GENETIC-MAP OF THE REGION AROUND GRIZZLED (GR) AND MOCHA (MH) ON MOUSE CHROMOSOME-10, HOMOLOGOUS TO HUMAN 19P13.3

Grizzled (gr) is a recessive mouse mutation resulting in a gray coat c olor and reduced perinatal viability. Mocha (mh) is one of several rec essive 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 Che diak-Higashi and Hermansky-Pudlak syndromes in humans. The genes for g r and mh are very closely linked to each other (0 +/- 1.2 cM). However , their relative position with respect to molecular markers was previo usly unknown. Thus, genetic mapping of the gr locus will also yield in formation about the mh location. To map these two genes genetically, w e have performed an intersubspecific backcross of grizzled mice with M us musculus castaneus. In 539 progeny tested, we found no recombinatio n between the gr gene, the gene for anti-Muellerian hormone (Amh), and the microsatellite markers D10Mit7, D10Mit21, and D10Mit23. One recom bination event for each of the flanking markers Basigin (Bsg) and D10M it22 was identified. These closely linked markers should provide entry points for positional cloning of the gr and mh genes. The region link ed to grizzled is homologous to a gene-rich region on human Chromosome 19p13.3. (C) 1994 Academic Press, Inc.