ZFIN ID: ZDB-PUB-130905-15
Normal Function of Myf5 During Gastrulation Is Required for Pharyngeal Arch Cartilage Development in Zebrafish Embryos
Lin, C.Y., Lee, H.C., Chen, H.C., Hsieh, C.C., and Tsai, H.J.
Date: 2013
Source: Zebrafish   10(4): 486-99 (Journal)
Registered Authors: Tsai, Huai-Jen
Keywords: none
MeSH Terms:
  • Animals
  • Branchial Region/embryology*
  • Cartilage, Articular/growth & development*
  • Chondrogenesis
  • Embryonic Development*
  • Gene Knockdown Techniques
  • Head/embryology
  • Muscles/embryology
  • Myogenic Regulatory Factor 5/deficiency
  • Myogenic Regulatory Factor 5/physiology*
  • Neural Crest/embryology
  • Signal Transduction/physiology
  • Zebrafish/embryology*
  • Zebrafish Proteins/deficiency
  • Zebrafish Proteins/physiology*
PubMed: 23992145 Full text @ Zebrafish

Myf5, a myogenic regulatory factor, plays a key role in regulating muscle differentiation. However, it is not known if Myf5 has a regulatory role during early embryogenesis. Here, we used myf5-morpholino oligonucleotides [MO] to knock down myf5 expression and demonstrated a series of results pointing to the functional roles of Myf5 during early embryogenesis: (1) reduced head size resulting from abnormal morphology in the cranial skeleton; (2) decreased expressions of the cranial neural crest (CNC) markers foxd3, sox9a, dlx2, and col2a1; (3) defect in the chondrogenic neural crest similar to that of fgf3 morphants; (4) reduced fgf3/fgf8 transcripts in the cephalic mesoderm rescued by co-injection of myf5 wobble-mismatched mRNA together with myf5-MO1 during 12 h postfertilization; (5) abnormal patterns of axial and non-axial mesoderm causing expansion of the dorsal organizer, and (6) increased bmp4 gradient, but reduced fgf3/fgf8 marginal gradient, during gastrulation. Interestingly, overexpression of fgf3 could rescue the cranial cartilage defects caused by myf5-MO1, suggesting that Myf5 modulates craniofacial cartilage development through the fgf3 signaling pathway. Together, the loss of Myf5 function results in a cascade effect that begins with abnormal formation of the dorsal organizer during gastrulation, causing, in turn, defects in the CNC and cranial cartilage of myf5-knockdown embryos.