Analysis of the microenvironment in the spermatheca for long-term sperm storage in ant queens

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06080
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39050:Insect science-related
• Research Institution: Konan University
• Principal Investigator: Gotoh Ayako 甲南大学, 理工学部, 准教授 (70734680)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 精子貯蔵 / 受精嚢 / 女王アリ / アリ

Outline of Final Research Achievements

Females of social Hymenoptera mate only at the beginning of their adult lives and produce offspring until their death without additional mating. In most ant species, queens live for over a decade, indicating that ant queens can store large numbers of spermatozoa throughout their long lives. To reveal the long-term sperm storage mechanism, I focused on the microenvironment in the spermathecal reservoir. Here, I showed that the spermathecal environment is nearly anoxic, which induces sperm immobilization. Furthermore, artificial anoxic conditions rather than aerobic conditions sustain viable sperm cells. Therefore, near-anoxia is a key factor influencing long-term sperm storage in ant queens.

Free Research Field

昆虫学、分子生態学

Academic Significance and Societal Importance of the Research Achievements

女王アリが受精嚢内で、非自己であるオスの精子を常温のままで10年以上生存させる現象は、細胞生物学の常識を覆すものである。また、アリ科女王の精子貯蔵能力は極めて特殊であり、高度な社会性をもつアリの繁殖戦略を考える上でも興味深い。
現在、畜産や不妊治療の現場では、家畜やヒトの精子は液体窒素により凍結されて保存されている。女王アリは、液体窒素を使わなくとも常温で長期間精子を貯蔵できるため、女王アリの特殊な精子貯蔵メカニズムが完全に解明されれば、将来、家畜やヒトの精子も低エネルギーかつ高品質で保存できるようになるかもしれない。