Analysis of neural basis of mate-guarding behavior focusing on medaka oxytocin

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K16247
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 46010:Neuroscience-general-related
• Research Institution: Hokkaido University
• Principal Investigator: Yokoi Saori 北海道大学, 薬学研究院, 助教 (10772048)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: オキシトシン / メダカ / 配偶者防衛

Outline of Final Research Achievements

In this study, we focused on oxytocin and analyzed the neural basis of mate-guarding behavior in medaka fish. Male medaka lacking oxytocin or its receptor gene showed low sexual motivation toward females they had never met before and exhibited little mate-guarding. On the other hand, when we used females kept in the same tank from birth to sexual maturity, male medaka lacking oxytocin or its receptor gene showed excessive mate-guarding. Transcriptome analysis revealed that the expression levels of all genes of the c1q component involved in synaptic pruning were decreased in oxytocin mutant medaka. It is possible that the abnormal mate-guarding behavior in oxytocin mutant males is caused by abnormal neural pruning.

Free Research Field

行動遺伝学

Academic Significance and Societal Importance of the Research Achievements

オキシトシンは、哺乳類において性別によらず絆形成に重要なホルモンであると考えられている。しかしながら、本研究で作出したオキシトシン変異メダカオスは、親密なメスに対してのみ過剰な配偶者防衛行動を示しており、これはメダカオスにおいてオキシトシンが絆形成を負に制御することを意味している。したがって、動物種や性別によってはオキシトシンの効果が異なるということを、今後念頭に置いて研究する必要性があると考えられる。