鸡PDKPDK4基因的克隆及组织差异表达研究

Cloning and Tissue Differential Expression Analysis of Chicken PDK4 Gene

丙酮酸脱氢酶激酶4(PDK4)基因在动物机体的糖-脂代谢过程中起着重要的调节作用。为揭示PDK4基因对家禽生长和脂肪沉积的影响,以快速生长型肉鸡(隐性白羽洛克鸡)和慢速生长型肉鸡(杏花鸡)为试验对象,采用分子克隆、生物信息学分析和实时荧光定量PCR等方法,克隆鸡PDK4基因并分析其多态位点及在不同生长速度肉鸡组织的表达差异。克隆获得杏花鸡PDK4基因全长3 473 bp序列,并筛查到22处核苷酸多态性位点。生物信息学分析结果表明鸡PDK4蛋白与哺乳动物该基因蛋白序列之间的同源性较高,与爪蟾、斑马鱼的同源性较低;实时荧光定量PCR结果表明PDK4基因在不同生长速度的肉鸡组织中的表达存在较大差异,从组织表达来看,PDK4基因在脂肪组织中(皮脂和腹脂)的表达高于下丘脑和肝脏;从品种来看,PDK4基因在杏花鸡各组织的表达高于隐性白洛克鸡。可见,PDK4基因对家禽的生长和脂肪沉积有重要影响,是影响家禽生长和脂肪沉积的重要候选基因。

Pyruvate dehydrogenase kinase 4 （PDK4）gene plays an important role in regulating glucose and lipid metabolism processes. The objective of this study was to investigate the effect of PDK4 gene expression on growth and fatdeposition in white recessive rocks,which is a fast-growing chicken breed,and Xinhua chicken,which is a slow-growing local chicken breed. We cloned PDK4 gene,analyzed the nucleotide polymorphism （SNP） and the expression of differential tissue in different growth rate chicken by molecular cloning technique,bioinformatics analysis and real-time PCR methods. The results showed that the total length of PDK4 gene in Xinghua chicken was 3 473 bp,and 22 SNPs was found in PDK4 genome of chicken. Bioinformatics study showed that the chicken PDK4 protein had a relative highly homology with mammals and a relatively lower homology with xenopus and danio. Real-time PCR analysis indicated that the tissue expression of PDK4 gene was significantly different in two broiler breeds. For the expression level in tissues of the same breed,the expression of PDK4 gene in adipose tissue （sebum and abdominal fat） showed higher than hypothalamus and liver. Compared the expression levels in different breeds, the expression of PDK4 gene in organizations tissues of Xinghua chicken were higher than that of white recessive rock chicken. Taken together, PDK4 gene played an important role in regulating body weight and fat deposition in chickens, and was a potential candidate gene of growth and fat deposition for molecular breeding in chicken.