Lis1 and Ndel1 contribute to PNEI. (A) COS-7 cell nuclei labeled with Hoechst. (left) A prophase nucleus before PNEI. (right) Nuclei with varying degrees of PNEI. (B, top) Lis1 shRNA (Lis1i) or dynein shRNA (DHCi) reduces protein expression by 48 h after transfection. (bottom) Relative to scrambled controls, the percentage of prophase cells with PNEI was reduced by Lis1 or DHC RNAi. (C) Similarly, Ndel1 RNAi reduced Ndel1 expression and PNEI. This was prevented by coexpression of Ndel1 but not Ndel15A, which has S/T→A mutations in five cdk sites. (D) Increased PNEI was caused by full-length Lis1 (FL), whereas a Lis1 fragment (N term) reduced PNEI. (E) Nocodazole treatment for 13 h after transfection prevents Ndel1-induced PNEI. (F) Neither Ndel15A nor Ndel13A (S/T→A mutations in the first three cdk sites) increased PNEI. (G) COS-7 cells express cdk5 and p35. (H) Cells were transfected with cdk5/p25, cdk1/cyclin B1, or dominant-negative kinases (dncdk5 and dncdk1). (I) The kinases described in H were cotransfected with Ndel1. Data are the mean ± SD for three cultures. Significance was determined by Student's t test. Error bars indicate ±SD. Bar, 10 μm.