Analysis of differentiation and cell cycle dynamics from live imaging.
(A) Analysis of Neurog3-RFP onset in four locations from three different time-lapse movies (n = 56, 89, 54, and 125, respectively). Each vertical bar symbol indicates an onset event, and the yellow area displays the probability, obtained by kernel density estimation, of an event occurring over time. These suggest that cell differentiation might not be a homogeneous process; however, further statistical analysis does not rule out this possibility (S1.4 Text). (B) Lag time of Neurog3-RFP onset between daughters derived from symmetric (R/R) divisions (n = 19). Symmetrically fated daughters exhibited synchronized expression of Neurog3-RFP, as pointed out by the highly correlated lag time between division and RFP onset (inset). (C) Lag time between division and Neurog3-RFP onset in asymmetric (P/R, n = 27) versus symmetric (R/R, n = 38) divisions. Note the data are pooled from three live imaging movies. RFP cells from P/R divisions took a significantly longer time to turn on RFP than cells from R/R divisions. Black-outlined red circles from P/R division (n = 14) indicate P/R divisions producing grand-daughters through progenitor daughter division. (D) Doubling time of progenitors originating from either symmetric (P/P, black circle) or asymmetric (P/N and P/R, pink circle) divisions. Doubling time of asymmetrically generated progenitors took longer than symmetrically generated progenitors. Statistical analyses were done using two-tailed Mann-Whitney test. *** p < 0.0001 and * p = 0.04 (C,D).