2023 Fiscal Year Final Research Report
Mechanism of diploid gamete formation and its application for genetic breeding
| Project/Area Number |
21H02278
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Review Section |
Basic Section 40040:Aquatic life science-related
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| Research Institution | Hokkaido University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
西村 俊哉 北海道大学, 水産科学研究院, 助教 (10758056)
田中 啓介 東京情報大学, 総合情報学部, 准教授 (60747294)
黒田 真道 東京農業大学, 生物産業学部, 助教 (70880764)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Keywords | 非還元配偶子形成 / クローン / 雑種 / ゲノム倍加 / 倍数体 |
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| Outline of Final Research Achievements |
Genetic analysis was carried out on two strains of dojo loach that are thought to be the origin of clonal dojo loach forming diploid clonal gametes. Whole genome and cytogenetic analyses revealed not only sequence diversity between genomes of the two strains, but also differences in chromosome structure, such as inversion. These genetic differences were considered to be related with diploid gamete formation. The measurement of nuclear sizes of germ cells during gonadal development revealed significant differences of nuclear size at oogonia between wild-type and clonal dojo loach. It suggests that genome doubling occurs at oogonia in clonal dojo loach.
In dojo loach, inter-group tetraploid hybrids were induced by inhibition of the first mitotic division after inter-group fertilization. The tetraploid hybrid males formed fertile diploid sperm, while inter-group diploid hybrid males showed sterility. The diploid sperm readily contributed to produce sterile triploids.
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| Free Research Field |
魚類育種遺伝学
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| Academic Significance and Societal Importance of the Research Achievements |
クローンドジョウの起源とされる遺伝的に異なる２系統のゲノム解析から、系統間では塩基配列多型とともに逆位などの染色体構造変異が推察された。この構造変異は減数分裂における相同染色体の対合異常の大きな要因になると考えられる。また、初期生殖細胞の発達における核の形態変化に基づいた分類と、本研究で樹立した生殖細胞を可視化した遺伝子組換えドジョウを利用することで、ゲノム倍加が生じる生殖細胞の識別が可能となる。さらに、魚類における不妊二倍体の四倍体化による二倍性配偶子形成は、不妊雑種の複二倍体化による新規配偶子生産の可能性を示し、新たな育種素材の開発に寄与する。
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