Genetic Diversity and Population Structure ofOrnamental Breeds of Japanese Native ChickenBased on Microsatellite DNA Polymorphisms

摘要

Japanese native chickens are valuable genetic resource in Japan ; however, their low pro-ductivity limits their industrial use and forces dependence on a personal breeder for their mainte-nance. To conserve these breeds, it is important to clarify their genetic diversity, relationships, and structure. In this study, microsatellite DNA polymorphisms were used to analyze the genetic rela-tionships and structure among ornamental breeds of Japanese native chickens. A total of 125 indi-viduals of seven breeds, Kurokashiwa, Minohiki, Minohiki-Chabo, Uzura-Chabo, Ukokkei, Chahn, and Issun-Chahn were used in analyses of 28 microsatellite loci recommended by ISAG/FAO. The results showed that ornamental breeds maintained by private breeders showed the same level of genetic diversity compared with populations maintained by institutes or breeding stations. Despite high genetic diversity, significant positive F_(IS) values indicating high inbreeding were estimated for all seven breeds analyzed in this study. Furthermore, genetic differentiation among sampling locations was observed in Minohiki, Minohiki-Chabo, and Ukokkei. While sub-clustered structure was observed in the DAS tree for these three breeds, in Uzura-Chabo, genetic differentiation was not observed and all specimens (including those from different sampling locations) were included in the same cluster.