Somatic cell cycle consists of four phases while early embryonic cell cycle alternates between S and M phases without intervening G1 and G2 phases. Different models of cell cycle regulation ...

In somatic cells, these phases are separated ... To maintain ploidy, unidirectional progression through the phases of the cell cycle (G1 → S → G2 → M → G1) is essential.

soma cell fate decision during embryogenesis. After a flurry of cell divisions from the starting “germ cell” (i.e. united egg and sperm), somatic cells begin to exit the cell cycle as the DREAM ...