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Deficiency of merosin in dystrophic dy mouse homologue of congenital muscular dystrophy

Journal Article · · American Journal of Human Genetics
OSTI ID:134335
;  [1];  [2]
  1. Univ. of Iowa, Iowa City, IA (United States)
  2. and others

Merosin (laminin M chain) is the predominant laminin isoform in the basal lamina of striated muscle and peripheral nerve and is a native ligand for {alpha}-dystroglycan, a novel laminin receptor. Merosin is linked to the subsarcolemmal actin cytoskeleton via the dystrophin-glycoprotein complex (DGC), which plays an important role for maintenance of normal muscle function. We have mapped the mouse merosin gene, Lamm, to the region containing the dystrophia muscularis (dy) locus on chromosome 10. This suggested the possibility that a mutation in the merosin gene could be responsible for the dy mouse, an animal model for autosomal recessive muscular dystrophy, and prompted us to test this hypothesis. We analyzed the status of merosin expression in dy mouse by immunofluorescence and immunoblotting. In dy mouse skeletal and cardiac muscle and peripheral nerve, merosin was reduced greater than 90% as compared to control mice. However, the expression of laminin B1/B2 chains and collagen type IV was smaller to that in control mice. These findings strongly suggest that merosin deficiency may be the primary defect in the dy mouse. Furthermore, we have identified two patients afflicted with congenital muscular dystrophy with merosin deficiency, providing the basis for future studies of molecular pathogenesis and gene therapy.

OSTI ID:
134335
Report Number(s):
CONF-941009--
Journal Information:
American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
Country of Publication:
United States
Language:
English