在动物辅助生殖技术中,高质量卵母细胞的生产至关重要。牦牛,在青藏高原生活了很长一段时间,具有受缺氧诱导因子1α(HIF-1α)调节的生殖细胞。本研究旨在探讨HIF-1α通过调控自噬对牦牛卵母细胞体外成熟及早期胚胎发育的影响。牦牛卵母细胞的体外成熟过程涉及添加HIF-1α诱导剂DFOM和抑制剂LW6来检测它们对牦牛卵母细胞成熟的影响,早期胚胎发育,细胞自噬,细胞色素P450s(CYP450s)酶表达,和积云扩散因子。结果显示DFOM显著上调HIF-1α的表达,导致积云扩散面积增加,卵母细胞的第一极体排出率升高,增强线粒体和肌动蛋白水平,ROS产量减少,降低卵母细胞早期凋亡水平。此外,DFOM促进自噬相关蛋白的表达,CYP450s酶,和积云扩散因子,从而促进卵母细胞成熟和早期胚胎发育。相反,LW6表现出相反的效果。在DFOM治疗期间用3-MA抑制自噬水平产生相似的结果。此外,减少自噬导致早期胚胎发育所有阶段的细胞凋亡水平增加,以及胚泡的总细胞数和ICM/TE比率显着降低。研究表明,牦牛卵母细胞体外成熟过程中,HIF-1α可通过调节自噬影响卵母细胞的卵丘扩张面积,第一极体排泄率,线粒体水平,肌动蛋白水平,ROS与早期凋亡水平,CYP450s酶,和积云扩张因子的表达,从而促进牦牛卵母细胞的体外成熟和早期胚胎发育。这些发现为低氧环境中牦牛的生殖调节机制提供了有价值的见解,并为牦牛辅助生殖技术的发展提出了潜在的策略。
In animal assisted reproductive technology, the production of high-quality oocytes is crucial. The yak, having lived in the Qinghai-Tibet Plateau for an extended period, has reproductive cells that are regulated by hypoxia-inducible factor 1α (HIF-1α). This study aimed to investigate the impact of HIF-1α on yak oocyte maturation and early embryonic development in vitro through the regulation of autophagy. The in vitro maturation process of yak oocytes involved the addition of the HIF-1α inducer DFOM and the inhibitor LW6 to examine their effects on yak oocyte maturation, early embryonic development, cell autophagy, cytochrome P450s (CYP450s) enzyme expression, and cumulus diffusion factors. The findings revealed that DFOM significantly upregulated the expression of HIF-1α, resulting in increased the cumulus diffusion area, elevated first polar body expulsion rate of oocytes, enhanced mitochondrial and actin levels, decreased ROS production, and reduced early apoptosis levels of oocytes. Moreover, DFOM promoted the expression of autophagy-related proteins, CYP450s enzymes, and cumulus diffusion factors, thereby enhancing oocyte maturation and early embryonic development. Conversely, LW6 exhibited opposite effects. The inhibition of autophagy levels with 3-MA during DFOM treatment yielded similar outcomes. Furthermore, reducing autophagy led to increased apoptosis levels at all stages of early embryonic development, as well as a significant decrease in total cell number and ICM/TE ratio of blastocysts. Studies have shown that during the in vitro maturation of yak oocytes, HIF-1α can affect the cumulus expansion area of oocytes by regulating autophagy, the first polar body excretion rate, mitochondrial level, actin level, ROS and early apoptosis level, the CYP450s enzyme, and the expression of cumulus expansion factors, thereby improving the in vitro maturation and early embryonic development of yak oocytes. These findings offer valuable insights into the reproductive regulation mechanism of yaks in hypoxic environments and suggest potential strategies for the advancement of yak assisted reproductive technology.