Trophectoderm regeneration to support full-term development in the inner cell mass isolated from bovine blastocyst

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H02321
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 42010:Animal production science-related
• Research Institution: Hokkaido University
• Principal Investigator: Kawahara Manabu 北海道大学, 農学研究院, 准教授 (70468700)
• Co-Investigator(Kenkyū-buntansha): 唄 花子 北海道大学, 農学研究院, 助教 (60775443) ; 永野 昌志 北里大学, 獣医学部, 教授 (70312402)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: ウシ / 胚盤胞期胚 / 個体発生 / 栄養膜細胞 / ゲノミック評価

Outline of Final Research Achievements

The blastocyst consists of two types of cells, the inner cell mass (ICM) and the trophectoderm (TE), which develop into an embryo proper and a large part of the placenta, respectively. We have shown that, since bovine ICM cells can regenerate TE, they are capable of forming both the embryo and placenta. To test developmental ability of TE-regenerated embryos, we then transferred the regenerated blastocysts to recipient females. After the embryo-transfer, to their surprise, one of the four cows became pregnant and a female calf was naturally born with an apparently normal placenta. Our study suggests that we can remove and use a large part of TE for genetic testing to breed cattle with improved qualities. Also, further studies could reveal the mechanism of cell fate decision in mammals and its differences between species.

Free Research Field

家畜繁殖学

Academic Significance and Societal Importance of the Research Achievements

今回の研究から、ウシ胚盤胞期胚のICMは完全なTE再生機能を保持していることが証明されたので、TEの大部分を利用して遺伝子検査に供した上で個体生産できる可能性が示された。さらに、ウシ胚のTEのYAP1局在はマウス胚TEとは異なって動的に局在様式が変化していることが判明し、これによりマウス胚などと比べて緩やかに細胞分化が進行するウシ胚の発生が調節されていると推察された。本研究を足掛かりに生理現象の中でのYAP1細胞内局在の多様な制御機構の理解が深まることが期待され、さらに研究を進めることで、哺乳類の細胞運命決定のメカニズムや種による違いが明らかになるかもしれない。