NUCLEOTIDE-SEQUENCE OF ENDOTHELIN-B RECEPTOR GENE REVEALS ORIGIN OF PIEBALD MUTATION IN LABORATORY MOUSE

Piebald (Ednrb(s)) is a coat color mutation of laboratory mice caused by a decreased expression of endothelin-B receptor gene (Ednrb). The I ITES and JF1 mouse strains, whose origins are believed to be different from those of the common laboratory inbred strains, also show a pheno type similar to Ednrb(s). In the present study, we found that the nucl eotide sequence of the Ednrb gene of the IITES and JF1 mice is identic al to that of the Ednrb(s) allele, Ednrb(s) allele has an RFLP of the Ednrb gene identical with that of M. m. molossinus but different from other subspecies, and at least particular regions of chromosome 14 pro ximal to the Ednrb locus of the IITES and JF1 strains are derived from M. m. molossinus. These findings clearly indicate that the Ednrb(s) a llele of the laboratory mice has its origin in M, m. molossinus.