title: Multiple regulatory elements with spatially and temporally distinct activities control the expression of the epithelial differentiation gene lin-26 in C. elegans.
abstract: Epithelial differentiation is a very early event during development of most species. The nematode Caenorhabditis elegans, with its well-defined and invariant lineage, offers the possibility to link cell lineage, cell fate specification and gene regulation during epithelial differentiation. Here, we focus on the regulation of the gene lin-26, which is required for proper differentiation of epithelial cells in the ectoderm and mesoderm (somatic gonad). lin-26 expression starts in early embryos and remains on throughout development, in many cell types originating from different sublineages. Using GFP reporters and mutant rescue assays, we performed a molecular dissection of the lin-26 promoter and could identify almost all elements required to establish its complex spatial and temporal expression. Most of these elements act redundantly, or synergistically once combined, to drive expression in cells related by function. We also show that lin-26 promoter elements mediate activation in the epidermis (hypodermis) by the GATA factor ELT-1, or repression in the foregut (pharynx) by the FoxA protein PHA-4. Taken together, our data indicate that lin-26 regulation is achieved to a large extent through tissue-specific cis-regulatory elements.
authors.affiliation: Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, BP101423, F-67404 Illkirch Cedex, C.U. de Strasbourg, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Landmann
authors.forename: Sophie
authors.initials: S
authors.lastname: Quintin
authors.forename: Michel
authors.initials: M
authors.lastname: Labouesse
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D015415:Biomarkers; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D050980:GATA Transcription Factors; D018507:Gene Expression Regulation, Developmental; D005809:Genes, Regulator; D017930:Genes, Reporter; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; C096869:ELT-1 protein, C elegans; D050980:GATA Transcription Factors; C113277:Pha-4 protein, C elegans; D015534:Trans-Activators; D014157:Transcription Factors; C090507:lin-26 protein, C elegans