title: Loss of Gα12/13 exacerbates apical area dependence of actomyosin contractility.
abstract: During development, coordinated cell shape changes alter tissue shape. In the Drosophila ventral furrow and other epithelia, apical constriction of hundreds of epithelial cells folds the tissue. Genes in the Gα12/13pathway coordinate collective apical constriction, but the mechanism of coordination is poorly understood. Coupling live-cell imaging with a computational approach to identify contractile events, we discovered that differences in constriction behavior are biased by initial cell shape. Disrupting Gα12/13exacerbates this relationship. Larger apical area is associated with delayed initiation of contractile pulses, lower apical E-cadherin and F-actin levels, and aberrantly mobile Rho-kinase structures. Our results suggest that loss of Gα12/13disrupts apical actin cortex organization and pulse initiation in a size-dependent manner. We propose that Gα12/13robustly organizes the apical cortex despite variation in apical area to ensure the timely initiation of contractile pulses in a tissue with heterogeneity in starting cell shape.
authors.affiliation: Computational and Systems Biology Program, Massachusetts Institute of Technology, Cambridge, MA 02142.
authors.forename: Shicong
authors.initials: S
authors.lastname: Xie
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142.
authors.forename: Frank M
authors.initials: FM
authors.lastname: Mason
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142 acmartin@mit.edu.
authors.forename: Adam C
authors.initials: AC
authors.lastname: Martin
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000205:Actomyosin / Q000378:metabolism*; D000818:Animals; D015820:Cadherins / Q000378:metabolism; D016764:Cell Polarity; D048430:Cell Shape / Q000502:physiology; D019295:Computational Biology / Q000379:methods; D004330:Drosophila / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D044365:GTP-Binding Protein alpha Subunits, G12-G13 / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D054262:Gastrulation / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D061848:Optical Imaging / Q000379:methods; D015398:Signal Transduction / Q000502:physiology; D054460:rho-Associated Kinases / Q000378:metabolism
chemical_list: D000199:Actins; D015820:Cadherins; D029721:Drosophila Proteins; D000205:Actomyosin; D054460:rho-Associated Kinases; D044365:GTP-Binding Protein alpha Subunits, G12-G13