title: Organelles maintain spindle position in plant meiosis.
abstract: Accurate positioning of spindles is a critical aspect of cell division as it ensures that each daughter cell contains a single nucleus. In many flowering plants, two meiotic chromosome separations occur without intervening cytokinesis, resulting in two spindles in one cell during the second division. Here we report a detailed examination of two mutants, jason (jas) and parallel spindle1 (ps1), in which disturbed spindle position during male meiosis II results in the incorporation of previously separated chromosome groups into a single cell. Our study reveals that an organelle band provides a physical barrier between the two spindles. The loss of a single protein, JAS, from this organelle band leads to its disruption and a random movement of the spindles. JAS is largely associated with vesicles in the organelle band, revealing a role for vesicles in plant meiosis and that cytoplasmic events maintain spindle position during the chromosome division.
authors.affiliation: Department of Biochemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
authors.forename: Lynette
authors.initials: L
authors.lastname: Brownfield
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center of Plant Biology, PO Box 7080, Uppsala SE-75007, Sweden.
authors.forename: Jun
authors.initials: J
authors.lastname: Yi
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center of Plant Biology, PO Box 7080, Uppsala SE-75007, Sweden.
authors.forename: Hua
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center of Plant Biology, PO Box 7080, Uppsala SE-75007, Sweden.
authors.forename: Elena A
authors.initials: EA
authors.lastname: Minina
authors.affiliation: Department of Biology, University of Leicester, Leicester LE1 7RH, UK.
authors.forename: David
authors.initials: D
authors.lastname: Twell
authors.affiliation: Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center of Plant Biology, PO Box 7080, Uppsala SE-75007, Sweden.
authors.forename: Claudia
authors.initials: C
authors.lastname: Köhler
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D020090:Chromosome Segregation; D048749:Cytokinesis; D015870:Gene Expression; D006056:Golgi Apparatus / Q000378:metabolism / Q000648:ultrastructure; D008540:Meiosis; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D009154:Mutation; D020675:Peroxisomes / Q000378:metabolism / Q000648:ultrastructure; D059828:Plant Cells / Q000378:metabolism / Q000648:ultrastructure; D018517:Plant Roots / Q000378:metabolism / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D012737:Sex Factors; D008941:Spindle Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C558441:Jason protein, Arabidopsis; C534518:PS1 protein, Arabidopsis; D015534:Trans-Activators