TY - JOUR
T1 - A soft cortex is essential for asymmetric spindle positioning in mouse oocytes
AU - Chaigne, Agathe
AU - Campillo, Clément
AU - Gov, Nir S.
AU - Voituriez, Raphaël
AU - Azoury, Jessica
AU - Umaña-Diaz, Claudia
AU - Almonacid, Maria
AU - Queguiner, Isabelle
AU - Nassoy, Pierre
AU - Sykes, Cécile
AU - Verlhac, Marie Hélène
AU - Terret, Marie Emilie
N1 - Ligue Nationale Contre le Cancer [EL2009-EL2012/LNCC/MHV]; Agence Nationale pour la Recherche [ANR-08-BLAN-0136-01, ANR-08-BLAN-0012-12]; Ecole Normale Superieure (ENS) Paris; Association pour la Recherche contre le Cancer (ARC); Mayent-Rothschild FoundationWe thank T. Pollard (Yale University, USA) for providing the CK666 and F. Perez (Curie Institute, France) for providing SF9-expressing plasmids. We thank J. Teillon for helping set up the photoactivation experiments. We thank C. Klein for his help with the analysis of the photoactivation data. We also thank A. Roux, M. Piel, A. Echard, A. Gautreau, E. Derivery and R. Li for helpful discussions. This work was supported by grants from the Ligue Nationale Contre le Cancer (EL2009-EL2012/LNCC/MHV) and from the Agence Nationale pour la Recherche (ANR-08-BLAN-0136-01 to MHV and ANR-08-BLAN-0012-12 to CS). A. Chaigne is a recipient of a fellowship from the Ecole Normale Superieure (ENS) Paris. C. Campillo acknowledges financial support from the Association pour la Recherche contre le Cancer (ARC). N. S. Gov wishes to thank the Mayent-Rothschild Foundation for the Visiting Professor grant at the Curie Institute.
PY - 2013/8
Y1 - 2013/8
N2 - At mitosis onset, cortical tension increases and cells round up, ensuring correct spindle morphogenesis and orientation. Thus, cortical tension sets up the geometric requirements of cell division. On the contrary, cortical tension decreases during meiotic divisions in mouse oocytes, a puzzling observation because oocytes are round cells, stable in shape, that actively position their spindles. We investigated the pathway leading to reduction in cortical tension and its significance for spindle positioning. We document a previously uncharacterized Arp2/3-dependent thickening of the cortical F-actin essential for first meiotic spindle migration to the cortex. Using micropipette aspiration, we show that cortical tension decreases during meiosis I, resulting from myosin-II exclusion from the cortex, and that cortical F-actin thickening promotes cortical plasticity. These events soften and relax the cortex. They are triggered by the Mos-MAPK pathway and coordinated temporally. Artificial cortex stiffening and theoretical modelling demonstrate that a soft cortex is essential for meiotic spindle positioning.
AB - At mitosis onset, cortical tension increases and cells round up, ensuring correct spindle morphogenesis and orientation. Thus, cortical tension sets up the geometric requirements of cell division. On the contrary, cortical tension decreases during meiotic divisions in mouse oocytes, a puzzling observation because oocytes are round cells, stable in shape, that actively position their spindles. We investigated the pathway leading to reduction in cortical tension and its significance for spindle positioning. We document a previously uncharacterized Arp2/3-dependent thickening of the cortical F-actin essential for first meiotic spindle migration to the cortex. Using micropipette aspiration, we show that cortical tension decreases during meiosis I, resulting from myosin-II exclusion from the cortex, and that cortical F-actin thickening promotes cortical plasticity. These events soften and relax the cortex. They are triggered by the Mos-MAPK pathway and coordinated temporally. Artificial cortex stiffening and theoretical modelling demonstrate that a soft cortex is essential for meiotic spindle positioning.
UR - https://www.scopus.com/pages/publications/84881474606
U2 - 10.1038/ncb2799
DO - 10.1038/ncb2799
M3 - Article
SN - 1465-7392
VL - 15
SP - 958
EP - 966
JO - Nature Cell Biology
JF - Nature Cell Biology
IS - 8
ER -