Deep sequencing shows that oocytes are not prone to accumulate mtDNA heteroplasmic mutations during ovarian ageing

AbstractSTUDY QUESTIONDoes ovarian ageing increase the number of heteroplasmic mitochondrial DNA (mtDNA) point mutations in oocytes?SUMMARY ANSWEROur results suggest that oocytes are not subject to the accumulation of mtDNA point mutations during ovarian ageing.WHAT IS KNOWN ALREADYAgeing is associated with the alteration of mtDNA integrity in various tissues. Primary oocytes, present in the ovary since embryonic life, may accumulate mtDNA mutations during the process of ovarian ageing.STUDY DESIGN, SIZE, DURATIONThis was an observational study of 53 immature oocyte –cumulus complexes retrieved from 35 women undergoing IVF at the University Hospital of Angers, France, from March 2013 to March 2014. The women were classified in two groups, one including 19 women showing signs of ovarian ageing objectified by a diminished ovarian reserve (DOR), and the other, i ncluding 16 women with a normal ovarian reserve (NOR), which served as a control group.PARTICIPANTS/MATERIALS, SETTING, METHODSmtDNA was extracted from isolated oocytes, and from their corresponding cumulus cells (CCs) considered as a somatic cell compartment. The average mtDNA content of each sample was assessed by using a quantitative real-time PCR technique. Deep sequencing was performed using the Ion Torrent Proton for Next-Generation Sequencing. Signal processing and base calling were done by the embedded pre-processing pipeline and the variants were analyzed using an in-house workflow. The distribution of the dif...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research