Association between spindle assembly checkpoint expression and maternal age in human oocytes

The spindle assembly checkpoint modulates the timing of anaphase initiation in response to the improper alignment of chromosomes at the metaphase plat e. If defects are detected, a signal is transduced to halt further progress ion of the cell cycle until correct bipolar attachment to the spindle is ac hieved. The mitotic arrest deficient (MAD2) and budding uninhibited by beno myl (BUB1) genes encode conserved kinetochore-associated proteins believed to be components of the checkpoint regulatory pathway. A failure in this su rveillance system could lead to genomic instability that may underlie the i ncreased incidence of aneuploidy in the gametes of older women. To explore this possibility, the concentrations of these transcripts in human oocytes at various stages of maturation were determined by real-time rapid cycle fl uorescent reverse transcription-polymerase chain reaction (RT-PCR). The res ults obtained following quantitative analysis suggest that these messages d egrade as oocytes age. Potentially, this may impair checkpoint function in older oocytes and may be a contributing factor in age-related aneuploidy.