The nucleotide sequences for the dopamine receptor D4 gene in the Japanese crested ibis

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.