Abstract
In Caenorhabditiselegans males, different subsets of ventral epidermal precursor (Pn.p) cells adopt distinct fates in a position-specific manner: three posterior cells, P(9-11).p, comprise the hook sensillum competence group (HCG) with three potential fates (1 degrees , 2 degrees , or 3 degrees ), while eight anterior cells, P(1-8).p, fuse with the hyp7 epidermal syncytium. Here we show that activation of the canonical BAR-1 beta-catenin pathway of Wnt signaling alters the competence of P(3-8).p and specifies ectopic HCG-like fates. This fate transformation requires the Hox gene mab-5. In addition, misexpression of mab-5 in P(1-8).p is sufficient to establish HCG competence among these cells, as well as to generate ectopic HCG fates in combination with LIN-12 or EGF signaling. While increased Wnt signaling induces predominantly 1 degrees HCG fates, increased LIN-12 or EGF signaling in combination with MAB-5 overexpression promotes 2 degrees HCG fates in anterior Pn.p cells, suggesting distinctive functions of Wnt, LIN-12, and EGF signaling in specification of HCG fates. Lastly, wild-type mab-5 function is necessary for normal P(9-11).p fate specification, indicating that regulation of ectopic HCG fate formation revealed in anterior Pn.p cells reflect mechanisms of pattern formation during normal hook development.
Copyright 2010 Elsevier Inc. All rights reserved.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Animals, Genetically Modified
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Body Patterning / genetics
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Body Patterning / physiology*
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Caenorhabditis elegans / genetics
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Caenorhabditis elegans / growth & development
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Caenorhabditis elegans / metabolism*
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Caenorhabditis elegans Proteins / genetics
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Caenorhabditis elegans Proteins / metabolism
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Caenorhabditis elegans Proteins / physiology*
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Cell Lineage
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Cell Proliferation
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Epidermal Cells
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Epidermal Growth Factor / genetics
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Epidermal Growth Factor / metabolism
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Epidermal Growth Factor / physiology
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Epidermis / metabolism
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Female
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Homeodomain Proteins / genetics
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Homeodomain Proteins / metabolism
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Homeodomain Proteins / physiology
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Male
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Membrane Proteins / physiology
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Microscopy, Fluorescence
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Mutation
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Receptors, G-Protein-Coupled / genetics
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Receptors, G-Protein-Coupled / metabolism
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Receptors, G-Protein-Coupled / physiology
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Receptors, Notch / genetics
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Receptors, Notch / metabolism
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Receptors, Notch / physiology
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Signal Transduction / genetics
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Signal Transduction / physiology
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Stem Cells / cytology
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Stem Cells / metabolism*
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Transcription Factors / genetics
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Transcription Factors / metabolism
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Transcription Factors / physiology
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Wnt Proteins / genetics
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Wnt Proteins / metabolism
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Wnt Proteins / physiology
Substances
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Caenorhabditis elegans Proteins
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Homeodomain Proteins
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LIN-17 protein, C elegans
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Lin-12 protein, C elegans
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Mab-5 protein, C elegans
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Membrane Proteins
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Receptors, G-Protein-Coupled
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Receptors, Notch
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Transcription Factors
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Wnt Proteins
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Epidermal Growth Factor