Abstract
Kuchinoshima cattle is a breed of the unique feral cattle originated from grazing Japanese native cattle in Kuchinoshima island of Tokara Islands in Kagoshima prefecture during Meiji and Taisho periods. The distribution and frequencies of alleles of the genes associated with economical traits and hereditary disorders have been reported in populations of Japanese Black cattle that is a major beef cattle breed in Japan and Mishima cattle that is another Japanese native cattle breed in Mishima island, but those of Kuchinoshima cattle have not been reported. Therefore, we investigated the allelic distribution and frequencies of the genes associated with economical traits, hereditary disorders, and coat color to reveal genetic characteristic of Kuchinoshima cattle by comparison of the distributions among Kuchinoshima, Japanese Black, and Mishima cattle. By using 32 DNA samples collected from Kuchinoshima cattle, we genotyped NCAPG, FASN, SCD, and SREBP-1 genes associated with economical traits including carcass weight and fatty acid composition, F11 gene responsible for factor XI deficiency, and MC1R gene involved in coat color determination by PCR or PCR-RFLP assay and compared these results with those of Japanese Black and Mishima cattle. As a result, we found that while both G and T alleles of NCAPG locus were observed in the population of Japanese black cattle, the locus was fixed to T allele in the populations of Kuchinoshima and Mishima cattle, and that while both TW and AR alleles of FASN locus were observed in Japanese black cattle, the locus was fixed to AR allele in Kuchinoshima cattle and TW allele in Mishima cattle. For the SCD and SREBP-1 loci, both A and V alleles of SCD locus were observed in Japanese Black, Kuchinoshima, and Mishima cattle, and both S and L alleles SREBP-1 locus were observed in Japanese Black and Mishima cattle but fixed to L allele in Kuchinoshima cattle. Furthermore, while both (+) and (-) alleles of F11 locus were observed in the population of Japanese black cattle, the locus was fixed to (+) allele in the populations of Kuchinoshima and Mishima cattle. Finally, we observed E + and e alleles of MC1R locus in Kuchinoshima cattle, while E D and E + allele but no e allele in Japanese Black cattle and only E + allele in Mishima cattle were observed. These findings indicate that Kuchinoshima cattle comprises a population of Japanese native cattle possessing unique genetic characteristics different from those of Japanese Black and Mishima cattle, which has been formed under geographically isolated circumstance with relatively small population without influence of foreign breeds.
