Developmental shift of myosin heavy chain mRNA expression due to neural factor(s) and muscle activity

Am J Physiol. 1996 Oct;271(4 Pt 1):C1350-7. doi: 10.1152/ajpcell.1996.271.4.C1350.

Abstract

The adult ventricular isoform of chicken myosin heavy chain (MHC-V) is transiently expressed in all skeletal muscle primordia analyzed and is completely repressed around embryonic days 10-12, when functional innervation is established. By ribonuclease protection assay, we demonstrated that denervation of the adult anterior latissimus dorsi muscle resulted in reexpression of MHC-V mRNA. In contrast, treatment of primary cultures of fetal breast or leg muscles with embryonic brain extract or conditioned media from glial or neuroblastoma cell lines, but not from a myogenic cell line or primary muscle cell cultures, led to inhibition of MHC-V expression. This inhibitory activity was abolished by heating and increased with protein concentration. The acquisition of both brain inhibitory activity and the competence of myogenic cells to downregulate MHC-V mRNA expression were age dependent. Furthermore, either paralysis of muscle in ovo by curare or contraction arrest of cultured myotubes resulted in persistent expression of MHC-V mRNA. Thus a putative soluble factor(s) of nerve origin as well as muscle activity are involved in the developmental downregulation of MHC-V expression in muscle primordia.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Factors
  • Animals
  • Brain / physiology
  • Cell-Free System
  • Cells, Cultured
  • Chick Embryo
  • Chickens
  • Down-Regulation
  • Female
  • Gene Expression Regulation / drug effects
  • Male
  • Muscle Contraction
  • Muscle Denervation
  • Muscle, Skeletal / physiology*
  • Myosin Heavy Chains / genetics*
  • Paralysis / physiopathology
  • RNA, Messenger / genetics
  • Tubocurarine / pharmacology
  • Up-Regulation

Substances

  • RNA, Messenger
  • Myosin Heavy Chains
  • Tubocurarine