Study of non-invasive artificial insemination method by artificial cell membrane fusion in sperm and oocyte.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K06005
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 42040:Laboratory animal science-related
• Research Institution: Central Institute for Experimental Animals
• Principal Investigator: ETO Tomoo 公益財団法人実験動物中央研究所, 生殖工学研究室, 室長 (30370175)
• Co-Investigator(Kenkyū-buntansha): 高橋 利一 公益財団法人実験動物中央研究所, 動物資源技術センター, センター長 (90206863) ; 外丸 祐介 広島大学, 自然科学研究支援開発センター, 教授 (90309352)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 膜融合 / 顕微授精 / 電圧の印可 / 精子 / アクロソーム / 卵子 / 凍結保存 / 電動・自動

Outline of Final Research Achievements

Intracytoplasmic sperm injection (ICSI) in mice and rats is used to produce fertilized oocytes for offspring, but the rate of fetal development tends to be lower than that of in vitro fertilization. Because physical obstacles and chemical toxicity are thought to be factors, we studied a microinsemination method that uses artificial cell membrane fusion.
First, we examined a method for removing the acrosome of sperm. Next, we used an automanipulator to motorize and automate the operation of microinsemination. We also developed a new method for freezing and preserving mouse oocytes for microinsemination. Fertilization was not observed when the method of applying voltage to the oocyte and sperm by pressing them together, or when reproducing the natural phenomenon of vibrating the sperm, was used. However, when acrosome-removed sperm was held pressed against the oocyte for one minute, fertilization and development were confirmed in some of the oocytes.

Free Research Field

生殖工学、発生工学、実験動物学

Academic Significance and Societal Importance of the Research Achievements

マニピュレーターの電動化・自動化は、顕微授精を含む顕微操作全体の、再現性の向上につながる。マウス卵子の新規凍結保存法は、体外受精・顕微授精に良好な状態の卵子提供がいつでも出来、遺伝子資源の保存や個体の計画生産および生殖補助医療につながる。
今回の研究では、低率ながら膜融合を介した授精から発生が確認された。この結果は、物理的障害や化学的な毒性を廃した顕微授精法の第一歩を示す。さらに研究が進み、膜融合授精法が確立すれば実験動物の、個体の計画生産や遺伝子資源の保存に貢献できる。さらにヒトの不妊治療や、家畜の計画生産、愛玩動物および絶滅危惧種の繁殖などへ応用が期待できる。