Establishment of ES cells derived from androgenic diploid embryos produced by interspecific sperm injection and induction of gametogenesis

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K06021
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 42030:Animal life science-related
• Research Institution: Kindai University
• Principal Investigator: Mitani Tasuku 近畿大学, 生物理工学部, 教授 (10322265)
• Co-Investigator(Kenkyū-buntansha): 田辺 秀之 総合研究大学院大学, 先導科学研究科, 准教授 (50261178) ; 岡村 大治 近畿大学, 農学部, 講師 (80393263)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 雄性2倍体胚 / ハイブリッド胚 / ES細胞

Outline of Final Research Achievements

For the purpose of establishing ES cells derived from androgenic diploid embryos produced by interspecific sperm injection, either rat or wood mouse (Apodemus sylvaticus) sperm were microinjected into mouse enucleated oocytes, but embryonic development was arrested. Therefore, in order to verify the acceptance of heterologous sperm in mouse oocytes, hybrid embryos were analyzed. As a result, the formation of the male pronucleus was delayed in the wood mouse sperm, and the delay in the formation of the heterologous male pronucleus was improved by the removal of the acrosomal enzyme or the destabilization of the sperm cell membrane. Due to COVID-19, original research plan was changed to establish ES cells from the embryos of Ryukyu spiny rat using interspecific somatic cell nuclear transfer. However, its developmental ability to the blastocysts was extremely low, and ntES cells could not be established.

Free Research Field

生殖生物学

Academic Significance and Societal Importance of the Research Achievements

不妊治療で使われている顕微授精技術を用いて、マウス精子2個を核を除いたマウス卵子に注入してオスのゲノムのみからなる胚（雄性2倍体胚）を作製すると発生し、ES細胞を樹立することができる。絶滅危惧動物の保全を目的に、この方法を異種の精子に適応してES細胞の樹立を試みたが十分な成果には至らなかった。しかし、その原因究明のため異種精子の受容能を評価する目的で行ったハイブリッド胚を用いた解析は、異種精子由来雄性２倍体胚の発生能の予測の指標として有効な手法となる可能性がある。また、哺乳動物の種間の生殖隔離という生物学的な問いに関する新たな仕組みを探る手法となりうる興味深い研究成果である。