Studies on the regulation of the gonadal regression of seasonal breeding using intraspecific variation in the teleost fish medaka, Oryzias latipes

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K06785
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45010:Genetics-related
• Research Institution: National Institute for Basic Biology (2022-2023); Center for Novel Science Initatives, National Institutes of Natural Sciences (2019-2021)
• Principal Investigator: Shinomiya Ai (四宮愛) 基礎生物学研究所, バイオリソース研究室, 助教 (60452067)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 光周性 / 季節繁殖 / QTL解析 / 種内変異 / メダカ

Outline of Final Research Achievements

Although the teleost medaka, Oryzias latipes, is known to be long-day breeder, we had previously shown that wild populations originating from low latitudes had genetically lower sensitivity to photoperiod. In this study, we used three wild populations including the short-day "responsive" Kiyosu and Kushima and "non-responsive" Miyazaki. Phenotypes of the F2 individuals in two types of crosses were examined, and three quantitative trait loci (QTLs) were identified on chromosomes 9, 6 and 20 by QTL analyses using whole genome sequences of the F2 generations. We compared the sequences of the QTL regions between "responsive" and "non-responsive" strains and performed transcriptome analyses (RNA-Seq) of Kiyosu and Miyazaki under long-day and short-day conditions, and discussed the genes involved in response to short-day and gonadal regression.

Free Research Field

遺伝学、生殖生物学

Academic Significance and Societal Importance of the Research Achievements

動植物の成長や繁殖に深く関わる季節適応の仕組みの解明は、基礎生物学的観点、また農水産業への応用の面からも重要である。多くの季節繁殖動物で、日長変化が繁殖期の引き金となることが知られているが、日長の感知とその下流で働く分子機構はまだ不明な点が多い。本研究で、メダカの日長変化への応答性の種内変異を利用して同定した、短日に応じた繁殖停止に関わる量的形質遺伝子座(QTLs)、短日応答時の遺伝子発現動態の変化は、季節繁殖停止の分子メカニズムの理解につながることが期待される。