Cell cycle proliferation decisions: the impact of single cell analyses. (5th October 2016) - Matson, Jacob P.
Abstract : Cell proliferation is a fundamental requirement for organismal development and homeostasis. The mammalian cell division cycle is tightly controlled to ensure complete and precise genome duplication and segregation of replicated chromosomes to daughter cells. The onset of DNA replication marks an irreversible commitment to cell division, and the accumulated efforts of many decades of molecular and cellular studies have probed this cellular decision, commonly called the restriction point. Despite a long‐standing conceptual framework of the restriction point for progression through G1 phase into S phase or exit from G1 phase to quiescence (G0), recent technical advances in quantitative single cell analysis of mammalian cells have provided new insights. Significant intercellular heterogeneity revealed by single cell studies and the discovery of discrete subpopulations in proliferating cultures suggests the need for an even more nuanced understanding of cell proliferation decisions. In this review, we describe some of the recent developments in the cell cycle field made possible by quantitative single cell experimental approaches. Abstract : Proliferating cells decide to pursue a next cell division or exit to G0. Recent single cell studies provide new insights into when the cell cycle cells commit to division. Actively proliferating cells have at least two decision points, the first in G2 phase and the second in G1, whereas cells entering the cycle from G0 (quiescence) decide in G1.