title: Differing roles for sur-2/MED23 in C. elegans and C. briggsae vulval development.
abstract: Normal vulval development in the nematode Caenorhabditis briggsae is identical to that in the related Caenorhabditis elegans. However, several experiments suggest that there are differences between the two species with respect to the contribution of EGF/Ras signaling. To investigate these differences genetically, we have characterized a C. briggsae mutant strain that phenocopies the effect observed when C. briggsae animals are treated with U0126, an inhibitor of the EGF pathway component MEK. We identify that the gene affected in the mutant strain is Cbr-sur-2, which encodes a MED23 mediator complex protein that acts downstream of EGF signaling in C. elegans and other organisms, such as mammals. When Cbr-sur-2 and Cel-sur-2 mutants are compared, we find that the production of additional vulval cells from P5.p and P7.p in C. elegans is dependent on proper development of P6.p, while C. briggsae does not have a similar requirement. Combined chemical and genetic interference with the EGF pathway completely eliminates vulval development in C. elegans but not in C. briggsae. Our results provide genetic evidence for the differing requirements for EGF signaling in the two species.
authors.affiliation: Department of Molecular Genetics, Ohio State University, Columbus, OH, 43210, USA.|Graduate Program in Molecular Cellular and Developmental Biology, Ohio State University, Columbus, OH, 43210, USA.
authors.forename: Karley K
authors.initials: KK
authors.lastname: Mahalak
authors.affiliation: Department of Molecular Genetics, Ohio State University, Columbus, OH, 43210, USA.
authors.forename: Abdulrahman M
authors.initials: AM
authors.lastname: Jama
authors.affiliation: Department of Molecular Genetics, Ohio State University, Columbus, OH, 43210, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Billups
authors.affiliation: Department of Molecular Genetics, Ohio State University, Columbus, OH, 43210, USA.|Department of Mathematics, Ohio State University, Columbus, OH, 43210, USA.
authors.forename: Adriana T
authors.initials: AT
authors.lastname: Dawes
authors.affiliation: Department of Molecular Genetics, Ohio State University, Columbus, OH, 43210, USA. chamberlin.27@osu.edu.
authors.forename: Helen M
authors.initials: HM
authors.lastname: Chamberlin
mesh_terms: D000818:Animals; D002107:Caenorhabditis / Q000145:classification / Q000254:growth & development*; D017173:Caenorhabditis elegans / Q000254:growth & development*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism; D005260:Female; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*; D014844:Vulva / Q000254:growth & development
chemical_list: D029742:Caenorhabditis elegans Proteins; C095846:Sur-2 protein, C elegans; D014157:Transcription Factors; D004815:Epidermal Growth Factor
keywords: Cell signaling; Cryptic evolution; Developmental patterning; Signaling network evolution