title: Drosophila RhoA regulates the cytoskeleton and cell-cell adhesion in the developing epidermis.
abstract: The small GTPase Rho is a molecular switch that is best known for its role in regulating the actomyosin cytoskeleton. We have investigated its role in the developing Drosophila embryonic epidermis during the process of dorsal closure. By expressing the dominant negative DRhoA(N19) construct in stripes of epidermal cells, we confirm that Rho function is required for dorsal closure and demonstrate that it is necessary to maintain the integrity of the ventral epidermis. We show that defects in actin organization, nonmuscle myosin II localization, the regulation of gene transcription, DE-cadherin-based cell-cell adhesion and cell polarity underlie the effects of DRhoA(N19) expression. Furthermore, we demonstrate that these changes in cell physiology have a differential effect on the epidermis that is dependent upon position in the dorsoventral axis. In the ventral epidermis, cells either lose their adhesiveness and fall out of the epidermis or undergo apoptosis. At the leading edge, cells show altered adhesive properties such that they form ectopic contacts with other DRhoA(N19)-expressing cells.
authors.affiliation: Developmental, Cell and Molecular Biology Group, Department of Biology, B330 LSRC Building, Duke University, Durham, NC 27708-1000, USA.
authors.forename: James W
authors.initials: JW
authors.lastname: Bloor
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Kiehart
mesh_terms: D000205:Actomyosin / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D015820:Cadherins / Q000378:metabolism; D002448:Cell Adhesion; D016764:Cell Polarity; D003599:Cytoskeleton / Q000378:metabolism*; D004330:Drosophila / Q000196:embryology* / Q000235:genetics; D004625:Embryo, Nonmammalian; D000078404:Epidermal Cells; D004817:Epidermis / Q000196:embryology* / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005799:Genes, Dominant; D048031:JNK Mitogen-Activated Protein Kinases; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D015398:Signal Transduction; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D015820:Cadherins; D000205:Actomyosin; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D020742:rhoA GTP-Binding Protein