Development of culture systems controlling cumulus cell function for the growth of oocytes from domestic animals

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K08137
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Integrative animal science
• Research Institution: Kobe University
• Principal Investigator: MIYANO Takashi 神戸大学, 農学研究科, 教授 (80200195)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 卵母細胞 / 卵丘細胞 / 顆粒膜細胞 / 体外培養 / transzonal projection

Outline of Final Research Achievements

Mammalian oocyte growth is supported by surrounding granulosa/cumulus cells which provide various small molecules to the oocytes. In the present study, bovine and porcine growing oocytes collected from early antral follicles (about 0.5 mm and 1.0-1.5 mm in diameters) were cultured with surrounding cumulus cells (oocyte-cumulus complexes: OCCs) for 5-14 days. OCCs developed and formed antral-like structures in which oocytes grew to the final size and acquired maturational competence. When bovine oocytes collected from early antral follicles were denuded from cumulus cells and then cultured with parietal granulosa cells, the cells formed transzonal projections to the oocytes, and the oocytes grew to the final size. Proliferation and morphology of cumulus cells were regulated by oocyte-derived growth factors (GDF9 and BMP15) in addition to FSH during the OCC culture.

Free Research Field

農学

Academic Significance and Societal Importance of the Research Achievements

家畜の卵巣内に多数存在する初期胞状卵胞内には，成熟する能力のない発育途上の卵母細胞が含まれている。これらの卵母細胞を，卵母細胞－卵丘複合体の状態で5～14日間，体外培養すれば，卵母細胞を最終の大きさへと発育させ，成熟させることが可能となった。この卵母細胞－卵丘複合体を用いた体外発育培養系は汎用性が高く，この培養系を用いることによって，家畜卵母細胞の体内における発育機構や，卵母細胞と卵丘細胞間の相互作用・結合にかかわる機構を解析することができる。