Defective nuclear transport in the absence of KCBP. (A) Nuclear migration defect observed immediately after cell division (0–18 min) of a KCBP KO cell. Time 0 corresponds to anaphase onset. Bar, 50 µm. White dotted lines indicate the position of the metaphase plate. (B) Position of the nucleus after anaphase onset in apical cells. Distance from the metaphase plate is plotted as the mean ± SEM. Control and kcbpΔ, n = 5; kcbpΔ with ectopic KCBP-b expression, n = 6. (C–E) MT polarity determination by EB1 imaging. (C) Snapshot (top) and kymograph (bottom) of EB1-citrine, whose moving direction indicates MT polarity. N, nucleus. Bars: (top) 10 µm; (horizontal) 5 µm; (vertical in kymograph) 2 min. (D) Directionality of EB1 motility was determined using a kymograph that spanned 30 µm from the phragmoplast equator (354 [control] or 248 [KO line] signals in five cells, mean ± SEM). (E) EB1-citrine movement near the nucleus (arrowheads). The tip of this cell is on the right. Bar, 2 µm. (F) Localization of citrine-tagged KCBP-b proteins. Arrowheads indicate nuclear signals (the other daughter nucleus is out of focus in this video). Note that autofluorescent chloroplasts are also visible as smaller ellipsoidal structures in this image sequence (marked with asterisks in the top panel). Time 0 corresponds to anaphase onset. Bar, 10 µm.