Origin and Relationships Among Native Japanese Horse Breeds

Currently, eight native horse breeds—the Hokkaido, Kiso, Misaki, Noma, Taishu, Tokara, Miyako, and Yonaguni—are bred in Japan. Native Japanese breeds are believed to have originated from Mongolian horses imported from the Korean Peninsula during fourth–fifth century. The phylogenetic relationships among these breeds are not well elucidated. This chapter first introduces the current theory behind the origin of native Japanese horses and then discusses the genetic diversity of native Japanese horses using genome-wide genetic markers, including autosomal chromosomes, the mitochondria genome (maternally inherited), and the Y chromosome (paternally inherited), and their origin. Finally, a synopsis of the results is used to propose an updated theory on the origin of native Japanese horses.