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KANBE Takashi
| Research Faculty of Agriculture Fundamental AgriScience Research Agrobiology and Bioresources | Research Fellow |
Research activity information
■ Papers- Genetic introgression among charr species in the Shiretoko Peninsula, Japan.
Tetsuya Ozawa; Takashi Kanbe; Tetsu Yatsuyanagi; Hitoshi Araki
Journal of fish biology, 02 Jul. 2026, [International Magazine]
English, Scientific journal, Introgressive hybridization is an important source of genetic variation and a driver of evolutionary diversification in fishes. On the Shiretoko Peninsula, a UNESCO World Natural Heritage site in northern Japan, the Southern Asian Dolly Varden Salvelinus curilus (SADV) is the only charr species present in most rivers. However, previous studies have suggested that some SADV individuals possess mitochondrial DNA (mtDNA) from the White-spotted charr Salvelinus leucomaenis, implying historical introgression. To quantify and map this introgression, we estimated the proportion of non-SADV mtDNA (%noSADV) across 40 rivers using environmental DNA (eDNA) metabarcoding. Because White-spotted charr were absent from the study rivers, %noSADV could be interpreted as reflecting mitochondrial introgression within SADV populations. Indeed, %noSADV estimates from eDNA concentrations were strongly correlated with those from conventional catch surveys in 10 rivers (r = 0.96), supporting the reliability of the eDNA-based estimates. In addition, a minor proportion of Salvelinus eDNA was assigned to Salvelinus malma, a charr species that does not occur in Japan. Tissue-based analysis confirmed that some SADV individuals indeed carried S. malma mtDNA, suggesting an additional, independent introgression event. Across the 40 rivers, %noSADV ranged 0%-97.2%, including 0%-0.47% assigned to S. malma mtDNA. Generalized linear models indicated significant positive associations between %noSADV assigned to S. leucomaenis and both latitude and forest coverage. These findings demonstrate that (1) results from mtDNA-based analyses of taxa in which genetic introgression occurs frequently should be interpreted with caution and (2) in cases where one of the donor species is absent, eDNA metabarcoding can be a useful tool for estimating the population-level proportion of introgression over broad spatial scales and uncovering hidden evolutionary legacies in freshwater fishes. This approach provides valuable insights for evolutionary ecology and conservation genetics, especially for rare fish species in regions where conventional, tissue-based surveys are logistically constrained. - Large-scale environmental DNA survey reveals niche axes of a regional coastal fish community
Yutaka Osada; Masaki Miya; Hitoshi Araki; Hideyuki Doi; Akihide Kasai; Reiji Masuda; Toshifumi Minamoto; Satoquo Seino; Teruhiko Takahara; Satoshi Yamamoto; Hiroki Yamanaka; Mitsuhiro Aizu-Hirano; Keiichi Fukaya; Takehiko Fukuchi; Ryo O. Gotoh; Masakazu Hori; Midori Iida; Tomohito Imaizumi; Tadashi Kajita; Takashi Kanbe; Tanaka Kenta; Yumi Kobayashi; Tomohiko Matsuura; Hiroki Mizumoto; Hiroyuki Motomura; Hiroaki Murakami; Kenji Nohara; Shin-ichiro Oka; Tetsuya Sado; Hiroshi Senou; Koichi Shibukawa; Tomoki Sunobe; Hiroshi Takahashi; Koji Takayama; Katsuhiko Tanaka; Hisashi Yamakawa; Satoru Yokoyama; Seokjin Yoon; Michio Kondoh
SCIENTIFIC REPORTS, 16, 1, 16 Feb. 2026
English, Scientific journal - Exploring the Dynamics of Environmental DNA: Effects of Early Developmental Stage and Physiological State in Chum Salmon
Masayuki K. Sakata; Takashi Kanbe; Shunpei Sato; Hitoshi Araki
Environmental DNA, Jun. 2025, [Peer-reviewed]
English, Scientific journal - Loss of Photoperiodic Control of Juvenile-Hormone Signaling Pathway Underlying the Evolution of Obligate Parthenogenesis in the Pea Aphid.
Asano Ishikawa; Hiroki Gotoh; Kota Ogawa; Takashi Kanbe; Shin-Ichi Akimoto; Toru Miura
Zoological science, 42, 2, 186, 195, Apr. 2025, [Peer-reviewed], [Domestic magazines]
English, Scientific journal, Phenotypic plasticity, the ability of organisms to change their phenotype depending on external stimuli, enables their survival in fluctuating environments. An extreme example is polyphenism, in which a single genotype produces discrete phenotypes in response to external cues. However, under persistent environmental conditions, natural selection would favor reduced plasticity. This study focused on the loss of reproductive polyphenism and revealed the underlying mechanism in the pea aphid Acyrthosiphon pisum. Although most populations exhibit reproductive polyphenism, known as cyclical parthenogenesis, with a seasonal shift between parthenogenesis and sexual reproduction, some exhibit obligate parthenogenesis. To investigate the potential role of changes in the environmental sensitivity of the juvenile hormone (JH) pathway during this evolutionary shift, we analyzed the expression of genes involved in JH synthesis and degradation. We found that five of seven JH-related genes exhibited photoperiodic responses in one cyclical-parthenogenetic strain, whereas none of them responded to photoperiod in the two obligate-parthenogenetic strains. Notably, CYP15A and JHEH genes, which are involved in the final step of JH synthesis and in the initiation of JH degradation, respectively, showed strong photoperiodic responses in the cyclical-parthenogenetic strain but showed no responses in the obligate-parthenogenetic strains. Acetone treatment induces male production in obligate-parthenogenetic strains, suggesting that the developmental pathway for male production remains functional in these strains. These results suggest that the loss of the photoperiodic response in both JH synthesis and degradation pathways is a key mechanism underlying the elimination of the sexual phase, resulting in the loss of reproductive polyphenism in aphids. - Human activity-associated establishment of invasive mink population estimated using environmental DNA
Toshihiro Takaba; Masayuki K. Sakata; Takashi Kanbe; Takashi Mitsuzuka; Shouko Inoue; Hiroki Mizumoto; Takahiro Nobetsu; Hitoshi Araki
Biological Invasions, Springer Science and Business Media LLC, 31 Jul. 2024, [Peer-reviewed]
Scientific journal - Environmental DNA unveils deep phylogeographic structure of a freshwater fish
Tetsu Yatsuyanagi; Takashi Kanbe; Kazuya Fujii; Shouko Inoue; Hitoshi Araki
Molecular Ecology, Wiley, Apr. 2024, [Peer-reviewed]
Scientific journal, Abstract
Phylogeography bears an important part in ecology and evolution. However, current phylogeographic studies are largely constrained by limited numbers of individual samples. Using an environmental DNA (eDNA) assay for phylogeographic analyses, this study provides detailed information regarding the history of Siberian stone loach Barbatula toni, a primary freshwater fish across the whole range of Hokkaido, Japan. Based on an eDNA metabarcoding on 293 river water samples, we detected eDNA from B. toni in 189 rivers. A total of 51 samples, representing the entire island, were then selected from the B. toni eDNA‐positive sample set for the subsequent analyses. To elucidate the phylogeographic structure of B. toni, newly developed eDNA metabarcoding primers (Barba‐cytb‐F/R) were applied to these samples, specifically targeting their haplotypic variation in cytochrome b. After a bioinformatic processing to mitigate haplotypic false positives, a total of 50 eDNA haplotypes were identified. Two regionally restricted, genetically distinct lineages of the species were revealed as a result of phylogeographic analyses on the haplotypes and tissue‐derived DNA from B. toni. According to a molecular clock analysis, they have been genetically isolated for at least 1.5 million years, suggesting their ancient origin and colonisation of Hokkaido, presumably in the glacial periods. These results demonstrate how freshwater fishes can alter their distributions over evolutionary timescales and how eDNA assay can deepen our understanding of phylogeography. - Co-occurrence patterns of endangered Sakhalin taimen and introduced rainbow trout in Hokkaido, Japan, inferred by environmental DNA metabarcoding
Takashi Kanbe; Hiroki Mizumoto; Takashi Mitsuzuka; Nobuyoshi Nakajima; Hitoshi Araki
Aquatic Conservation: Marine and Freshwater Ecosystems, 33, 12, 1492, 1500, Dec. 2023, [Peer-reviewed]
Scientific journal - Application of eDNA methods to evaluate abundance and reproduction of winter-breeding freshwater mussels (Buldowskia iwakawai) in the Ishikari River floodplain
J. Wu; J. N. Negishi; H. Izumi; T. Kanbe; H. Mizumoto; H. Araki
Hydrobiologia, 2023, [Peer-reviewed]
Scientific journal - Effectiveness of check-dam improvement on freshwater fishes: assessment based on long-term monitoring and environmental DNA applicability.
HAYAMIZU Masato; ISHIYAMA Nobuo; MIZUMOTO Hiroki; KANBE Takashi; SHIMODA Kazutaka; MISAKA Naoyuki; URABE Hirokazu; NAGASAKA Akiko; NAGASAKA Yu; ONO Satoru; ARAKI Hitoshi; NAKAJIMA Nobuyoshi; FUKUSHIMA Michio
Ecology and Civil Engineering, 24, 1, 61, 73, Ecology and Civil Engineering Society, 28 Jul. 2021, [Peer-reviewed]
Japanese, 河川上流域に多数設置された治山ダムは，渓流や森林の荒廃を防ぐ重要な役割を果たす一方で，渓流魚の河川内の自由な移動を阻害している．こうした状況に鑑み，河川生態系の保全を目的とした改良事業（魚道の設置，堤体の切り下げ）が国内の多くの治山ダムで実施されている．本研究では，北海道 3 河川に設置された治山ダムを対象に，魚道設置と切り下げによるダム改良工事が，その上下流の渓流魚類相に与える影響について，改良工事前後で行われた採捕調査によって検証した．同時に，ダム改良後の採捕結果と環境 DNA メタバーコーディングによる魚類相推定結果を比較し，治山ダム改良事業における環境 DNA メタバーコーディングを用いた魚類相推定の有効性を検討した．採捕調査の結果，治山ダムの改良事業によって，遡河回遊魚であるアメマスとサクラマスのダム上流への移動を可能にし，10 年後においても効果が確認された．環境 DNA メタバーコーディングでは，採捕された全 9 種に加え，採捕では確認されなか ったニジマスの計 10 種が検出され，治山ダム上下流に設定した各調査地点における遡河回遊魚のアメマス・サクラマスや，ハナカジカの採捕結果との一致率は 70-90 ％であった．環境 DNA メタバーコーディングを治山ダム改良事業に適用する場合，評価対象魚種の特性や過去の採捕記録を考慮する必要はあるものの，改良前の治山ダムにおける魚類の遡上阻害の推定や，改良後の河川の魚類相・生息状況の推定に有効であることが示唆された．但し，治山ダムの切り下げを例にとると，遡上阻害の改善効果が維持される期間は工法によって異なる可能性もあり，正確な評価には様々な河川・工法を対象としたさらなる研究の蓄積が必要である． - Efficient PCR Amplification Protocol of Nuclear Microsatellites for Exuviae-Derived DNA of Cicada, Yezoterpnosia nigricosta
Keisuke Yumoto; Takashi Kanbe; Yoko Saito; Shingo Kaneko; Yoshiaki Tsuda
Frontiers in Insect Science, 1, Frontiers Media SA, 05 Jul. 2021, [Peer-reviewed]
Scientific journal, Although insect exuviae-based genetics is challenging, it can be a valuable method for obtaining reliable DNA resources by non-invasive sampling. This approach is especially effective when the target species is endangered/endemic or when sampling the adult is difficult. One example is cicadas, which during molt leave their exoskeletons on tree trunks, making them easily collectable. While cicada exuviae-derived DNA has previously been employed for mitochondrial DNA sequencing, this study aimed to develop a reliable method for the PCR amplification of nuclear microsatellite loci from cicada exuviae derived DNA for application in molecular ecology, conservation and population genetics. Five different PCR amplification protocols were performed, and the fragment patterns compared with those obtained using DNA extracted from adult individuals. Moreover, the relationship between the freshness of the exuviae and genotyping success was evaluated.TaKaRa LA Taq provided the best performance in the PCR amplification of DNA isolated from cicada exuviae and the electropherogram showed a clear fragment pattern that was equivalent to that obtained from the DNA extracted from the adult individual. This result suggests that cicada exuviae-derived DNA can be amplified by PCR and that multiple independent loci of nuclear DNA microsatellite markers can be easily genotyped. This study demonstrates that fresh cicada exuviae provide high quality DNA, which can be used for microsatellite genotyping. The methods developed in this study are applicable not only for cicada but other insect species for which exuviae are available. Thus, this study can make a significant contribution to insect sciences. - Heat shock alters pea aphid– Buchnera interactions: negative allometry of gene densities
Nousheen Parven; Izumi Yao; Takashi Kanbe; Shin‐ichi Akimoto
Entomologia Experimentalis et Applicata, 169, 5, 462, 471, Wiley, May 2021, [Peer-reviewed]
Scientific journal - Isolation and characterization of microsatellites from a cicada, Yezoterpnosia nigricosta (Hemiptera: Cicadidae), distributed in subarctic and cool temperate forests
Takashi Kanbe; Keisuke Yumoto; Uchu Yamakawa; Souta Nakajima; Shingo Kaneko; Keiko Kitamura; Yoko Saito; Yoshiaki Tsuda
GENES & GENETIC SYSTEMS, 95, 5, 269, 273, Oct. 2020, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal - Suppression of autumnal sexual morph production in spring by a seasonal timer in an aphid
Naoki Matsuda; Takashi Kanbe; Jun Endo; Shin‐Ichi Akimoto; Hideharu Numata
Physiological Entomology, 45, 2-3, 103, 109, Wiley, Sep. 2020, [Peer-reviewed]
English, Scientific journal - Evaluation of an Environmental DNA Method as a Potential Tool for Monitoring Salmonid Fishes in the Wild
Hitoshi Araki; Hiroki Mizumoto; Takashi Kanbe; Shunpei Sato
Technical Report, 15, 164, 167, North Pacific Anadromous Fish Commission, Dec. 2019
Scientific journal - Environmental DNA monitoring for short-term reproductive migration of endemic anadromous species, Shishamo smelt (Spirinchus lanceolatus)
YATSUYANAGI Tetsu; ISHIDA Ryotaro; SAKATA Masayuki K; KANBE Takashi; MIZUMOTO Hiroki; KOBAYASHI Yumi; KAMADA Shoko; NAMBA Satoko; NII Hisaya; MINAMOTO Toshifumi; ARAKI Hitoshi
Environmental DNA, (in press), 2, 130, 139, Wiley, Nov. 2019, [Peer-reviewed]
English, Scientific journal - Spatiotemporal distribution of juvenile chum salmon in Otsuchi Bay, Iwate, Japan, inferred from environmental DNA
Yuki Minegishi; Marty Kwok-Shing Wong; Takashi Kanbe; Hitoshi Araki; Tomomi Kashiwabara; Minoru Ijichi; Kazuhiro Kogure; Susumu Hyodo
PLOS ONE, 14, 9, e0222052, Sep. 2019, [Peer-reviewed]
English, Scientific journal - Ongoing localized extinctions of stream-dwelling white-spotted charr populations in small dammed-off habitats of Hokkaido Island, Japan
Kentaro Morita; Genki Sahashi; Masaki Miya; Shouko Kamada; Takashi Kanbe; Hitoshi Araki
Hydrobiologia, 840, 1, 207, 213, Sep. 2019, [Peer-reviewed]
English, Scientific journal - Establishing an environmental DNA method to detect and estimate the biomass of Sakhalin taimen, a critically endangered Asian salmonid
Hiroki Mizumoto; Hirokazu Urabe; Takashi Kanbe; Michio Fukushima; Hitoshi Araki
Limnology, 19, 2, 219, 227, 01 Apr. 2018, [Peer-reviewed]
English, Scientific journal - IV-5. Environmental DNA for salmonid studies
Araki Hitoshi; Kanbe Takashi; Mizumoto Hiroki; Kamada Shoko; Sato Shunpei
NIPPON SUISAN GAKKAISHI, 84, 5, 936, 936, 2018, [Peer-reviewed]
Japanese, Scientific journal - Transgenerational seasonal timer for suppression of sexual morph production in the pea aphid, Acyrthosiphon pisum
Naoki Matsuda; Takashi Kanbe; Shin-ichi Akimoto; Hideharu Numata
JOURNAL OF INSECT PHYSIOLOGY, 101, 1, 6, Aug. 2017, [Peer-reviewed]
English, Scientific journal - A new species of Megoura (Hemiptera, Aphididae) from Japan
Wonhoon Lee; Takashi Kanbe; Shin-ichi Akimoto
ZOOKEYS, 417, 417, 37, 44, 2014, [Peer-reviewed]
English, Scientific journal - Male-specific flight apparatus development in Acyrthosiphon pisum (Aphididae, Hemiptera, Insecta): comparison with female wing polyphenism
Kota Ogawa; Asano Ishikawa; Takashi Kanbe; Shin-ichi Akimoto; Toru Miura
ZOOMORPHOLOGY, 131, 3, 197, 207, Sep. 2012, [Peer-reviewed]
English, Scientific journal - Unique haplotypes in ant-attended aphids and widespread haplotypes in non-attended aphids
Izumi Yao; Takashi Kanbe
ECOLOGY AND EVOLUTION, 2, 9, 2315, 2324, Sep. 2012, [Peer-reviewed]
English, Scientific journal - Juvenile hormone titre and related gene expression during the change of reproductive modes in the pea aphid
A. Ishikawa; K. Ogawa; H. Gotoh; T. K. Walsh; D. Tagu; J. A. Brisson; C. Rispe; S. Jaubert-Possamai; T. Kanbe; T. Tsubota; T. Shiotsuki; T. Miura
INSECT MOLECULAR BIOLOGY, 21, 1, 49, 60, Feb. 2012, [Peer-reviewed]
English, Scientific journal - Host Race Formation and Origin of Asexual Populations in Aphids
秋元 信一; 神戸 崇
植物防疫, 66, 2, 71, 76, 日本植物防疫協会, Feb. 2012
Japanese - Collecting Records of Reesa vespulae (Coleoptera, Dermestidae) in Japan
KITANO Takanobu; HIRANO Yukihiko; KANBE Takashi
1, 2, 273, 274, 31 Dec. 2011
English - Allelic and genotypic diversity in long-term asexual populations of the pea aphid, Acyrthosiphon pisum in comparison with sexual populations
Takashi Kanbe; Shin-Ichi Akimoto
MOLECULAR ECOLOGY, 18, 5, 801, 816, Mar. 2009, [Peer-reviewed]
English, Scientific journal
- Relationship between the genetic structure of cicada and the past distribution shift of their host forest trees
Yumoto Keisuke; Kato Akane; Tanaka Keisuke; Kanbe Takashi; Koido Ririko; Umino Taichi; Kaneko Shingo; Saito Yoko; Nobis Michael P; Tsuda Yoshiaki, The Japanese Forest Society Congress, 133, 151, 30 May 2022
THE JAPANESE FORESTRY SOCIETY, English - edna2021: The fourth annual meeting of The eDNA Society “Species distributions, and beyond”
Hitoshi Araki; Takashi Kanbe; Hiroki Yamanaka; Yuki Minegishi; Noriyuki Koizumi, Environmental DNA, 4, 3, 487, 491, May 2022
Report scientific journal - Life history traits and genetic structure of Yezoterpnosia nigricosta on local and wide scale in Japan
Yumoto Keisuke; Kanbe Takashi; Kato Akane; Kaneko Shingo; Ikeda Hiroshi; Saito Yoko; Michael Nobis P.; Tsuda Yoshiaki, The Japanese Forest Society Congress, 132, 145, 24 May 2021
[in Japanese], THE JAPANESE FORESTRY SOCIETY, Japanese - Life history traits and genetic population demography of Yezoterpnosia nigricosta in Japan
Yumoto Keisuke; Kanbe Takashi; Kato Akane; Saito Yoko; Tsuda Yoshiaki, The Japanese Forest Society Congress, 131, 623, 25 May 2020
[in Japanese], THE JAPANESE FORESTRY SOCIETY, Japanese - Life history traits and genetic structure of Terpnosia nigricosta in Sugadaira highland, Japan
Yumoto Keisuke; Kanbe Takashi; Kato Akane; Yamakawa Uchu; Imai Ryosuke; Saito Yoko; Tsuda Yoshiaki, The Japanese Forest Society Congress, 130, 423, 27 May 2019
[in Japanese], THE JAPANESE FORESTRY SOCIETY, Japanese - 環境DNAから探る,日本固有種シシャモの遡上と分布
八柳哲; 神戸崇; 水本寛基; 小林由美; 坂田雅之; 源利文; 石田良太郎; 新居久也; 荒木仁志, 日本生態学会大会講演要旨(Web), 66th, 2019 - 環境DNAを通して観る,北の海の生物と多様性
荒木仁志; 神戸崇; 水本寛基; 鎌田祥子; 南波聡子; 矢部衞; 大橋優季; 池田実; 峰岸有紀; 佐土哲也; 宮正樹, 日本魚類学会年会講演要旨, 50th, 139, 14 Sep. 2017
Japanese - 環境DNAを用いた生物フロンティアの開拓
荒木仁志; 神戸崇; 鎌田頌子; 宮正樹; 佐土哲也; 池田実; 佐藤行人; 峰岸有紀; 永野優季; 矢部衞, 日本進化学会大会プログラム・講演要旨集(Web), 18th, ROMBUNNO.O‐1E‐1 (WEB ONLY), 25 Aug. 2016
Japanese - 環境DNA研究の実践と課題:生態学フロンティアへの挑戦
荒木仁志; 神戸崇; 鎌田頌子; 源利文; 佐藤行人; 宮正樹, 日本生態学会大会講演要旨(Web), 63th, T20‐1 (WEB ONLY), 2016
Japanese - 北の海に未知なる生命と生物多様性を探る
荒木仁志; 宮正樹; 池田実; 矢部衞; 永野優季; 神戸崇; 鎌田頌子; 佐土哲也; 峰岸有紀; 佐藤行人; 佐藤俊平; MASLENIKOV Katherine, 日本進化学会大会プログラム・講演要旨集(Web), 17th, ROMBUNNO.W6‐2 (WEB ONLY), 20 Aug. 2015
Japanese
- セミの脱皮殻を利用した非侵襲的なDNA採取法
神戸 崇
日本昆虫学会第78回大会, 10 Sep. 2018, Japanese, Oral presentation
[Domestic Conference] - 遺伝子解析におけるセミの脱皮殻の利用可能性
神戸 崇
日本応用動物昆虫学会・日本昆虫学会共催北海道支部大会, 22 Jan. 2013, Japanese, Oral presentation
札幌市, [Domestic Conference] - Evolution of asexuality in the pea aphid, Acyrthosiphon pisum
Kanbe T; Akimoto S
XXIV International Congress of Entomology, 22 Aug. 2012, English, Invited oral presentation
Daegu, KOREA, [Invited], [International presentation] - 核遺伝子の解析から推定された無性生殖型アブラムシの起源
神戸 崇; 秋元信一
日本昆虫学会第71回大会, 18 Sep. 2011, Japanese, Oral presentation
長野県松本市, [Domestic Conference] - 無性生殖型エンドウヒゲナガアブラムシは交雑起源か―核遺伝子の解析から―
神戸 崇
日本アブラムシ研究会第1回研究集会, 05 Aug. 2011, Japanese, Invited oral presentation
愛知県岡崎市, [Invited], [Domestic Conference]
- Aug. 2018 - Present
The eDNA Society - The Hemipterological Society of Japan
- SOCIETY OF EVOLUTIONARY STUDIES, JAPAN
- JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY
- THE ENTOMOLOGICAL SOCIETY OF JAPAN
- 「チョウとガ」が超わかる本
北海道大学総合博物館, 大原昌宏; 佐野正和; 神戸 崇, Jun. 2011, [Others] - 昼行性のレピドプテラ・夜行性のレピドプテラ（ポスター）
北海道大学総合博物館, 北海道大学総合博物館; 神戸 崇, 2011, [Others]
- Epigenetic control mechanisms underlying behavioral plasticity in ant-attended aphids
Grants-in-Aid for Scientific Research
01 Apr. 2026 - 31 Mar. 2030
八尾 泉; 神戸 崇
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 26K09415 - Evolutionary dynamics of sexual and asexual lineages of pea aphid in coexistence regions
Grants-in-Aid for Scientific Research
01 Apr. 2019 - 31 Mar. 2023
秋元 信一; 神戸 崇
令和３年度は，研究計画におけるクローン間の進化動態を探るために，制御された環境下でのクローン間の競争実験を行なった．有性生殖クローンと無性生殖クローンの共存地域においては，両クローン間の競争が同一植物上で生じると予測される．どのような条件下で，いずれのクローンが優勢となるのかを明らかにするためには，クローン間競争がどのように生じ，どのようなクローンが競争に勝利を納めるのかを明らかにする必要がある．
２クローンの増殖競争の実態を正確に把握するために，まず，寒天―切葉法を開発し，寒天上においたソラマメの葉上に２頭の異なるクローンの成虫を置くことによって，15日間の増殖を観察した．この実験では，クローンの識別が必須であるため、色彩突然変異（黄色）が生じたクローンとその元のクローン（緑色）を実験に供した．各クローンから１頭の成虫を用いた１頭区，同一クローンの２頭の成虫を含む２頭区，黄色と緑クローンから１頭ずつの成虫を含む混合区を準備し，毎日のアブラムシの増殖パターンを記録した．この結果，クローンは他のクローンを識別可能であり，自分自身のクローンと他クローンの密度を把握して，成長と産子のパターンを決めていることが明らかとなった．とりわけ，あるクローンが先に増殖すると，先手を取られたクローンは繁殖率を低下させることが明らかになった．
有性生殖クローンと無性生殖クローンとが共存する地域では，早春に無性生殖クローンが先に繁殖を始める．このために，植物の質の良いスペースを無性生殖クローンが独占し，一方，卵から孵化した後に繁殖を開始する有性生殖クローンは増殖の遅れから，無性生殖クローンと共存した場合に圧倒的に不利となる．この結果，有性生殖クローンが生存可能となるためには，無性生殖クローンとは異なる株に寄生することが必要となると予測された．
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 19K06848 - Transgenerational seasonal timer in an aphod
Grants-in-Aid for Scientific Research
30 Jun. 2017 - 31 Mar. 2020
NUMATA Hideharu
In the pea aphid, Acyrthosiphon pisum, a seasonal timer that suppresses induction of sexual morphs by short days did not count the number of generations but that of days, and its period depended on temperature but not on photoperiod.
The results of rearing aphids under natural temperatures and photoperiods showed that the seasonal timer prevents untimely emergence of sexual morphs in warm spring.
Aphids with an expired seasonal timer showed transcriptional up-regulation of genes related to histone modifications Moreover, the results of analysis in open-chromatin regions suggested that epigenetic modifications might be involved in a mechanism of maternal switching from the parthenogenetic to sexual morph production.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Exploratory), Kyoto University, 17K19264 - セミの抜け殻から集団構造と大発生のメカニズムを探る
科学研究費助成事業（若手研究(B)）
Apr. 2015 - Mar. 2019
神戸 崇
日本学術振興会, Principal investigator, Competitive research funding - エンドウヒゲナガアブラムシの無性生殖系統におけるMeselson Effectの検証
グローバルCOE若手研究者公募研究助成
Nov. 2008 - Mar. 2009
神戸 崇
北海道大学グローバルCOEプログラム「統合フィールド環境科学の教育研究拠点形成」, Principal investigator, Competitive research funding
Others
