title: A lateral belt of cortical LGN and NuMA guides mitotic spindle movements and planar division in neuroepithelial cells.
abstract: To maintain tissue architecture, epithelial cells divide in a planar fashion, perpendicular to their main polarity axis. As the centrosome resumes an apical localization in interphase, planar spindle orientation is reset at each cell cycle. We used three-dimensional live imaging of GFP-labeled centrosomes to investigate the dynamics of spindle orientation in chick neuroepithelial cells. The mitotic spindle displays stereotypic movements during metaphase, with an active phase of planar orientation and a subsequent phase of planar maintenance before anaphase. We describe the localization of the NuMA and LGN proteins in a belt at the lateral cell cortex during spindle orientation. Finally, we show that the complex formed of LGN, NuMA, and of cortically located Gαi subunits is necessary for spindle movements and regulates the dynamics of spindle orientation. The restricted localization of LGN and NuMA in the lateral belt is instructive for the planar alignment of the mitotic spindle, and required for its planar maintenance.
authors: Université de la Méditerranée/Aix-Marseille II, Developmental Biology Institute (IBDML), Centre National de la Recherche Scientifique UMR6216, Case 907, Campus de Luminy, 13288 Marseille, France.
authors: Elise
authors: E
authors: Peyre
authors: Florence
authors: F
authors: Jaouen
authors: Mehdi
authors: M
authors: Saadaoui
authors: Laurence
authors: L
authors: Haren
authors: Andreas
authors: A
authors: Merdes
authors: Pascale
authors: P
authors: Durbec
authors: Xavier
authors: X
authors: Morin
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002455:Cell Division; D002642:Chick Embryo; D002645:Chickens; D051379:Mice; D008807:Mice, Inbred BALB C; D008938:Mitosis; D008969:Molecular Sequence Data; D046569:Neuroepithelial Cells / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D008941:Spindle Apparatus / Q000378:metabolism*; D014793:Visual Cortex / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; C502655:LGN protein, mouse; D028861:Nuclear Pore Complex Proteins