LAMININ ALPHA-2 CHAIN-NULL MUTANT MICE BY TARGETED DISRUPTION OF THE LAMA2GENE - A NEW MODEL OF MEROSIN (LAMININ 2)-DEFICIENT CONGENITAL MUSCULAR-DYSTROPHY

Using the gene targeting technique, we have generated a new mouse mode l of congenital muscular dystrophy (CMD), a null mutant for the lamini n alpha 2 chain, These homozygous mice, designated dy(3K)/dy(3K), char acterized by growth retardation and severe muscular dystrophic symptom s and die by 5 weeks of age, Light microscopy revealed that muscle fib er degeneration in these mice begins no later than postnatal day 9. In degenerating muscles, considerable amounts of TUNEL positive nuclei m ere detected as well as DNA laddering, suggesting increased apoptotic cell death was involved in the process of muscle fiber degeneration, ( C) 1997 Federation of European Biochemical Societies.