title: DRhoGEF2 regulates cellular tension and cell pulsations in the Amnioserosa during Drosophila dorsal closure.
abstract: Coordination of apical constriction in epithelial sheets is a fundamental process during embryogenesis. Here, we show that DRhoGEF2 is a key regulator of apical pulsation and constriction of amnioserosal cells during Drosophila dorsal closure. Amnioserosal cells mutant for DRhoGEF2 exhibit a consistent decrease in amnioserosa pulsations whereas overexpression of DRhoGEF2 in this tissue leads to an increase in the contraction time of pulsations. We probed the physical properties of the amnioserosa to show that the average tension in DRhoGEF2 mutant cells is lower than wild-type and that overexpression of DRhoGEF2 results in a tissue that is more solid-like than wild-type. We also observe that in the DRhoGEF2 overexpressing cells there is a dramatic increase of apical actomyosin coalescence that can contribute to the generation of more contractile forces, leading to amnioserosal cells with smaller apical surface than wild-type. Conversely, in DRhoGEF2 mutants, the apical actomyosin coalescence is impaired. These results identify DRhoGEF2 as an upstream regulator of the actomyosin contractile machinery that drives amnioserosa cells pulsations and apical constriction.
authors.affiliation: Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal.
authors.forename: Dulce
authors.initials: D
authors.lastname: Azevedo
authors.forename: Marco
authors.initials: M
authors.lastname: Antunes
authors.forename: Soren
authors.initials: S
authors.lastname: Prag
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Ma
authors.forename: Udo
authors.initials: U
authors.lastname: Hacker
authors.forename: G Wayne
authors.initials: GW
authors.lastname: Brodland
authors.forename: M Shane
authors.initials: MS
authors.lastname: Hutson
authors.forename: Jerome
authors.initials: J
authors.lastname: Solon
authors.forename: Antonio
authors.initials: A
authors.lastname: Jacinto
mesh_terms: D000205:Actomyosin / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D018797:Cell Cycle Proteins; D048430:Cell Shape / Q000235:genetics / Q000502:physiology; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D009154:Mutation; D014743:Videotape Recording; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; C465504:sav protein, Drosophila; D049452:Green Fluorescent Proteins; D000205:Actomyosin; D020741:rho GTP-Binding Proteins