Sooty foot, a novel mouse mutation that affects the pigmentation of exposed skin, but not hair, maps to Chromosome 2

Abstract

We have characterized a novel recessive mouse mutation, named sooty foot, that increases the pigmentation of the exposed skin on the foot pads, the genital region, around the snout and muzzle, the ears, and the tail. By contrast, the pigmentation of the hair is unaffected. We have localized the mutation to Chromosome 2 by polymerase chain reaction (PCR) amplification of simple sequence repeats from pooled DNA from backcross progeny. In an extended backcross we have generated a detailed map of the region around sooty foot.

This novel recessive mutation, sooty foot (soo), occurred in the inbred strain CBA during transgenic experiments, although it is not caused by transgenic insertion into the genome. The mutation has no apparent effect on hair pigmentation, but darkens the pigmentation of the non-hairy skin of the ears, tail, and other locations and greatly increases pigmentation of the ventral feet and footpad. Using the DNA pooling method of Taylor (Taylor et al. 1994), we localized soo to Chr 2 and have accurately mapped the mutation within the central part of that chromosome.