The pig oocyte maturation protocol differs from other mammalian species due to dependence on follicular fluid (FF) supplementation. One of the most abundant components of the porcine follicular fluid are fatty acids (FAs). Although evidence from other mammalian models revealed a negative impact of saturated fatty acids (SFA) on developmental competence of oocytes, pig has not yet been widely analyzed. Therefore, we aimed to investigate whether supplementation of IVM medium with 150 μM of stearic acid (SA) and oleic acid (OA) affects lipid content and expression of genes related to fatty acid metabolism in porcine cumulus–oocyte complexes and parthenogenetic embryo development. We found significant influence of fatty acids on lipid metabolism in cumulus cells without affecting the oocyte proper. The expression of ACACA, SCD, PLIN2, FADS1, and FADS2 genes was upregulated (P < 0.01) in cumulus cells, while their expression in oocytes did not change. The increase in gene expression was more pronounced in the case of OA (e.g., up to 30-fold increase in PLIN2 transcript level compared to the control). The number of lipid droplets and occupied area increased significantly in the cumulus cells and did not change in oocytes after SA treatment. Oleic acid improved the blastocyst rate (48 vs 32% in control), whereas stearic acid did not affect this parameter (27%). Additionally, we have discovered a phenotypic diversity of LD in cumulus cells in response to FA supplementation, suggesting extensive lipolysis in response to SA. Stearic acid excess in maturation media led to the formation of multiple micro lipid droplets in cumulus cells.

中文翻译：

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脂肪酸诱导的脂肪分解会影响猪卵丘细胞中的胚胎发育、基因表达和脂滴形成†。

由于依赖卵泡液 (FF) 补充剂，猪卵母细胞成熟方案不同于其他哺乳动物物种。猪卵泡液中最丰富的成分之一是脂肪酸 (FA)。尽管来自其他哺乳动物模型的证据表明饱和脂肪酸 (SFA) 对卵母细胞的发育能力有负面影响，但尚未对猪进行广泛分析。因此，我们旨在研究在 IVM 培养基中添加 150 μM 硬脂酸 (SA) 和油酸 (OA) 是否会影响猪卵丘-卵母细胞复合体和孤雌生殖胚胎发育中与脂肪酸代谢相关的基因的脂质含量和表达。我们发现脂肪酸对卵丘细胞的脂质代谢有显着影响，而不会影响卵母细胞本身。ACACA的表达、SCD、PLIN2、FADS1和FADS2基因 在卵丘细胞中上调（P < 0.01），而它们在卵母细胞中的表达没有变化。在 OA 的情况下，基因表达的增加更为明显（例如，PLIN2增加了 30 倍）转录水平与对照相比）。SA处理后卵丘细胞中脂滴的数量和占据面积显着增加，而卵母细胞中没有变化。油酸提高了囊胚率（对照组为 48% 对 32%），而硬脂酸不影响该参数（27%）。此外，我们还发现了 FA 补充后卵丘细胞中 LD 的表型多样性，表明对 SA 有广泛的脂解作用。成熟培养基中过量的硬脂酸导致在卵丘细胞中形成多个微脂滴。