Molecular and genetic mapping of the mouse mdx locus

Abstract mdx is an X-linked muscular dystrophy mutant of the mouse and a putative homolog of the human X-linked muscular dystrophy locus—Duchenne muscular dystrophy ( DMD ). Utilizing a C57BL/10/ Mus Spretus interspecific cross in which the mdx mutation was segregating, we have constructed a detailed genetic map around the mdx locus on the mouse X chromosome. We were unable to detect recombinants between mdx and exonic probes derived from the human DMD gene. These genetic data support the contention from biochemical studies ( E. P. Hoffman, R. H. Brown, and L. M. Kunkel, 1987 , Cell 51: 919–928) that DMD and mdx are homologous genes.