The beta-catenin homolog BAR-1 and LET-60 Ras coordinately regulate the Hox gene lin-39 during Caenorhabditis elegans vulval development.
In C. elegans, the epithelial Pn.p cells adopt either a vulval precursor cell fate or fuse with the surrounding hypodermis (the F fate). Our results suggest that a Wnt signal transduced through a pathway involving the beta-catenin homolog BAR-1 controls whether P3.p through P8.p adopt the vulval precursor cell fate. In bar-1 mutants, P3.p through P8.p can adopt F fates instead of vulval precursor cell fates. The Wnt/bar-1 signaling pathway acts by regulating the expression of the Hox gene lin-39, since bar-1 is required for LIN-39 expression and forced lin-39 expression rescues the bar-1 mutant phenotype. LIN-39 activity is also regulated by the anchor cell signal/let-23 receptor tyrosine kinase/let-60 Ras signaling pathway. Our genetic and molecular experiments show that the vulval precursor cells can integrate the input from the BAR-1 and LET-60 Ras signaling pathways by coordinately regulating activity of the common target LIN-39 Hox.
Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA.
D M
DM
Eisenmann
J N
JN
Maloof
J S
JS
Simske
C
C
Kenyon
S K
SK
Kim
D000818:Animals; D019521:Body Patterning / Q000235:genetics; D015820:Cadherins / Q000235:genetics / Q000502:physiology*; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development*; D029742:Caenorhabditis elegans Proteins; D002454:Cell Differentiation / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000502:physiology*; D047108:Embryonic Development; D066246:ErbB Receptors / Q000235:genetics / Q000502:physiology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D015801:Helminth Proteins / Q000235:genetics / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics* / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D015534:Trans-Activators; D014844:Vulva / Q000254:growth & development; D051176:beta Catenin; D018631:ras Proteins / Q000235:genetics / Q000502:physiology*
D015820:Cadherins; D029742:Caenorhabditis elegans Proteins; D003598:Cytoskeletal Proteins; D015801:Helminth Proteins; D018398:Homeodomain Proteins; D015534:Trans-Activators; C115014:bar-1 protein, C elegans; D051176:beta Catenin; C108673:lin-39 protein, C elegans; C066646:let-60 protein, C elegans; D066246:ErbB Receptors; C085873:let-23 protein, C elegans; D018631:ras Proteins