It is empirically known that there is variation in vigilance-related behavior in captive population of the Japanese crested ibis in the Sado island. Such personality-related behavioral variation could have important conservational consequences, because of a selective advantage of less alert and more alert birds under serene and wild conditions, respectively. In this study, we determined the nucleotide sequences of the dopamine receptor D4 gene (DRD4), which is one of the most promising candidate genes related to personality-related behavioral variation, in the Japanese crested ibis. The DRD4 cDNA sequence composed of all of 1158 bp coding sequence and 75 bp 3’-noncoding sequence was determined by using reverse transcriptionpolymerase chain reaction and rapid amplification of cDNA ends. Further, we determined the DRD4 genomic sequence composed of four exons and spanning around 17 kb. In addition, we identified the Japanese crested ibis nucleotides corresponding to the domestic chicken or the great tit polymorphisms associated with personality-related behavioral variation. The sequence data obtained in this study will allow evaluation of the involvement of the DRD4 in personality-related behavioral variation in the Japanese crested ibis population in the Sado island through polymorphism detection and association study.
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 ED 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.