The Caenorhabditis elegans vulva: A post-embryonic gene regulatory network controlling organogenesis
- Howard Hughes Medical Institute and Division of Biology, California Institute of Technology, Pasadena, CA 91125
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Edited by Michael S. Levine, University of California, Berkeley, CA, and approved August 25, 2008 (received for review July 10, 2008)
Abstract
The Caenorhabditis elegans vulva is an elegant model for dissecting a gene regulatory network (GRN) that directs postembryonic organogenesis. The mature vulva comprises seven cell types (vulA, vulB1, vulB2, vulC, vulD, vulE, and vulF), each with its own unique pattern of spatial and temporal gene expression. The mechanisms that specify these cell types in a precise spatial pattern are not well understood. Using reverse genetic screens, we identified novel components of the vulval GRN, including nhr-113 in vulA. Several transcription factors (lin-11, lin-29, cog-1, egl-38, and nhr-67) interact with each other and act in concert to regulate target gene expression in the diverse vulval cell types. For example, egl-38 (Pax2/5/8) stabilizes the vulF fate by positively regulating vulF characteristics and by inhibiting characteristics associated with the neighboring vulE cells. nhr-67 and egl-38 regulate cog-1, helping restrict its expression to vulE. Computational approaches have been successfully used to identify functional cis-regulatory motifs in the zmp-1 (zinc metalloproteinase) promoter. These results provide an overview of the regulatory network architecture for each vulval cell type.
Footnotes
- 1To whom correspondence should be addressed. E-mail: pws{at}caltech.edu
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Author contributions: T.O.R., J.S.F., and P.W.S. designed research; T.O.R. and J.S.F. performed research; T.O.R., J.S.F., and P.W.S. analyzed data; and T.O.R., J.S.F., and P.W.S. wrote the paper.
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This paper results from the Arthur M. Sackler Colloquium of the National Academy of Sciences, “Gene Networks in Animal Development and Evolution,” held February 15–16, 2008, at the Arnold and Mabel Beckman Center of the National Academies of Sciences and Engineering in Irvine, CA. The complete program and audio files of most presentations are available on the NAS web site at http://www.nasonline.org/SACKLER_Gene_Networks.
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The authors declare no conflict of interest.
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This article is a PNAS Direct Submission.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0806377105/DCSupplemental.
- © 2008 by The National Academy of Sciences of the USA
