Mechanism for sperm motility initiation involving in the adaptive evolution to establish internal fertilization

2014 Fiscal Year Final Research Report

• Project/Area Number: 24570246
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Evolutionary biology
• Research Institution: Yamagata University
• Principal Investigator: WATANABE AKIHIKO 山形大学, 理学部, 教授 (30250913)
• Co-Investigator(Kenkyū-buntansha): WATANABE Eriko 山形大学, 基盤教育院, 准教授 (20337405) ; NAKAUCHI Yuni 山形大学, 理学部, 助教 (60250908)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 体内受精 / 精子運動 / 機能進化 / 両生類 / 輸卵管

Outline of Final Research Achievements

SMIS, a key protein for internal fertilization of the newt, C. pyrrhogaster, localizes granules in the surface of egg jelly and induces sperm motility in female body. It acts in a different manner among amphibians and is hypothesized to contribute to the diversification of reproductive modes to evolve internal fertilization. To address this hypothesis, we examined ultrastructure of egg jelly and SMIS localization in C. ensicauda and P. waltl that undergo internal fertilization, R. arboreus that do arboreal fertilization, and B. japonicus that do external fertilization. Distributions of SMIS-localizing granules suggested changes in machinery of SMIS action adaptively to various factors including reproductive modes. We also found that C. pyrrhogaster SMIS gene was constructed by 3 exons and succeeded to establish a new method to identify SMIS homologous genes using RNAseq, which will be available to analyze the correlation of SMIS structure with its different action in future study.

Free Research Field

生殖生物学