Genetic map of the region around grizzled (gr) and mocha (mh) on mouse chromosome 10, homologous to human 19p13.3

Abstract

Grizzled (gr) is a recessive mouse mutation resulting in a gray coat color and reduced perinatal viability. Mocha (mh) is one of several recessive mouse mutants characterized by platelet storage pool disorder, pigment abnormalities, reduced fertility, kidney function deficiencies, and, in some mutants, inner ear and natural killer cell deficiencies. Murine platelet storage pool deficient mutants may be models for Chediak-Higashi and Hermansky-Pudlak syndromes in humans. The genes for gr and mh are very closely linked to each other (0 +/- 1.2 cM). However, their relative position with respect to molecular markers was previously unknown. Thus, genetic mapping of the gr locus will also yield information about the mh location. To map these two genes genetically, we have performed an intersubspecific backcross of grizzled mice with Mus musculus castaneus. In 539 progeny tested, we found no recombination between the gr gene, the gene for anti-Muellerian hormone (Amh), and the microsatellite markers D10Mit7, D10Mit21, and D10Mit23. One recombination event for each of the flanking markers Basigin (Bsg) and D10Mit22 was identified. These closely linked markers should provide entry points for positional cloning of the gr and mh genes. The region linked to grizzled is homologous to a gene-rich region on human Chromosome 19p13.3.