title: The plasma membrane flattens out to fuel cell-surface growth during Drosophila cellularization.
abstract: Cell-shape change demands cell-surface growth, but how growth is fueled and choreographed is still debated. Here we use cellularization, the first complete cytokinetic event in Drosophila embryos, to show that cleavage furrow ingression is kinetically coupled to the loss of surface microvilli. We modulate furrow kinetics with RNAi against the Rho1-GTPase regulator slam and show that furrow ingression controls the rate of microvillar depletion. Finally, we directly track the microvillar membrane and see it move along the cell surface and into ingressing furrows, independent of endocytosis. Together, our results demonstrate that the kinetics of the ingressing furrow regulate the utilization of a microvillar membrane reservoir. Because membranes of the furrow and microvilli are contiguous, we suggest that ingression drives unfolding of the microvilli and incorporation of microvillar membrane into the furrow. We conclude that plasma membrane folding/unfolding can contribute to the cell-shape changes that promote embryonic morphogenesis.
authors: Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA.
authors: Lauren
authors: L
authors: Figard
authors: Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors: Heng
authors: H
authors: Xu
authors: Department of Physics, Princeton University, Princeton, NJ 08544, USA.
authors: Hernan G
authors: HG
authors: Garcia
authors: Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA.
authors: Ido
authors: I
authors: Golding
authors: Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: sokac@bcm.edu.
authors: Anna Marie
authors: AM
authors: Sokac
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D021961:Cell Membrane Structures / Q000378:metabolism; D048749:Cytokinesis; D004330:Drosophila / Q000196:embryology* / Q000378:metabolism* / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D047108:Embryonic Development; D004705:Endocytosis; D005453:Fluorescence; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008871:Microvilli / Q000378:metabolism*; D009024:Morphogenesis / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics; D059008:Time-Lapse Imaging
chemical_list: D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; D034741:RNA, Small Interfering; C555022:Slam protein, Drosophila