Genetic characterization of Japanese native horse breeds by genotyping variants that are associated with phenotypic traits.

Concerns have been raised about the loss of genetic diversity in Japanese native horses because of their declining populations. In this study, we investigated the genetic variation of four genes, myostatin (MSTN), ligand-dependent nuclear receptor corepressor like (LCORL), doublesex and mab-3 related transcription factor 3 (DMRT3), and 5-hydroxytryptamine receptor 1A (HTR1A), which are associated with horse phenotypic traits, in six Japanese horse breeds (Hokkaido, Kiso, Noma, Misaki, Tokara, and Yonaguni). MSTN, LCORL, DMRT3, and HTR1A showed polymorphisms in the Kiso; Hokkaido and Noma; Hokkaido; and Kiso, Tokara, and Yonaguni breeds, respectively. The Misaki did not show polymorphisms in any of the genes. This study may serve as a basis for developing future breeding strategies focusing on traits in Japanese native horses.