Pasquariello Rolando, Zhang Mingxiang, Herrick Jason R, Ermisch Alison, Becker John, Schoolcraft William B, Barfield Jennifer P, Yuan Ye, Krisher Rebecca L
R Pasquariello, Colorado Center for Reproductive Medicine, Lone Tree, United States.
M Zhang, Colorado Center for Reproductive Medicine, Lone Tree, United States.
Reprod Fertil. 2023 Nov 1;4(4). doi: 10.1530/RAF-23-0057.
The refinement of embryo culture media is essential in improving embryo viability and in vitro production efficiency. Our previous work demonstrated that the nutrients (carbohydrates, amino acids, and vitamins) in traditional culture media far exceed the need for an embryo and producing developmentally competent embryos in a reduced nutrient environment is feasible. Here, we aim to evaluate the impact of exogenous lipid and L-carnitine supplementation on bovine blastocyst development and refine our RN condition further. Zygotes were cultured in the control medium (100% nutrients) and reduced nutrient media containing 6.25% of the standard nutrient concentrations supplemented with L-carnitine and lipid free or lipid rich BSA. Increased blastocyst development was observed in the reduced nutrient lipid rich medium compared to the other two groups. However, in both reduced nutrient conditions, blastocyst cell numbers were lower than those obtained in the control condition. We then examined the expression level of 18 transcripts correlated with lipid metabolism, glucose metabolism, redox balance, and embryo quality, along with mitochondrial DNA copy numbers, ATP productions, and lipid profile. The results indicated lipid metabolism, embryo quality, and redox enzyme related genes were upregulated while glucose related gene was downregulated in embryos derived from reduced nutrient lipid rich condition Finally, we identified that the lipid rich BSA has enriched linoleic, stearic, oleic, palmitic, and alpha-linoleic fatty acids, a lipid profile that may contribute to the increased lipid metabolism and improved blastocyst development of the bovine embryos under the reduced nutrient condition.
胚胎培养基的优化对于提高胚胎活力和体外生产效率至关重要。我们之前的研究表明，传统培养基中的营养物质（碳水化合物、氨基酸和维生素）远远超过胚胎的需求，在营养成分减少的环境中培养出具有发育能力的胚胎是可行的。在此，我们旨在评估外源脂质和左旋肉碱补充对牛囊胚发育的影响，并进一步优化我们的减少营养条件（RN）。将合子培养在对照培养基（100%营养物质）和含有标准营养浓度6.25%的减少营养培养基中，补充左旋肉碱以及不含脂质或富含脂质的牛血清白蛋白（BSA）。与其他两组相比，在减少营养且富含脂质的培养基中观察到囊胚发育增加。然而，在两种减少营养条件下，囊胚细胞数量均低于对照条件下获得的细胞数量。然后，我们检测了与脂质代谢、葡萄糖代谢、氧化还原平衡和胚胎质量相关的18种转录本的表达水平，以及线粒体DNA拷贝数、ATP产量和脂质谱。结果表明，在营养成分减少且富含脂质条件下产生的胚胎中，与脂质代谢、胚胎质量和氧化还原酶相关的基因上调，而与葡萄糖相关的基因下调。最后，我们确定富含脂质的BSA富含亚油酸、硬脂酸、油酸、棕榈酸和α-亚麻酸，这种脂质谱可能有助于在营养成分减少的条件下增加牛胚胎的脂质代谢并改善囊胚发育。
