Cis regulatory requirements for vulval cell-specific expression of the Caenorhabditis elegans fibroblast growth factor gene egl-17.
The Caenorhabditis elegans EGL-17/FGF protein is involved in the gonadal signaling that guides the migrations of sex myoblasts (SMs). egl-17::GFP reporter constructs are expressed dynamically in vulval cell lineages. Expression in the primary vulval cells is correlated with the precise positioning of SMs. We have investigated the cis-regulatory requirements for cell- and stage-specific expression of egl-17. Three enhancer elements that specify the expression of the egl-17::GFP reporter gene in primary or secondary vulval cells at certain stages were identified. Sequence analysis has suggested a number of potential transcription factor binding sites within the enhancer elements. egl-17 is most likely a direct target of the LIN-39 Hox protein because mutations either in the lin-39/hox gene or at the consensus HOX/PBC binding site within the distal enhancer of the egl-17 gene eliminated distal enhancer-activated egl-17 expression. Since expression of egl-17::GFP driven by the distal enhancer can no longer be turned off at late stages in lin-1 and lin-31 mutants, egl-17 may also be regulated by Ras signaling through repression of LIN-1 and LIN-31 activities. Interspecies transformation experiments showed that egl-17 cis-regulatory elements are structurally and functionally conserved between C. elegans and C. briggsae.
Cui
Mingxue
M
Howard Hughes Medical Institute, and Department of Molecular, Cellular, and Developmental Biology, University of Colorado, 80309-0347, Boulder, CO, USA
Han
Min
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D004742:Enhancer Elements, Genetic; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D018398:Homeodomain Proteins / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion; D014844:Vulva / Q000196:embryology
D029742:Caenorhabditis elegans Proteins; C105157:Egl-17 protein, C elegans; D018398:Homeodomain Proteins; D036341:Intercellular Signaling Peptides and Proteins; C108673:lin-39 protein, C elegans