Figure 1: Centriole block to reduplication is short ranged.

(a–c) Stills from time-lapse recordings showing centrioles in reduplication. (a) Two Plk1TD–RFP signals indicate two centrosomes. Each Plk1TD–RFP signal is associated with one brighter C1–GFP signal (mother centriole) and one or two dimmer C1–GFP signals (daughter centrioles). The two centrosomes separate during imaging, revealing that one mother centriole is associated with two daughter centrioles (80-min time frame, indicated by an arrow). The mother moves in the cytoplasm associated with both daughter centrioles (150 min, indicated by an arrow). (b) A mother centriole (red arrow) in reduplication is still closely associated with an older daughter centriole (white arrow). Scale bars, 2 μm (a,b). (c) Correlative light and electron analysis of centrioles in reduplication. Two centrosomes in a Plk1TD–RFP-expressing cell were first followed by time lapse. Initially two symmetrical signals are visible. Later, the signals became more elongated, indicating that the daughter centriole matured and accumulated Plk1TD–RFP. Scale bar, 2 μm. At that point, the cell was fixed and the same centrosomes were analysed by electron microscopy. Electron microscopy revealed that both mother centrioles (M1 and M2) reduplicated and were associated with shorter daughter centrioles (D1–2 and D2–2) at the distance of ∼65 nm, and with the original longer daughter centriole (D1 and D2) in orthogonal or almost orthogonal orientation, but at a distance greater than 80 nm.