Figure 5.

Telomere Shortening Accompanies Cell-Cycle Elongation

ESCs labeled with CFSE dye followed by culture for 48 hr were sorted by FACS into three groups according to the dilution of the dye, which gives cohorts of fast, medium, or slow cell cycles (upper panel). The telomere length of each cohort was measured by flow-FISH using a Cy3-conjugated telomere probe (lower panels). The average telomere intensity (×1,000) per cell ±SD is indicated. n > 5,000 cells. Two technical replicates showed the same tendency. Telomeres were shorter in the cells with longer cell cycles. See also Figure S6A.