Triggering a cell shape change by exploiting preexisting actomyosin contractions.
Apical constriction changes cell shapes, driving critical morphogenetic events, including gastrulation in diverse organisms and neural tube closure in vertebrates. Apical constriction is thought to be triggered by contraction of apical actomyosin networks. We found that apical actomyosin contractions began before cell shape changes in both Caenorhabitis elegans and Drosophila. In C. elegans, actomyosin networks were initially dynamic, contracting and generating cortical tension without substantial shrinking of apical surfaces. Apical cell-cell contact zones and actomyosin only later moved increasingly in concert, with no detectable change in actomyosin dynamics or cortical tension. Thus, apical constriction appears to be triggered not by a change in cortical tension, but by dynamic linking of apical cell-cell contact zones to an already contractile apical cortex.
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Minna
M
Roh-Johnson
Gidi
G
Shemer
Christopher D
CD
Higgins
Joseph H
JH
McClellan
Adam D
AD
Werts
U Serdar
US
Tulu
Liang
L
Gao
Eric
E
Betzig
Daniel P
DP
Kiehart
Bob
B
Goldstein
D000205:Actomyosin / Q000737:chemistry / Q000502:physiology*; D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology* / Q000196:embryology*; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D048430:Cell Shape; D003198:Computer Simulation; D003599:Cytoskeleton / Q000502:physiology / Q000648:ultrastructure; D004331:Drosophila melanogaster / Q000166:cytology* / Q000196:embryology*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000502:physiology; D036681:Fluorescence Recovery After Photobleaching; D054262:Gastrulation; D007365:Intercellular Junctions / Q000502:physiology / Q000648:ultrastructure; D055595:Mechanical Phenomena; D008954:Models, Biological; D009024:Morphogenesis; D009218:Myosins / Q000737:chemistry / Q000502:physiology
D000205:Actomyosin; D009218:Myosins