Vitrification of immature bovine cumulus-oocyte complexes: effects of cryoprotectants, the vitrification procedure and warming time on cleavage and embryo development

Reproductive Biology and Endocrinology

Research

Muhammad Anzar¹  Jennifer R Prentice-Biensch¹  Reuben J Mapletoft²  Jaswant Singh³ 

[1] Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, Saskatchewan, Canada;Department of Veterinary Biomedical Sciences,Western College of Veterinary Medicine, University of Saskatchewan, Saskatchewan, Saskatoon, Canada;Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatchewan, Saskatoon, Canada;Department of Veterinary Biomedical Sciences,Western College of Veterinary Medicine, University of Saskatchewan, Saskatchewan, Saskatoon, Canada;

关键词: Cattle;    Cumulus-oocyte-complexes;    Germinal vesicle stage;    Cryoprotectants;    Ethylene glycol;    Dimethyl sulfoxide;    Vitrification;    Warming time;    In vitro;    In vitro;   

DOI  :  10.1186/1477-7827-10-73

 received in 2012-04-26, accepted in 2012-08-30,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundThe present studies evaluated the effects of cryoprotectants, the vitrification procedure and time in the warming solution containing sucrose on cleavage and embryo development of immature (GV stage) bovine cumulus-oocyte complexes (COCs).MethodsTwo experiments were conducted. In Experiment 1, COCs (n = 420) were randomly assigned to four groups: 1) Control group: no treatment; 2) VS1 group: COCs were exposed to vitrification solution 1 (VS1) containing 7.5% ethylene glycol [EG] + 7.5% dimethyl sulfoxide [DMSO] + 20% calf serum [CS] in TCM-199 at 37 C for 5 min; 3) VS1 + VS2 group: COCs were exposed to VS1 for 5 min followed by VS2 (15% EG + 15% DMSO + 17.1% sucrose + 20% CS) at 37 C for 45–60 sec; and 4) Vitrified group: COCs were exposed to VS1 and VS2, loaded on cryotops, vitrified in liquid nitrogen and then warmed in TCM-199 + 17.1% sucrose + 20% CS at 37 C for 1 min. In Experiment 2, COCs (n = 581) were assigned to the same groups, but those in VS1, VS1 + VS2 and Vitrified groups were sub-divided and exposed to the warming solution for either 1 or 5 min. After treatment and/or warming, all COCs in both experiments underwent in vitro maturation, in vitro fertilization and in vitro culture.ResultsCleavage and blastocyst rates did not differ among Control, VS1 and VS1 + VS2 groups in either experiment. In Experiment 2, there was no effect of time in the warming solution.However, both cleavage and blastocyst rates were lower (P < 0.001) in the Vitrified group than in the Control, VS1 and VS1 + VS2 groups (40.9 and 1.6% vs 92.2 and 34.4%, 79.4 and 25.2%, and 80.2 and 20.8%, respectively in Experiment 1, and 25.0 and 1.7% vs 75.3 and 27.2%, 67.9 and 19.5%, and 62.7 and 22.5%, respectively in Experiment 2).ConclusionsThe permeating cryoprotectants (EG and DMSO) present in VS1 and VS2 solutions and the time in the warming solution containing sucrose had no adverse effects on cleavage and blastocyst rates of immature bovine COCs. However, cleavage rate and early embryo development were reduced following the vitrification and warming.

【 授权许可】

Unknown   
© Prentice-Biensch et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.