Molecular mechanisms of the reproductive system for avoiding inbreeding evolved in the invasive ant

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K19338
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 45:Biology at organismal to population levels and anthropology, and related fields
• Research Institution: Utsunomiya University
• Principal Investigator: Miyakawa Hitoshi 宇都宮大学, バイオサイエンス教育研究センター, 准教授 (30631436)
• Co-Investigator(Kenkyū-buntansha): 宮川 美里 (岡本) 宇都宮大学, バイオサイエンス教育研究センター, 学振特別研究員 (00648082)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: 雄性発生 / ウメマツアリ / 近親交配回避 / 染色体挙動 / 繁殖戦略

Outline of Final Research Achievements

In Vollenhovia emeryi, female queens are produced by inheriting only the maternal genome (parthenogenesis) and males by inheriting only the paternal genome (androgenesis), so there is no substantial genetic exchange to produce reproductives between the sexes and inbreeding does not produce diploid sterile males. In this study, we established a method for extracting RNA from individuals necessary for molecular biology experiments such as RNA-seq, observing the pronucleus immediately after spawning by DAPI staining, observing the mitotic apparatus by immunostaining with an anti-tubulin antibody, and live nuclear observation using microinjection of a nucleic acid staining reagent. This research enables analysis of the developmental processes of both reproductives (queens and males) in comparison with worker eggs, establishing an experimental basis for understanding the evolutionary genetic background of this unique reproductive strategy.

Free Research Field

環境生理学

Academic Significance and Societal Importance of the Research Achievements

アリ類は世界中に分布しており、IUCNが公表した世界の侵略的外来種ワースト100のうち5種を占めるほど生態系や人への影響が大きい生物種である。日本でもヒアリの侵入・拡大が問題になり、昨年はウメマツアリ同様に雄性発生を行う侵略的外来種コカミアリの国内初侵入も報告された。侵略種は繁殖力や他種との競争力の強さ、環境適応能力に注目が集まるが、本研究で取り扱った雄性発生のような近親交配の回避に繋がる形質もまた、アリ類の管理施策を行う上で重要な要素である。本研究を継続し雄性発生に関わる遺伝的変異が明らかになれば、他種での保存性の確認や、近親交配の回避に繋がる形質の進化にも迫ることができるだろう。