G0 phase

Many mammal cells, such as this 9x Hneuron, remain permanently or semipermanently in G0.

The G0 phase, G zero alpha phase, or 'resting phase' is a period in the cell cycle in which cells exist in a quiescent state. Mammalian cell devision cycle is controlled with extreme precision in order to complete the duplication of the genome and the segregation of replicated chromosome to daughter cells.[1] G0 phase is viewed as either an extended G1 phase, where the cell is neither dividing nor preparing to divide, or a distinct quiescent stage that occurs inside of the cell cycle.[2] Some types of cells, such as nerve and heart muscle cells, become quiescent when they reach maturity (i.e., when they are terminally differentiated) but continue to perform their main functions for the rest of the organism's life. Multinucleated muscle cells that do not undergo cytokinesis are also often considered to be in the G0 stage.[2] On occasion, a distinction in terms is made between a G0 cell and a 'quiescent' cell (e.g., heart muscle cells and neurons), which will never enter the G1 phase, whereas other G0 cells may.

Distinction from senescent cells

Cellular senescence is distinct from quiescence because it is a state that occurs in response to DNA damage or degradation that would make a cell's progeny nonviable. Senescence then, unlike quiescence, is often a biochemical alternative to the self-destruction of such a damaged cell by apoptosis. Furthermore, quiescence is reversible whereas senescence is not.[3][4]

References

  1. ↑ Matson, Jacob P.; Cook, Jeanette G. (2016-09-16). "Cell cycle proliferation decisions: the impact of single cell analyses". The FEBS journal. doi:10.1111/febs.13898. ISSN 1742-4658. PMID 27634578.
  2. 1 2 Re: Are the cells in the G0 (g zero) phase of mitosis really suspended? Erin Cram, Grad student, Molecular and Cellular Biology, University of California, Berkeley. 1999. MadScience Network. Question ID 942142089.Cb.
  3. ↑ Blagosklonny, Mikhail (9 February 2011). "Cell cycle arrest is not senescence". Aging (Albany NY). 3 (2): 94–101. doi:10.18632/aging.100281. PMID 3082019. Retrieved 11 November 2016.
  4. ↑ Beauséjour CM, Krtolica A, Galimi F, et al. Reversal of human cellular senescence: roles of the p53 and p16 pathways. The EMBO Journal. 2003;22(16):4212-4222. doi:10.1093/emboj/cdg417.

See also

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