The Bh (Black at hatch) gene that causes abnormal feather pigmentation maps to chromosome 1 of the Japanese quail

Japanese quail embryos normally have longitudinal black and brown stripes formed by colored feather buds on their back whereas an autosomal dominant mutation, black at hatch (Bh), disrupts this pigmentation pattern by causing overall black and brown coating in heterozygotes and homozygotes, respectively. These phenotypes of the Bh mutant embryos suggest that the Bh locus plays an important role in the pigment pattern formation of plumage, but its genetic origin, including cloning of the responsible gene, has been insufficiently studied. In this study, we adapted genetically directed representational difference analysis with elimination of excessive clones (GDRDA-WEEC) to Bh quails and isolated two genetic markers linked to the Bh locus as DNA fragments. Cytogenetic study by fluorescence in situ hybridization (FISH) of the DNA fragments used as probes demonstrated that the marker loci were located in the same region on the long arm of chromosome 1. Close genetic linkage between the Bh and the marker loci, and the chromosomal location of the latter suggested that the Bh locus is located on the long-arm of chromosome 1 of the Japanese quail.