【摘要】 【目的】探究褪黑素（MT）对产蛋末期欧洲肉鸽卵巢抗氧化及抗凋亡相关基因表达的影响。【方法】随机选取36对公母配对、体重相近的5年龄产蛋末期欧洲肉鸽，随机分为两组，每组3个重复，每个重复6对。试验组（MT组）母鸽注射2 mg/kg MT，对照组（NS组）母鸽注射等量生理盐水，连续注射5 d后，采集母鸽松果体进行HE染色；采集母鸽血清、第一大卵泡（F1）和第二大卵泡（F2）卵黄测定MT含量与抗氧化相关指标；采集母鸽卵巢和卵泡颗粒层检测MT受体（MT1）基因、氧化应激及细胞凋亡相关基因的表达水平。【结果】与NS组相比，(1)MT组母鸽松果体细胞核直径显著增大（P<0.05），血清、F1及F2卵黄中MT浓度显著或极显著升高（P<0.05;P<0.01），卵巢、F1及F2颗粒层中MT1基因表达水平显著或极显著升高（P<0.05;P<0.01）。(2)MT组母鸽血清、F1和F2卵黄中活性氧（ROS）与丙二醛（MDA）含量均显著或极显著降低（P<0.05;P<0.01），超氧化物歧化酶（SOD）活性显著或极显著升高（P<0.05;P<0.01）；血清中谷胱甘肽过氧化物酶（GSH-Px）活性极显著升高（P<0.01）,F1卵黄中GSH-Px活性显著升高（P<0.05）；卵巢及F1颗粒层中超氧化物歧化酶1(SOD1)基因表达水平显著或极显著升高（P<0.05;P<0.01）;MT组母鸽卵巢与F2颗粒层中过氧化氢酶（CAT）基因表达水平均显著升高（P<0.05）。(3)MT组母鸽F2颗粒层中B细胞淋巴瘤因子2(BCL2)基因表达水平极显著升高（P<0.01）,F1颗粒层中BCL2相关X蛋白（BAX）基因表达水平显著降低（P<0.05）。【结论】外源MT可通过促进MT1基因表达，上调抗氧化基因（SOD1、CAT）及酶活性，并调节凋亡相关基因（BCL2、BAX）的平衡，从而显著提高产蛋末期母鸽卵巢的抗氧化与抗凋亡能力。更多还原

【Abstract】 【Objective】 This study aimed to investigate the effect of melatonin(MT) on the expression of genes related to ovarian antioxidation and anti-apoptosis in European meat pigeons at the late laying stage.【Method】 36 pairs of 5-year-old European meat pigeons in the late laying stage(with paired males and females and similar body weights) were randomly selected and divided into two groups. Each group had 3 replicates, with 6 pairs per replicate. Female pigeons in the experimental group(MT group) were injected with MT at a dose of 2 mg/kg, while those in the control group(NS group) received an equal volume of normal saline. After 5 consecutive days of injection, the pineal glands of female pigeons were collected for hematoxylin-eosin(HE) staining. Serum, as well as yolk from the first(F1) and second(F2) largest follicles, were collected to determine MT content and antioxidant-related indicators. Ovaries and follicular granulosa layers were collected to detect the expression levels of MT receptor(MT1) gene, oxidative stress and apoptosisrelated genes.【Result】 Compared with the NS group,(1) The nuclear diameter of pinealocytes in laying hens was significantly increased in the MT group(P<0.05). MT concentrations in serum and yolk of F1 and F2 were significantly or extremely significantly elevated(P<0.05 or P<0.01). The gene expression level of MT1 in the ovary and granulosa layers of F1 and F2 were significantly or extremely significantly up-regulated(P<0.05 or P<0.01).(2) The contents of reactive oxygen species(ROS) and malondialdehyde(MDA) in serum and yolk of F1 and F2 were significantly or extremely significantly decreased in the MT group(P<0.05 or P<0.01), while the activity of superoxide dismutase(SOD) was significantly or extremely significantly increased(P<0.05 or P<0.01). The activity of glutathione peroxidase(GSH-Px) in serum was extremely significantly elevated(P<0.01), and GSH-Px activity in F1 yolk was significantly increased(P<0.05). The gene expression level of superoxide dismutase 1(SOD1) in the ovary and granulosa layer of F1 were significantly or extremely significantly up-regulated(P<0.05 or P<0.01). The gene expression level of catalase(CAT) in the ovary and granulosa layer of F2 in the MT group was significantly increased(P<0.05).(3) The gene expression level of B-cell lymphoma-2(BCL2) in the granulosa layer of F2 was extremely significantly up-regulated(P<0.01), the gene expression level of BCL2-associated X protein(BAX) in the granulosa layer of F1 was significantly down-regulated(P<0.05).【Conclusion】 Exogenous MT could significantly improve the antioxidant and anti-apoptotic abilities of the ovary in laying hens at the late laying stage by promoting the expression of MT1 gene, up-regulating the expression and enzyme activities of antioxidant genes(SOD1 and CAT), and regulating the balance of apoptosis-related genes(BCL2 and BAX).更多还原