National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Molecules. 2017 Nov 27;22(12):2059. doi: 10.3390/molecules22122059.
The inferior oocytes (IOs), which are not suitable for embryo development, occupy roughly one-third or more of the collected immature bovine oocytes. The IOs are usually discarded from the in vitro bovine embryo production process. Improving the quality of the inferior oocytes (IOs) and make them available in in vitro embryo production would have important biological, as well as commercial, value. This study was designed to investigate whether melatonin could improve the quality of IOs and make them usable in the in vitro maturation (IVM) and subsequent (in vitro fertilization) IVF embryo development. The results indicated that: the maturation rate of IOs and their subsequent IVF embryo developments were impaired compared to cumulus-oocyte complexes and melatonin treatment significantly improved the quality of IOs, as well as their IVF and embryo developments. The potential mechanisms are that: (1) melatonin reduced reactive oxygen species (ROS) and enhanced glutathione (GSH) levels in the IOs, thereby protecting them from oxidative stress; (2) melatonin improved mitochondrial normal distribution and function to increase ATP level in IOs; and (3) melatonin upregulated the expression of , , , , , and , which are critical genes for oocyte maturation and embryo development and downregulated apoptotic gene expression of caspase-3.
质量较差的卵母细胞（IOs）不适合胚胎发育，约占采集到的未成熟牛卵母细胞的三分之一或更多。在体外牛胚胎生产过程中，这些质量较差的卵母细胞通常会被丢弃。提高质量较差的卵母细胞（IOs）的质量并使其可用于体外胚胎生产具有重要的生物学和商业价值。本研究旨在探讨褪黑素是否可以改善 IOs 的质量并使其可用于体外成熟（IVM）和随后的（体外受精）IVF 胚胎发育。结果表明，与卵丘-卵母细胞复合物相比，IOs 的成熟率及其随后的 IVF 胚胎发育受损，而褪黑素处理显著改善了 IOs 的质量及其 IVF 和胚胎发育。潜在的机制是：（1）褪黑素降低了 IOs 中的活性氧（ROS）并增强了谷胱甘肽（GSH）水平，从而保护它们免受氧化应激；（2）褪黑素改善了线粒体的正常分布和功能，增加了 IOs 中的 ATP 水平；和（3）褪黑素上调了关键基因的表达，这些基因对于卵母细胞成熟和胚胎发育至关重要，并下调了凋亡基因 caspase-3 的表达。
