Fig. 2.

In Kif20b mutant brains, a subset of NSCs furrows more slowly. (A) Representative images and traced silhouettes of cytokinetic furrow ingression in one E13.5 control (A, a), one normally furrowing Kif20b mutant (−/−) NSC (A, b), and one abnormally slow furrowing mutant NSC (A, c). Furrowing was considered complete when no additional narrowing of furrow width occurred and the membrane between sister cells appeared continuous. Times shown in minutes (′). (B, C, E, and F) Furrow width and pole to pole length were plotted over time in E11.5 (B and C) and E13.5 (E and F) control (black lines) and Kif20b^−/− (gray lines) cortical slab explants. Most Kif20b^−/− cells furrow at a similar rate to controls, but a subset (red lines) furrows more slowly and takes 24 min to complete. (D and G) Time to furrow completion was increased in E11.5 and E13.5 Kif20b mutant cortices, with a subset of NSCs taking 24 min to complete. Blue lines are medians. (B–G) E11.5: n = 43 control cells from two brains (one +/− and one +/+), n = 35 total Kif20b^−/− cells from two brains, n = 5 Kif20b^−/− cells in slow subset (red lines); E13.5: n = 25 control cells (from two +/− brains and one +/+ brain), n = 27 total Kif20b^−/− cells from three brains, n = 7 Kif20b^−/− cells in slow subset (red lines). For (D and G) P values from Mann–Whitney (M-W) test. *P < 0.05 (Student's t test); **P < 0.01 (Student's t test); ****P < 0.0001 (Student's t test).