2020 Fiscal Year Final Research Report
Transition to multicellularity and evolution of female-male genders based on whole genome data
| Project/Area Number |
16H02518
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Evolutionary biology
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| Research Institution | The University of Tokyo |
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Principal Investigator |
Nozaki Hisayoshi 東京大学, 大学院理学系研究科(理学部), 准教授 (40250104)
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| Co-Investigator(Kenkyū-buntansha) |
宮城島 進也 国立遺伝学研究所, 遺伝形質研究系, 教授 (00443036)
関本 弘之 日本女子大学, 理学部, 教授 (20281652)
西山 智明 金沢大学, 学際科学実験センター, 助教 (50390688)
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| Project Period (FY) |
2016-04-01 – 2020-03-31
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| Keywords | 多細胞化 / 雌雄性進化 / 全ゲノム解析 / 群体性ボルボックス目 / 性特異的遺伝子 / 性染色体領域 / ボルボックス系列 |
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| Outline of Final Research Achievements |
We studied both evolutionary transitions to multicellularity and male and female dimorphism by conducting comparative biological analysis utilizing whole-genome information using "colonial Volvocales", which is the only extant lineage that can be experimentally studied in bot transitions. Research was started with the aim of clarifying the gene/genome level basis of these two evolutionary events.
From genome analysis, evolution of cell cycle and cytokinesis genes might have occured at the stage of 4 cells of this group and is involved in multicellular body formation. It was speculated that the single male-specific gene was important for the initial evolution of male and female (anisogamy) and expansion of the sex chromosomal region was involved in the acquisition of Volvox's male and female differentiation in sexual spheroid development. In addition, a correlation between multicellularization and evolution of sex-related traits was observed in colonial Volvocales.
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| Free Research Field |
進化生物学
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| Academic Significance and Societal Importance of the Research Achievements |
我々ヒトの一生は「メスとオス」の出会いに始まり、同様の出会いで子を残し、最終的には複雑な多細胞生物に必然的な「老衰死」を迎える。「雌雄性」と「多細胞化」という仏教の開祖のブッタをも悩ませた人類の最大の命題に着目し、両者を実験生物学的に研究できる「群体性ボルボックス目」を用いた全ゲノム解析を実施した。その結果、単細胞から4細胞に転換した多細胞化の極初期で細胞周期と細胞質分裂関連の遺伝子の進化が大きく多細胞化に寄与したことが推測された。また、雌雄性の極初期段階では1個のオス特異的遺伝子の進化が重要で、雌雄で異なる性染色体領域の拡大は配偶子以外の雌雄で異なる特徴の進化に寄与したことが推測された。
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