In Vivo Regulation of Somite Differentiation and Proliferation by Sonic Hedgehog
Abstract
In vertebrates, somite differentiation is mediated in part by Sonic Hedgehog (Shh), secreted by the notochord and the floor plate. However, Shh-null mice display close to normal expression of molecular markers for dermomytome, myotome, and sclerotome, indicating that Shh might not be required for their initial induction. In this paper, we have addressed the capacity of Shh to regulate in vivo the expression of the somite differentiation markers Pax-1, MyoD, and Pax-3 after separation of paraxial mesoderm from axial structures. We show that Pax-1, which is lost under these experimental conditions, is rescued by Shh. In contrast, Shh maintains, but cannot induce MyoD expression, while Pax-3 expression is independent of the presence of axial structures or Shh. Finally, we demonstrate that Shh is a potent mitogen for somitic cells, supporting the idea that it may serve to expand subpopulations of cells within the somite.
Additional Information
© 1999 Academic Press. Received for publication March 16, 1999. Revised June 16, 1999. Accepted June 16, 1999. Available online 2 April 2002. We are grateful to the following for their generous gifts of reagents used in this study: Dr. Rudy Balling for the Pax-1 probe, Dr. Cliff Tabin for the Shh probe, and Dr. Bruce Patterson for the chick MyoD probe. This work was supported by grants from the Muscular Dystrophy Foundation to C.M. and M.B.F., NIH Grant NSO 7251 to S.A., and NIH Grant 34671 to M.B.F.Additional details
- Eprint ID
- 65603
- DOI
- 10.1006/dbio.1999.9389
- Resolver ID
- CaltechAUTHORS:20160323-071054297
- Muscular Dystrophy Foundation
- NSO 7251
- NIH
- 34671
- NIH
- Created
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2016-03-23Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field