PES-1 IS EXPRESSED DURING EARLY EMBRYOGENESIS IN CAENORHABDITIS-ELEGANS AND HAS HOMOLOGY TO THE FORK HEAD FAMILY OF TRANSCRIPTION FACTORS

Promoter trapping has identified a gene, pes-1, which is expressed dur ing C. elegans embryogenesis. The beta-galactosidase expression patter n, directed by the pes-1/lacZ fusion through which this gene was clone d, has been determined precisely in terms of the embryonic cell lineag e and has three components. One component is in a subset of cells of t he AB founder cell lineage during early embryogenesis, suggesting pes- 1 may be regulated both by cell autonomous determinants and by interce llular signals. Analysis of cDNA suggests pes-l has two sites for init iation of transcription and the two transcripts would encode related b ut distinct proteins. The predicted PES-1 proteins have homology to th e fork head family of transcription factors and therefore may have imp ortant regulatory roles in early embryogenesis.