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Premeiotic, post meiotic, pre mitotic, or postmitotic events are all possibilities if imprints are created during male and female gametogenesis. However, if only one of the daughter cells receives parental imprints following mitosis, this would result in two functionally different female gametes or two functionally different sperm cells.
It is an epigenetic process that involves DNA methylation and histone methylation without altering the genetic sequence. These epigenetic marks are established ("imprinted") in the germline (sperm or egg cells) of the parents and are maintained through mitotic cell divisions in the somatic cells of an organism.
The cell cycle in eukaryotes: I = Interphase, M = Mitosis, G 0 = Gap 0, G 1 = Gap 1, G 2 = Gap 2, S = Synthesis, G 3 = Gap 3. Cell division is the process by which a parent cell divides into two daughter cells. [1] Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing.
Between the beginning of the G 1 phase (which is also after mitosis has occurred) and R, the cell is known as being in the G 1-pm subphase, or the post-mitotic phase. After R and before S, the cell is known as being in G 1-ps, or the pre S phase interval of the G 1 phase. [4]
Mitotic germ stem cells, oogonia, divide by mitosis to produce primary oocytes committed to meiosis. Unlike sperm production, oocyte production is not continuous. These primary oocytes begin meiosis but pause in diplotene of meiosis I while in the embryo. All of the oogonia and many primary oocytes die before birth.
Though Wee1 is a fairly conserved negative regulator of mitotic entry, no general mechanism of cell size control in G2 has yet been elucidated. Biochemically, the end of G 2 phase occurs when a threshold level of active cyclin B1 / CDK1 complex, also known as Maturation promoting factor (MPF) has been reached. [ 4 ]
The spindle checkpoint, also known as the metaphase-to-anaphase transition, the spindle assembly checkpoint (SAC), the metaphase checkpoint, or the mitotic checkpoint, is a cell cycle checkpoint during metaphase of mitosis or meiosis that prevents the separation of the duplicated chromosomes until each chromosome is properly attached to the ...
During this time, necessary mitotic proteins are produced and the cell is once more subjected to regulatory mechanisms to ensure proper status for entry into the proliferative Mitotic (M) phase. Multiple mechanistic checkpoints are involved in this transition from G2 to M, with a common uniting factor of cyclin-Cdk activity.