Genomics and expression profiles of the Hedgehog and Notch signaling pathways in sea urchin development.

Published

Journal Article

The Hedgehog (Hh) and Notch signal transduction pathways control a variety of developmental processes including cell fate choice, differentiation, proliferation, patterning and boundary formation. Because many components of these pathways are conserved, it was predicted and confirmed that pathway components are largely intact in the sea urchin genome. Spatial and temporal location of these pathways in the embryo, and their function in development offer added insight into their mechanistic contributions. Accordingly, all major components of both pathways were identified and annotated in the sea urchin Strongylocentrotus purpuratus genome and the embryonic expression of key components was explored. Relationships of the pathway components, and modifiers predicted from the annotation of S. purpuratus, were compared against cnidarians, arthropods, urochordates, and vertebrates. These analyses support the prediction that the pathways are highly conserved through metazoan evolution. Further, the location of these two pathways appears to be conserved among deuterostomes, and in the case of Notch at least, display similar capacities in endomesoderm gene regulatory networks. RNA expression profiles by quantitative PCR and RNA in situ hybridization reveal that Hedgehog is produced by the endoderm beginning just prior to invagination, and signals to the secondary mesenchyme-derived tissues at least until the pluteus larva stage. RNA in situ hybridization of Notch pathway members confirms that Notch functions sequentially in the vegetal-most secondary mesenchyme cells and later in the endoderm. Functional analyses in future studies will embed these pathways into the growing knowledge of gene regulatory networks that govern early specification and morphogenesis.

Full Text

Duke Authors

Cited Authors

  • Walton, KD; Croce, JC; Glenn, TD; Wu, S-Y; McClay, DR

Published Date

  • December 2006

Published In

Volume / Issue

  • 300 / 1

Start / End Page

  • 153 - 164

PubMed ID

  • 17067570

Pubmed Central ID

  • 17067570

Electronic International Standard Serial Number (EISSN)

  • 1095-564X

International Standard Serial Number (ISSN)

  • 0012-1606

Digital Object Identifier (DOI)

  • 10.1016/j.ydbio.2006.08.064

Language

  • eng