Molecular analysis of a spontaneous dystrophin 'knockout' dog

We have determined the molecular basis for skeletal myopathy and dilated ca rdiomyopathy in two male German short-haired pointer (GSHP) littermates. An alysis of skeletal muscle demonstrated a complete absence of dystrophin on Western blot analysis. PCR analysis of genomic DNA revealed a deletion enco mpassing the entire dystrophin gene. Molecular cytogenetic analysis of lymp hocytes from the dam and both dystrophic pups confirmed a visible deletion in the p21 region of the affected canine X chromosome. Utrophin is up-regul ated in the skeletal muscle, but does not appear to ameliorate the dystroph ic canine phenotype. This new canine model should further our understanding of the physiological and biochemical processes in Duchenne muscular dystro phy. (C) 1999 Elsevier Science B.V. All rights reserved.