Figure 1.

Plk4 Regulates Centriole Dynamics in Interphase, Impacting Spindle Orientation

(A) Schematic drawing representing two consecutive cell cycles of a Drosophila NB depicting centrosome behavior.

(B–E) Images from time-lapse movies of Ctrl (B), Plk4^KD (C and D), and Plk4^WT (E) larval NBs. Tubulin in red. RFP-Sas-6 (B), GFP-Plk4^KD (C and D), and GFP-Plk4^WT (E) in green. See also Figures S1 and S2. The blue arrow denotes the centrosome (or centriole in the case of Plk4^KD) inherited by the NB at the end of mitosis in the first column but, in all other images, marks the centriole that was localized at the apical cortex (apical centriole) after disengagement. White arrows point to the centriole that moves basally in Ctrl NBs. The yellow arrow points to the centrosome positioned at the spindle pole at the end of mitosis in Plk4^WT NBs. Time, minutes. Scale, 4 μm. Diagrams on the right illustrate centriole behavior in early interphase.

(F) Graph shows the percentage of centriole behavior categories during interphase in the indicated genotypes. Centriole behavior was categorized as apical-like in (B) or (C), apical-mobile-like in (D), when the centrosome moved laterally even if remained localized within the apical hemisphere, or basal-like in (E).

(G) Quantification of the angle between two consecutive mitoses in Ctrl, Plk4^KD and Plk4^WT. Statistical significance (SS) was assessed by unpaired t test.