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Oocyte abnormalities can be caused by a variety of genetic factors affecting different stages in meiosis. [1] Moreover, ageing is associated with oocyte abnormalities since higher maternal age is associated with oocytes with a reduced gene expression of spindle assembly checkpoints which are important in maintaining stability in the genome.
The arrest of ooctyes at the four genome copy stage appears to provide the informational redundancy needed to repair damage in the DNA of the germline. [26] The repair process used likely involves homologous recombinational repair. [26] [27] [28] Prophase arrested oocytes have a high capability for efficient repair of DNA damages. [27]
In mammalian females the period of arrest may last for years. During this period of arrest, oocytes are subject to spontaneous DNA damage including double-strand breaks. However, the oocytes can efficiently repair DNA double-strand breaks, allowing the restoration of genetic integrity and the protection of offspring health. [8]
This is an accepted version of this page This is the latest accepted revision, reviewed on 26 January 2025. Cell division producing haploid gametes For the figure of speech, see Meiosis (figure of speech). For the process whereby cell nuclei divide to produce two copies of themselves, see Mitosis. For excessive constriction of the pupils, see Miosis. For the parasitic infestation, see Myiasis ...
BRCA1 and ATM proteins are employed in repair of DNA double-strand break during meiosis. These proteins appear to have a critical role in resisting ovarian aging. [25] However, homologous recombinational repair of DNA double-strand breaks mediated by BRCA1 and ATM weakens with age in oocytes of humans and other species. [25]
The species with longer lifespans were found to have slower accumulation of DNA damage, a finding consistent with the DNA damage theory of aging. [119] In healthy humans after age 50, endogenous DNA single- and double-strand breaks increase linearly, and other forms of DNA damage also increase with age in blood mononuclear cells. [ 120 ]
The peer-reviewed research from Harvard Medical School found that DEET had negative impacts on the reproductive systems of Caenorhabditis elegans, a species of worm with genetic similarities to ...
The response of oocytes to DNA double-strand break damage involves a pathway hierarchy in which ATR kinase signals to CHEK2 which then activates p53 and p63 proteins. [ 15 ] In the fruit fly Drosophila , irradiation of germ line cells generates double-strand breaks that result in cell cycle arrest and apoptosis .