aMTOCs aid formation of monopolar spindles in acentriolar cells that also lack misato.

<p>(A) Larval brain cells of <i>WT</i>, <i>mst; Sas-4</i> and <i>mst; asl</i> double mutants were stained with antibodies against α-tubulin (red) and Cnn (green), DNA is in blue. <i>mst; Sas-4</i> cells have aMTOCs (arrow) on the poles of monopolar spindles. Scale bar represents 5μm. (B) Quantification of monopolar spindles in <i>mst; Sas-4</i> and <i>mst; asl</i> cells (a minimum of 263 cells in 8 brains were quantified per genotype). In <i>mst; Sas-4</i> mutants 59.32% ± 3.81 of cells form monopolar spindles while in <i>mst; asl</i> only 25.15% ± 3.34 of cells form monopolar spindles (the remaining cells do not exhibit any monopolar or bipolar spindles). (C) Quantification of regrowth of monopolar spindles after cold-induced depolymerisation at different time points after release from cold treatment. In <i>mst; Sas-4</i> brains 0% ± 0 of cells formed monopolar spindles at 0 minutes, 8% ± 4.25 at 2 minutes, 12.5% ± 7.89 at 5 minutes, 24.24% ± 6.1 at 10 minutes, 38.27% ± 3.24 at 20 minutes and 47.96% ± 3.09 at 30 minutes. In <i>mst; asl</i> brains 4.7% ± 2.62 of cells formed monopolar spindles at 0 minutes, 3.03% ± 1.55 at 2 minutes, 8.93% ± 2.9 at 5 minutes, 2% ± 3.93 at 10 minutes, 0% ± 0 at 20 minutes and 3.74% ± 2.74 at 30 minutes (a minimum of 43 cells from 4 brains were quantified for each timepoint). All data are expressed as mean±SEM with average per brain representing one data point. P-values were calculated using a Mann-Whitney test.