[Influence of two different vitrification cryopreservation methods on spindles of mouse oocytes].
OBJECTIVE
To investigate the influence of two different vitrification cryopreservation methods on the spindles of mouse M II oocytes.


METHODS
Three groups were included in the experiment, Group A, Group B and the control ( fresh oocytes). Mouse oocytes were vitrified by using cryoloop, with ethylene glycol( EG) in Group A and with EG + dimethyl sulphoxide ( DMSO) in Group B as cryoprotectants, and then the oocytes were placed directly into liquid nitrogen. Three hours after the frozen oocytes were thawed they were fixed, and the microtubule and chromosome were stained by indirect immunofluorescent method.


RESULTS
The survival rates of the oocytes after treated by the two vitrification cryopreservation methods had no difference ( 80. 3% vs 87. 5% , P > 0. 05) . The rate of the intact spindles in Group A was much lower than that of the control and Group B ( 15. 2% vs 78.7% , 15. 2% vs 77. 5% , P < 0. 05). But there was no difference between the latter two groups (78. 7% vs 77. 5% , P >0. 05). The oocytes with normal chromosome in Group A were much less than in the control and Group B (17.4% vs 76. 6% , 17. 4% vs 72. 5% , P <0. 05) , with no difference between the latter two groups(76. 6% vs 72. 5% , P >0. 05) ; The oocytes with abnormal chromosome were more in Group A than in the control and Group B (82. 6% vs 19. 1% , 82. 6% vs 27. 5% , P <0. 05) , with no difference between the latter two groups (19.1% vs 27.5% , P >0.05).


CONCLUSIONS
The changed vitrification cryopreservation method helps conserve the intact spindle configuration of mouse oocytes.
Sun
Hai-xiang
HX
Reproductive Medicine Center, Drum Tower Hospital, Nanjing University Medical College, Nanjing, Jiangsu 210008, China. stevensunz@163.com
Hu
Ya-li
YL
Chen
Lin-jun
LJ
Zhang
Ning-yuan
NY
Xu
Zhi-peng
ZP
D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents; D005260:Female; D005307:Fertilization in Vitro; D051379:Mice; D008813:Mice, Inbred ICR; D009865:Oocytes / Q000166:cytology; D008941:Spindle Apparatus
D003451:Cryoprotective Agents