The attempt to improve the developmental competence of oocytes using in vitro growth model of bovine follicles and the application for the production of wildlife oocytes

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K08043
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Veterinary medical science
• Research Institution: Hokkaido University
• Principal Investigator: Nagano Masashi 北海道大学, 獣医学研究院, 准教授 (70312402)
• Research Collaborator: YANAGAWA Yojiro ; SAKAGUCHI Kenichiro ; KANNO Chihiro
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 卵子 / 体外受精 / 体外発育培養

Outline of Final Research Achievements

To clarify the relationship between the steroidogenesis and the acquisition of developmental competence of bovine oocytes during follicular development or degradation, I cultured the developing bovine oocytes surrounded by granulosa cell layers. When FSH and BMP-4 were added to culture media of oocytes, luteinization of granulosa cells were inhibited but the developmental competence of oocytes decreased. Then I try to develop the new co-culture system with oocyte-granulosa cell complex (OGC) and theca cells which secrets several growth factors having the function for the development and the acquisition of developmental competence of oocytes. When OGC cultured with theca cells, theca and granulosa cells secreted androstenedione and estradiol-17β, respectively. And oocytes acquired the developmental competence to transferrable embryos. However, the developmental rate was low. We should develop the culture system which can support the function of theca and granulosa cells.

Free Research Field

繁殖学

Academic Significance and Societal Importance of the Research Achievements

体外受精は家畜生産およびヒトの不妊治療分野で広く用いられているが作製された胚の発生能は低い。本研究の成果は卵子が発生能を獲得する過程を体外で明らかにする培養系の開発につながり、発生能の高い胚の体外生産にも資する。すなわち、家畜生産効率や不妊治療成功率の向上につながり、絶滅の危機にある野生動物の増殖にも寄与できる。