Microphthalmia Cloudy-Eye (mice): A New Murine Allele

In 1989, a white, pink-eyed mouse was discovered in a production colony of DBA/2N mice supported by the National Cancer Institute (NCI). Genetic profiling by enzyme electrophoresis suggested that the phenotype was the result of a new mutation rather than genetic contamination. A more complete characterization of the mice revealed 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. Complementation analysis defined the mutant allele as an autosomal recessive mutation that is an allele of the microphthalmia (mi) locus on mouse chromosome 6. The allele has been designated microphthalmia cloudy-eye (mice).