In the present study, the potential of different grades of cumulus-oocyte complexes (COCs) for in vitro maturation (IVM) and embryonic development was assessed. Further, the association of the expression pattern of anti-apoptotic Mcl-1 and pro-apoptotic Bax genes in embryonic development was analyzed. Abattoir derived oocytes were graded into grade A and B based on surrounding cumulus rings. Out of 1050 ovaries, a total number of 770 and 1360, were of grade A and B COCs, respectively, were aspirated. After IVM, grade A COCs had a significantly higher number of polar bodies (92.04 ± 0.60%) as compared to grade B (85.88 ± 0.46%). On IVF and embryo culture, grade A COCs produced the significantly higher rate of cleavage and blastocyst (90.44 ± 0.71% and 41.55 ± 0.96%) as compared to grade B COCs (79.77 ± 0.76% and 30.44 ± 0.96%). The transcriptional analysis of apoptotic genes expression by Real-time PCR revealed a significantly higher expression of Mcl-1 gene in embryos of grade A as compared to grade B, whereas, the relative expression of Bax gene was down-regulated in grade A than grade B embryos. Thus it was concluded that the pattern of apoptotic genes expression in early-stage embryos can be used as a marker gene to predict the developmental competence of COCs.

中文翻译：

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卵卵母细胞复合物的卵丘细胞对水牛（Bubalus bubalis）体外受精后体外成熟，胚胎发育和凋亡基因表达模式的影响。

在本研究中，评估了不同等级的卵-卵母细胞复合物（COC）在体外成熟（IVM）和胚胎发育中的潜力。此外，分析了抗凋亡Mcl-1和促凋亡Bax基因在胚胎发育中的表达模式的关联。屠宰场衍生的卵母细胞根据周围的卵丘环分为A级和B级。在1050个卵巢中，分别有770个和1360个A级和B级COC卵巢被吸出。在IVM之后，与B级（85.88±0.46％）相比，A级COC的极体数量（92.04±0.60％）明显更高。在IVF和胚胎培养上，与B级COC（79.77±0.76％和30.44±0.96％）相比，A级COC产生的卵裂和囊胚发生率显着更高（90.44±0.71％和41.55±0.96％）。通过实时荧光定量PCR对凋亡基因表达的转录分析表明，与B级相比，A级胚胎中Mcl-1基因的表达明显更高，而Bax基因的相对表达在A级中比在B级中下调。 B胚胎。因此可以得出结论，早期胚胎中凋亡基因的表达模式可以用作预测COCs发育能力的标记基因。