Oocyte ageing is associated with an increased risk of
aneuploidy, contributing to infertility and pregnancy loss in older females.
Chromosomal cohesion during meiosis is critical for accurate segregation, and
this process relies on proteins such as cohesin and separase.

Which mechanistic scenario best explains why
ageing oocytes are more prone to aneuploidy?

Question

Oocyte ageing is associated with an increased risk of
aneuploidy, contributing to infertility and pregnancy loss in older females.
Chromosomal cohesion during meiosis is critical for accurate segregation, and
this process relies on proteins such as cohesin and separase.

Which mechanistic scenario best explains why
ageing oocytes are more prone to aneuploidy?

Accepted Answer

Reduced
levels of cohesin in older oocytes weaken chromosome cohesion, which can lead
to premature separation of homologues or sister chromatids during meiosis

Answer

Ageing
oocytes maintain normal cohesin levels but low levels of separase, leading to
excessive oxidative damage that increases the risk of aneuploidy

Answer

Decreased
separase activity in older oocytes leads to failure of anaphase progression in
meiosis I, halting all oocytes before completion

Answer

Increased
cohesin in older oocytes causes chromosomes to stick together excessively,
impairing segregation

Crowdly

Oocyte ageing is associated with an increased risk of aneuploidy, contributing ...

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