Triggering a Cell Shape Change by Exploiting Preexisting Actomyosin Contractions

• Published in: Science (American Association for the Advancement of Science) Vol. 335; no. 6073; pp. 1232 - 1235
• Main Authors: Roh-Johnson, Minna, Shemer, Gidi, Higgins, Christopher D., McClellan, Joseph H., Werts, Adam D., Tulu, U. Serdar, Gao, Liang, Betzig, Eric, Kiehart, Daniel P., Goldstein, Bob
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 09-03-2012; The American Association for the Advancement of Science
• Subjects: Actins; Actomyosin - chemistry; Actomyosin - physiology; Animals; Biological and medical sciences; Caenorhabditis elegans - cytology; Caenorhabditis elegans - embryology; Cell lines; Cell Membrane - physiology; Cell Membrane - ultrastructure; Cell membranes; Cell physiology; Cell Shape; Cellular biology; Computer Simulation; Cytoskeleton - physiology; Cytoskeleton - ultrastructure; Developmental biology; Drosophila; Drosophila melanogaster - cytology; Drosophila melanogaster - embryology; Embryo, Nonmammalian - cytology; Embryo, Nonmammalian - physiology; Embryos; Fluorescence Recovery After Photobleaching; Fundamental and applied biological sciences. Psychology; Gastrulation; Gene expression regulation; Intercellular Junctions - physiology; Intercellular Junctions - ultrastructure; Lasers; Mechanical Phenomena; Models, Biological; Molecular and cellular biology; Morphogenesis; Morphology; Muscle contraction; Myosins - chemistry; Myosins - physiology; Neurons; Particle decay; Particle tracks; Proteins; Enzyme; Insecta; Drosophila; Cell cell interaction; Contraction; Drosophilidae; Caenorhabditis elegans; Myosin ATPase; Arthropoda; Helmintha; Morphogenetic movement; Hydrolases; Nemathelminthia; Invertebrata; Nematoda; Cell; Triggering; Diptera
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1217869

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.