Department of Anatomy, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran.
J Assist Reprod Genet. 2010 May;27(5):239-46. doi: 10.1007/s10815-010-9401-z. Epub 2010 Mar 9.
The purpose of this study was to evaluate the effects of cryotop vitrification of sheep cumulus-oocyte complexes (COCs) on oocyte maturation, apoptotic gene expression and incidence of chromosomal abnormalities.
Freshly isolated (control group) and vitrified-warmed COCs (cryotop group) were matured in vitro. The expression of pro- and anti-apoptotic genes was investigated by real-time PCR. The incidence of numerical chromosomal abnormalities was evaluated by cytogenetic analysis.
The mean percentage of oocytes in the cryotop and control groups that reached metaphase II was 49.25 +/- 3.01% and 51.94 +/- 2.7% respectively. The expression rates of pro- and anti-apoptotic genes were similar in both groups, whereas the incidence of numerical chromosomal abnormalities was higher in the cryotop group compared to the control group (42.5% vs. 20%, p < 0.05).
Although cryotop vitrification of COCs did not affect the incidence of oocyte maturation or apoptotic gene expression, significant deficiencies in the maintenance of oocyte chromosomal organization were seen.
本研究旨在评估绵羊卵丘-卵母细胞复合物(COCs)的 cryotop 玻璃化冷冻对卵母细胞成熟、凋亡基因表达和染色体异常发生率的影响。
新鲜分离的(对照组)和玻璃化冷冻-复温的 COCs(cryotop 组)在体外成熟。通过实时 PCR 研究促凋亡和抗凋亡基因的表达。通过细胞遗传学分析评估染色体数目异常的发生率。
cryotop 组和对照组中达到中期 II 期的卵母细胞百分比分别为 49.25 +/- 3.01%和 51.94 +/- 2.7%。两组的促凋亡和抗凋亡基因的表达率相似,而 cryotop 组的染色体数目异常发生率明显高于对照组(42.5%比 20%,p < 0.05)。
尽管 COCs 的 cryotop 玻璃化冷冻对卵母细胞成熟或凋亡基因表达的发生率没有影响,但在维持卵母细胞染色体结构方面存在明显缺陷。