The first polar body does not predict accurately the location of the metaphase II meiotic spindle in mammalian oocytes

Fertil Steril. 1999 Apr;71(4):719-21. doi: 10.1016/s0015-0282(98)00530-5.


Objective: To evaluate how well polar body location predicts spindle localization and to examine spindle morphology.

Design: Randomized, controlled animal study.

Setting: University-affiliated research laboratory.

Animal(s): Mature, female golden hamsters.

Intervention(s): After superovulation with pregnant mare serum gonadotropin and hCG, metaphase II oocytes were obtained and imaged under digital polarization microscopy.

Main outcome measure(s): Identify the meiotic spindle in living, unfixed hamster oocytes and determine spindle location relative to the polar body.

Result(s): Spindles were imaged in 30 oocytes and only in 5 of them could the polar body predict the spindle localization. In the remaining oocytes, the spindles presented a random distribution within the cytoplasm.

Conclusion(s): These data show that the polar body location is not an accurate predictor for meiotic spindle location in mammalian oocytes.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Chromosomes / ultrastructure*
  • Cricetinae
  • Female
  • Meiosis*
  • Mesocricetus
  • Metaphase*
  • Oocytes / ultrastructure*
  • Organelles / ultrastructure*
  • Pregnancy