Researcher Database

Researcher Profile and Settings

Master

Affiliation (Master)

  • Research Faculty of Agriculture Fundamental AgriScience Research Applied Bioscience

Affiliation (Master)

  • Research Faculty of Agriculture Fundamental AgriScience Research Applied Bioscience

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Profile and Settings

Profile and Settings

  • Name (Japanese)

    Sato
  • Name (Kana)

    Masanao
  • Name

    201701011669372275

Achievement

Research Interests

  • gene regulatory network, systems biology, host-microbe interactions   

Research Areas

  • Life sciences / Virology / Baculoviruses, Potyviruses
  • Life sciences / Genomics / Gene regulatory networks, Transcriptome

Research Experience

  • 2022/07 - Today Hokkaido University Graduate School of Agriculture Research Faculty of Agriculture Division of Applied Bioscience Associate Professor
  • 2016/04 - 2022/06 北海道大学大学院農学研究院 応用分子昆虫学 助教
  • 2015/04 - 2016/03 Keio University
  • 2009/08 - 2015/03 National Institute for Basic Biology Developmental Genetics Assistant professor

Published Papers

  • Toshiki Nakanishi, Shin-ichiro Asano, Hisanori Bando, Masanao Sato
    Journal of Insect Biotechnology and Sericology 93 (1) 1 - 10 2024/05/28 [Refereed]
  • Chika Takemura, Wakana Senuma, Masayuki Tsuzuki, Yuki Terazawa, Kanako Inoue, Masanao Sato, Akinori Kiba, Kouhei Ohnishi, Kenji Kai, Yasufumi Hikichi
    Molecular plant pathology 2023/07/14 
    The gram-negative plant-pathogenic β-proteobacterium Ralstonia pseudosolanacearum strain OE1-1 produces methyl 3-hydroxymyristate as a quorum sensing (QS) signal through methyltransferase PhcB and senses the chemical via the sensor histidine kinase PhcS. This leads to activation of the LysR family transcription regulator PhcA, which regulates the genes (QS-dependent genes) responsible for QS-dependent phenotypes, including virulence. The transcription regulator ChpA, which possesses a response regulator receiver domain and also a hybrid sensor histidine kinase/response regulator phosphore-acceptor domain but lacks a DNA-binding domain, is reportedly involved in QS-dependent biofilm formation and virulence of R. pseudosolanacearum strain GMI1000. To explore the function of ChpA in QS of OE1-1, we generated a chpA-deletion mutant (ΔchpA) and revealed that the chpA deletion leads to significantly altered QS-dependent phenotypes. Furthermore, ΔchpA exhibited a loss in its infectivity in xylem vessels of tomato plant roots, losing virulence on tomato plants, similar to the phcA-deletion mutant (ΔphcA). Transcriptome analysis showed that the transcript levels of phcB, phcQ, phcR, and phcA in ΔchpA were comparable to those in OE1-1. However, the transcript levels of 89.9% and 88.9% of positively and negatively QS-dependent genes, respectively, were significantly altered in ΔchpA compared with OE1-1. Furthermore, the transcript levels of these genes in ΔchpA were positively correlated with those in ΔphcA. Together, our results suggest that ChpA is involved in the regulation of these QS-dependent genes, thereby contributing to the behaviour in host plant roots and virulence of OE1-1.
  • Masanao Sato, Masahide Seki, Yutaka Suzuki, Shoko Ueki
    Data in Brief 48 109071 - 109071 2352-3409 2023/06 [Refereed][Not invited]
  • Hiroaki Mon, Masanao Sato, Jae Man Lee, Takahiro Kusakabe
    Insect biochemistry and molecular biology 151 103875 - 103875 2022/12 
    Advances in sequencing technology and bioinformatics have accelerated gene discovery and homology-based functional annotation in many species, and numerous targeted gene studies have greatly expanded the understanding of gene functions. Nevertheless, there are still many genes that lack homology with genes in other evolutionary lineages and are left as genes with unknown functions. We constructed a gene co-expression network from the Bombyx mori ovary-derived cell line, BmN4, and attempted to infer the biological roles of uncharacterized genes based on the correlation between the function-known and unknown genes. Within this network, we focused on the co-expression modules involved in chromosome architecture, dynamics, and integrity, and selected the uncharacterized genes for subsequent RNAi-based phenotypic screening. This approach enabled the identification of 5 genes whose knockdown led to abnormalities in chromosome dynamics and spindle morphology in mitosis. One of them was a recently characterized gene, BmCenp-T, which plays a central role in building the kinetochore protein complex on the silkworm holocentric chromosomes. In this study, we suggest a method for constructing the gene co-expression network and selecting candidate genes for small-scale RNAi screening. This approach is complementary to homology-based annotation and may be useful for the analysis of lineage-specific uncharacterized genes such as orphan genes.
  • Jesús Morón-López, Karen Vergara, Masanao Sato, Gonzalo Gajardo, Shoko Ueki
    PloS one 17 (8) e0273330  2022 
    Intraspecies nucleotide sequence variation is a key to understanding the evolutionary history of a species, such as the geographic distribution and population structure. To date, numerous phylogenetic and population genetics studies have been conducted based on the sequences of a gene or an intergenic region on the mitochondrial genome (mtDNA), such as cytochrome c oxidase subunits or the D-loop. To evaluate the credibility of the usage of such 'classic' markers, we compared the phylogenetic inferences based on the analyses of the partial and entire mtDNA sequences. Importantly, the phylogenetic reconstruction based on the short marker sequences did not necessarily reproduce the tree topologies based on the analyses of the entire mtDNA. In addition, analyses on the datasets of various organisms revealed that the analyses based on the classic markers yielded phylogenetic trees with poor confidence in all tested cases compared to the results based on full-length mtDNA. These results demonstrated that phylogenetic analyses based on complete mtDNA sequences yield more insightful results compared to those based on mitochondrial genes and segments. To ameliorate the shortcomings of the classic markers, we identified a segment of mtDNA that may be used as an 'approximate marker' to closely reproduce the phylogenetic inference obtained from the entire mtDNA in the case of mammalian species, which can be utilized to design amplicon-seq-based studies. Our study demonstrates the importance of the choice of mitochondrial markers for phylogenetic analyses and proposes a novel approach to choosing appropriate markers for mammalian mtDNA that reproduces the phylogenetic inferences obtained from full-length mtDNA.
  • Takemura, C., Senuma, W., Hayashi, K., Minami, A., Terazawa, Y., Kaneoka, C., Sakata, M., Chen, M., Zhang, Y., Nobori, T., Sato, M., Kiba, A., Ohnishi, K., Tsuda, K., Kai, K., Hikichi, Y.
    Molecular Plant Pathology 22 (12) 1538 - 1552 1364-3703 2021/12 [Refereed][Not invited]
  • Mami Sakai, Satoshi Kakutani, Shin-Ichiro Asano, Masanao Sato, Hisanori Bando
    Virus research 291 198195 - 198195 2021/01/02 [Refereed]
     
    The Bombyx mori nucleopolyhedrovirus (BmNPV)-based baculoviral expression vector system is among the most efficient expression vector systems for eukaryotic proteins especially when used in combination with silkworms as a host. We newly isolated a novel BmNPV strain (BmNPV H4) in Hokkaido, Japan that outperforms the type strain T3 in terms of both proliferation and expression of polyhedrin protein in silkworm larvae; however, it proliferates poorly in the BmN cell line. We inferred the gene responsible for the differences in proliferation between viral strains by quantifying amino acid similarity distances in protein functional domains and identifying highly divergent alleles between the H4 and T3 strains. Among proteins that differ markedly in functional domain sequence between H4 and T3, we identified the F gene, which encodes the F protein, as a putative cause of proliferative differences between the two strains. Using recombinant viruses with the F protein-coding sequence exchanged between H4 and T3, we determined that the T3 F protein increases H4 proliferation in BmN while the H4 F protein does not improve T3 proliferation in silkworm larvae. Our results suggest that the BmNPV F protein can strongly affect viral proliferation in a genetic background-specific manner and may be an important target for manipulating the proliferation characteristics of BmNPV-based expression vectors.
  • Sekiguchi, M., Ishikawa, S., Asano, S.-I., B, o, H., Sato, M.
    Journal of Insect Biotechnology and Sericology 89 (3) 45 - 53 1884-7978 2020/10 [Refereed]
  • Harada, N., Ishibashi, D., Asano, S.-I., Sato, M., B, o, H.
    Journal of Insect Biotechnology and Sericology 87 (3) 97 - 108 2018/10 [Refereed][Not invited]
  • Nakaishi, Y., Sato, M., B, o, H., Asano, S.-I.
    Journal of Insect Biotechnology and Sericology 87 (2) 45 - 51 1346-8073 2018 [Refereed]
  • Ryoma Ota, Shumpei Morita, Masanao Sato, Shuji Shigenobu, Makoto Hayashi, Satoru Kobayashi
    DEVELOPMENT GROWTH & DIFFERENTIATION 59 (9) 713 - 723 0012-1592 2017/12 [Refereed][Not invited]
     
    In Drosophila, Sex lethal (Sxl), an RNA binding protein, is required for induction of female sexual identity in both somatic and germline cells. Although the Sxl-dependent feminizing pathway in the soma was previously elucidated, the downstream targets for Sxl in the germline remained elusive. To identify these target genes, we selected transcripts associated with Sxl in primordial germ cells (PGCs) of embryos using RNA immunoprecipitation coupled to sequencing (RIP-seq) analysis. A total of 308 transcripts encoded by 282 genes were obtained. Seven of these genes, expressed at higher levels in PGCs as determined by microarray and insitu hybridization analyses, were subjected to RNAi-mediated functional analyses. Knockdown of Neos, Kap-alpha3, and CG32075 throughout germline development caused gonadal dysgenesis in a sex-dependent manner, and Su(var)2-10 knockdown caused gonadal dysgenesis in both sexes. Moreover, as with knockdown of Sxl, knockdown of Su(var)2-10 in PGCs gave rise to a tumorous phenotype of germline cells in ovaries. Because this phenotype indicates loss of female identity of germline cells, we consider Su(var)2-10 to be a strong candidate target of Sxl in PGCs. Our results represent a first step toward elucidating the Sxl-dependent feminizing pathway in the germline.
  • Hiroaki Mon, Jae Man Lee, Masanao Sato, Takahiro Kusakabe
    INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 86 1 - 8 0965-1748 2017/07 [Refereed][Not invited]
     
    The kinetochore creates chromosomal attachment sites for microtubules. The kinetochore-microtubule interface plays an important role in ensuring accurate transmission of genetic information to daughter cells. Bombyx marl is known"to possess holocentric chromosomes, where spindle microtubules attach along the entire length of the chromosome. Recent evidence suggests that CENP-A and CENP-C, which are essential for centromere structure and function in other species, have lost in holocentric insects, implying that B. mori is able to build its kinetochore regardless of the lack of CENP-A and CENP-C. Here we report the identification of three outer kinetochore genes in the silkworm B. mori by using bioinformatics and RNA interference-based screening. While the homologs of Ndc80 and Mis12 have strong similarity with those of other organisms, the five encoded proteins (BmNuf2, BmSpc24, BmSpc25, BmDsnl and BmNnfl) are highly diverged from their counterparts in other species. Microscopic studies show that the outer kinetochore protein is distributed along the entire length of the chromosomes, which is a key feature of holocentric chromosomes. We also demonstrate that BmDsnl forms a heterotrimeric complex with BmMis12 and BmNnfl, which acts as a receptor of the Ndc80 complex. In addition, our study suggests that a small-scale RNAi-based candidate screening is a useful approach to identify genes which may be highly divergent among different species. (C) 2017 Elsevier Ltd. All rights reserved.
  • Makoto Suzuki, Masanao Sato, Hiroshi Koyama, Yusuke Hara, Kentaro Hayashi, Naoko Yasue, Hiromi Imamura, Toshihiko Fujimori, Takeharu Nagai, Robert E. Campbell, Naoto Ueno
    DEVELOPMENT 144 (7) 1307 - 1316 0950-1991 2017/04 [Refereed][Not invited]
     
    Early in the development of the central nervous system, progenitor cells undergo a shape change, called apical constriction, that triggers the neural plate to form a tubular structure. How apical constriction in the neural plate is controlled and how it contributes to tissue morphogenesis are not fully understood. In this study, we show that intracellular calcium ions (Ca2+) are required for Xenopus neural tube formation and that there are two types of Ca(2+)concentrationchanges, a single-cell and a multicellular wave-like fluctuation, in the developing neural plate. Quantitative imaging analyses revealed that transient increases in Ca2+ concentration induced cortical F-actin remodeling, apical constriction and accelerations of the closing movement of the neural plate. We also show that extracellular ATP and N-cadherin (cdh2) participate in the Ca2+-induced apical constriction. Furthermore, our mathematical model suggests that the effect of Ca2+ fluctuations on tissue morphogenesis is independent of fluctuation frequency and that fluctuations affecting individual cells are more efficient than those at the multicellular level. We propose that distinct Ca2+ signaling patterns differentially modulate apical constriction for efficient epithelial folding and that this mechanism has a broad range of physiological outcomes.
  • Makoto Hayashi, Yuko Shinozuka, Shuji Shigenobu, Masanao Sato, Michihiko Sugimoto, Seiji Ito, Kuniya Abe, Satoru Kobayashi
    SCIENTIFIC REPORTS 7 40056  2045-2322 2017/01 [Refereed][Not invited]
     
    Ovo, which encodes a transcription factor with Zn-finger domains, is evolutionarily conserved among animals. In Drosophila, in addition to its zygotic function for egg production, maternal ovo activity is required in primordial germ cells (PGCs) for expression of germline genes such as vasa and nanos. In this study, we found that maternal Ovo accumulates in PGC nuclei during embryogenesis. In these cells, ovo serves a dual function: activation of genes expressed predominantly in PGCs, and conversely suppression of somatic genes. Reduction of ovo activity in PGCs makes them unable to develop normally into germ cells of both sexes. In mice, knockout of the ovo ortholog, Ovol2, which is expressed in PGCs, decreases the number of PGCs during early embryogenesis. These data strongly suggest that ovo acts as part of an evolutionarily conserved mechanism that regulates germline development in animals.
  • Yuka Hagiwara-Komoda, Sun Hee Choi, Masanao Sato, Go Atsumi, Junya Abe, Junya Fukuda, Mie N. Honjo, Atsushi J. Nagano, Keisuke Komoda, Kenji S. Nakahara, Ichiro Uyeda, Satoshi Naito
    SCIENTIFIC REPORTS 6 21411  2045-2322 2016/02 [Refereed][Not invited]
     
    RNA viruses use various strategies to condense their genetic information into small genomes. Potyviruses not only use the polyprotein strategy, but also embed an open reading frame, pipo, in the P3 cistron in the -1 reading frame. PIPO is expressed as a fusion protein with the N-terminal half of P3 (P3N-PIPO) via transcriptional slippage of viral RNA-dependent RNA polymerase (RdRp). We herein show that clover yellow vein virus (ClYVV) produces a previously unidentified factor, P3N-ALT, in the +1 reading frame via transcriptional slippage at a conserved G(1-2)A(6-7) motif, as is the case for P3N-PIPO. The translation of P3N-ALT terminates soon, and it is considered to be a C-terminal truncated form of P3. In planta experiments indicate that P3N-ALT functions in cell-to-cell movement along with P3N-PIPO. Hence, all three reading frames are used to produce functional proteins. Deep sequencing of ClYVV RNA from infected plants endorses the slippage by viral RdRp. Our findings unveil a virus strategy that optimizes the coding capacity.
  • Yudistira Wahyu Kurnia, Ryosuke Fujita, Masanao Sato, Haruhiko Isawa, Shin Ichiro Asano, Ngo Dinh Binh, Hisanori Bando
    Journal of Insect Biotechnology and Sericology 85 (2) 39 - 47 1346-8073 2016 [Refereed][Not invited]
     
    © 2016, Journal of Insect Biotechnology and Sericology. All rights reserved. The Okushiri virus (OKV), isolated from Aedes larvae collected on Okushiri Island, Hokkaido, Japan, is a member of the Negevirus family, a newly proposed insect-specific virus group (genus). To enable genetic manipulation of the genome, we constructed an infectious cDNA clone of OKV. RNA synthesized in vitro from pFBOKV, a full-length OKV cDNA, in the presence or absence of cap analogue produced infectious progeny viruses effectively in mosquito C6/36 cells. Subsequently, ORF3 in pFBOKV was replaced with a GFP coding sequence to generate a construct designated as pO2GFP. C6/36 cells transfected with pO2GFP-derived RNA successfully expressed GFP, but failed to produce progeny viruses. Co-transfection of C6/36 cells with pO2GFP- and pFBOKV-derived RNA revealed that it is possible to produce infectious pO2GFP-derived progeny viruses by supplying OKV genetic elements and/or gene product deleted in pO2GFP even though the infectivity appeared to be low. Although improvements are required to construct viral vectors that propagate more efficiently, this is, to our knowledge, the first report of construction of a negevirus-based foreign gene expression system. The cDNA clones constructed and biological insights obtained in this study will be powerful tools allowing for reverse genetics of OKV and providing a basis to develop efficient negevirus-based expression vector systems.
  • Minami Baba, Masanao Sato, Katsuya Kitoh, Yasuhiro Takashima
    EXPERIMENTAL PARASITOLOGY 155 74 - 81 0014-4894 2015/08 [Refereed][Not invited]
     
    Tachyzoites of Toxoplasma gondii, an obligate intracellular parasite, actively invade almost all types of nucleated cells. However, T. gondii tachyzoites preferentially infect particular types of animal tissue cells. The mechanism underlying the host cell preference of T. gondii is not yet known. In this study, we found that enzymatic removal of alpha 2,3- but not alpha 2,6-linked sialic acids on the surface of Vero cells decreased T. gondii tachyzoite adhesion or invasion to the treated cells. Although Chinese hamster ovary (CHO) cells express only alpha 2,3-linked sialic acid, a genetically modified CHO cell line constructed by transfection with the alpha 2,6-sialiltransferase gene contains subpopulations with a variety of expression patterns of alpha 2,3- and alpha 2,6-linked sialic acids. When T gondii tachyzoites were added to the modified CHO cells, the tachyzoites preferentially attached to cells belonging to a subpopulation of cells that highly expressed alpha 2,3-linked sialic acids. Additionally, multiple regression analysis performed to analyse the relationship between the amount of alpha 2,3-linked/alpha 2,6-linked sialic acids and parasite-expressed fluorescence intensity suggested that more tachyzoites adhered to individual alpha 2,3-linked sialic acid rich-cells than to alpha 2,3-linked sialic acid-poor/null cells. The results of confocal laser microscopy confirmed this finding. These results indicate that the host cell preference of T. gondii was, at least partially, affected by the distribution pattern of alpha 2,3-, but almost never alpha 2,6-linked sialic acids on host cells. (C) 2015 Elsevier Inc. All rights reserved.
  • Hitoshi Miyakawa, Masanao Sato, John K. Colbourne, Taisen Iguchi
    PLOS ONE 10 (3) e0121324  1932-6203 2015/03 [Refereed][Not invited]
     
    Phenotypic plasticity is the ability held in many organisms to produce different phenotypes with a given genome in response to environmental stimuli, such as temperature, nutrition and various biological interactions. It seems likely that environmental signals induce a variety of mechanistic responses that influence ontogenetic processes. Inducible defenses, in which prey animals alter their morphology, behavior and/or other traits to help protect against direct or latent predation threats, are among the most striking examples of phenotypic plasticity. The freshwater microcrustacean Daphnia pulex forms tooth-like defensive structures, "neckteeth," in response to chemical cues or signals, referred to as "kairomones," in this case released from phantom midge larvae, a predator of D. pulex. To identify factors involved in the reception and/or transmission of a kairomone, we used microarray analysis to identify genes up-regulated following a short period of exposure to the midge kairomone. In addition to identifying differentially expressed genes of unknown function, we also found significant up-regulation of genes encoding ionotropic glutamate receptors, which are known to be involved in neurotransmission in many animal species. Specific antagonists of these receptors strongly inhibit the formation of neckteeth in D. pulex, although agonists did not induce neckteeth by themselves, indicating that ionotropic glutamate receptors are necessary but not sufficient for early steps of neckteeth formation in D. pulex. Moreover, using co-exposure of D. pulex to antagonists and juvenile hormone (JH), which physiologically mediates neckteeth formation, we found evidence suggesting that the inhibitory effect of antagonists is not due to direct inhibition of JH synthesis/secretion. Our findings not only provide a candidate molecule required for the inducible defense response in D. pulex, but also will contribute to the understanding of complex mechanisms underlying the recognition of environmental changes, which form the basis of phenotypic plasticity.
  • Chikako Ono, Masanao Sato, Hitomi Taka, Shin-ichiro Asano, Yoshiharu Matsuura, Hisanori Bando
    PLOS ONE 10 (3) e0119580  1932-6203 2015/03 [Refereed][Not invited]
     
    To infect their hosts, DNA viruses must successfully initiate the expression of viral genes that control subsequent viral gene expression and manipulate the host environment. Viral genes that are immediately expressed upon infection play critical roles in the early infection process. In this study, we investigated the expression and regulation of five canonical regulatory immediate-early (IE) genes of Autographa californica multicapsid nucleopolyhedrovirus: ie0, ie1, ie2, me53, and pe38. A systematic transient gene-expression analysis revealed that these IE genes are generally transactivators, suggesting the existence of a highly interactive regulatory network. A genetic analysis using gene knockout viruses demonstrated that the expression of these IE genes was tolerant to the single deletions of activator IE genes in the early stage of infection. A network graph analysis on the regulatory relationships observed in the transient expression analysis suggested that the robustness of IE gene expression is due to the organization of the IE gene regulatory network and how each IE gene is activated. However, some regulatory relationships detected by the genetic analysis were contradictory to those observed in the transient expression analysis, especially for IE0-mediated regulation. Statistical modeling, combined with genetic analysis using knockout alleles for ie0 and ie1, showed that the repressor function of ie0 was due to the interaction between ie0 and ie1, not ie0 itself. Taken together, these systematic approaches provided insight into the topology and nature of the IE gene regulatory network.
  • Masanori Mukai, Seiji Hira, Katsuhiro Nakamura, Shoichi Nakamura, Hiroshi Kimura, Masanao Sato, Satoru Kobayashi
    BIOLOGY OPEN 4 (2) 119 - 124 2046-6390 2015/02 [Refereed][Not invited]
     
    Epigenetic silencing is critical for maintaining germline stem cells in Drosophila ovaries. However, it remains unclear how the differentiation factor, Bag-of-marbles (Bam), counteracts transcriptional silencing. We found that the trimethylation of lysine 36 on histone H3 (H3K36me3), a modification that is associated with gene activation, is enhanced in Bam-expressing cells. H3K36me3 levels were reduced in flies deficient in Bam. Inactivation of the Set2 methyltransferase, which confers the H3K36me3 modification, in germline cells markedly reduced H3K36me3 and impaired differentiation. Genetic analyses revealed that Set2 acts downstream of Bam. Furthermore, orb expression, which is required for germ cell differentiation, was activated by Set2, probably through direct H3K36me3 modification of the orb locus. Our data indicate that H3K36me3-mediated epigenetic regulation is activated by bam, and that this modification facilitates germ cell differentiation, probably through transcriptional activation. This work provides a novel link between Bam and epigenetic transcriptional control.
  • Atsushi J Nagano, Mie N Honjo, Motohiro Mihara, Masanao Sato M, Hiroshi Kudoh
    Methods in molecular biology (Clifton, N.J.) 1236 89 - 98 1064-3745 2015 [Refereed][Invited]
     
    Sequencing of RNA by next generation sequencers, RNA-Seq, is revolutionizing virus detection. In addition to the unbiased detection of various viruses from wild plants in natural environments, RNA-Seq also allows for the parallel collection of host plant transcriptome data. Host transcriptome data are highly valuable for studying the responses of hosts to viral infections, as well as viral host manipulation. When detecting viruses using RNA-Seq, it is critical to choose appropriate methods for the removal of rRNA from total RNA. Although viruses with polyadenylated genomes can be detected by RNA-Seq following mRNA purification using oligo-dT beads, viruses with non-polyadenylated genomes are not effectively detected. However, such viruses can be detected by RNA-Seq using the rRNA selective depression method. The high-throughput and cost-effective method of RNA-Seq library preparation which is described here allows us to detect a broad range of viruses in wild plants.
  • Makoto Hayashi, Masanao Sato, Yasuhiko Nagasaka, Sakiko Sadaie, Satoru Kobayashi, Goro Yoshizaki
    BIOLOGY OF REPRODUCTION 91 (1) 23  0006-3363 2014/07 [Refereed][Not invited]
     
    Spermatogenesis originates from a small population of spermatogonial stem cells; this population can maintain continuous sperm production throughout the life of fish via self-renewal and differentiation. Despite their biological importance, spermatogonial stem cells are not thoroughly characterized because they are difficult to distinguish from their progeny cells that become committed to differentiation. We previously established a novel technique for germ cell transplantation to identify spermatogonial stem cells based on their colonizing activity and their ability to initiate donor-derived gametogenesis in the rainbow trout (Oncorhynchus mykiss). Although spermatogonial stem cells can be retrospectively identified after transplantation, there is currently no technique to prospectively enrich for or purify spermatogonial stem cells. Here, we describe a method for spermatogonial stem cell enrichment using a side population. With optimized Hoechst 33342 staining conditions, we successfully identified side-population cells among type A spermatogonia. Side-population cells were transcriptomically and morphologically distinct from non-side-population cells. To functionally determine whether the transplantable spermatogonial stem cells were enriched in the side-population fraction, we compared the colonization activity of side-population cells with that of non-side-population cells. Colonization efficiency was significantly higher with side-population cells than with non-side-population cells or with total type A spermatogonia. In addition, side-population cells could produce billions of sperm in recipients. These results indicated that transplantable spermatogonial stem cells were enriched in the side-population fraction. This method will provide biological information that may advance our understanding of spermatogonial stem cells in teleosts. Additionally, this technique will increase the efficiency of germ cell transplantation used in surrogate broodstock technology.
  • Shuhei Kimura, Masanao Sato, Mariko Okada-Hatakeyama
    IPSJ Transactions on Bioinformatics 7 30 - 38 1882-6679 2014 [Refereed][Not invited]
     
    The inference of genetic networks is a problem to obtain mathematical models that can explain observed time-series of gene expression levels. A number of models have been proposed to describe genetic networks. The S-system model is one of the most studied models among them. Due to its advantageous features, numerous inference algorithms based on the S-system model have been proposed. The number of the parameters in the S-system model is however larger than those of the other well-studied models. Therefore, when trying to infer S-system models of genetic networks, we need to provide a larger amount of gene expression data to the inference method. In order to reduce the amount of gene expression data required for an inference of genetic networks, this study simplifies the S-system model by fixing some of its parameters to 0. In this study, we call this simplified S-system model a reduced S-system model. We then propose a new inference method that estimates the parameters of the reduced S-system model by minimizing two-dimensional functions. Finally, we check the effectiveness of the proposed method through numerical experiments on artificial and actual genetic network inference problems.
  • Shuhei Kimura, Masanao Sato, Mariko Okada-Hatakeyama
    PLOS ONE 8 (12) e83308  1932-6203 2013/12 [Refereed][Not invited]
     
    The inference of a genetic network is a problem in which mutual interactions among genes are inferred from time-series of gene expression levels. While a number of models have been proposed to describe genetic networks, this study focuses on a mathematical model proposed by Vohradsky. Because of its advantageous features, several researchers have proposed the inference methods based on Vohradsky's model. When trying to analyze large-scale networks consisting of dozens of genes, however, these methods must solve high-dimensional non-linear function optimization problems. In order to resolve the difficulty of estimating the parameters of the Vohradsky's model, this study proposes a new method that defines the problem as several two-dimensional function optimization problems. Through numerical experiments on artificial genetic network inference problems, we showed that, although the computation time of the proposed method is not the shortest, the method has the ability to estimate parameters of Vohradsky's models more effectively with sufficiently short computation times. This study then applied the proposed method to an actual inference problem of the bacterial SOS DNA repair system, and succeeded in finding several reasonable regulations.
  • Hitomi Taka, Chikako Ono, Masanao Sato, Shin-Ichiro Asano, Hisanori Bando
    Journal of Insect Biotechnology and Sericology 82 (1) 25 - 32 1346-8073 2013/08/05 [Not refereed][Not invited]
     
    About two thirds of open reading frames (orfs) predicted on Bombyx mori nucleopolyhedrovirus (BmNPV) genome were dispensable for expression of the reporter gene derived from the polyhedrin promoter in BmN cells when knocked out one at a time (Ono et al., 2012). Effects of removal of multiple genes of BmNPV and genetic interactions of the viral genes have been poorly investigated. In this study, we constructed BmNPV lacking multiple non-essential genes at the orf11-12-13-14 gene cluster and analyzed the expression of EGFP under the control of the polyhedrin gene promoter. Viruses lacking more than two genes except for the one lacking orf13 and orf14 showed distinct phenotypes compared to the single gene knockout viruses. Synergistic, compensatory, and additive relationships were observed in the genetic interaction analyses between pairs of adjacent genes in the gene cluster. In addition, the virus lacking both orf12 and orf13 but carrying the orf12 genomic region at downstream of the polyhedrin locus expressed EGFP at higher levels than the control virus BmGFP (Ono et al., 2012) although the transcription of orf12 was not changed by insertion at the different locus. This increased EGFP expression was not observed with the virus in which the defect of orf12 and orf13 was rescued with orf13 at the same position. These observations suggested that inserting orf12 at the position specifically affected expression of the reporter gene at the polyhedrin locus.
  • Shuhei Kimura, Masanao Sato, Mariko Okada-Hatakeyama
    Proceedings of the International Joint Conference on Neural Networks 2161-4393 2013 [Refereed][Not invited]
     
    Vohradský has proposed a neural network model to describe biochemical networks. Based on this model, several researchers have proposed genetic network inference methods. When trying to analyze large-scale genetic networks, however, these methods must solve high-dimensional function optimization problems. In order to resolve the high-dimensionality in the estimation of the parameters of the Vohradský's neural network model, this study proposes a new method. The proposed method estimates the parameters of the neural network model by solving two-dimensional function optimization problems. Although these two-dimensional problems are non-linear, their low-dimensionality would make the estimation of the model parameters easier. Finally, we confirm the effectiveness of the proposed method through numerical experiments. © 2013 IEEE.
  • Kenichi Tsuda, Akira Mine, Gerit Bethke, Daisuke Igarashi, Christopher J. Botanga, Yayoi Tsuda, Jane Glazebrook, Masanao Sato, Fumiaki Katagiri
    PLoS Genetics 9 (12) e1004015  1553-7390 2013 [Refereed][Not invited]
     
    Network robustness is a crucial property of the plant immune signaling network because pathogens are under a strong selection pressure to perturb plant network components to dampen plant immune responses. Nevertheless, modulation of network robustness is an area of network biology that has rarely been explored. While two modes of plant immunity, Effector-Triggered Immunity (ETI) and Pattern-Triggered Immunity (PTI), extensively share signaling machinery, the network output is much more robust against perturbations during ETI than PTI, suggesting modulation of network robustness. Here, we report a molecular mechanism underlying the modulation of the network robustness in Arabidopsis thaliana. The salicylic acid (SA) signaling sector regulates a major portion of the plant immune response and is important in immunity against biotrophic and hemibiotrophic pathogens. In Arabidopsis, SA signaling was required for the proper regulation of the vast majority of SA-responsive genes during PTI. However, during ETI, regulation of most SA-responsive genes, including the canonical SA marker gene PR1, could be controlled by SA-independent mechanisms as well as by SA. The activation of the two immune-related MAPKs, MPK3 and MPK6, persisted for several hours during ETI but less than one hour during PTI. Sustained MAPK activation was sufficient to confer SA-independent regulation of most SA-responsive genes. Furthermore, the MPK3 and SA signaling sectors were compensatory to each other for inhibition of bacterial growth as well as for PR1 expression during ETI. These results indicate that the duration of the MAPK activation is a critical determinant for modulation of robustness of the immune signaling network. Our findings with the plant immune signaling network imply that the robustness level of a biological network can be modulated by the activities of network components. © 2013 Tsuda et al.
  • Lin Wang, Kenichi Tsuda, William Truman, Masanao Sato, Le V. Nguyen, Fumiaki Katagiri, Jane Glazebrook
    PLANT JOURNAL 67 (6) 1029 - 1041 0960-7412 2011/09 [Refereed][Not invited]
     
    Arabidopsis thaliana calmodulin binding protein 60g (CBP60g) contributes to production of salicylic acid (SA) in response to recognition of microbe-associated molecular patterns (MAMPs) such as flg22, a fragment of bacterial flagellin. Calmodulin binding is required for the function of CBP60g in limiting growth of the bacterial pathogen Pseudomonas syringae pv. maculicola (Pma) ES4326 and activation of SA synthesis. Here, we describe a closely related protein, SARD1. Unlike CBP60g, SARD1 does not bind calmodulin. Growth of Pma ES4326 is enhanced in sard1 mutants. In cbp60g sard1 double mutants, growth of Pma ES4326 is greatly enhanced, and SA levels and expression of PR-1 and SID2 are dramatically reduced. Expression profiling placed the CBP60g/SARD1 node between the PAD4/EDS1 and SA nodes in the defense signaling network, and indicated that CBP60g and SARD1 affect defense responses in addition to SA production. A DNA motif bound by CBP60g and SARD1, GAAATTT, was significantly over-represented in promoters of CBP60g/SARD1-dependent genes, suggesting that expression of these genes is modulated by CBP60g/SARD1 binding. Gene expression patterns showed a stronger effect of cbp60g mutations soon after activation of a defense response, and a stronger effect of sard1 mutations at later times. The results are consistent with a model in which CBP60g and SARD1 comprise a partially redundant protein pair that is required for activation of SA production as well as other defense responses, with CBP60g playing a more important role early during the defense response, and SARD1 to playing a more important role later.
  • Yiping Qi, Kenichi Tsuda, Anna Joe, Masanao Sato, Le V. Nguyen, Jane Glazebrook, James R. Alfano, Jerry D. Cohen, Fumiaki Katagiri
    MOLECULAR PLANT-MICROBE INTERACTIONS 23 (12) 1573 - 1583 0894-0282 2010/12 [Refereed][Not invited]
     
    RNA-bmdmg proteins (RBP) can control gene expression at both transcriptional and post-transcriptional levels Plants respond to pathogen infection with rapid reprogramming of gene expression However, little is known about how plant RBP function in plant immunity Here, we describe the involvement of an RBP, Arabidopsis thaliana RNA-bind mg protein-defense related 1 (AtRBP-DR1, At4g03110), in resistance to the pathogen Pseudomonas syringae pv tomato DC3000 AtRBP-DR1 loss of function mutants showed enhanced susceptibility to P syringae pv tomato DC3000 Overexpression of AtRBP-DR1 led to enhanced resistance to P syringae pv tomato DC3000 strains and dwarfism The hypersensitive response triggered by P syringae pv tomato DC3000 avrRpt2 was compromised in the Atrbp-dr1 mutant and enhanced in the AtRBP-DR1 overexpression line at early time points AtRBP-DR1 overexpression lines showed higher mRNA levels of SID2 and PR1, which are salicylic acid (SA) inducible, as well as spontaneous cell death in mature leaves Consistent with these observations, the SA level was low in the Atrbp-dr1 mutant but high in the overexpression line The SA-related phenotype in the overexpression line was fully dependent on SID2 Thus, AtRBP-DR1 is a positive regulator of SA-mediated immunity, possibly acting on SA signaling-related genes at a post-transcriptional level
  • Masanao Sato, Kenichi Tsuda, Lin Wang, John Coller, Yuichiro Watanabe, Jane Glazebrook, Fumiaki Katagiri
    PLOS PATHOGENS 6 (7) e1001011  1553-7366 2010/07 [Refereed][Not invited]
     
    Biological signaling processes may be mediated by complex networks in which network components and network sectors interact with each other in complex ways. Studies of complex networks benefit from approaches in which the roles of individual components are considered in the context of the network. The plant immune signaling network, which controls inducible responses to pathogen attack, is such a complex network. We studied the Arabidopsis immune signaling network upon challenge with a strain of the bacterial pathogen Pseudomonas syringae expressing the effector protein AvrRpt2 (Pto DC3000 AvrRpt2). This bacterial strain feeds multiple inputs into the signaling network, allowing many parts of the network to be activated at once. mRNA profiles for 571 immune response genes of 22 Arabidopsis immunity mutants and wild type were collected 6 hours after inoculation with Pto DC3000 AvrRpt2. The mRNA profiles were analyzed as detailed descriptions of changes in the network state resulting from the genetic perturbations. Regulatory relationships among the genes corresponding to the mutations were inferred by recursively applying a non-linear dimensionality reduction procedure to the mRNA profile data. The resulting static network model accurately predicted 23 of 25 regulatory relationships reported in the literature, suggesting that predictions of novel regulatory relationships are also accurate. The network model revealed two striking features: (i) the components of the network are highly interconnected; and (ii) negative regulatory relationships are common between signaling sectors. Complex regulatory relationships, including a novel negative regulatory relationship between the early microbe-associated molecular pattern-triggered signaling sectors and the salicylic acid sector, were further validated. We propose that prevalent negative regulatory relationships among the signaling sectors make the plant immune signaling network a "sector-switching'' network, which effectively balances two apparently conflicting demands, robustness against pathogenic perturbations and moderation of negative impacts of immune responses on plant fitness.
  • Hong-Gu Kang, Chang-Sik Oh, Masanao Sato, Fumiaki Katagiri, Jane Glazebrook, Hideki Takahashi, Pradeep Kachroo, Gregory B. Martin, Daniel F. Klessig
    PLANT CELL 22 (3) 918 - 936 1040-4651 2010/03 [Refereed][Not invited]
     
    Resistance gene-mediated immunity confers protection against pathogen infection in a wide range of plants. A genetic screen for Arabidopsis thaliana mutants compromised for recognition of turnip crinkle virus previously identified CRT1, a member of the GHKL ATPase/kinase superfamily. Here, we demonstrate that CRT1 interacts with various resistance proteins from different structural classes, and this interaction is disrupted when these resistance proteins are activated. The Arabidopsis mutant crt1-2 crh1-1, which lacks CRT1 and its closest homolog, displayed compromised resistance to avirulent Pseudomonas syringae and Hyaloperonospora arabidopsidis. Additionally, resistance-associated hypersensitive cell death was suppressed in Nicotiana benthamiana silenced for expression of CRT1 homolog(s). Thus, CRT1 appears to be a general factor for resistance gene-mediated immunity. Since elevation of cytosolic calcium triggered by avirulent P. syringae was compromised in crt1-2 crh1-1 plants, but cell death triggered by Nt MEK2(DD) was unaffected in CRT1-silenced N. benthamiana, CRT1 likely functions at an early step in this pathway. Genome-wide transcriptome analysis led to identification of CRT1-Associated genes, many of which are associated with transport processes, responses to (a) biotic stress, and the endomembrane system. Confocal microscopy and subcellular fractionation revealed that CRT1 localizes to endosome-like vesicles, suggesting a key process in resistance protein activation/signaling occurs in this subcellular compartment.
  • Kenichi Tsuda, Masanao Sato, Thomas Stoddard, Jane Glazebrook, Fumiaki Katagiri
    PLOS GENETICS 5 (12) e1000772  1553-7390 2009/12 [Refereed][Not invited]
     
    Two modes of plant immunity against biotrophic pathogens, Effector Triggered Immunity (ETI) and Pattern-Triggered Immunity (PTI), are triggered by recognition of pathogen effectors and Microbe-Associated Molecular Patterns (MAMPs), respectively. Although the jasmonic acid (JA)/ethylene (ET) and salicylic acid ( SA) signaling sectors are generally antagonistic and important for immunity against necrotrophic and biotrophic pathogens, respectively, their precise roles and interactions in ETI and PTI have not been clear. We constructed an Arabidopsis dde2/ein2/pad4/sid2-quadruple mutant. DDE2, EIN2, and SID2 are essential components of the JA, ET, and SA sectors, respectively. The pad4 mutation affects the SA sector and a poorly characterized sector. Although the ETI triggered by the bacterial effector AvrRpt2 (AvrRpt2-ETI) and the PTI triggered by the bacterial MAMP flg22 (flg22-PTI) were largely intact in plants with mutations in any one of these genes, they were mostly abolished in the quadruple mutant. For the purposes of this study, AvrRpt2-ETI and flg22-PTI were measured as relative growth of Pseudomonas syringae bacteria within leaves. Immunity to the necrotrophic fungal pathogen Alternaria brassicicola was also severely compromised in the quadruple mutant. Quantitative measurements of the immunity levels in all combinatorial mutants and wild type allowed us to estimate the effects of the wild-type genes and their interactions on the immunity by fitting a mixed general linear model. This signaling allocation analysis showed that, contrary to current ideas, each of the JA, ET, and SA signaling sectors can positively contribute to immunity against both biotrophic and necrotrophic pathogens. The analysis also revealed that while flg22-PTI and AvrRpt2-ETI use a highly overlapping signaling network, the way they use the common network is very different: synergistic relationships among the signaling sectors are evident in PTI, which may amplify the signal; compensatory relationships among the sectors dominate in ETI, explaining the robustness of ETI against genetic and pathogenic perturbations.
  • Lin Wang, Kenichi Tsuda, Masanao Sato, Jerry D. Cohen, Fumiaki Katagiri, Jane Glazebrook
    PLOS PATHOGENS 5 (2) e1000301  1553-7366 2009/02 [Refereed][Not invited]
     
    Salicylic acid (SA)-induced defense responses are important factors during effector triggered immunity and microbeassociated molecular pattern (MAMP)-induced immunity in plants. This article presents evidence that a member of the Arabidopsis CBP60 gene family, CBP60g, contributes to MAMP-triggered SA accumulation. CBP60g is inducible by both pathogen and MAMP treatments. Pseudomonas syringae growth is enhanced in cbp60g mutants. Expression profiles of a cbp60g mutant after MAMP treatment are similar to those of sid2 and pad4, suggesting a defect in SA signaling. Accordingly, cbp60g mutants accumulate less SA when treated with the MAMP flg22 or a P. syringae hrcC strain that activates MAMP signaling. MAMP-induced production of reactive oxygen species and callose deposition are unaffected in cbp60g mutants. CBP60g is a calmodulin-binding protein with a calmodulin-binding domain located near the N-terminus. Calmodulin binding is dependent on Ca(2+). Mutations in CBP60g that abolish calmodulin binding prevent complementation of the SA production and bacterial growth defects of cbp60g mutants, indicating that calmodulin binding is essential for the function of CBP60g in defense signaling. These studies show that CBP60g constitutes a Ca(2+) link between MAMP recognition and SA accumulation that is important for resistance to P. syringae.
  • Lin Wang, Raka M. Mitra, Keegan D. Hasselmann, Masanao Sato, Lisa Lenarz-Wyatt, Jerry D. Cohen, Fumiaki Katagiri, Jane Glazebrook
    MOLECULAR PLANT-MICROBE INTERACTIONS 21 (11) 1408 - 1420 0894-0282 2008/11 [Refereed][Not invited]
     
    Expression profiling of wild-type plants and mutants with defects in key components of the defense signaling network was used to model the Arabidopsis network 24 h after infection by Pseudomonas syringae pv. maculicola ES4326. Results using the Affymetrix ATH1 array revealed that expression levels of most pathogen-responsive genes were affected by mutations in coi1, ein2, npr1, pad4, or sid2. These five mutations defined a small number of different expression patterns displayed by the majority of pathogen-responsive genes. P. syringae pv. tomato strain DC3000 elicited a much weaker salicylic acid (SA) response than ES4326. Additional mutants were profiled using a custom array. Profiles of pbs3 and ndr1 revealed major effects of these mutations and allowed PBS3 and NDR1 to be placed between the EDS1/PAD4 node and the SA synthesis node in the defense network. Comparison of coi1, dde2, and jar1 profiles showed that many genes were affected by coi1 but very few were affected by dde2 or jar1. Profiles of coi1 plants infected with ES4326 were very similar to those of wild-type plants infected with bacteria unable to produce the phytotoxin coronatine, indicating that, essentially, all COI1-dependent gene expression changes in this system are caused by coronatine.
  • Kenichi Tsuda, Masanao Sato, Jane Glazebrook, Jerry D. Cohen, Fumiaki Katagiri
    PLANT JOURNAL 53 (5) 763 - 775 0960-7412 2008/03 [Refereed][Not invited]
     
    Plants respond to pathogen infection using an innate immune system with at least two distinct recognition mechanisms. One mechanism recognizes microbe-associated molecular patterns (MAMPs). The other is based on resistance (R) genes and specifically recognizes certain pathogen virulence factors, including those delivered through the type III secretion system (TTSS) of bacteria. Salicylic acid (SA)-mediated responses are an important part of the R gene-mediated defense. Substantial overlaps between MAMP-triggered and SA-mediated responses have been reported. However, interactions between MAMP-triggered and SA-mediated signaling mechanisms have not been well documented. Here we report intimate interactions between MAMP-triggered and SA-mediated signaling. We found that SA accumulated at a higher level 6 h after treatment with a MAMP, flg22 or inoculation with Pseudomonas syringae pv. tomato DC3000 (PstDC3000) hrcC mutant, which is deficient in TTSS function. Disruptions of SA signaling components, such as SID2 and PAD4, strongly affected MAMP-triggered responses monitored by expression profiling. We found two groups of genes that were induced by PstDC3000 hrcC in an SA-dependent manner. One group was SID2-dependent at all time points, whereas the other was SID2-independent at early time points and SID2-dependent at later time points. Thus, the expression of the latter genes responds to MAMPs through both SA-independent and SA-dependent signaling mechanisms. Strong resistance to PstDC3000 hrcC was dependent on SA signaling. These results indicate that the SA increase triggered by MAMPs is a major component of the MAMP-triggered signaling mechanism, explaining the overlapping spectra of MAMP-triggered and SA-mediated responses.
  • Tsuda, K., Sato, M., Glazebrook, J., Cohen, J.D., Katagiri, F.
    Plant Journal 55 (6) 1061 - 1061 2008
  • Ma. Leonora M. Yambao, Haruka Yagihashi, Hiroshi Sekiguchi, Toru Sekiguchi, Toru Sasaki, Masanao Sato, Go Atsumi, Yoko Tacahashi, Kenji S. Nakahara, Ichiro Uyeda
    Archives of Virology 153 (1) 105 - 115 0304-8608 2008/01 [Refereed][Not invited]
     
    Helper component protease (HC-Pro) is a potyvirus-encoded multifunctional protein and a major determinant of symptom expression in a susceptible plant. Here, we show the involvement of clover yellow vein virus (ClYVV) HC-Pro in necrotic symptom expression in broad bean (Vicia faba cv. Wase). In this host, lethal necrosis was induced by ClYVV no. 30, from which a spontaneous, mosaic-inducing mutant (MM) was obtained. Mapping with chimeric viruses between ClYVV no. 30 and MM attributed the symptom attenuation to two mutations at the HC-Pro positions 27 (threonine to isoleucine) and 193 (aspartic acid to tyrosine). Although neither mutant with the single amino acid substitution at position 27 or 193 (ClYVV/T27I or D193Y) induced the lethal necrosis, ClYVV/T27I still retained the ability to induce necrotic symptoms, but ClYVV/D193Y scarcely did so. The virus accumulation of ClYVV/D193Y was also lower than that of ClYVV no. 30. The mutations, T27I and D193Y, are located in a putative zinc finger domain and in one (N-terminal) of the two RNA binding domains, respectively, of HC-Pro. RNA-silencing suppression (RSS) activity of P1/HC-Pro in Nicotiana benthamiana was weakened by both mutations. Our results suggest a correlation between viral virulence and RSS function and the importance of the two domains in HC-Pro. © 2007 Springer-Verlag.
  • Remco M. P. Van Poecke, Masanao Sato, Lisa Lenarz-Wyatt, Sanford Weisberg, Fumiaki Katagiri
    PLANT CELL 19 (12) 4046 - 4060 1040-4651 2007/12 [Refereed][Not invited]
     
    Natural variation in gene expression (expression traits or e-traits) is increasingly used for the discovery of genes controlling traits. An important question is whether a particular e-trait is correlated with a phenotypic trait. Here, we examined the correlations between phenotypic traits and e-traits among 10 Arabidopsis thaliana accessions. We studied defense against Pseudomonas syringae pv tomato DC3000 (Pst), with a focus on resistance gene-mediated resistance triggered by the type III effector protein AvrRpt2. As phenotypic traits, we measured growth of the bacteria and extent of the hypersensitive response (HR) as measured by electrolyte leakage. Genetic variation among accessions affected growth of Pst both with (Pst avrRpt2) and without (Pst) the AvrRpt2 effector. Variation in HR was not correlated with variation in bacterial growth. We also collected gene expression profiles 6 h after mock and Pst avrRpt2 inoculation using a custom microarray. Clusters of genes whose expression levels are correlated with bacterial growth or electrolyte leakage were identified. Thus, we demonstrated that variation in gene expression profiles of Arabidopsis accessions collected at one time point under one experimental condition has the power to explain variation in phenotypic responses to pathogen attack.
  • Marcelo Andrade, Masanao Sato, Ichiro Uyeda
    PHYTOPATHOLOGY 97 (5) 544 - 550 0031-949X 2007/05 [Refereed][Not invited]
     
    This study characterized resistance in pea lines PI 347295 and PI 378159 to Clover yellow vein virus (ClYVV). Genetic cross experiments showed that a single recessive gene controls resistance in both lines. Conventional mechanical inoculation did not result in infection; however, particle bombardment with infectious plasmid or mechanical inoculation with concentrated viral inocula did cause infection. When ClYVV No. 30 isolate was tagged with a green fluorescent protein (GFP) and used to monitor infection, viral cell-to-cell movement differed in the two pea lines. In PI 347595, ClYVV replicated at a single-cell level. but did not move to neighboring cells, indicating that resistance operated at a cell-to-cell step. In PI 378159, the virus moved to cells around the infection site and reached the leaf veins, but viral movement was slower than that in the susceptible line. The viruses observed around the infection sites and in the veins were then recovered and inoculated again by a conventional mechanical inoculation method onto PI 378159 demonstrating that ClYVV probably had mutated and newly emerged mutant viruses can move to neighboring cells and systemically infect the plants. Tagging the virus with GFP was an efficient tool for characterizing resistance modes. Implications of the two resistance modes are discussed.
  • Gerald Ravelo, Uiko Kagaya, Tsuyoshi Inukai, Masanao Sato, Ichiro Uyeda
    Journal of General Plant Pathology 73 (1) 59 - 65 1345-2630 2007/02 [Refereed][Not invited]
     
    Clover yellow vein virus (ClYVV) elicits lethal tip necrosis in the pea line PI 118501. Pea line PI 118501 develops necrotic lesions and veinal necrosis on inoculated leaves, followed by systemic necrosis, leading to plant death. To understand the genetic basis of this lethal tip necrosis, we crossed lines PI 226564 and PI 250438, which develop mosaic symptoms in response to ClYVV inoculation. In reciprocal crosses of PI 118501 with PI 226564, all F 1 plants had mosaic symptoms with slight stem necrosis and early yellowing of upper leaves. Essentially the same symptom was manifested in PI 118501 × PI 250438 F1 plants. In F2 populations from the cross between PI 118501 and PI 226564, the observed ratios of necrosis, mosaic with slight stem necrosis, and mosaic fit the expected 1:2:1 ratio. These results indicate that a single incompletely dominant gene confers the induction of necrosis in PI 118501. This locus in pea, conferring necrosis induction to ClYVV infection, was designated Cyn1 (Clover yellow vein virus-induced necrosis). A linkage analysis using 100 recombinant inbred lines derived from a cross of PI 118501 and PI 226564 demonstrated that Cyn1 was located 7.5 cM from the SSR marker AD174 on linkage group III. © 2007 The Phytopathological Society of Japan and Springer-Verlag.
  • Masanao Sato, Raka M. Mitra, John Coller, Dong Wang, Natalie W. Spivey, Julia Dewdney, Carine Denoux, Jane Glazebrook, Fumiaki Katagiri
    PLANT JOURNAL 49 (3) 565 - 577 0960-7412 2007/02 [Refereed][Not invited]
     
    Studies of the behavior of biological systems often require monitoring of the expression of many genes in a large number of samples. While whole-genome arrays provide high-quality gene-expression profiles, their high cost generally limits the number of samples that can be studied. Although inexpensive small-scale arrays representing genes of interest could be used for many applications, it is challenging to obtain accurate measurements with conventional small-scale microarrays. We have developed a small-scale microarray system that yields highly accurate and reproducible expression measurements. This was achieved by implementing a stable gene-based quantile normalization method for array-to-array normalization, and a probe-printing design that allows use of a statistical model to correct for effects of print tips and uneven hybridization. The array measures expression values in a single sample, rather than ratios between two samples. This allows accurate comparisons among many samples. The array typically yielded correlation coefficients higher than 0.99 between technically duplicated samples. Accuracy was demonstrated by a correlation coefficient of 0.88 between expression ratios determined from this array and an Affymetrix GeneChip, by quantitative RT-PCR, and by spiking known amounts of specific RNAs into the RNA samples used for profiling. The array was used to compare the responses of wild-type, rps2 and ndr1 mutant plants to infection by a Pseudomonas syringae strain expressing avrRpt2. The results suggest that ndr1 affects a defense-signaling pathway(s) in addition to the RPS2-dependent pathway, and indicate that the microarray is a powerful tool for systems analyses of the Arabidopsis disease-signaling network.
  • Sato, M., Katagiri, F.
    Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme 52 (6 Suppl) 2007
  • C Morita-Yamamuro, T Tsutsui, M Sato, H Yoshioka, M Tamaoki, D Ogawa, H Matsuura, T Yoshihara, A Ikeda, Uyeda, I, J Yamaguchi
    PLANT AND CELL PHYSIOLOGY 46 (6) 902 - 912 0032-0781 2005/06 [Refereed][Not invited]
     
    To clarify the processes involved in plant immunity, we have isolated and characterized a single recessive Arabidopsis mutant, cad1 (constitutively activated cell death 1), which shows a phenotype that mimics the lesions seen in the hypersensitive response (HR). This mutant shows spontaneously activated expression of pathogenesis-related (PR) genes, and leading to a 32-fold increase in salicylic acid (SA). Inoculation of cad1 mutant plants with Pseudomonas syringae pv tomato DC3000 shows that the cad1 mutation results in the restriction of bacterial growth. Cloning of CAD1 reveals that this gene encodes a protein containing a domain with significant homology to the MACPF (membrane attack complex and perforin) domain of complement components and perforin proteins that are involved in innate immunity in animals. Furthermore, cell death is suppressed in transgenic cad1 plants expressing nahG, which encodes an SA-degrading enzyme. We therefore conclude that the CAD1 protein negatively controls the SA-mediated pathway of programmed cell death in plant immunity.
  • Masanao Sato, Kenji Nakahara, Moyasu Yoshii, Masayuki Ishikawa, Ichiro Uyeda
    FEBS LETTERS 579 (5) 1167 - 1171 0014-5793 2005/02 [Refereed][Not invited]
     
    Arabidopsis thaliana plants with mutations in the genes encoding eukaryotic initiation factor (eIF4E) or isoform of eIF4E (eIF(iso)4E) were tested for susceptibility to Clover yellow vein virus (ClYVV), a member of the genus Potyvirus. ClYVV accumulated in both inoculated and upper uninoculated leaves of mutant plants lacking eIF(iso)4E, but not in mutant plants lacking eIF4E. In contrast, Turnip mosaic virus (TuMV), another member of the genus Potyvirus, multiplied in mutant plants lacking eIF4E but not in mutant plants lacking eIF(iso)4E. These results suggest the selective involvement of members of the eIF4E family in infection by potyviruses. (C) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
  • Masanao Sato, Chikara Masuta, Ichiro Uyeda
    MOLECULAR PLANT-MICROBE INTERACTIONS 16 (11) 994 - 1002 0894-0282 2003/11 [Refereed][Not invited]
     
    We characterized the resistance of the common bean cv. Jolanda to Clover yellow vein virus no. 30 (ClYVV). After inoculation, the virus was detected in neither inoculated nor upper leaves, suggesting that the resistance operates at either the viral replication or cell-to-cell movement level. To analyze the mechanism of resistance, we developed a green fluorescent protein (GFP)-tagged ClYVV, and monitored GFP fluorescence at sites of infection on ClYVV-inoculated leaves. No GFP fluorescence was detected in Jolanda, whereas its expression in single cells and spread on inoculated leaves were observed clearly in susceptible cultivars. ClYVV-introduced Jolanda cells were found to be still viable; therefore, it is unlikely that the restriction of multiplication was due to rapid cell death. Genetic analysis indicated that a single recessive locus controlled the resistant phenotype of Jolanda. We designated this locus desc (determinant of susceptibility to ClYVV). Meanwhile, a spontaneous mutant virus that overcomes the resistance (ClYVV-Br) was isolated. Inoculation assays using chimeric viruses suggested that a viral genome-linked protein (VPg) might be the avirulence determinant. The resistance mechanism may be associated with the role of VPg in the viral infection cycle.
  • Positional effect of gene insertion on genetic stability of a clover yellow vein virus-based expression vector
    Zhen Dong Wang, Shigenori Ueda, Ichiro Uyeda, Haruka Yagihashi, Hiroshi Sekiguchi, Yoko Tacahashi, Masanao Sato, Kenji Ohya, Chihiro Sugimoto, Takeshi Matsumura
    Journal of General Plant Pathology 69 327 - 334 2003/10 [Refereed]
  • Chikara Masuta, Toshikazu Yamana, Yoko Tacahashi, Ichiro Uyeda, Masanao Sato, Shigenori Ueda, Takeshi Matsumura
    PLANT JOURNAL 23 (4) 539 - 546 0960-7412 2000/08 [Refereed][Not invited]
     
    A highly infectious cDNA clone of clover yellow vein virus (pCIYVV) was tested as a viral vector, especially for legume species. The genes for green fluorescent protein (GFP) and soybean glutamine synthetase (GS) were inserted between the genes for pi and HC-Pro on pCIYVV to create three recombinant plasmids: pCIYVV-GFP, pCIYVV-GFP-GS, and pCIYVV-GFP:GS. In the former two constructs all the junctions between the inserted proteins contained the sequences of protease cleavage recognition sites, whereas the third construct expressed a fusion of GFP and GS. Western blot analyses showed that GFP and GS appeared to have been precisely excised from the viral polyprotein with the viral proteases (P1 and Nla). Under UV irradiation, green fluorescence was detected in infected broad bean, kidney bean, and soybean plants. The stability of the constructs in the symptomatic tissues was confirmed by RT-PCR and Western blot analyses. The plants expressing GS together with GFP became tolerant to the herbicide glufosinate, and flowered early. As the GS gene, one of the nodulin genes for nitrogen fixation, is expressed in legume species, this system will be useful for examining the function of genes important to legume plants.

MISC

Books etc

Presentations

  • BmNPVにおける膜タンパク質(GP64)のアミノ酸バリアントが増殖に与える影響
    関口真理, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2020
  • 蛍光レポーター発現細胞クラスター認識を自動化・定量化する画像解析アプローチ
    中西登志紀, 関口真理, 浅野眞一郎, 伴戸久徳, 佐藤昌直
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2020
  • Identification of key targets and components of PRC2-mediated systemic defense priming in Arabidopsis thaliana
    田島由理, 佐藤昌直, LOO Eliza Po-Iian, 西條雄介
    日本植物病理学会大会プログラム・講演要旨予稿集  2020
  • Polycomb repressive complex 2 positively regulates systemic immunity and priming in Arabidopsis thaliana  [Not invited]
    Yuri Tajima, Masanao Sato, Eva-Maria Reimer-Michalski, Eliza Po-iian Loo, Barbara Kracher, Franziska Turck, Yusuke Saijo
    2019 IS-MPMI XVIII Congress  2019/07
  • カイコに存在する2つのTOR遺伝子の機能的違い
    小林政彦, 門宏明, 李在萬, 佐藤昌直, 藤田龍介, 日下部宜宏
    日本分子生物学会年会プログラム・要旨集(Web)  2019
  • ポリコーム抑制複合体を介した植物免疫プライミング機構
    田島由理, REIMER-MICHALSKI Eva-Maria, LOO Eliza Po-Iian, KRACHER Barbara, TURCK Franziska, 佐藤昌直, 西條雄介, 西條雄介
    日本植物病理学会大会プログラム・講演要旨予稿集  2019
  • BmN細胞におけるSmall Molecule Assisted Shutoffの検証
    中西登志紀, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2019
  • カイコ核多角体病ウイルス新規株H4の膜タンパク質GP64の機能解析
    関口真理, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2019
  • カイコRNA-seqデータ自動解析および可視化プログラムの作成と利用
    佐藤昌直, 横井翔, 坪田拓也, 瀬筒秀樹
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2019
  • 機能未知遺伝子ライブラリーから得られたカイコ分散型動原体を構成する新規遺伝子の解析
    門宏明, 佐藤昌直, 藤田龍介, 李在萬, 日下部宜宏
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2019
  • Gene ontology解析:トランスクリプトーム情報から生物学的解釈を得る
    佐藤昌直
    日本植物病理学会植物感染生理談話会論文集  2019
  • 大量ショートリードデータからトランスクリプトーム情報を抽出する
    佐藤昌直
    日本植物病理学会植物感染生理談話会論文集  2019
  • 機能性糖質によるラット盲腸内細菌叢の改変に基づいたデオキシコール酸生成菌と相互作用する腸内細菌種の同定
    吹谷智, 佐竹実菜子, 佐藤昌直, 石塚敏, 小椋義俊, 林哲也, 横田篤
    日本乳酸菌学会誌  2019
  • 稲垣幸, 門田満隆, KEELEY Sean D, KEELEY Sean D, 中村奈月, 佐藤昌直, 工樂樹洋, 影山裕二, 影山裕二
    日本RNA学会年会要旨集  2018/07
  • 浅野眞一郎, 小野山雄亮, 中神あゆみ, 中尾悠太, 佐藤昌直, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2018/03
  • 原田直人, 石橋大樹, 浅野眞一郎, 佐藤昌直, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2018/03
  • 丸山望, 石賀貴子, 石賀康博, 佐藤昌直, 鈴木智子, 加来久敏, 尾花望, 一瀬勇規, 野村暢彦, 別役重之
    日本植物病理学会大会プログラム・講演要旨予稿集  2018/03
  • 田島由理, REIMER‐MICHALSKI Eva‐Maria, LOO Eliza Po‐iian, 白石菜月, KRACHER Barbara, TURCK Franziska, 佐藤昌直, 西條雄介, 西條雄介
    日本植物病理学会大会プログラム・講演要旨予稿集  2018/03
  • 佐竹実菜子, 吹谷智, 佐藤昌直, 石塚敏, 小椋義俊, 林哲也, 横田篤
    日本農芸化学会大会講演要旨集(Web)  2018/03
  • ウイルス感染時におけるAGO1-vsiRNAの標的となる植物mRNAの予測
    堀裕和, 岩橋美穂, 白谷公孝, 佐藤昌直, 峯彰, 峯彰, 竹田篤史, 竹田篤史, 竹田篤史
    日本分子生物学会年会プログラム・要旨集(Web)  2018
  • Lobe-less RNAはショウジョウバエの胚発生期において軸索走行制御に寄与する長鎖ノンコーディングRNAである
    稲垣幸, 門田満隆, KEELEY Sean D., KEELEY Sean D., 中村奈月, 佐藤昌直, 工樂樹洋, 影山裕二, 影山裕二
    日本RNA学会年会要旨集  2018
  • 稲垣幸, 中野美幸, 中村奈月, 門田満隆, KEELEY Sean D, 佐藤昌直, 工樂樹洋, 影山裕二, 影山裕二
    日本RNA学会年会要旨集  2017/07
  • 佐藤昌直, 門宏明, 日下部宜宏
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2017/03
  • 浅野眞一郎, 中神あゆみ, 中尾悠太, 佐藤昌直, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2017/03
  • 高ひとみ, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2017/03
  • 動的なカルシウムシグナルによる頂端収縮と神経管閉鎖の制御
    鈴木誠, 佐藤昌直, 小山宏史, 上野直人
    日本数理生物学会年会(Web)  2017
  • ショウジョウバエLobe-less RNAは胚発生期の軸索走行シグナルを制御している
    稲垣幸, 中野美幸, 中村奈月, 門田満隆, KEELEY Sean D., 佐藤昌直, 工樂樹洋, 影山裕二, 影山裕二
    日本RNA学会年会要旨集  2017
  • BmNPV非必須遺伝子arif-1,pif-2による補償的な必須遺伝子発現制御
    高ひとみ, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2017
  • 門宏明, 佐藤昌直, 李在萬, 日下部宜宏
    日本生化学会大会(Web)  2017
  • 諸熊大輔, 門宏明, 佐藤昌直, 李在萬, 伴戸久徳, 日下部宜宏
    日本生化学会大会(Web)  2017
  • 白谷公孝, 舛田さくら, 長田怜子, 唐戸俊介, 都筑正行, 佐藤昌直, 渡邊雄一郎, 竹田篤史
    日本植物学会大会研究発表記録  2016/09
  • 大崎彰梧, 佐藤昌直, 矢澤良輔
    日本水産学会大会講演要旨集  2016/03
  • 浜島りな, 佐藤昌直, 小林迪弘, 池田素子
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2016/03
  • 安達広明, 波多江健太, 佐藤昌直, 吉岡博文
    日本植物病理学会大会プログラム・講演要旨予稿集  2016/03
  • 植物micro-RNAの認識特異性に関する研究とその応用
    白谷公孝, 舛田さくら, 長田怜子, 唐戸俊介, 都筑正行, 佐藤昌直, 渡邊雄一郎, 竹田篤史
    日本植物学会大会研究発表記録  2016
  • RNA-seq法を用いた核多角体病ウイルス感染カイコ細胞のトランスクリプトーム解析
    浜島りな, 佐藤昌直, 小林迪弘, 池田素子
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2016
  • 高ひとみ, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本分子生物学会年会プログラム・要旨集(Web)  2016
  • 高ひとみ, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2015/09
  • 平田一真, 佐藤昌直, 徐剣, 季明明, 祝力, 日野真人, 山下真実, 諸熊大輔, 門宏明, 李在萬, 日下部宜宏
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2015/09
  • 佐藤昌直, 佐藤昌直, 高ひとみ, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2015/09
  • 宇多桃香, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2015/09
  • 遺伝子ネットワークのreduced S-systemモデルの効率的同定法の提案
    木村 周平, 佐藤 昌直, 岡田(畠山) 眞里子
    情報処理学会研究報告. BIO, バイオ情報学  2015/03  一般社団法人情報処理学会
     
    遺伝子ネットワーク同定とは,観察された遺伝子発現データに合うような遺伝子ネットワークのモデルのパラメータを推定する問題のことである.遺伝子ネットワークを記述するために多くの数理モデルが提案されているが,中でも S-system モデルは最も使用されてモデルの一つである. S-system モデルは生化学反応を近似したモデルであり,遺伝子ネットワークの記述に適していると考えられている.そのため S-system モデルを用いた遺伝子ネットワーク同定法が,これまでに数多く提案されている.しかしながら S-system に含まれるパラメータ数は,他の頻繁に使用されているモデルのパラメータ数よりも多い.従って遺伝子ネットワークの S-system モデルを同定するためには,より多くの遺伝子発現データを与える必要があると考えられる.遺伝子ネットワーク同定に必要な遺伝子発現データの量を減らすために,本研究では S-system モデルの一部のパラメータを 0 に固定することでモデルを単純化する.本研究では単純化した S-system モデルを,reduced S-system モデルと呼ぶ.次に遺伝子ネットワークの reduced S-system モデルを効率的に同定するための新たな方法を提案する.最後に数値実験を通して,提案手法の有効性を示す.
  • 木村周平, 佐藤昌直, 岡田(畠山)眞里子
    情報処理学会研究報告(Web)  2015/03
  • 薦田(萩原)優香, CHOI S. H, 佐藤昌直, 厚見剛, 阿部純也, 中原健二, 上田一郎, 内藤哲
    日本植物病理学会大会プログラム・講演要旨予稿集  2015/03
  • 安達広明, 佐藤昌直, 吉岡博文
    日本植物病理学会大会プログラム・講演要旨予稿集  2015/03
  • 安達広明, 佐藤昌直, 吉岡博文
    日本植物生理学会年会要旨集  2015/03
  • バキュロウイルスゲノム人工合成系の確立
    石橋大樹, 佐藤昌直, 高ひとみ, 武内潤一, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2015
  • 中村翔一, 塩田孝祐, 小林悟, 佐藤昌直, 向正則
    日本生化学会大会(Web)  2015
  • 佐藤昌直, 佐藤昌直, 門宏明, 徐剣, 李在萬, 笠嶋めぐみ, 鈴木誉保, 坪田拓也, 小林悟, 瀬筒秀樹, 日下部宜宏
    日本生化学会大会(Web)  2015
  • 白谷公孝, 舛田さくら, 長田怜子, 唐戸俊介, 都筑正行, 佐藤昌直, 佐藤昌直, 渡邊雄一郎, 竹田篤史, 竹田篤史
    日本生化学会大会(Web)  2015
  • 別役重之, 加藤新平, 佐藤昌直, 浜田紗稀, 福田裕穂
    日本植物病理学会植物感染生理談話会論文集  2014/07
  • 稲垣幸, 佐藤昌直, 中村奈月, 小林悟, 影山裕二
    日本RNA学会年会要旨集  2014/07
  • 熊倉直祐, 大月陽路香, 佐藤昌直, 渡邊雄一郎
    日本RNA学会年会要旨集  2014/07
  • 小野慎子, 高ひとみ, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2014/03
  • 高ひとみ, 小野慎子, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2014/03
  • 高ひとみ, 小野慎子, 佐藤昌直, 浅野眞一郎, 伴戸久徳
    日本分子生物学会年会プログラム・要旨集(Web)  2014
  • 満留卓実, 門宏明, 佐藤昌直, 末次克行, 山本公子, 李志清, 徐剣, 祝力, LEE Jae M, 日下部宜宏, 益田篤
    日本分子生物学会年会プログラム・要旨集(Web)  2014
  • 篠塚裕子, 佐藤昌直, 小林悟
    日本動物学会大会予稿集  2013/08
  • 満留卓実, 門宏明, 佐藤昌直, 末次克行, 山本公子, 李志清, 徐剣, 祝力, 李在萬, 日下部宜宏
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2013/03
  • 益田篤, 佐藤昌直, 末次克行, 山本公子, 門宏明, 李在萬, 日下部宜宏
    日本蚕糸学会大会・蚕糸・昆虫機能学術講演会講演要旨集  2013/03
  • 稲垣幸, 佐藤昌直, 宮下知之, 中村奈月, 小林悟, 斉藤実, 影山裕二
    日本分子生物学会年会プログラム・要旨集(Web)  2013
  • 林誠, 佐藤昌直, 岩崎佳子, 小野澤健明, 長坂安彦, 定家咲子, 小林悟, 吉崎悟朗
    日本分子生物学会年会プログラム・要旨集(Web)  2012
  • 益田篤, 佐藤昌直, 門宏明, LEE Jae Man, 日下部宜宏
    日本分子生物学会年会プログラム・要旨集(Web)  2012
  • 佐藤昌直, LENARZ‐WYATT Lisa, HERNICK Charles, GLAZEBROOK Jane, 渡辺雄一郎, 片桐文章
    日本植物生理学会年会要旨集  2009/03
  • 津田賢一, 佐藤昌直, STODDARD Thomas, GLAZEBROOK Jane, 片桐文章
    日本植物生理学会年会要旨集  2009/03
  • (403) Mutual Inhibition between Salicylate-mediated and MAMPs-induced Signaling Revealed by a Network Analysis(Abstracts of the Papers Presented at the Annual Meeting of the Society)
    Sato M., Tsuda K., Glazebrook Jane, Watanabe Y., Katagiri F.
    Annals of the Phytopathological Society of Japan  2008/08  The Phytopathological Society of Japan (PSJ)
  • 津田賢一, 佐藤昌直, GLAZEBROOK Jane, COHEN Jerry, 片桐文章
    日本植物生理学会年会要旨集  2008/03
  • 佐藤昌直, 津田賢一, GLAZEBROOK Jane, 渡辺雄一郎, 片桐文章
    日本植物生理学会年会要旨集  2008/03
  • (283) Statistical Models that Predict the in planta Bacterial Growth based on Early Expression Levels of a Small Number of Arabidopsis Genes in the RPS2-mediated Resistance(Abstracts of the Papers Presented at the Annual Meeting of the Society)
    Sato M., Lenarz-Wtatt Lisa, Watanabe Y., Katagiri F.
    Annals of the Phytopathological Society of Japan  2007/08  The Phytopathological Society of Japan (PSJ)
  • 津田賢一, 佐藤昌直, 片桐文章
    日本植物生理学会年会要旨集  2007/03
  • 佐藤昌直, LENARZ‐WYATT Lisa, 渡辺雄一郎, 片桐文章
    日本植物生理学会年会要旨集  2007/03
  • Sato Masanao, Lenarz-Wyatt Lisa, Watanabe Yuichiro, Katagiri Fumiaki
    Plant and Cell Physiology Supplement  2007  The Japanese Society of Plant Physiologists
     
    Elucidation of the plant defense signaling network controlling responses to pathogen infection, has been challenging for several biological reasons. First, plant defense signaling pathways are highly interconnected. Second, plants receive multiple stimuli associated with pathogen infection including pathogen-associated molecular patterns and effectors delivered directly into plant cells. Third, part of the signaling network is robust to perturbations.
    To reveal the structure and function of this signaling network, we have employed a strategy using parallel and quantitative data collection. Our objective is to collect hundreds of observations about the behavior of the system after introducing specific perturbations. To this end, we have developed a high-performance, inexpensive custom microarray and have initiated gene expression profiling combined with a reverse genetics strategy. Analysis of known mutants as reference points within the signaling network revealed a model for the topology of the network and key players controlling signaling pathways utilized to process different stimuli.
  • Tsuda Kenichi, Sato Masanao, Katagiri Fumiaki
    Plant and Cell Physiology Supplement  2007  The Japanese Society of Plant Physiologists
     
    Plants change expression of numerous genes upon pathogens attack, and many of the changes compose plant defense mechanisms. The hrcC mutant of the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 is defect in injecting type III effectors (T3Es) into the plant cell, and plant responses induced by the mutant strain is considered mostly based on recognition of pathogen-associated molecular patterns (PAMPs). It is not clear whether PAMPs have any effects on salicylic acid (SA) -mediated responses, which are induced by recognition of some T3Es. Several Arabidopsis defense mutants were analyzed by mRNA profiling using a small-scale custom microarray after inoculation of the hrcC strain. We found that induction of some genes by the hrcC strain depends on the ICS1 gene, which is essential for the pathogen-induced SA synthesis. This strongly suggests that PAMPs can induce SA-mediated defense responses. We will also discuss expression profiles of other Arabidopsis mutants.
  • 渡邊雄一郎, 稲葉直子, 滝澤真理, 佐藤昌直
    日本生体防御学会学術総会講演抄録集  2007
  • (212) Development of an Arabidopsis Pathoarray to Study Arabidopsis thaliana-pathogen Interactions(Abstract of the Paper Presented at the 2006 Annual Meeting in Sapporo)
    Sato M., Mitra Raka M., Poecke Remco M. van, Collar John, Glazebrook Jane, Katagin F.
    Annals of the Phytopathological Society of Japan  2006/11  The Phytopathological Society of Japan (PSJ)
  • 佐藤昌直, MITRA Raka M, VAN POECKE Remco M, COLLER John, GLAZEBROOK Jane, 片桐文章
    日本植物病理学会報  2006/11
  • (347) Characterization of the Resistance in Pea to Clover Yellow Vein Virus using a Green Fluorescent Protein Tagged Virus(Abstracts of the Papers Presented at the 2005 Annual Meeting in Shizuoka)
    Andrade M., Sato M., Uyeda I.
    Annals of the Phytopathological Society of Japan  2005/08  The Phytopathological Society of Japan (PSJ)
  • (293) Isolation of Resistance-breaking Strains of Clover yellow vein virus from Pea(Abstracts of the Papers Presented at the Annual Meeting of the Society, Fukuoka, March 28-30, 2004)
    Andrade M., Yambao M. L. M., Sato M., Uyeda I.
    Annals of the Phytopathological Society of Japan  2004/08  The Phytopathological Society of Japan (PSJ)
  • (7) Resistance to Clover yellow vein virus (C1YVV) in Some Lines of Pea is Governed by a Single Recessive Gene.(Abstracts Presented at the Meeting of the Hokkaido Division) (Abstracts of Papers Presented at the Division Meetings of the Phytopathological Society of Japan, 2003)
    Andrade M., Sato M., Uyeda I.
    Annals of the Phytopathological Society of Japan  2004/02  The Phytopathological Society of Japan (PSJ)
  • (6)A Point Mutation in the Helper Component-protease (HC-Pro) Gene of Clover yellow vein virus Associates with Symptom Attenuation in Broad Beans.(Abstracts Presented at the Meeting of the Hokkaido Division) (Abstracts of Papers Presented at the Division Meetings of the Phytopathological Society of Japan, 2003)
    Yambao M. L. M., Sato M., Uyeda I.
    Annals of the Phytopathological Society of Japan  2004/02  The Phytopathological Society of Japan (PSJ)
  • (5) Genetic Analyses of Symptom Determinants in Clover yellow vein virus-infected Pea (Abstracts Presented at the Meeting of the Hokkaido Division) (Abstracts of Papers Presented at the Division Meetings of the Phytopathological Society of Japan, 2003)
    Kagaya U., Sato M., Uyeda I.
    Annals of the Phytopathological Society of Japan  2004/02  The Phytopathological Society of Japan (PSJ)
  • (427)Fine Mappinf of the Pathogenic Determinants of Clover yellow vein virus Genome(Abstracts of the Papers Presented at the 2003 Annual Meeting in Tokyo)
    Yambo M. L. M., Sasaki T., Ueda I., Sato M., Sekiguchi H., Yagihashi H., Takahashi Y.
    Annals of the Phytopathological Society of Japan  2003/08  The Phytopathological Society of Japan (PSJ)
  • Comparison of Reactions to Clover yellow vein virus Infection between Different Pea Cultivars(Abstracts of the Papers Presented at the 2003 Annual Meeting in Tokyo)
    Sato M., Ueda I.
    Annals of the Phytopathological Society of Japan  2003/08  The Phytopathological Society of Japan (PSJ)
  • Symptom Analysis of Chimeric Viruses between Wild and MM Isolates of Clover yellou vein virus
    Yambao M.L.M., Sasaki T., Uyeda I., Sato M., Sekiguchi H., Yagihashi H., Takahashi Y.
    Annals of the Phytopathological Society of Japan  2003/02  The Phytopathological Society of Japan (PSJ)
     
    Wild type Clover yellow vein virus (ClYVV) induces severe necrosis in broad bean plants. A spontaneous mutant (MM) that induces mosaic symptoms with replication efficiency similar to wild type was isolated. To determine the domain in the viral genome involve in necrosis induction, cDNAs to genomic RNA of MM mutant were exchanged with corresponding wild type fragment. Three chimeric clones, pClYVV/CN, pClYVV/NS and pClYVV/SS were made and inoculated to broad beans. Symptom severity was scored and viral accumulation was measured by western blot. pClYVV/NS and pClYVV/SS induced symptoms essentially the same as the wild type. Viral accumulation in broad beans after inoculation of these constructs are also similar to the wild type. On the other hand, pClYVV/CN containing the C-terminal P1 to N-terminal P3 of MM caused a drastic symptom change to mild chlorosis with debilitated infectivity. Sequence analysis of this MM regions showed amino acid substitutions at P1 (E182G), HCPro (T27I, I33V, R51I, D193Y, L327Q, V393I) and P3 (N122S). These results indicate that the ability to induce necrosis and the control of viral accumulation are mapped in the C-terminal P1 to N-terminal P3 region of ClYVV.
  • ClYVV Resistance of Common Bean cv. Jolanda Analyzed by Reporter Genes
    Sato M., Masuta C., Uyeda I.
    Annals of the Phytopathological Society of Japan  2003/02  The Phytopathological Society of Japan (PSJ)
     
    インゲンマメ品種Jolandaはクローバー葉脈黄化ウイルス(ClYVV)に対して抵抗性を示す.我々はgreen fluorescent protein(GFP,C3-S65T)を発現するpClYVV/C3-S65Tを構築し,その組み換えウイルスに対してもJolandaが抵抗性を示すことを確認した.pClYVV/C3-S65Tをパーティクルボンバードメントで導入した場合に感受性品種ではウイルス感染の進行と共にGFP蛍光は広がっていったが,Jolandaでは全く観察されなかった.この結果から,1細胞レベルで抵抗性が発揮されていることが明らかになった.次に感染性が失われた欠失クローンpClYVVΔSac/Gを大正金時およびJolandaに導入したところ両者でGFP蛍光は観察されたが,JolandaでのGFP蛍光発現に遅れが見られた.この遺伝子発現の遅れが感受性・抵抗性に関与するかを解析するために,ClYVVの非翻訳領域(NTR)とホタル由来のルシフェラーゼを連結した発現ベクターpClnLを用いた.このルシフェラーゼを用いた解析から,Jolandaの抵抗性とClYVVのNTRによる発現制御は無関係であることが判明した.
  • (225)The Genetic Background of Resistance to C1YVV in Jolanda Bean
    Sato M., Masuta C., Uyeda I.
    Annals of the Phytopathological Society of Japan  2002/08  The Phytopathological Society of Japan (PSJ)
  • Analysis of Clover yellow vein virus Mutant Can Overcome the Resistance in Common Bean Clover yellow vein virus
    Sato M., Masuta C., Uyeda I.
    Annals of the Phytopathological Society of Japan  2001/08  The Phytopathological Society of Japan (PSJ)
  • Modefication of Clover Yellow Vein Viral Expression Vector and Stability of the Expressed Gene(Abstracts Presented at the Meeting of the Hokkaido Division)
    Wang Z.D., Uyeda I., Ueda S., Sekiguchi H., Takahashi Y., Sato M.
    Annals of the Phytopathological Society of Japan  2000/12  The Phytopathological Society of Japan (PSJ)
  • Monitoring of Clover Yellow Vein Virus Infection by Green Fluorescent Protein (GFP) (Abstracts Presented at the Meeting of the Hokkaido Division)
    Sato M., Masuta C., Uyeda I.
    Annals of the Phytopathological Society of Japan  1999/12  The Phytopathological Society of Japan (PSJ)
  • 山名利一, 増田税, 高橋葉子, 佐藤昌直, 松村健, 上田一郎
    日本植物細胞分子生物学会大会・シンポジウム講演要旨集  1999/07
  • Construction of a Plant Virus Based Vector and Highly Efficient Expression of a Foreign Gene in Legume Plants
    Yamana T., Masuta C., Takahashi Y., Sato M., Matsumura T., Uyeda E.
    Annals of the Phytopathological Society of Japan  1999/06  The Phytopathological Society of Japan (PSJ)

Research Projects

  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2018/06 -2021/03 
    Author : Takeda Atsushi
     
    To date, it is unclear how AGO1 and AGO2 determine the target mRNAs to be degraded in plants. To predict the target host mRNAs of AGO1-virus-derived siRNAs (vsiRNAs) and AGO2-vsiRNAs more precisely, I analyzed target specificities of AGO1-miRNA and AGO2-miRNA in plants. In case of AGO1-mediated silencing, I tested effects of G:U wobbles between miRNA and mRNAs. Results of a series of transient assay showed that G:U wobble has an intermediate effect between the base paring and the mismatch in a position-dependent manner. In case of AGO2-mediated silencing, I established a transient system to test the requirement of complementarities between miRNA and mRNAs by using a newly generated ago triple mutant of Nicotiana banthamiana. This system allows us to analyze mechanisms of the AGO2 specificity in plants. These basic analyses will help establish algorisms to predict host mRNAs targeted by AGO1-vsiRNAs and AGO2-vsiRNAs in future.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2018/03 
    Author : Bando Hisanori, TAKA Hitomi, ISHIBASHI Taiki, HARADA Naoto, SAITO Ryo
     
    In Bombyx mori nucleopolyhedrovirus (BmNPV) genome comprised of 143 genes, more than 60 % of them are nonessential genes for efficient multiplication in Bombyx mori cell line BmN. However, a combination of nonessential genes was found to play a critical role in efficient viral multiplication, suggested essentiality of nonessential genes as a collected gene. A study using reverse genetics identified genetic interactions among nonessential gens in such a combination and emphasized importance of a methodology to advance the reverse combinatorial genetics of BmNPVs; thus we established a platform for BmNPV genome assembly from PCR-amplified DNA fragments using Gibson Assembly for further analysis of the essentiality of nonessential genes and for reconstruction of BmNPV vector system based on logical design.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2018/03 
    Author : KUSAKABE TAKAHIRO
     
    Lepidopteran insects are known to have specific chromosomes called heliocentric chromosome having multiple centromeres along the entire length. In this study, we clarified the molecular basis of kinetochore formation of the heliocentric chromosome and newly found six centromere-related genes specific to silkworm using the gene network analysis. Based on these results and analysis on replication related genes, an artificial chromosome functioning by tethering DNA replication factor and kinetochore protein was synthesized. On the other hand, as for the genome-wide gene expression regulation and molecular basis of chromatin structure, we focused on histone acetylation and deacetylation enzymes, and performed gene knockdown on these genes. As a result, we found that HDAC 8 plays an important role in the silkworm.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2017/03 
    Author : Hisanori Bando, ASANO SHINICHIRO
     
    Bombyx mori nucleopolyhedrovirus (BmNPV) H4 that had genome sharing high sequence similarity (approx. 97%) with that of the type strain of BmNPV T3 showed marked growth advantage in silkworm larvae. Studies using chimeric recombinant BmNPV between H4 and T3 demonstrated that a viral membrane protein gene gp64 as a determinant in the in vivo fitness of BmNPV H4. Further analyses identified amino acid positions involved in the BmNPV H4 phenotype of efficient growth in silkworm larvae. These results suggested the possibility to control growth ability of BmNPV in silkworm larvae by gp64-targetted genome manipulation.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2017/03 
    Author : Takeda Atsushi, SATO MASANAO
     
    In plants, viral infection induces RNA silencing, which is a basal immune response against viruses. In the anti-viral pathways of plant RNA silencing, abundant viral-derived small-interfering RNAs (vsiRNAs) are generated through functions of Dicer-like enzymes (DCLs). A class of 21 nt vsiRNAs cleaved by DCL4 is incorporated into Argonaute 1 (AGO1). The AGO1-vsiRNA complex has a potential to cleave not only viral RNAs but also endogenous mRNAs dependent on the complementarity between target RNAs and vsiRNAs in AGO1. However, determinants of target specificity of AGO1-vsiRNA complex are unknown and thus we cannot predict the target mRNAs downregulated upon viral infection. In this study, we examined the AGO1 specificity in plants experimentally by using a massive transient luciferase assay. We identified several determinants of the plant AGO1 specificity, which can help predict the target mRNAs of vsiRNAs in viral-infected plants in future.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2017/03 
    Author : Sato Masanao
     
    Microbes and hosts have been co-evolved as they have repeatedly developed a better strategy to infect/defend in infection processes and to counter it. Such coevolution processes result in development of highly complex gene network in both host and microbes. To elucidate the gene network in host or microbe for their interaction, high throughput molecular profiling and genetic interaction analyses have identified thousands of genes in host or microbe. A major next challenge in research on host-microbe interactions is to elucidate interactions between host and microbial gene networks. In this study, I aimed at development of a method to efficiently collect genetic information on how host and microbial gene networks interact in an seamlessly integrated manner. The developed protocol and data analysis pipeline accurately collect readouts in an inter-species genetic interactions en masse.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2017/03 
    Author : Ueki Shoko, Higashi Aiko, Kobashi Rieko
     
    The initial goal of the project was to analyze the infection process of Heterosigma akashiwo virus (HaV) to its host population, bloom-forming algae, Heterosigma akashiwo, that consisted from strains showing the different reactions to HaV infection. During the project, we completed the whole genome sequencing and gene predictions of HaV, and obtained the insights into the evolutionary and phylogenetical position to other giant double-stranded DNA viruses. In addition, contradicting to the initial understanding, we found out that the host reactions to HaV infection were not only determined by the host genotypes, but also by the presence/absence or the species of the accomplice bacteria associating to the host. The project developed into direction unpredicted when it was initially planed: however, the insights obtained by the project will provide infrastructure for future studies about H. akashiwo and its virus from cellular and molecular biology view points.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2013/04 -2015/03 
    Author : BANDO Hisanori, SATO Masanao
     
    The technologies that enable flexible manipulation of virus genome are very important technical base for improving viral vectors. The aim of this study is to establish a method for assembling baculovirus genome DNA from both synthetic and natural DNA fragments to improve baculovectors. First, we constructed a baculovirus of the silkworm (BmNPV/bacmid) carrying an yeast replication origin (Yori). Second, we cloned 21 overlapping DNA fragments covering whole sequence of the BmNPV/bacmid genome DNA with Yori in bacterial cells using a plasmid vector. Lastly, we assembled the 21 fragments in yeast to form the complete BmNPV genome DNA.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2010/04 -2014/03 
    Author : BANDO Hisanori, KUSAKABE Takahiro, SATOU Masanao
     
    By taking a systems biology approach, a baculovirus gene network models was built and host factors involved in recombinant protein expression from a baculovector system were identified.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2011 -2013 
    Author : SATO Masanao
     
    The signaling network in a germline cell was modeled using BmN4, the cell line derived from a Bombyx mori ovary. The network model is composed of genes that are evolutionarily conserved between B. mori and Drosophila melanogaster and that have been known as regulators for signal transduction in D. melanogaster germline or somatic cell development. The model suggested a gene known as a regulator of germline development in D. melanogaster as a hub in the network. In addition, the model inferred roles of genes of which mutations caused sterility by unknown reasons. Furthermore, the model inferred roles of genes, which have been known to function in somatic cells, in germline cells.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
    Date (from‐to) : 2008 -2012 
    Author : KOBAYASHI Satoru, ASAOKA Miho, HAYASHI Yoshiki, SATO Masanao, KITADATE Yu, ABE Kuniya
     
    In this study, we have been trying to clarify the mechanisms regulating "GSC Niche System" in Drosophila. We found that 1) heparan sulphate proteoglycans (HSPG) are deeply involved in GSC maintenance by restricting the function of growth factors in a narrow region (Niche field) around "Niche cells", 2) Notch, Sevenless and Egfr signaling are required for proper formation of "Niche cells" in the anterior region of male embryonic gonads, and that 3) maternal Ovo and Sxl are required for germline-specific gene expression and sex determination of primordial germ cells, respectively.


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