Mechanisms that specify the animal-vegetal axis in early animal embryos

2019 Fiscal Year Final Research Report

• Project/Area Number: 15H04377
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Developmental biology
• Research Institution: Osaka University
• Principal Investigator: Nishida Hiroki 大阪大学, 理学研究科, 教授 (60192689)
• Co-Investigator(Kenkyū-buntansha): 今井 薫 (佐藤薫) 大阪大学, 理学研究科, 准教授 (00447921) ; 小沼 健 大阪大学, 理学研究科, 助教 (30632103)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: ホヤ / オタマボヤ / 動植軸 / 胚発生 / 母性局在因子 / 局在mRNA / 胚葉 / 卵成熟

Outline of Final Research Achievements

The animal-vegetal (A-V) axis is already set in unfertilized eggs. It plays crucial roles to coordinate germ-layer formation. However, how the A-V axis is set has not been well studied. In this study, we investigated mechanisms of how A-V axis is set in ascidians and larvaceans. Especially we show that, in ascidians, when the germinal vesicle of full-grown oocytes were experimentally translocated to the opposite pole by centrifugal force, every aspect that designates A-V polarity was reversed in the eggs and embryos. This is the first report in which the A-V axis was experimentally and completely reversed in animal oocytes before fertilization.

Free Research Field

生物科学・発生生物学

Academic Significance and Societal Importance of the Research Achievements

動物－植物極は全ての動物卵に存在しており、その決定機構を理解することは大きなインパクトを持つ。マボヤとオタマボヤを用いて、様々な実験を行った結果、特に重要な成果として、マボヤでは卵母細胞の中での卵核胞の偏りが動植軸を決めており、卵成熟過程で起こる細胞質の流れによって、卵細胞質因子の局在が引き起こされ、動植軸が確定することを明らかにした。これは、動物の未受精卵において動物－植物軸を人為的に反転させることができた最初の例であり、学術的な意義は大きい。