title: RacGap50C negatively regulates wingless pathway activity during Drosophila embryonic development.
abstract: The Wingless (Wg)/Wnt signal transduction pathway directs a variety of cell fate decisions in developing animal embryos. Despite the identification of many Wg pathway components to date, it is still not clear how these elements work together to generate cellular identities. In the ventral epidermis of Drosophila embryos, Wg specifies cells to secrete a characteristic pattern of denticles and naked cuticle that decorate the larval cuticle at the end of embryonic development. We have used the Drosophila ventral epidermis as our assay system in a series of genetic screens to identify new components involved in Wg signaling. Two mutant lines that modify wg-mediated epidermal patterning represent the first loss-of-function mutations in the RacGap50C gene. These mutations on their own cause increased stabilization of Armadillo and cuticle pattern disruptions that include replacement of ventral denticles with naked cuticle, which suggests that the mutant embryos suffer from ectopic Wg pathway activation. In addition, RacGap50C mutations interact genetically with naked cuticle and Axin, known negative regulators of the Wg pathway. These phenotypes suggest that the RacGap50C gene product participates in the negative regulation of Wg pathway activity.
authors.affiliation: Department of Biology, Duke University, Durham, North Carolina 27708-1000, USA.
authors.forename: Whitney M
authors.initials: WM
authors.lastname: Jones
authors.forename: Amy
authors.initials: A
authors.lastname: Bejsovec
mesh_terms: D000483:Alleles; D000818:Animals; D051186:Armadillo Domain Proteins; D060466:Axin Protein; D019521:Body Patterning; D003433:Crosses, Genetic; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism*; D004817:Epidermis / Q000196:embryology / Q000378:metabolism; D020690:GTPase-Activating Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000378:metabolism; D017403:In Situ Hybridization; D009154:Mutation; D010641:Phenotype; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D012313:RNA / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics; D015398:Signal Transduction; D015534:Trans-Activators / Q000096:biosynthesis; D019076:Transgenes; D014921:Wings, Animal / Q000196:embryology*; D051155:Wnt1 Protein
chemical_list: D051186:Armadillo Domain Proteins; D060466:Axin Protein; D029721:Drosophila Proteins; D020690:GTPase-Activating Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D051155:Wnt1 Protein; C502951:tum protein, Drosophila; C074622:wg protein, Drosophila; D049452:Green Fluorescent Proteins; D012313:RNA