TY - JOUR
T1 - The muscular dysgenesis mutation in mice leads to arrest of the genetic program for muscle differentiation
AU - Chaudhari, Nirupa
AU - Beam, Kurt G.
N1 - Funding Information:
This research was supported by grants from the Graduate School and the College of Veterinary Medicine and Biomedical Sciences to N.C. and by grants from MDA and NIH (NS-24444 and R.C.D.A. NS-01190) to K.G.B.
PY - 1989/6
Y1 - 1989/6
N2 - Muscular dysgenesis (mdg) is a mutation in mice which causes the failure of excitation-contraction coupling in skeletal muscle. Although the sarcolemma, the sarcoplasmic reticulum, and the contractile apparatus all maintain nearly normal function, sarcolemmal depolarization fails to cause calcium release from the sarcoplasmic reticulum. Recently, the primary genetic defect in this mutation was shown to be located in the structural gene for the dihydro-pyridine receptor. We have examined the developmental expression from Fetal Day 15 onward, in normal and mutant muscle, of several unidentified genes as well as genes which are known markers of muscle differentiation. We find that the majority of mRNA sequences are found at similar concentrations in normal and dysgenic muscles at birth. Many differentiation-related genes also are expressed at normal levels early during myogenesis in mutant mice. However, as late fetal development progresses in dysgenic muscle, the mRNA concentrations for these genes fail to undergo the rapid rise which is characteristic of normal muscle. Several additional, unidentified genes, which normally would be down-regulated during development, remain expressed at a high level in dysgenic muscle. Thus, the primary absence of a functional dihydropyridine receptor appears to prevent the changes in gene expression which are necessary for maturation of skeletal muscle.
AB - Muscular dysgenesis (mdg) is a mutation in mice which causes the failure of excitation-contraction coupling in skeletal muscle. Although the sarcolemma, the sarcoplasmic reticulum, and the contractile apparatus all maintain nearly normal function, sarcolemmal depolarization fails to cause calcium release from the sarcoplasmic reticulum. Recently, the primary genetic defect in this mutation was shown to be located in the structural gene for the dihydro-pyridine receptor. We have examined the developmental expression from Fetal Day 15 onward, in normal and mutant muscle, of several unidentified genes as well as genes which are known markers of muscle differentiation. We find that the majority of mRNA sequences are found at similar concentrations in normal and dysgenic muscles at birth. Many differentiation-related genes also are expressed at normal levels early during myogenesis in mutant mice. However, as late fetal development progresses in dysgenic muscle, the mRNA concentrations for these genes fail to undergo the rapid rise which is characteristic of normal muscle. Several additional, unidentified genes, which normally would be down-regulated during development, remain expressed at a high level in dysgenic muscle. Thus, the primary absence of a functional dihydropyridine receptor appears to prevent the changes in gene expression which are necessary for maturation of skeletal muscle.
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U2 - 10.1016/0012-1606(89)90049-3
DO - 10.1016/0012-1606(89)90049-3
M3 - Article
C2 - 2731637
AN - SCOPUS:0024328640
VL - 133
SP - 456
EP - 467
JO - Developmental Biology
JF - Developmental Biology
SN - 0012-1606
IS - 2
ER -