Elucidation of the evolutionary mechanism for thermosensory system by reconstruction of ancestral thermal sensors and genome editing

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07470
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Evolutionary biology
• Research Institution: National Institute for Physiological Sciences (2018); Okazaki Research Facilities, National Institutes of Natural Sciences (2016-2017)
• Principal Investigator: Shigeru Saito 生理学研究所, 生体機能調節研究領域, 助教 (50422069)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 温度センサー / 温度適応 / ツメガエル / 温度感受性TRPチャネル / 祖先タンパク質 / ゲノム編集

Outline of Final Research Achievements

During the adaptation to different thermal niches, thermosensory system must have shifted in order to fit with thermal condition of habitats. In the present study, comparative analysis was performed among closely related clawed frog species that were adapted to different thermal niches. Thermal responses of heat sensors were compared between warm-adapted and cool-adapted species (two species in each group). The results revealed that the activity of a heat sensor from warm-adapted species was lower than that of cool-adapted species, suggesting that alteration of thermal property in heat sensors likely contributed to the adaptation process to different thermal niches. In addition, in order to investigate the role of thermal sensors in behavioral responses, clawed frog strains in which genes for thermal receptors were disrupted were constructed.

Free Research Field

進化生理学

Academic Significance and Societal Importance of the Research Achievements

環境の温度条件は時に生存をも左右する要因であり、生物は進化の過程で形態的および生理的な変化を遂げて多様な温度環境に適応してきた。異なる環境に適応した種の間で温度耐性を調べる研究はこれまで盛んに行われてきたが、温度感覚と環境適応との関連性に着目した分子レベルの研究はほとんど進んでいなかった。本研究では、温度感覚のセンサー分子としてはたらくタンパク質を対象にして、異なる温度環境に適応したツメガエル種の間で比較解析を行った。その結果、各種が生息する温度環境に関連して温度センサーの特性が変化してきたことが示され、温度感覚の進化的な変化が環境適応において重要な役割を担ってきたことが明らかとなった。