Cells enter the G0 phase from a cell cycle checkpoint in the G1 phase, such as the restriction point (animal cells) or the start point (yeast). This usually occurs in response to a lack of growth factors or nutrients. During the G0 phase, the cell cycle machinery is dismantled and cyclins and cyclin-dependent kinases disappear. read more
The G 0 phase describes a cellular state outside of the replicative cell cycle. Classically, cells were thought to enter G 0 primarily due to environmental factors, like nutrient deprivation, that limited the resources necessary for proliferation. read more