2023 Fiscal Year Final Research Report

Understanding the genetic mechanism of adaptive evolution and parallel evolution in East African cichlids

Research Project

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Project/Area Number	20KK0167
Research Category	Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
Allocation Type	Multi-year Fund
Review Section	Medium-sized Section 45:Biology at organismal to population levels and anthropology, and related fields
Research Institution	Tokyo Institute of Technology
Principal Investigator	Nikaido Masato 東京工業大学, 生命理工学院, 准教授 (70432010)
Co-Investigator(Kenkyū-buntansha)	長澤竜樹東京工業大学, 生命理工学院, 助教 (60782828) 高橋鉄美兵庫県立大学, 自然・環境科学研究所, 教授 (70432359)
Project Period (FY)	2020-10-27 – 2024-03-31
Keywords	シクリッド / 平行進化 / 適応放散 / 祖先多型
Outline of Final Research Achievements	In this research plan, we comprehensively explored candidate genes involved in adaptation and speciation based on a whole-genome comparative analysis of Lake Victoria cichlids (three species, 6 individuals/species). Phylogenetic analysis of the candidate genes for the three major East African lake cichlids, revealed that the origin of the alleles of these 99 candidate genes were older than the common ancestor of Lake Victoria, indicating that they were derived from ancestral polymorphisms. This suggests that ancestral polymorphisms retained in the ancestral population have contributed to the genomic basis of the adaptive radiation and parallel evolution of cichlids.
Free Research Field	進化生物学
Academic Significance and Societal Importance of the Research Achievements	種分化やそれが連続して起こる適応放散、そしてその一環として起きた平行進化のメカニズムについては、現代進化学でも完全なる理解に至っていない命題といえる。本研究では適応放散や平行進化の典型例として知られる東アフリカ産シクリッドに着目して、この問題に取り組んだ。その結果、東アフリカ産シクリッドのゲノム中には、多くの祖先多型が存在していることが分かり、これが適応放散や平行進化の遺伝的基盤となった可能性を示唆することに成功し、この学術的意義は大きいと考えられる。