Study on the mechanism of oocyte aneuploidy by spectral karyotyping / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish the method of detecting oocyte aneuploidy by spectral karyotyping (SKY).</p><p><b>METHODS</b>The unfertilized oocytes were fixed 1-2 days after oocyte retrieval. Spectral karyotyping was performed according to the protocol.</p><p><b>RESULTS</b>64% of oocytes were normal, 36% of oocytes were aneuploidy, of which 22% were due to nondisjunction and 14% unbalanced predivision.</p><p><b>CONCLUSION</b>SKY is an effective method for detecting oocyte aneuploidy. Both nondisjunction and unbalanced predivision are involved in oocyte aneuploidy formation.</p>

Study on the mechanism of oocyte aneuploidy formation by multicolor fluorescence in situ hybridization / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the mechanism of oocyte aneuploidy formation.</p><p><b>METHODS</b>The unfertilized oocytes were fixed 1-3 days after oocyte retrieval. Multicolor fluorescence in situ hybridization (M-FISH) was performed according to the Vysis protocol to check the chromosome status in oocytes by using centromeric enumerator probes for chromosomes 16, 18 and locus-specific probes for chromosomes 13, 21 and 22.</p><p><b>RESULTS</b>47% oocytes were found to be normal, while 53 % oocytes were abnormal. Nondisjunction was found in 22(18%) oocytes, unbalanced predivision of chromatids in 15(12%) oocytes, balanced predivision of chromatids in 45(36%) oocytes. The balanced predivision rate in oocytes aged in vitro>24h was much higher than that in oocytes aged in vitro<or=24h (P<0.01).</p><p><b>CONCLUSION</b>Both nondisjunction, balanced and unbalanced predivision of chromatids are involved in the oocyte aneuploidy formation. Balanced predivision is related to the time in culture.</p>