Parallel evolution of complex adaptations through introgression: the study case of pelvic fin brooding in Sulawesi medaka.

2021 Fiscal Year Annual Research Report

• Project/Area Number: 19K16203
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Montenegro Javier 国立研究開発法人海洋研究開発機構, 超先鋭研究開発部門(超先鋭技術開発プログラム), 特任研究員 (70835347)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: Pelvic-fin brooding / QTLs / Admixture / New Species / Sex Chromosome

Outline of Annual Research Achievements

Our analyzes revealed that females of pelvic-fin brooders have longer pelvic fins and a deeper abdominal concavity, and that they can carry eggs for longer than non-brooding species. QTL analyses revealed that pelvic-fin brooding is controlled by multiple and unliked loci. Genome wide comparative analyses detected no signatures of admixture between the two lineages of pelvic-fin brooders.

A previously unknown species of pelvic-fin brooder Oryzias was discover from central Sulawesi. Phylogenetic analyses reveled that the new species belongs to the same clades as other pelvic fin brooders in genus Oryzias.

A pure strain of O. eversi was rear. All F1 individuals were ddRAD sequenced. A single SNP was found to be perfectly associated, heterozygote for all males and homozygotes for all females.