Abstract
A mutation in a coat color gene in mice provides an opportunity to study the genetics and physiology of pigmentation, which is a powerful tool for understanding many biological processes, especially development. In 1989, a white, pink-eyed mutant mouse was discovered in a colony of DBA/2N mice at the National Cancer Institute (NCI). Proteins from the mutant mouse were tested with standard biochemical assays to determine whether the presence of this unexpected phenotype was due to genetic contamination or to a mutation of the inbred DBA/2N strain. The assays demonstrated that the new phenotype was likely the result of a new mutation and was not caused by genetic contamination. A more complete examination of the mice revealed that the mutant gene has pleiotropic effects: a white coat color due to absence of melanocytes; small, malformed eyes (microphthalmia) with reduced pigment in the retina, choroid, and iris; abnormally thin or absent stria vascularis of the inner ear; and a reproductive defect in the females. The autosomal recessive mutation was mapped to the microphthalmia (mi) locus on mouse chromosome six, 46 cM from the centromere, through linkage analysis and complementation matings and the allele has been designated cloudy-eyed (mi[^ce]). The affects of mi[^ce] on the structure, function or embryonic development of pigmentation, skeleton, eyes, inner ears, and reproductive function is examined with respect to the other alleles at the mi locus and the ret proto-oncogene which is also positioned on chromosome six, 46cM from the centromere.
Zimring, Debra Carol Sanders (1992). Characterization of a new microphthalmia mutation in the DBA/2N strain of inbred mice. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1348964.