title: Dissection of cis-regulatory elements in the C. elegans Hox gene egl-5 promoter.
abstract: Hox genes are highly conserved segmental identity genes well known for their complex expression patterns and divergent targets. Here we present an analysis of cis-regulatory elements in the Caenorhabditis elegans Hox gene egl-5, which is expressed in multiple tissues in the posterior region of the nematode. We have utilized phylogenetic footprinting to efficiently identify cis-regulatory elements and have characterized these with gfp reporters and tissue-specific rescue experiments. We have found that the complex expression pattern of egl-5 is the cumulative result of the activities of multiple tissue or local region-specific activator sequences that are conserved both in sequence and near-perfect order in the related nematode Caenorhabditis briggsae. Two conserved regulatory blocks analyzed in detail contain multiple sites for both positively and negatively acting factors. One of these regions may promote activation of egl-5 in certain cells via the Wnt pathway. Positively acting regions are repressed in inappropriate tissues by additional negative pathways acting at other sites within the promoter. Our analysis has allowed us to implicate several new regulatory factors significant to the control of egl-5 expression.
authors.affiliation: Department of Molecular Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
authors.forename: Yingqi
authors.initials: Y
authors.lastname: Teng
authors.forename: Lisa
authors.initials: L
authors.lastname: Girard
authors.forename: Henrique B
authors.initials: HB
authors.lastname: Ferreira
authors.forename: Paul W
authors.initials: PW
authors.lastname: Sternberg
authors.forename: Scott W
authors.initials: SW
authors.lastname: Emmons
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D019521:Body Patterning; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism*; D019070:Cell Lineage; D004742:Enhancer Elements, Genetic; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009024:Morphogenesis; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D051153:Wnt Proteins
chemical_list: D029742:Caenorhabditis elegans Proteins; C477318:Egl-5 protein, C elegans; D018398:Homeodomain Proteins; D036341:Intercellular Signaling Peptides and Proteins; D014157:Transcription Factors; D051153:Wnt Proteins