Red-eyed dilution (rd), a novel coat-color mutant gene in the musk shrew (Suncus murinus, Insectivora).

Abstract

A novel coat-color mutant was found in the musk shrew (Suncus murinus). Mutant shrews were characterized by light-gray coat, pinkish skin and red eyes. Mating experiment demonstrated that the mutant character was controlled by a single autosomal recessive gene. The gene could be traced back to at least four heterozygous carriers captured in Naha city, Okinawa in 1983. The name, red-eyed dilution, was proposed for this mutant character with the gene symbol rd. Linkage analysis proved no close relationship of the rd locus with the cr (cream coat color) and ch (curly hair) loci. The red-eyed dilution shrews (+/+, rd/rd) could easily be distinguished from the cream coat shrews with dark-red eyes (cr/cr, +/+) and the double homozygotes exhibiting light-cream coat with pink eyes (cr/cr, rd/rd). The rd gene has been maintained in the OKI line about at 75% of its frequency in every generation. We have started to develop a new line triple-homozygous for the cr, ch and rd genes.