Patterns & Phenotypes
Expression patterns of collagen I (α1) encoding gene and muscle-specific genes reveal that the lateral domain of the fish somite forms a connective tissue surrounding the myotome
Version of Record online: 14 MAR 2005
Copyright © 2005 Wiley-Liss, Inc.
Special Issue: Special Focus on Limb Development
Volume 233, Issue 2, pages 605–611, June 2005
How to Cite
Rescan, P.Y., Ralliere, C., Chauvigné, F. and Cauty, C. (2005), Expression patterns of collagen I (α1) encoding gene and muscle-specific genes reveal that the lateral domain of the fish somite forms a connective tissue surrounding the myotome. Dev. Dyn., 233: 605–611. doi: 10.1002/dvdy.20337
- Issue online: 12 MAY 2005
- Version of Record online: 14 MAR 2005
- Manuscript Accepted: 29 NOV 2004
- Manuscript Revised: 19 NOV 2004
- Manuscript Received: 8 OCT 2004
- Institut National de la recherche Agronomique (INRA)
- connective tissue;
Somites are repeated, epithelial structures that are derived from the unsegmented paraxial mesoderm located lateral to the notochord. In higher vertebrates, somites differentiate into a sclerotome that subsequently forms the vertebrae and the ribs and into a dermomyotome that gives rise to a myotome, from which arises the skeletal muscle, and to a dermatome, from which arises the dermis. Fish somites have been shown to produce a sclerotome and a myotome, but very little is known regarding their participation in the formation of connective tissues, especially at the junction between the epidermis and the myotome. To investigate the formation of connective tissues in fish somites, we have examined the expression pattern of the collagen I (α1) chain. As somitogenesis proceeds rostrocaudally, collagen I (α1) expression marks the sclerotomal cells and delineates the formation of the vertebrae. Surprisingly, after the completion of the segmentation, transcript for the collagen I (α1) chain appeared in a distinct epithelial-like monolayer situated at the periphery of the developing somite facing the surface epidermis. This epithelial monolayer of somitic cells that covered the superficial slow muscle cells, did not express the myogenic transcriptional regulator myogenin and was devoid of contractile filament. As the somite increased in size, these collagen-expressing epithelial cells flattened, forming a thin cellular layer underlying the epidermis and recovering the lateral surface of the myotome. In conclusion, the lateral domain of the fish somite forms a distinct epithelial cell layer sharing many characteristics with amniote dermatome. Developmental Dynamics 233:605–611, 2005. © 2005 Wiley-Liss, Inc.