Capsulin and Musculin are basic helix-loophelix transcription factors, but their biophysiological roles in zebrafish cranial myogenesis are unclear. Expressions of endogenous capsulin transcripts are detected at the central-(∼24-hpf) and at dorsal-and ventral-mesoderm cores (∼30-72 hpf) of branchial arches. In contrast, musculin transcripts are expressed as a two-phase manner: early phase (20-22 hpf) expressions of musculin are detected at the head mesoderm, whereas late-phase (36-72 hpf) are detected at all presumptive head-muscle precursors. Knockdown of either capsulin or musculin leads to loss of all cranial muscles without affecting trunk muscle development. The defective phenotypes of Capsulin-and Musculin-morphant can be rescued by co-injection of mRNA of each other. Both myf5 and myod transcripts are down-regulated in the Capsulin-morphant while myod transcripts are up-regulated in the Musculin-morphant. Therefore, we propose a putative regulatory network to understand how capsulin/musculin regulate distinctly either myf5 or myod during zebrafish craniofacial myogenesis.
All Science Journal Classification (ASJC) codes
- Molecular Medicine
- Molecular Biology
- Cellular and Molecular Neuroscience
- Cell Biology