Expression of alpha-cardiac and alpha-skeletal actin mRNAs in relation to innervation in regenerating and non-regenerating rat skeletal muscles.
The expression of alpha-cardiac and alpha-skeletal actin mRNA in regenerating muscle was examined. Changes in mRNA levels were analyzed in autografted extensor digitorum longus (EDL) muscles in rats using alpha-isoform specific synthetic oligonucleotides and beta-actin cDNA as probes. After autografting, the expression of alpha-cardiac actin mRNA was induced; concomitantly that of alpha-skeletal actin mRNA was reduced. The pattern of alpha-actin mRNA expression appeared to be similar to that seen in embryonic skeletal muscle. In order to evaluate the effects of innervation on alpha-actin mRNA expression in regenerating muscle, nerveless, standard, and nerve-intact autografted muscles were examined. More complete innervation facilitated the recovery of alpha-skeletal actin mRNA to control levels, but had little effect on the amount of alpha-cardiac actin mRNA. We found that regenerating muscle shows that embryonic pattern of alpha-actin mRNAs in the early stage and concluded that the recovery of alpha-skeletal actin mRNA expression to the adult pattern is influenced by innervation, while alpha-cardiac actin mRNA expression is nerve independent.
Toyofuku
T
T
Department of Medicine, University of Chicago, Illinois 60637.
Hoffman
J R
JR
Zak
R
R
Carlson
B M
BM
D000199:Actins / Q000096:biosynthesis* / Q000737:chemistry; D000818:Animals; D001483:Base Sequence; D004247:DNA; D005786:Gene Expression Regulation; D008297:Male; D008969:Molecular Sequence Data; D009121:Muscle Denervation; D009132:Muscles / Q000294:innervation / Q000378:metabolism* / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D012038:Regeneration
D000199:Actins; D012333:RNA, Messenger; D004247:DNA