Morphological diversification of female internal genitalia mediated by male nuptial gift

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K15152
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 45030:Biodiversity and systematics-related
• Research Institution: Kyorin University
• Principal Investigator: Hashimoto Kosei 杏林大学, その他部局等, 助教 (50836517)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 性選択 / 種多様性 / 共進化

Outline of Final Research Achievements

In the family Oedemeridae, the morphology of female spiny bursa varies among species, and the length of spiny area were associated with the spermatophore traits. Species that provide larger spermatophores showed higher estimated quantities of defense chemical assumed to derive from male spermatophore contents in female eggs. From the molecular phylogenetic tree of Japanese Oedemeridae, it is suggested that the bursal spines and spermatophore formation were independently acquired in multiple lineages. Considering the higher allometry observed in male genitalia in some species of the genus Nacerdes, it is possible that there is a conflict between males and females over the transfer and digestion of spermatophores (nuptial gifts).

Free Research Field

生態学

Academic Significance and Societal Importance of the Research Achievements

一般に、交尾器形態はその他の部位よりも速く進化し、その背景として雌雄交尾器の接触による相互作用の影響が考えられてきた。本研究では、メスの交尾器形態の多様化は、オス交尾器との接触だけでなく、交尾時の婚姻贈呈物の形成による影響を受けてきた可能性を示した。その背景の１つとして考えられることは、婚姻贈呈物の生産（オス側）とその効率的消化（メス側）との間にある利害の不一致である。繁殖に関わる形質の速やかな進化のメカニズムとその背景を解明することは、どのように生物の多様性が形成・維持されているかを知るための鍵の１つとなりうる。