日粮硒缺乏对肉鸡硒蛋白基因及胰岛素信号相关基因表达的影响

发布时间：2018-01-11 04:17

  本文关键词：日粮硒缺乏对肉鸡硒蛋白基因及胰岛素信号相关基因表达的影响　出处：《四川农业大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 肉鸡 硒 硒蛋白基因 胰岛素信号 表达

【摘要】：胰腺是肉鸡硒缺乏最为敏感的器官,长期饲喂肉鸡缺硒日粮可导致胰腺病变萎缩,意味着硒在胰腺功能维持中起着重要作用,但日粮缺硒对肉鸡胰岛素代谢是否有影响尚不清楚。胰腺是分泌胰岛素的器官,肝脏和肌肉是两个重要的胰岛素效应靶组织,硒主要通过硒蛋白在机体组织中发挥作用,然而日粮硒缺乏对肉鸡上述组织中硒蛋白基因和胰岛素代谢相关基因表达是否有影响尚不清楚。本试验以肉鸡为研究材料,研究日粮硒缺乏对肉鸡生产性能,生理生化指标、组织硒蛋白基因和胰岛素信号相关基因表达的影响,试验结果可为探索硒在胰岛素代谢中的生物学机制提供线索。本试验采用四川严重缺硒地区(汉源山区)生长的大豆、玉米为原料,配制基础日粮(Se0.02mg Se/Kg),进而研究日粮硒缺乏对肉鸡胰岛素合成与作用靶组织中硒蛋白基因表达的影响。试验采用120只一日龄健康科宝肉鸡,随机分成2个处理组(n=60)。分别饲喂缺硒日粮(Se, 0mg/kg)和对照日粮(Se,0.3 mg/kg),试验期5周。每周称量肉鸡体重和计算生长性能,并记录渗出性素质和其他典型硒缺乏症。于试验末期第35d,每个处理选取6只鸡屠宰,采集血液、肝脏、胰腺和肌肉,用于测定硒含量、抗氧化性能、生化指标测定,同时考察日粮硒缺乏对肝脏、脂肪和胰腺组织23各硒蛋白基因及17个胰岛素信号相关基因表达量影响。实验结果如下：1.日粮硒缺乏对肉鸡病理、生长性能及组织硒含量的影响日粮硒缺乏导致肉鸡出现渗出性素质、胰腺萎缩和其它硒缺乏症,并伴随高发病率(90%)和死亡率(62%)。同时日粮硒缺乏降低了肉鸡生长性能,从14日龄到35日龄平均体重与对照组相比显著降低(P0.05)。同对照组相比,缺硒组血清和肝脏中的硒含量降低了80%和73%(P0.01)。2.日粮硒缺乏对肉鸡生理生化指标的影响日粮硒缺乏导致肉鸡血清葡萄糖浓度、白介素6(IL-6)和肿瘤坏死因子a(TNF-a)含量分别升高了233.3%、40%和23%(P0.05),血清胰岛素浓度、甘油三酯(TG)和总胆固醇(TCH)含量分别降低了32%、61%和45%(P0.05)。此外,缺硒组肉鸡血清谷胱甘肽过氧化物酶(GSH-PX)活性和总抗氧化能力(T-AOC)与对照日粮组相比降低了76%和57%(P0.05)；另外肝脏组织GSH-Px活性和超氧化物歧化酶(SOD)还降低了66%和24%(P0.05),丙二醛(MDA)含量升高了63%(P0.05)。在肌肉组织中仅有GSH-Px活性受到缺硒影响而降低了48%(P0.05);胰腺组织中GSH-Px和SOD活性受缺硒影响降低了32%(P0.05)。3.日粮硒缺乏对肉鸡组织硒蛋白基因表达影响与对照组相比,日粮硒缺乏下调了(P0.05)肝脏组织中9个硒蛋白基因(Gpx1、 Gpx2、Gpx3、Gpx4、Diol、Seli、Selm、Selt和Selu的表达丰度),其中除Gpxl和Selt这2个基因为差异显著外(P0.05),其余7个基因均为差异极显著(P0.01),同时,日粮缺硒还上调了肝脏组织中2个硒蛋白基因Txnrd1和SeIs的表达(P0.05)。日粮缺硒下调了肉鸡肌肉组织中14个硒蛋白基因(Gpx2、Gpx3、Dio1、Dio3、Txnrd1、 Selk、Seli、Selm、Selo、Sels、Selt、Sepn1、Sepp1和Selx)的表达丰度(P0.05)。相比肝脏和肌肉组织,胰腺是受日粮缺硒影响改变硒蛋白基因表达量最多的组织,下调了18个硒蛋白基因(Gpx2、Gpx3、Gpx4、Txnrd1、Txnrd3、Selk、Seli、Selm、Selo、 Sels、Selu、Selt、Sep15、Sepn1、Sepp1、Sepw1、Selx和Sephs2)的表达丰度(P0.05),其中只有Txnrd1基因表现为显著下调(P0.05),其余的17个基因均表现为极显著下调(P0.01)。4.日粮硒缺乏对肉鸡组织胰岛素信号相关基因表达影响与对照组相比,日粮缺硒显著下调了肉鸡肝脏组织中2个胰岛素信号相关蛋白基因Ins和Ptpn1的表达(P0.05)：极显著地下调了Irs2、Pdx1和Slc2A2这3个基因的表达(P0.01),其中Irs2基因的表达量下调最大。同时,日粮缺硒极显著上调了3个基因Foxa2、Gcg和Irsl的表达(P0.01),其中Irsl基因表达量上调最高。日粮硒缺乏下调了肌肉组织中14个胰岛信号相关基因表达,其中4个基因(Irs1、Ins、 Neurod1和Slc2A2)为显著下调(P0.05)；Akt1、Braf、Foxo1、Foxa2、Ir、Irs2、 Ptpn1、Pi3k和Ucp等9个基因为极显著下调(P0.01)。日粮缺硒使胰腺组织中的6个胰岛素信号相关基因表达下调,其中Akt1、Foxa2、Enf1A和Hnf4A为极显著下调(P0.01)。结论：日粮硒缺乏降低肉鸡的生长性能,减少肉鸡血清和肝脏中硒沉积,影响了肉鸡血清和胰岛素代谢相关组织的抗氧化活性。同时,缺硒还导致肉鸡出现低胰岛素和高血糖症,影响血液中甘油三酯和胆固醇的正常代谢。RT-PCR结果分析表明：日粮缺硒不同程度的影响肉鸡肝脏、肌肉和胰腺组织中胰岛素信号通路相关基因的表达,在这三个组织中,肌肉组织中受影响基因最多,其次为肝脏和胰腺组织,多数受影响的基因表现为下调表达。与此同时三个组织中硒蛋白基因的普遍下调表达,其中胰腺中下调的硒蛋白基因最多,其次为肌肉组织和肝脏组织,在三个组织中,只有肝脏中上调的硒蛋白基因。上述研究结果表明,日粮硒缺乏影响肉鸡胰岛素代谢相关组织中硒蛋白基因与胰岛素信号相关基因的表达,导致肉鸡血脂代谢异常,出现低胰岛素血症和高葡萄糖血症,这预示着受影响的硒蛋白基因在维持胰岛素合成和正常代谢中发挥着重要作用。
[Abstract]:Chicken pancreas is the most sensitive organ selenium deficiency, long-term feeding broiler diets deficient in selenium can lead to pathological changes in the pancreas atrophy, mean Se in pancreatic function plays an important role in the maintenance of dietary selenium deficiency, but whether the effect of insulin metabolism in broilers is unclear. Pancreatic insulin secretion is the organ, liver and muscle is the two important effect of insulin target tissue selenium mainly through selenoproteins in the tissue play a role, but the lack of dietary selenium on selenoprotein gene in the tissues of the broiler and insulin metabolism related gene expression has any effect is not clear. In this experiment, broilers as research materials, research of dietary selenium deficiency on broiler performance. Physiological and biochemical indexes, the effects of expression of genes related to selenoprotein gene and insulin signaling, the test results may provide clues for exploring the biological mechanism of selenium in insulin metabolism in this experiment. The Sichuan severe selenium deficiency (Hanyuan mountain) the growth of soybean, corn as raw materials, preparation of the basal diet (Se0.02mg Se/Kg), and study the dietary effects of selenium deficiency on the expression of selenoprotein insulin synthesis and action of chicken genes in target tissues. In this experiment, 120 one day old healthy Kebao broiler were randomly divided into 2 treatments group (n=60). With selenium deficiency diet (Se, 0mg/kg) and control diet (Se, 0.3 mg/kg), the experimental period was 5 weeks. The weekly weighing weight and calculating the growth performance of broilers, and record the exudative diathesis and other typical selenium deficiency. At the end of the test section 35d, each select 6 chicken slaughter, blood, liver, pancreas and muscle, for the determination of selenium content, antioxidant properties, biochemical indexes, and the effects of dietary selenium deficiency on the liver, fat and 23 of the selenoprotein gene in pancreatic tissue and 17 insulin signal related gene expression effect. The results are as follows: 1. dietary selenium deficiency on broiler pathological effects of dietary selenium deficiency, growth performance and tissue selenium content resulting in broiler appear exudative diathesis, pancreatic atrophy and other selenium deficiency, and with high incidence rate (90%) and mortality (62%). At the same time, the lack of dietary selenium reduced growth of broiler the performance, from the age of 14 days to 35 days of age, average weight significantly reduced compared with the control group (P0.05). Compared with the control group, the content of selenium in selenium deficiency group in serum and liver were reduced by 80% and 73% (P0.01).2. dietary selenium deficiency on physiological and biochemical indexes of broiler dietary selenium deficiency in Broiler Serum the concentration of glucose and interleukin 6 (IL-6) and tumor necrosis factor A (TNF-a) content were increased by 233.3%, 40% and 23% (P0.05), serum insulin, triglyceride (TG) and total cholesterol (TCH) decreased by 32%, 61% and 45% (P0.05). In addition, the serum selenium deficiency group glutathione 鐢樿偨杩囨哀鍖栫墿閰，

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