Essential amino acids (EAA) of inappropriate concentration have been reported to compromise the development of embryo. This study aimed to investigate the effect of EAA on the developmental competence of porcine embryos produced by either handmade cloning (HMC) or parthenogenetic activation (PA). In experiment 1, we examined the in vitro developmental competence of PA embryos after culture in PZM-3 containing different concentrations (v/v) of EAA (0%, 1%, and 2%). The results indicated that reducing the concentration of EAA from 2% to 1% significantly improved the blastocyst formation (36% vs. 54%), while 0% would compromise the blastocyst formation rate (54% vs. 38%). In experiment 2, we further investigated the effect of EAA concentration (1% and 2%) on the in vitro developmental competence and gene expression of HMC embryos. Blastocyst rate significantly increased by reducing concentration of EAA (41% vs. 53%) and those genes upregulated were enriched in oxidative phosphorylation, PPAR signaling pathway, and metabolism-related pathways. In experiment 3, the in vivo developmental competence of HMC embryos cultured in the medium supplemented with 1% EAA was examined. Embryos derived from both non-gene-modified fetal fibroblasts (FFs) and gene-modified fetal fibroblasts (GMFFs) were transferred to recipients. The pregnancy rates were 83% and 78% separately. Out of the pregnancies, 5 (FFs) and 6 (GMFFs) were successfully developed to term. Our study indicates that supplementing EAA to embryo culture medium at a concentration of 1% can improve the in vitro developmental competence of porcine HMC embryos and the blastocyst obtained can successfully develop to term, which could be beneficial for the production of gene-modified piglets.

中文翻译：

---

PZM-3中的低浓度必需氨基酸提高手工克隆产生的猪胚胎的发育能力

据报道，不适当浓度的必需氨基酸 (EAA) 会影响胚胎的发育。本研究旨在研究 EAA 对手工克隆 (HMC) 或孤雌激活 (PA) 产生的猪胚胎发育能力的影响。在实验 1 中，我们检查了PA 胚胎在含有不同浓度 (v/v) 的 EAA（0%、1% 和 2%）的 PZM-3 中培养后的体外发育能力。结果表明，将 EAA 浓度从 2% 降低到 1% 会显着改善囊胚形成（36% 对 54%），而 0% 会降低囊胚形成率（54% 对 38%）。在实验 2 中，我们进一步研究了 EAA 浓度（1% 和 2%）对体外HMC胚胎的发育能力和基因表达。降低 EAA 浓度可显着提高囊胚率（41% 对 53%），上调的基因富含氧化磷酸化、PPAR 信号通路和代谢相关通路。在实验 3 中，检查了在补充有 1% EAA 的培养基中培养的 HMC 胚胎的体内发育能力。来自非基因修饰胎儿成纤维细胞 (FFs) 和基因修饰胎儿成纤维细胞 (GMFFs) 的胚胎被转移给受体。妊娠率分别为83%和78%。在这些妊娠中，有 5 例（FFs）和 6 例（GMFFs）成功发育到足月。我们的研究表明，在胚胎培养基中添加浓度为 1% 的 EAA 可以提高体外猪HMC胚胎的发育能力和获得的囊胚可以成功发育至足月，这可能有利于基因修饰仔猪的生产。