In vivo developmental modifications of the expression of genes encoding muscle-specific enzymes in rat.

F Schweighoffer,P Maire,D Tuil,S Gautron,D Daegelen,L Bachner,A Kahn

doi:10.1016/s0021-9258(18)67519-2

Abstract

cDNA clones for rat muscle-type creatine kinase and glycogen phosphorylase and aldolase A were isolated from a rat muscle cDNA library. An additional clone recognizing an unidentified 2.7-kilobase pair mRNA species was also isolated. These cDNA clones were used as probes to investigate the expression of the corresponding mRNAs during muscle development. Two aldolase A mRNA species were detected, one of 1650 bases expressed in non-muscle tissues, fetal muscle, and adult slow-twitch muscle, the other of 1550 bases was highly specific of adult fast-twitch skeletal muscle differentiation. These aldolase A mRNAs were shown by primer extension to differ by their 5' ends. The accumulation of muscle-type phosphorylase and creatine kinase and muscle-specific aldolase A mRNA accumulation during muscle development seems to be a coordinate process occurring progressively from the 17th day of intrauterine life up to the 30th day after birth. In contrast, the 2.7-kilobase pair RNA species is maximally expressed at the 1st week after birth as is the neonatal form of myosin heavy chain mRNA.

Highlights

CDNA clones for rat muscle-tycpreeatinekinase and adult stage and are the only ones to be expressed in adult glycogen phosphorylase and aldolase A were isolated skeletal muscle
Screening of the cDNA Library-The cDNA library was screened at high density by insitu hybridization using as probes different cDNA inserts coding for either heterologous enzymes ora different isozymic homologousform
The 400 bp sequenced from the 1.7-kb rat muscle phosphorylase cDNA exactly matched the sequence of the ratmuscle phosphorylase mRNA published by Hwang et al [28], as did the 500 bp of our 1.1-kb creatine kinase M cDNA clone with the sequence of the rat creatine kinase M mRNA previously reported by Benfield et al [29]

Summary

Introduction

CDNA clones for rat muscle-tycpreeatinekinase and adult stage and are the only ones to be expressed in adult glycogen phosphorylase and aldolase A were isolated skeletal muscle. The2.7-kilobase pair RNA species is creasing in a parallel fashion from the 17th day of fetal life maximally expressedat the 1st week after birth as is up to the30th day of postnatal development. These increases the neonatal form of myosin heavy chaminRNA. The availability of DNA probes for various sion pattern which mimics that of the mRNA which encodes a perinatal myosin heavy chain form recently described [17]: RNA concentration reaches a transient maximum at the 1st week of postnatal development

Methods

Results

Conclusion