1. Acute Plk1 inhibition impacts mitotic spindle orientation.
Acute Plk1 inhibition impacts mitotic spindle orientation. (A) Schematic representation of the mitotic spindle on an L-shaped micro-pattern. The spindle is shown in brown, and centrosomes in cyan and chromosomes in blue. Spindle orientation was determined as an angle as depicted, with 0° being defined as the position of spindle along the hypotenuse as shown. (B–E) Synchronized HeLa cells on a L-shaped fibronectin micropattern either treated with DMSO (B, D) or BI 2536 (C, E). Cells are stained for NuMA (red) and γ-tubulin (green). DNA is shown in blue. D and E represent the frequency of angular distribution of spindle positioning every 15°. Note the change in the axis of the spindle orientation in cell treated with Plk1 inhibitor BI 2536 in contrast to the control condition. Also note cortical NuMA enrichment in cell treated with BI 2536 (N = 25 for DMSO control and N = 27 for BI 2536). P < between DMSO and BI 2536 treated cells, two-tailed t test. (F–I) hTERT-RPE1 cells were treated with DMSO control (F) or BI 2536 for 30 min post 7.5 h release of double thymidine (G). Cell were stained for γ-tubulin (red). DNA is shown in blue. The arrow represents the brightest γ-tubulin signal in the z-axis. Please note the metaphase spindle is tilted for a cell treated with Plk1 inhibitor BI 2536 in contrast to control. (H, I) represents pole–pole distance in the z-axis for control (H) or for BI 2536 (I) treated metaphase cells. Individual cells are plotted on the y-axis, and the distance between spindle pole is shown in μm on the x-axis. Please note that a few cells in the control and those treated with BI 2536 are on the same z-plane and thus show 0 μm distance on the z-axis (shown by dots) between spindle-poles (N = 30 for both conditions). P < 0.05 between DMSO control and BI 2536–treated cells, two-tailed t test.
Shrividya Sana et al. LSA 2018;1:e
© 2018 Sana et al.