Author/Authors :
Mahmoudi، Reza نويسنده , , Amiri، Iraj نويسنده , , Pasbakhsh، Parichehr نويسنده , , Ragardi Kashani، Iraj نويسنده , , Abbasi، Mehdi نويسنده , , Aboulhasani، Farid نويسنده Department of Anatomy, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran , , Mehrannia، Tooba نويسنده Department of Anatomy, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran. , , Sobhani، Aligholi نويسنده ,
Abstract :
Background: Routine oocytes cryopreservation remained an elusive technique in the
wide ranges of available assisted reproductive technologies. The microtubules of
oocytes are vulnerable to cryoprotectants and thermal change during cryopreservation.
Objective: The effects of a vitrification protocol were investigated on the spindle and
chromosome configurations of mice oocytes cryopreserved at the germinal vesicle
stage.
Materials and Methods: Germinal vesicle with cumulus cells were transferred to
vitrification solution which was composed of 30% (v/v) ethylene glycol, 18% Ficoll-70
and 0.3 M Sucrose either by single step or in step-wise way. Following vitrification and
in vitro maturation (MII), the matured oocytes were immonostained for meiotic spindles
and chromosomes, before visualization using fluorescent microscopy.
Results: A statistically significant increase was observed in the survival and maturation
rate in step-wise vitrification (88.96% and 71.23% respectively) compared to single step
vitrification (70.6% and 62.42% respectively) (p < 0.05). Normal spindle morphology
after vitrification-thawing in step-wise vitrification group (77.26%) was higher than
single step vitrification group (64.24%) but lower than control group (94.75%)
(p < 0.05).
Conclusion: The results suggest that vitrification with step-wise procedure on mice
germinal vesicle oocytes has positive effects on survival and maturation rate and normal
spindle configuration compare with single step vitrification procedure.
