pha-4, anHNF-3 homolog, specifies pharyngeal organ identity inCaenorhabditis elegans
- Michael A. Horner1,
- Sophie Quintin2,
- Mary Ellen Domeier1,
- Judith Kimble3,
- Michel Labouesse2, and
- Susan E. Mango1,4
- 1Huntsman Cancer Institute, Center for Children, Department of Oncological Sciences, University of Utah, Salt Lake City, Utah 84112 USA; 2Institut de Genetique et de Biologie Moleculaire et Cellulaire, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale/Université Louis Pasteur (CNRS/INSERM/ULP), 67404 Illkirch Cedex, France; 3Howard Hughes Medical Institute, Department of Biochemistry, University of Wisconsin–Madison, Madison, Wisconsin 53706 USA
Abstract
To build complex organs, embryos have evolved mechanisms that integrate the development of cells unrelated to one another by cell type or ancestry. Here we show that the pha-4 locus establishes organ identity for the Caenorhabditis elegans pharynx. Inpha-4 mutants, pharyngeal cells are transformed into ectoderm. Conversely, ectopic pha-4 expression produces excess pharyngeal cells. pha-4 encodes an HNF-3 homolog selectively expressed in the nascent digestive tract, including all pharynx precursors at the time they are restricted to a pharyngeal fate. We suggest that pha-4 is a key component of a transcription-based mechanism to endow cells with pharyngeal organ identity.
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Footnotes
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↵4 Corresponding author.
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E-MAIL smango{at}genetics.utah.edu; FAX (801) 581-7796.
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- Received February 12, 1998.
- Accepted April 28, 1998.
- Cold Spring Harbor Laboratory Press
