Evolution of taste receptors in leaf-eating primates: focusing on lemurs

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20674
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0703:Biology at organismal to population levels and anthropology, and related fields
• Research Institution: Meiji University (2022); Kyoto University (2021)
• Principal Investigator: ITOIGAWA Akihiro 明治大学, 研究・知財戦略機構(生田), 研究推進員(ポスト・ドクター) (30910492)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 霊長類 / 味覚受容体 / 甘味 / キツネザル / 分子進化 / 採食

Outline of Final Research Achievements

Sweetness is an indicator of carbohydrates and is perceived via sweet taste receptor, T1R2/T1R3 heterodimer. Most primates prefer sweet taste, but a folivorous primate colobine do not prefer sugars and have sweet taste receptor which doesn't respond to natural sugars. In this study, we investigated whether this character is common among folivorous primate lineages using lemuriformes including three folivorous families. We identifed that sweet taste receptors of two highly folivorous species in Indriidae showed lower sugar sensitivity than frugivorous or frugo-folivorous species. Furthermore, a key residue for functional decline of their sweet taste receptors was identified by site-directed mutagenesis.

Free Research Field

分子遺伝学

Academic Significance and Societal Importance of the Research Achievements

近年の研究でT1Rの機能は食性と強く関連しながら進化し、時に新規の採食ニッチの獲得にも寄与する重要なファクターであることが分かってきている。本研究でも、葉食性と関連した甘味受容体の機能変化が見いだされており、互いに遠縁だが類似の食性を持つ種同士で並行的に味物質感受性の低下が見つかった点は、特定の食性に共通した味覚的特徴（もしくは進化傾向）が存在する可能性を示唆し、動物の食性進化メカニズムの分子基盤理解への一助となったと考えている。