Localization of the bronx waltzer (by) deafness gene to mouse Chromosome 5

The bronx waltzer (by) mutation is an autosomal recessive mutation that is manifested as head tossing and circling in the mouse. The mutation affects the inner hair cells (IHCs) and pillar cells in the organ of Corti of the cochlea and the maculae and cristae of the vestibular part of the inner ear. IHCs begin to degenerate by a controlled mechanism of cell death as early as gestational day 17 (G17) in the basal coil of the cochlea, and few surviving IHCs are seen in the adult. As a first step towards the identification of by, we analyzed a total of 20 loci in 118 mice from an intraspecific backcross giving the gene order: centromere-D5Mit1-D5Mit73-D5Mit55-[D5Mit12, Nds4 (Afp)]-D5Mit87-[D5Mit205, 20, 88, 208, 93-D5Mit338]-D5Mit25-D5Mit209-bv-D5hMit188-D5Mit367-D5Mit95-D5Mit43-D5Mit102 A total of 701 mice were then analyzed for the markers D5Mit93 and D5Mit95, defining a region of 12.08 cM flanking by. Mice that were recombinant between D5Mit93 and D5Mit95 were analyzed for D5Mit338, D5Mit25, D5Mit209, by, D5Mit188, and D5Mit367. by maps 0.14 chi distal of the marker D5Mit209 and 1.14 cM proximal of the marker D5Mit188 in 701 backcross progeny.