PUBLICATION

Mef2s are required for thick filament formation in nascent muscle fibres

Authors
Hinits, Y., and Hughes, S.M.
ID
ZDB-PUB-070614-22
Date
2007
Source
Development (Cambridge, England)   134(13): 2511-2519 (Journal)
Registered Authors
Hinits, Yaniv, Hughes, Simon M.
Keywords
Mef2c, Mef2d, Myosin, Muscle, Zebrafish, Myofibril, Somite, tnnc, Myogenin, Hoover, prdm1, eng2a, acta1, actc1, smyhc1, myhz1, tpma, mybpc1, hsp90a
MeSH Terms
  • Animals
  • Base Sequence
  • Embryo, Nonmammalian/embryology
  • Embryo, Nonmammalian/metabolism
  • Gene Expression Regulation, Developmental*
  • Heart/embryology
  • Molecular Sequence Data
  • Muscle Fibers, Skeletal/metabolism*
  • Mutation/genetics
  • Myocardium/metabolism
  • Myogenic Regulatory Factors/genetics
  • Myogenic Regulatory Factors/metabolism*
  • Sequence Alignment
  • Sequence Homology, Nucleic Acid
  • Transcription, Genetic/genetics
  • Zebrafish/embryology
  • Zebrafish/genetics
  • Zebrafish/metabolism
  • Zebrafish Proteins/deficiency
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed
17537787 Full text @ Development
Abstract
During skeletal muscle differentiation, the actomyosin motor is assembled into myofibrils, multiprotein machines that generate and transmit force to cell ends. How expression of muscle proteins is coordinated to build the myofibril is unknown. Here we show that zebrafish Mef2d and Mef2c proteins are required redundantly for assembly of myosin-containing thick filaments in nascent muscle fibres, but not for the earlier steps of skeletal muscle fibre differentiation, elongation, fusion or thin filament gene expression. mef2d mRNA and protein is present in myoblasts, whereas mef2c expression commences in muscle fibres. Knockdown of both Mef2s with antisense morpholino oligonucleotides or in mutant fish blocks muscle function and prevents sarcomere assembly. Cell transplantation and heat-shock-driven rescue reveal a cell-autonomous requirement for Mef2 within fibres. In nascent fibres, Mef2 drives expression of genes encoding thick, but not thin, filament proteins. Among genes analysed, myosin heavy and light chains and myosin-binding protein C require Mef2 for normal expression, whereas actin, tropomyosin and troponin do not. Our findings show that Mef2 controls skeletal muscle formation after terminal differentiation and define a new maturation step in vertebrate skeletal muscle development at which thick filament gene expression is controlled.
Genes / Markers
Figures
Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping
Errata and Notes