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BP: Fachverband Biologische Physik
BP 8: Posters: Active cell and tissue mechanics
BP 8.5: Poster
Montag, 31. März 2014, 17:30–19:30, P3
Cellular chirality derives from active torques generated in the actomyosin cytoskeleton — •Sundar Naganathan1, Sebastian Fürthauer2, Frank Jülicher3, and Stephan Grill1,3,4 — 1MPI-CBG, Pfotenhauerstr. 108, 01307, Dresden — 2Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, N.Y. 10012 — 3MPI-PKS, Nöthnitzerstr. 38, 01187, Dresden — 4Biotechnology Center, TU Dresden, Tatzberg 47/49, 01307, Dresden
Many developmental processes break left/right (L/R) symmetry with a consistent handedness, which require cells to be chirally asymmetric. The mechanisms by which cell chirality is established remain unclear, but the actomyosin cytoskeleton appears to be involved. To address this problem, we investigated flows in the actomyosin cortex of the one-cell stage C. elegans embryo. In addition to anterior-directed cortical flow, we observe the cortex to break chiral symmetry by counter-rotating flow with a consistent handedness in the anterior and posterior halves. Using active chiral fluid theory, we demonstrate that this motion derives from an active torque-generation process of defined chirality in the actomyosin cortex. This torque generation depends on myosin activity and can be independently regulated from tension generation though mild changes in Rho pathway activity, which we show by weak perturbation RNAi experiments. Our experiments suggest that chirality and torque generation is an emergent network property of the cortex. Interestingly, genes that affect the establishment of the C. elegans L/R body axis also regulate active torques, setting the stage for a mechanistic understanding of chiral morphogenesis in development.