The importance of DNA repair for maintaining oocyte quality in response to anti-cancer treatments, environmental toxins and maternal ageing

AbstractBACKGROUNDWithin the ovary, oocytes are stored in long-lived structures called primordial follicles, each comprising a meiotically arrested oocyte, surrounded by somatic granulosa cells. It is essential that their genetic integrity is maintained throughout life to ensure that high quality oocytes are available for ovulation. Of all the possible types of DNA damage, DNA double-strand breaks (DSBs) are considered to be the most severe. Recent studies have shown that DNA DSBs can accumulate in oocytes in primordial follicles during reproductive ageing, and are readily induced by exogenous factors such as γ-irradiation, chemotherapy and environmental toxicants. DSBs can induce oocyte death or, alternatively, activate a program of DNA repair in order to restore genetic integrity and promote survival. The repair of DSBs has been intensively studied in the context of meiotic recombination, and in recen t years more detail is becoming available regarding the repair capabilities of primordial follicle oocytes.OBJECTIVE AND RATIONALEThis review discusses the induction and repair of DNA DSBs in primordial follicle oocytes.SEARCH METHODSPubMed (Medline) and Google Scholar searches were performed using the key words: primordial follicle oocyte, DNA repair, double-strand break, DNA damage, chemotherapy, radiotherapy, ageing, environmental toxicant. The literature was restricted to papers in the English language and limited to reports in animals and humans dated from 1964 until 201...
Source: Human Reproduction Update - Category: OBGYN Source Type: research