Genetic and Physical Mapping of the Dreher Locus on Mouse Chromosome 1

Mutations in the mouse dreher (dr) gene cause skeletal defects, hyperactivity, abnormal gait, deafness, white belly spotting, and hypoplasia of Müllerian duct derivatives. To map dr to high resolution, we utilized two crosses. Initially, we analyzed an intersubspecific intercross to construct a detailed genetic map of simple sequence length polymorphism markers within a 6.3-cM region surrounding the dr locus. Subsequently, we analyzed a second intersubspecific intercross segregating for the dr(6J) allele, which positioned dr within a 0.13-cM region between Rxrg and D1Mit370. A physical contig of BAC clones spanning the dr critical region was constructed, and eight potential dr candidate genes were excluded by genetic or physical mapping. Together these results lay the foundation for positional cloning of the dr gene.