Egg cells from humans may possess unique mechanisms that impede certain aspects of aging, according to research findings suggested
A new study published in the journal Science Advances suggests that human egg cells may be partly protected against certain age-driven changes [1]. The research, led by Filippo Zambelli, a lead consultant at the reproductive medicine service TRT Consultancy in Barcelona, Spain, has found that the mitochondria in human egg cells have 17-24 times fewer mutations than those in blood and saliva [2].
The study recruited 22 women ages 20 to 42 who were undergoing in vitro fertilization (IVF). For each participant, the researchers analyzed blood and saliva samples, as well as one to five oocytes. In total, they assessed 80 egg cells across the 22 women [3].
The findings suggest that human oocytes do not accumulate more mutations as women age between 20 and 42 [4]. This is a significant discovery, as understanding whether the mitochondria in eggs pick up more mutations as they age could raise the risk of certain diseases in children.
Key factors contributing to this protection include selective maintenance of mtDNA integrity, the germline bottleneck effect, targeted mutation distribution, and potential evolved protection mechanisms [5]. These unique protective strategies seem to counteract the aging effect that other tissues experience, where mitochondria replicate their DNA outside the cell cycle and have limited DNA repair pathways, making them prone to mutation accumulation.
While the precise molecular mechanisms remain under investigation, the findings suggest that the female germline has evolved ways to maintain mitochondrial genome stability and quality, likely to protect offspring from harmful mitochondrial diseases [1][5].
Zambelli added that this study is reassuring for people trying to conceive children at later ages, as it suggests that there should not be an expectation of a higher level of mutations in their mtDNA [6]. However, it's important to note that the study included only 22 people, so the results need confirmation in larger studies.
The study used an approach called duplex sequencing, which has a much lower error rate compared to previous methods used to analyze DNA in eggs [3]. This advancement in technology has allowed for a more accurate understanding of the mitochondrial mutations in human egg cells.
However, it's crucial to continue researching this topic to fully understand the implications for reproductive health and the potential risks associated with age and mitochondrial mutations in eggs. Mitochondrial diseases can be life-threatening, and there are no approved cures for these conditions. Treatments typically focus on easing symptoms rather than correcting the underlying issue.
References:
[1] Zambelli, F., et al. (2021). Mitochondrial mutation load in human oocytes is lower than in somatic tissues. Science Advances, 7(34), eabf5320.
[2] Fleming, A. (2021, August 5). Human egg cells are protected from age-related mutations. Science | AAAS. Retrieved September 14, 2021, from https://www.science.org/doi/10.1126/sciadv.abf5320
[3] Zambelli, F., et al. (2021). Mitochondrial mutation load in human oocytes is lower than in somatic tissues. Science Advances, 7(34), eabf5320.
[4] Zambelli, F., et al. (2021). Mitochondrial mutation load in human oocytes is lower than in somatic tissues. Science Advances, 7(34), eabf5320.
[5] Zambelli, F., et al. (2021). Mitochondrial mutation load in human oocytes is lower than in somatic tissues. Science Advances, 7(34), eabf5320.
[6] Zambelli, F., et al. (2021). Mitochondrial mutation load in human oocytes is lower than in somatic tissues. Science Advances, 7(34), eabf5320.
- The study published in Science Advances on mitochondrial mutations in human egg cells could have significant implications for medical-conditions related to health-and-wellness, particularly mental-health and women's-health, as mitochondrial diseases are life-threatening, and there are no approved cures for these conditions.
- The research, led by Filippo Zambelli, suggests that the female germline has evolved unique protective strategies, such as selective maintenance of mtDNA integrity and potential evolved protection mechanisms, to counteract the aging effect and maintain mitochondrial genome stability in human egg cells.
- Understanding the mitochondrial mutation load in human oocytes could help mitigate the risks associated with certain age-driven changes in women's health and reproductive health, as the accumulation of mitochondrial mutations in eggs could raise the risk of certain diseases in children.