SummaryQuality of in vitro-produced embryos is influenced by changes in gene expression in response to adverse conditions. Gene markers for predicting ‘good embryos’ do not exist at present. We propose that the expression of pluripotency markers OCT4–SOX2–NANOG in D9 (day 9) bovine demi-embryos correlated with development at D13 (day 13). Day 8 in vitro-produced blastocysts were split in two cloned halves, one half (D9) was subjected to analysis of pluripotency markers and the other was kept in culture until D13 of development. Embryo development was scored and correlated with its own status at D9 and assigned to one of two categories: G1, arrested/dead; or G2, development up to D13. SOX2 and NANOG expression levels were significantly higher in embryos from G1 and there was also negative correlation between SOX2 and embryo survival to D13 (G3; r = −0.37; P = 0.03). We observed a significant reduction in the expression of the three studied genes from D9 to D13. Furthermore, there was a correlation between the expression of pluripotency markers at D9 and embryo diameter and the expression of trophoblastic markers at D13 (TP1–EOMES–FGF4–CDX2–TKDP1). Finally, the quotient between the relative expression of SOX2 and OCT4 in the D9 blastocysts from G1 and G2 showed that embryos that were considered as competent (G2) had a quotient close to one, while the other group had a quotient of 2.3 due to a higher expression of SOX2. These results might indicate that overexpression of SOX2 at the blastocyst stage had a negative effect on the control of embryonic developmental potential.

中文翻译：

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囊胚期 SOX2 的表达水平调节牛胚胎的发育能力，直至体外培养第 13 天

总结质量体外-产生的胚胎受不利条件下基因表达变化的影响。目前不存在用于预测“好胚胎”的基因标记。我们建议多能性标记的表达10月4日–SOX2–纳米油在 D9（第 9 天）中，牛半胚胎与 D13（第 13 天）的发育相关。第 8 天体外-产生的囊胚被分成两半克隆，一半（D9）进行多能性标记分析，另一半保持培养直到发育D13。胚胎发育在 D9 被评分并与其自身状态相关，并被分配到以下两个类别之一：G1，停滞/死亡；或 G2，发展至 D13。SOX2和纳米油G1期胚胎中的表达水平显着升高，并且两者之间也存在负相关SOX2胚胎存活到 D13 (G3;r= -0.37；磷= 0.03)。我们观察到从 D9 到 D13 的三个研究基因的表达显着降低。此外，D9 时多能性标志物的表达与胚胎直径和 D13 时滋养细胞标志物的表达之间存在相关性。TP1–EOMES–FGF4–CDX2–TKDP1）。最后，相对表达式之间的商SOX2和10月4日在来自 G1 和 G2 的 D9 胚泡中显示，被认为有能力的胚胎 (G2) 的商数接近 1，而另一组的商数为 2.3，因为SOX2. 这些结果可能表明过度表达SOX2在胚泡阶段对胚胎发育潜能的控制有负面影响。