Figure 3.

Pins and Mud Are Required for Spindle Orientation in the Follicle Cells

(A and A′) The centrosomes (marked by centrosomin, red) align with the lateral cortex in untreated cells, and the metaphase plate (marked with DAPI, blue) is positioned vertically. The centrosomes and the metaphase plate are misoriented after treatment with the microtubule depolymerizing drug colcemid.

(B and C) Pins-YFP (B, red) and Mud (C, red) colocalize with Dlg (green) along the lateral cortex in mitotic follicle cells (DAPI, blue).

(D) Metaphase spindles are misoriented in the absence of pins function. Cells homozygous for pins^p62 are marked by the absence of GFP (green). Boxes highlight two metaphase cells with misaligned spindles.

(E) Cumulative plot of metaphase spindle angles in pins^p62 mutant cells showing that the spindles are randomly oriented. Spindle angles in pins^p62 mutant cells (n = 32) differ significantly from the wild-type, with a p value of <0.005 as determined by the Kolmogorov-Smirnov test.

(F and F′) pins^p62 mutant cells marked by the absence of RFP (green in F) form normal bipolar spindles (green in F′) with centrosomes at each pole (marked by Centrosomin, in red).

(G) Metaphase spindles are misoriented in mud²/mud³ follicle cells.

(H) Cumulative plot of metaphase spindle angles in mud²/mud³ mutant follicle cells showing spindle misorientation with clustering at approximately 45°. Spindle angles in mud²/mud³ mutant cells (n = 24) differ significantly from those in the wild-type (p value of <0.005 as determined by the Kolmogorov-Smirnov test). See also Figure S2.