特開2016-187337, 2016
• チョウザメ類脊索から簡便な抽出方法で得られるＩＩ型コラーゲン
  Patent right, 都木靖彰; 浦和寛, 国立大学法人北海道大学
  特願2011-147490(P2011-147490), 01 Jul. 2011
  特許第5043215号(P5043215)
  10 Oct. 2012