1. Hox gene expression in a single Caenorhabditis elegans cell is regulated by a caudal homolog and intercellular signals that inhibit wnt signaling.
- Author
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Hunter CP, Harris JM, Maloof JN, and Kenyon C
- Subjects
- Animals, Embryonic Development, Fluorescent Antibody Technique, Glycoproteins genetics, Helminth Proteins genetics, Homeodomain Proteins genetics, Lac Operon genetics, Male, Mutation genetics, Pedigree, Phenotype, Signal Transduction genetics, Transcription Factors genetics, Transcriptional Activation genetics, Wnt Proteins, Caenorhabditis elegans genetics, Caenorhabditis elegans Proteins, Gene Expression Regulation, Developmental genetics, Genes, Homeobox genetics, Proto-Oncogene Proteins genetics, Trans-Activators, Zebrafish Proteins
- Abstract
In Caenorhabditis elegans males, a row of epidermal precursor cells called seam cells generates a pattern of cuticular alae in anterior body regions and neural sensilla called rays in the posterior. The Hox gene mab-5 is required for two posterior seam cells, V5 and V6, to generate rays. In mab-5 mutant males, V5 and V6 do not generate sensory ray lineages but instead generate lineages that lead to alae. Here we show that two independent regulatory pathways can activate mab-5 expression in the V cells. First, the caudal homolog pal-1 turns on mab-5 in V6 during embryogenesis. Second, a Wnt signaling pathway is capable of activating mab-5 in the V cells during postembryonic development; however, during normal development Wnt signaling is inhibited by signals from neighboring V cells. The inhibition of this Wnt signaling pathway by lateral signals between the V cells limits the number of rays in the animal and also determines the position of the boundary between alae and rays.
- Published
- 1999
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