Fig. 6. Lineage analysis by time-lapse video microscopy of control and Par6-transduced progenitors. (A-G) Examples of lineage trees from control (A-D) and Par6-transduced (E-G) cells obtained from time-lapse images taken every 2 minutes over a period of 5 days. Horizontal grid lines indicate every 12 hours of the experiment. Colored stars indicate cell divisions generating two progenitors (green), two postmitotic cells (black) or one progenitor and one postmitotic cell (red). Most cells leaving the cell cycle more than 36 hours before the end of the movies were identified in subsequent immunolabelings as MAP2-positive neurons (N) (see also Fig. S2 in the supplementary material). Horizontal lines indicate the time point of cell division. The length of the horizontal line is arbitrary and has no significance. The lengths of the vertical lines depicts the time elapsed between two cell divisions, i.e. the cell cycle length. (H) Quantification of symmetric progenitor, symmetric terminal and asymmetric cell divisions in the first, second, third and fourth cell divisions. Note the higher frequency of symmetric progenitor cell divisions in the lineages derived from Par6-transduced cells (n=56) in comparison to controls (n=68).