Systematic analyses of binarized images of the G1/S transition.

<p>(A) Two quantitative indices, the anterior-most red cell (ARC) and posterior-most green cell (PGC), are introduced as illustrated. (B) The positions of the ARC and PGC as a function of time. The upper and lower sequences of notochordal cells along the anterior-posterior axis are drawn individually. (C) The total number of green (S) cells in the G1/S transition window, defined as seven cells anterior to the PGC, as well as the PGC (total: 8 cells) (also demonstrated in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003957#pcbi.1003957.s001" target="_blank">Figure S1</a>), as a function of time. The blue and green lines with ‘+’ markers indicate the upper and lower sequence data, respectively. (D) Number of green cell pairs in the G1/S transition window as a function of time. The red ‘+’ markers indicate the data obtained from the experiments. The black and blue lines indicate data obtained using random and biased simulation, respectively (see <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003957#s4" target="_blank">Methods</a>).