Cell cycle positioning drives heterogeneity within the pluripotent stem cell compartment

Heterogeneity in pluripotent cells marks a metastable state where cells may drift between native and lineage-primed populations. While the role for these heterogeneities are unclear, they may reflect the dynamic equilibriums of signaling networks and have a direct effect on differentiation potentialities. Here, we report the role of the cell cycle in establishing heterogeneity of human pluripotent stem cells. By utilizing the FUCCI cell cycle indicator system coupled to fluorescent activated cell sorting (FACS), we have uncovered that the cell cycle drives heterogeneity at the epigenetic, transcriptional and post-transcriptional levels. Our data show widespread dynamics in 5-hydroxymethylcytosine (5hmC) during the cell cycle. Furthermore, transcript profiling by RNA-sequencing identified >500 genes that were cell cycle-regulated, of which the largest cohort of genes were transcriptional regulators. In sum, we demonstrate the role of the cell cycle in coordinating cellular transitions between metastable states in pluripotent stem cells. mRNA sequencing of the cell cycle phases; early & late G1, S and G2/S from human ES cells in triplicate.