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Published on: December 6, 2017
Why is chromosome segregation error in oocytes increased with maternal aging?
Zhen-Bo Wang1, Heide Schatten, Qing-Yuan Sun
1State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Physiology (Bethesda, Md.)
|October 21, 2011
Summary
Female fertility declines with age due to oocyte chromosome abnormalities, primarily caused by reduced centromeric cohesion. Other factors like weakened recombination and spindle issues also contribute to these errors.
Area of Science:
- Reproductive biology
- Cell biology
- Genetics
Background:
- Female fertility significantly decreases with advanced maternal age.
- This decline is strongly linked to an increased incidence of chromosome abnormalities in oocytes.
- Centromeric cohesion reduction is a primary driver of chromosome missegregation in aging oocytes.
Purpose of the Study:
- To elucidate the multifaceted causes of chromosome errors in oocytes from aging females.
- To highlight the critical role of centromeric cohesion and other contributing factors in age-related female infertility.
Main Methods:
- Review of existing literature on oocyte aging and chromosome segregation.
- Analysis of molecular mechanisms underlying cohesion, recombination, and spindle function.
- Examination of epigenetic modifications and extra-oocyte influences.
Main Results:
- Advanced maternal age is associated with reduced centromeric cohesion, leading to increased chromosome missegregation.
- Weakened homologous recombination, aberrant spindle organization, and spindle assembly checkpoint (SAC) malfunction are identified as significant contributors.
- Epigenetic alterations in chromatin and external oocyte factors also play a role in age-related chromosome errors.
Conclusions:
- Chromosome abnormality in oocytes is a major cause of decreased fertility in older women.
- Centromeric cohesion reduction is the principal mechanism, but other factors exacerbate chromosome missegregation.
- Understanding these complex mechanisms is crucial for addressing age-related infertility.
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