title: Confinement induces actin flow in a meiotic cytoplasm.
abstract: In vivo, F-actin flows are observed at different cell life stages and participate in various developmental processes during asymmetric divisions in vertebrate oocytes, cell migration, or wound healing. Here, we show that confinement has a dramatic effect on F-actin spatiotemporal organization. We reconstitute in vitro the spontaneous generation of F-actin flow using Xenopus meiotic extracts artificially confined within a geometry mimicking the cell boundary. Perturbations of actin polymerization kinetics or F-actin nucleation sites strongly modify the network flow dynamics. A combination of quantitative image analysis and biochemical perturbations shows that both spatial localization of F-actin nucleators and actin turnover play a decisive role in generating flow. Interestingly, our in vitro assay recapitulates several symmetry-breaking processes observed in oocytes and early embryonic cells.
authors: Institut Curie, Unite Mixte de Recherche 144 Centre National de la Recherche Scientifique, 12 rue Lhomond, 75005 Paris, France.
authors: Mathieu
authors: M
authors: Pinot
authors: Villier
authors: V
authors: Steiner
authors: Benoit
authors: B
authors: Dehapiot
authors: Byung-Kuk
authors: BK
authors: Yoo
authors: Franck
authors: F
authors: Chesnel
authors: Laurent
authors: L
authors: Blanchoin
authors: Charles
authors: C
authors: Kervrann
authors: Zoher
authors: Z
authors: Gueroui
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D003593:Cytoplasm / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted; D066298:In Vitro Techniques; D007700:Kinetics; D008540:Meiosis / Q000502:physiology*; D008856:Microscopy, Fluorescence; D014981:Xenopus / Q000378:metabolism / Q000502:physiology*
chemical_list: D000199:Actins