Abstract
Telomeres promote genome integrity by protecting chromosome ends from the activation of the DNA damage response and protecting chromosomes from the loss of coding sequences due to the end replication problem. Telomere length (TL) is progressively shortened as age progresses, thus resulting in cellular senescence. Therefore, TL is in strong adverse linear correlation with aging. Mounting evidence supports the notion that telomeres and male/female infertility are in a close relationship, posing the biology of telomeres as a hot topic in the era of human-assisted reproduction. Specifically, the length of sperm telomeres is gradually increasing as men get older, while the telomere length of the oocytes seems not to follow similar patterns with that of sperm. Nonetheless, the telomere length of the embryos during the cleavage stages seems to have a paternal origin, but the telomere length can be further extended by telomerase activity during the blastocyst stage. The latter has been proposed as a new molecular biomarker with strong predictive value regarding male infertility. As far as the role of telomeres in assisted reproduction, the data is limited but the length of telomeres in both gametes seems to be affected mainly by the cause of infertility rather than the assisted reproductive therapy (ART) procedure itself. The present review aims to shed more light into the role of telomeres in human embryological parameters, including gametes and embryos and also presents opinions regarding the association between telomeres and in vitro fertilization (IVF).
Highlights
Aging is an irreversible process accompanied by cellular senescence
As far as the endogenous factors aspect is concerned, normal diet and the supplementation of basic nutrients preserve a normal body mass index (BMI), which is correlated with male and female infertility cases [35], but further reduces the telomere-shortening rate [36]. Along these lines of genetic- and epigenetic-related factors that exert an impact on telomere length, it is worth highlighting the prolonged role of culture of gametes and pre-implantation embryos
Women undergoing in vitro fertilization (IVF)-ET treatments—regardless of their etiology—seem to present with shorter Telomere length (TL) in comparison to healthy controls [67]. It appears that the etiology of infertility constitutes the trigger for telomere erosion, which results in sub-fertility. This notion has been further supported by the assessment of LTLs in women who have at least one live birth compared to women who have solely experienced a biochemical pregnancy, spontaneous abortion or miscarriage
Summary
Aging is an irreversible process accompanied by cellular senescence This physiological process has been further characterized by a decline in reproductive potential. Telomerase activity (TA) has been associated with telomere lengthening as well as telomere length stabilization [6]. It is inactivated in somatic cells where telomeres shorten in each cell division. Aneuploid embryos demonstrated shorter telomeres, which has been inevitably associated with lower pregnancy rates [13]. In this regard, this aneuploidy is frequently detected during cancer development and initiated by critically short telomeres.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
