The Caenorhabditis elegans gene lin-1 encodes an ETS-domain protein and defines a branch of the vulval induction pathway. (original) (raw)

  1. G J Beitel,
  2. S Tuck,
  3. I Greenwald, and
  4. H R Horvitz
  5. Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.

Abstract

The Caenorhabditis elegans gene lin-1 appears to act after the Ras-Raf-MEK-MAPK signaling cascade that mediates vulval induction. We show that lin-1 is a negative regulator of vulval cell fates and encodes an ETS-domain putative transcription factor containing potential MAPK phosphorylation sites. In lin-1 null mutants, the vulval precursor cells (VPCs) still respond to signaling from the gonadal anchor cell, indicating that lin-1 defines a branch of the inductive signaling pathway. We also provide evidence that the inductive and lateral signaling pathways are integrated to control the 1 degree and 2 degrees vulval cell fates after the point at which lin-1 acts in the inductive pathway and that VPCs can assess the relative rather than absolute levels of inductive and lateral signaling in determining whether to express the 1 degree or 2 degrees vulval cell fates.

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