Cell cycle levels in S and at their lowest near mitosis. Cell cycle The cell cycle, or cell-division cycle, is the series of events that take place in a cell leading to its division and duplication of its DNA (DNA replication) to produce two daughter cells. In bacteria, which lack a cell nucleus, the cell cycle is divided into the B, C, and D periods. The B period extends from the end of cell division to the beginning of DNA replication. DNA replication occurs during the C period. The D period refers to the stage between the end of DNA replication and
Epigenetics in stem-cell differentiation one. "DNMT3A" and "DNMT3B" have both been linked to a role in the establishment of DNA methylation pattern in the early development of the stem cell, whereas "DNMT1" is required to methylate a newly synthesized strand of DNA after the cell has undergone replication in order to sustain the epigenetic regulatory state. Numerous proteins can physically interact with "DNMTs" themselves, which help target "DNMT1" to hemi-methylated DNA. Several new studies point to the central role of DNA methylation interacting with the regulation of cell cycles and DNA repair pathways in order to maintain the undifferentiated state. In embryonic stem cells,