The first polar body does not predict accurately the location of the metaphase II meiotic spindle in mammalian oocytes.
OBJECTIVE
To evaluate how well polar body location predicts spindle localization and to examine spindle morphology.


METHODS
Randomized, controlled animal study.


METHODS
University-affiliated research laboratory.


METHODS
Mature, female golden hamsters.


METHODS
After superovulation with pregnant mare serum gonadotropin and hCG, metaphase II oocytes were obtained and imaged under digital polarization microscopy.


METHODS
Identify the meiotic spindle in living, unfixed hamster oocytes and determine spindle location relative to the polar body.


RESULTS
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.


CONCLUSIONS
These data show that the polar body location is not an accurate predictor for meiotic spindle location in mammalian oocytes.
Silva
C P
CP
Department of Obstetrics and Gynecology, Women and Infants Hospital, Brown University School of Medicine, Providence, Rhode Island 02905, USA.
Kommineni
K
K
Oldenbourg
R
R
Keefe
D L
DL
D000818:Animals; D002875:Chromosomes / Q000648:ultrastructure*; D006224:Cricetinae; D005260:Female; D008540:Meiosis; D008647:Mesocricetus; D008677:Metaphase; D009865:Oocytes / Q000648:ultrastructure*; D015388:Organelles / Q000648:ultrastructure*; D011247:Pregnancy