Animal Production Department, Faculty of Agriculture, Mansoura University, Mansoura, Egypt.
Key Laboratory of Buffalo Genetics, Breeding and Reproduction Technology, Ministry of Agriculture and Guangxi, Buffalo Research Institute, Chinese Academy of Agricultural Sciences, Nanning, 530001, China.
Zygote. 2021 Oct;29(5):393-400. doi: 10.1017/S0967199421000162. Epub 2021 Mar 26.
This study examined the effects of zinc chloride (ZnCl2) and sodium selenite (Na2SeO3) supplementation in maturation medium on in vitro maturation (IVM) rate, oxidative biomarkers and gene expression in buffalo oocytes. Ovaries from a slaughterhouse were aspirated and good quality cumulus-oocyte complexes (COCs) with at least four layers of compact cumulus cells and evenly granulated dark ooplasm were selected. COCs were randomly allocated during IVM (22 h) to one of four treatment groups: (1) control maturation medium (basic medium), or basic medium supplemented with (2) ZnCl2 (1.5 µg/ml), (3) Na2SeO3 (5 µg/l), or (4) ZnCl2 + Na2SeO3 (1.5 µg/ml + 5 µg/l, respectively). Oocytes were denuded after 22 h of IVM in the first four replicates. Specimens were fixed and stained to evaluate the stage of nuclear maturation. The spent medium was collected for biochemical assays of total antioxidant capacity (TAC), malondialdehyde (MDA) and hydrogen peroxide concentrations. A second four replicates were used for COCs for RNA extraction. The expression levels of antioxidant (SOD1, GPX4, CAT and PRDX1), antiapoptotic (BCL2 and BCL-XL) and proapoptotic (BAX and BID) genes were measured. Supplementation with ZnCl2 and Na2SeO3 during IVM increased the ratio of oocytes reaching metaphase II at 22 h, increased TAC and decreased MDA and H2O2 concentrations in the maturation medium (P < 0.05). Moreover, beneficial effects were associated with complementary changes in expression patterns of antioxidative, antiapoptotic and proapoptotic genes, suggesting lower oxidative stress and apoptosis. Supplementation medium with zinc chloride and sodium selenite improves the maturation rate, reduces oxidative stress and increases expression levels of antioxidative and antiapoptotic genes.
本研究探讨了在成熟培养基中添加氯化锌（ZnCl2）和亚硒酸钠（Na2SeO3）对水牛卵母细胞体外成熟（IVM）率、氧化生物标志物和基因表达的影响。从屠宰场抽吸卵巢，选择至少有四层致密颗粒细胞和均匀颗粒状暗卵质的优质卵丘-卵母细胞复合物（COCs）。COCs 在 IVM（22 小时）期间随机分配到以下四个处理组之一：（1）对照成熟培养基（基础培养基），或基础培养基分别添加（2）ZnCl2（1.5 µg/ml）、（3）Na2SeO3（5 µg/l）或（4）ZnCl2+Na2SeO3（1.5 µg/ml+5 µg/l）。在前四个重复中，在 IVM 22 小时后除去卵母细胞。固定和染色标本以评估核成熟阶段。收集耗竭的培养基进行总抗氧化能力（TAC）、丙二醛（MDA）和过氧化氢浓度的生化测定。第二个四个重复用于提取 COCs 的 RNA。测量抗氧化（SOD1、GPX4、CAT 和 PRDX1）、抗凋亡（BCL2 和 BCL-XL）和促凋亡（BAX 和 BID）基因的表达水平。在 IVM 期间添加 ZnCl2 和 Na2SeO3 提高了在 22 小时达到中期 II 的卵母细胞比例，增加了 TAC 并降低了成熟培养基中的 MDA 和 H2O2 浓度（P<0.05）。此外，有益的效果与抗氧化、抗凋亡和促凋亡基因表达模式的互补变化有关，表明氧化应激和凋亡降低。补充氯化锌和亚硒酸钠的培养基可提高成熟率，降低氧化应激并增加抗氧化和抗凋亡基因的表达水平。
