Decision of spindle poles and division plane by double preprophase bands in a BY-2 cell line expressing GFP-tubulin

• Published in: Plant and cell physiology 2005-03, Vol.46 (3), p.531-538
• Main Authors: Yoneda, A.(Tokyo Univ. (Japan)), Akatsuka, M, Hoshino, H, Kumagai, F, Hasezawa, S
• Format: Article
• Language: English
• Subjects: 6-diamidino-2-phenylindole; ACTIN; Actin Cytoskeleton - metabolism; actin microfilament; actin-depleted zone; Actin-depleted zone (ADZ); ACTINA; ACTINE; ADZ; bistheonellide A; BY-2 cell line expressing GFP–tubulin; BY-GT16; BY-GT16 cells; CELL CULTURE; CELL CYCLE; CELL DIVISION; Cell Line; CICLO CELULAR; CLSM; confocal laser scanning microscopy; CULTIVO DE CELULAS; CULTURE DE CELLULE; CYCLE CELLULAIRE; cytochalasin B; cytochalasin D; Cytokinesis; Cytokinesis - physiology; DAPI; DIVISION CELLULAIRE; DIVISION CELULAR; Double preprophase bands; GFP; green fluorescent protein; Green Fluorescent Proteins; Metaphase - physiology; MICROTUBULE; MICROTUBULES; Microtubules - metabolism; MICROTUBULOS; Multipolar spindle; Nicotiana - cytology; Nicotiana - physiology; PBS; phosphate-buffered saline; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; PPB; preprophase band; Prophase - physiology; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Spindle Apparatus - metabolism; Tubulin - genetics; Tubulin - metabolism
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pci055

The preprophase band (PPB) of microtubules is thought to be involved in deciding the future division site. In this study, we investigated the effects of double PPBs on spindle formation and the directional decision of cytokinesis by using transgenic BY-2 cells expressing green fluorescent protein (GFP)-tubulin. At prophase, most of the cells with double PPBs formed multipolar spindles, whereas all cells with single PPBs formed normal bipolar spindles, clearly implicating the PPB in deciding the spindle poles. At metaphase, however, both cell types possessed the bipolar spindles, indicating the existence of correctional mechanism(s) at prometaphase. From prometaphase to metaphase, the spindles in double PPB cells altered their directions to become oblique to the cell-elongating axis, and these orientations were maintained in the phragmoplast and resulted in the oblique division planes. These oblique cell plates decreased when actin microfilaments were disrupted, and double actin-depleted zones (ADZs) appeared where the double PPBs had existed. These results suggest that the information necessary for proper cytokinesis may be transferred from the PPBs to the ADZs, even in the case of the double PPBs.