NEUROMUSCULAR DEGENERATION (NMD) - A MUTATION ON MOUSE CHROMOSOME-19 THAT CAUSES MOTOR-NEURON DEGENERATION

Neuromuscular degeneration, nmd, is a spontaneous autosomal recessive mutation in the mouse producing progressive hindlimb impairment caused by spinal muscular atrophy. We used an intersubspecific intercross between B6.BKs-nmd(2J)/+ and Mus musculus castaneus (CAST/Ei) to map the nmd mutation to mouse Chromosome (Chr) 19 with the most likely gene order: nmd(D19Se12, Pygm)-Cntf-Pomc2-D19Mit16-Cyp2c-Got1. nmd maps near muscle deficient, mdf and has a very similar clinical phenotype, but allele tests and histological differences suggest that nmd is a distinct mutation at a different locus. Although closely linked, nmd recombined with the candidate genes muscle glycogen phosphorylase, Pygm, and ciliary neurotrophic factor, Cntf.