Fig. 3. In the presence of extrinsic cues, G2 centrosome position remains constant and correlates with a reproducible division axis. (A-E) Series of still images from a time-lapse confocal movie of a clustered neuroblast dissociated from G147-GFP embryos, during three consecutive cell cycles. Mitotic stages and cell cycles are as indicated. A red line connects both apical and basal centrosomes during mitosis through the spindle axis or the G2 centrosome and approximate cell center during interphase. The white arrows indicate the two centrosomes that remain closely apposed at G2. The asterisk indicates an epithelial cell dividing symmetrically. (F-I) Quantitation of the angle between the following two lines: (F) a line connecting the G2 centrosomes to cell center and a line through the metaphase spindle; (G) a line through the metaphase spindle and a line through the telophase spindle; (H) a line through the telophase spindle and a line connecting the G2 centrosomes to cell center in the subsequent division; and (I) a line connecting the G2 centrosomes to cell center and a line connecting the G2 centrosomes to cell center in the following division. Black bars indicate neuroblast percent. Scale bar: 10 µm.