Mathematical modeling of sex change in coral fishes: integration of the sex controlling gene expression and the evolutionary responses to social status

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K18624
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Ecology/Environment
• Research Institution: Nara Women's University (2018-2019); Kanagawa University (2016-2017)
• Principal Investigator: YAMAGUCHI Sachi 奈良女子大学, 大和・紀伊半島学研究所, 協力研究員 (20709191)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: ホルモンダイナミックス / アロマターゼ / 双方向性転換 / 社会的地位 / 遺伝子発現 / 温度性決定 / 雌雄同体 / 自家受精

Outline of Final Research Achievements

In order to establish a new approach that bridges between physiology/molecular biology and ecology/behavioral biology, I focused on “sexual” phenomena, such as sex change in fish and temperature sex determination in fish and reptiles. I start with mathematical models of gene expression and physiological mechanism and examined the evolutionary processes acting on the system. I made progresses on the following four points: [1] time asymmetry in bidirectional sex change brought by hormone-enzyme kinetics; [2] the advantage of bisexual gonad in bidirectional sex changers; [3] why is bidirectional change rare? and [4] modeling the physiological mechanism of temperature-dependent sex determination. Focusing on "adaptability", I analyzed [1] coexistence conditions of selfing hermaphrodites and males, and [2] task allocation in eusocial ants.

Free Research Field

数理生物学

Academic Significance and Societal Importance of the Research Achievements

生物適応戦略モデルは、生物個体が残す子どもの数が最も多い生き方が広まり集団が置き換わる、という進化プロセスに注目し、適応度最大化問題に帰着させて大きな成功を収めてきた。他方、近年の分子生物学の目覚ましい発展により、環境や社会相互作用への応答、つまり表現型可塑性の分子生物学的基盤が明らかになりつつある。本研究では、表現型をもたらす生理学的機構をモデルに取り入れ、遺伝子発現や遺伝子制御ネットワークを考慮した新しい進化生物学モデルの展開を行った。このアプローチは、分子生物学や生理学の実験研究と動物行動学や生態学の研究を、数理生物学によってつなぐ、全く新しい共同研究の在り方を推進するものである。