The complete mtDNA D-loop regions of Japanese and Korean cattle were analyzed for their mtDNA variations and genetic relationships. Sequencing the 30 Higo substrain and 30 Tosa substrain of Japanese Brown, respectively 12 and 17 distinct Bos haplotypes were identified from 77 polymorphic nucleotide sites. In order to focus on the relationships among Japanese and Korean cattle, two types of phylogenetic tree were constructed using individual sequences; first, a neighbor-joining tree with all sequences and second, reduced median networks within each Japanese and Korean cattle group. The trees revealed that two major mtDNA haplotype groups, T3 and T4, were represented in Japanese and Korean cattle. The T4 haplogroup predominated in Japanese Black and Japanese Brown cattle (frequency of 43.3-66.7%), while the T3 haplogroup was predominant (83.3%) and T4 was represented only twice in the Korean cattle. The results suggested that the mitochondrial origins of Japanese Brown were Japanese ancient cattle as well as Japanese Black in despite of the considerable introgression of Korean and European cattle into Japanese Brown.

The domestic goat is one of the most important livestock species, but its origins and genetic diversity still remain uncertain. Multiple highly divergent maternal lineages of goat have been reported in previous studies. Although one of the mitochondrial DNA lineages, lineage B, was detected only in eastern and southern Asia, the geographic distribution of these lineages was previously unclear. Here, we examine the genetic diversity and phylogeographic structure of Asian goats by mitochondrial DNA sequences and morphological characteristics. The analyses of a total of 1661 Asian goats from 12 countries revealed a high frequency of lineage B in Southeast Asia. The frequency of this lineage tended to be higher in mountain areas than in plain areas in Southeast Asian countries, and there was a significant correlation between its frequency and morphological traits. The results suggest an original predominance of lineage B in Southeast Asia and the recent infiltration of lineage A into Southeast Asian goats.

Korean native goats have lived on the Korean peninsula for more than 2,000 years and are regarded as a valuable genetic resource for the world. As an initial step to investigate the genetic structures of this breed, phylogenetic analysis and calculation of genetic diversities have been performed using mitochondrial DNA (mtDNA) sequence variations. A total of 19 Korean native goats were grouped into six haplotypes and the large majority of haplotypes were present in 13 animals. All mtDNA of these Korean goats belonged to the mitochondrial (mt) lineage A and revealed remarkably small genetic distances within the population when compared with other Asian goat populations, indicating less genetic variation in the Korean native goats. These results indicate high-inbred status of the Korean native goats and will influence breeding and conservation strategies adopted for this breed.

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