title: [Study on the mechanism of oocyte aneuploidy formation by multicolor fluorescence in situ hybridization].
abstract: OBJECTIVE
  To investigate the mechanism of oocyte aneuploidy formation.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  Both nondisjunction, balanced and unbalanced predivision of chromatids are involved in the oocyte aneuploidy formation. Balanced predivision is related to the time in culture.
authors.affiliation: Department of Gynecology and Obstetrics, Tongji Hospital of Tongji Medical College, Huazhong Science and Technology University, Wuhan, Hubei, 430030 PR China. chenwenyyy@yahoo.com
authors.forename: Wen
authors.initials: W
authors.lastname: Chen
authors.forename: Liselotte
authors.initials: L
authors.lastname: Mettler
mesh_terms: D000328:Adult; D000782:Aneuploidy; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007621:Karyotyping; D009865:Oocytes / Q000648:ultrastructure*