ZFIN ID: ZDB-PUB-181127-56
Genetic Mutations in jamb, jamc, and myomaker Revealed Different Roles on Myoblast Fusion and Muscle Growth
Si, Y., Wen, H., Du, S.
Date: 2018
Source: Marine biotechnology (New York, N.Y.)   21(1): 111-123 (Journal)
Registered Authors: Du, Shao Jun (Jim)
Keywords: Jamb, Jamc, Muscle fusion, Myomaker, Zebrafish
MeSH Terms:
  • Animals
  • Animals, Genetically Modified
  • Cell Communication
  • Cell Differentiation
  • Cell Fusion
  • Embryo, Nonmammalian
  • Gene Expression Regulation, Developmental
  • Junctional Adhesion Molecule B/deficiency
  • Junctional Adhesion Molecule B/genetics*
  • Membrane Proteins/deficiency
  • Membrane Proteins/genetics*
  • Muscle Development/genetics*
  • Muscle Fibers, Skeletal/cytology
  • Muscle Fibers, Skeletal/metabolism
  • Muscle Proteins/deficiency
  • Muscle Proteins/genetics*
  • Muscle, Skeletal/cytology
  • Muscle, Skeletal/growth & development
  • Muscle, Skeletal/metabolism*
  • Mutation
  • Myoblasts/cytology
  • Myoblasts/metabolism*
  • Receptors, Cell Surface/deficiency
  • Receptors, Cell Surface/genetics*
  • Zebrafish/genetics*
  • Zebrafish/growth & development
  • Zebrafish/metabolism
  • Zebrafish Proteins/deficiency
  • Zebrafish Proteins/genetics*
PubMed: 30467785 Full text @ Mar. Biotechnol.
Myoblast fusion is a vital step for skeletal muscle development, growth, and regeneration. Loss of Jamb, Jamc, or Myomaker (Mymk) function impaired myoblast fusion in zebrafish embryos. In addition, mymk mutation hampered fish muscle growth. However, the effect of Jamb and Jamc deficiency on fish muscle growth is not clear. Moreover, whether jamb;jamc and jamb;mymk double mutations have stronger effects on myoblast fusion and muscle growth remains to be investigated. Here, we characterized the muscle development and growth in jamb, jamc, and mymk single and double mutants in zebrafish. We found that although myoblast fusion was compromised in jamb and jamc single or jamb;jamc double mutants, these mutant fish showed no defect in muscle cell fusion during muscle growth. The mutant fish were able to grow into adults that were indistinguishable from the wild-type sibling. In contrast, the jamb;mymk double mutants exhibited a stronger muscle phenotype compared to the jamb and jamc single and double mutants. The jamb;mymk double mutant showed reduced growth and partial lethality, similar to a mymk single mutant. Single fiber analysis of adult skeletal myofibers revealed that jamb, jamc, or jamb;jamc mutants contained mainly multinucleated myofibers, whereas jamb;mymk double mutants contained mostly mononucleated fibers. Significant intramuscular adipocyte infiltration was found in skeletal muscles of the jamb;mymk mutant. Collectively, these studies demonstrate that although Jamb, Jamc, and Mymk are all involved in myoblast fusion during early myogenesis, they have distinct roles in myoblast fusion during muscle growth. While Mymk is essential for myoblast fusion during both muscle development and growth, Jamb and Jamc are dispensable for myoblast fusion during muscle growth.