家鸡似G蛋白偶联受体119基因的克隆与组织表达分析

Molecular Cloning and Tissue Expression of Chicken GPR119-like Gene

G蛋白偶联受体119(GPR119)是A型视紫红质G蛋白偶联受体家族成员。在哺乳动物中,该基因高表达于胰腺β细胞和PP细胞以及小肠组织的内分泌L细胞,参与胰岛素释放调节。本文以家鸡Gallus gallus小肠cDNA为模板,首次克隆到似GPR119新基因,将其命名为cGPR119b基因。结果显示:cGPR119b基因的cDNA全长954 bp,编码具317个氨基酸的前体蛋白。将家鸡GPR119b前体蛋白氨基酸序列与绿头鸭Anas platyrhynchos、绿海龟Chelonia mydas、西部锦龟Chrysemys picta bellii和火鸡Meleagris gallopavo的序列进行比对,分别具有79.9%、61.0%、62.3%、95.5%的相似度。利用反转录PCR和RACE技术,家鸡GPR119b的5'-UTR亦获分离,该片段678 bp。本研究亦采用实时荧光定量PCR探究cGPR119b基因的组织表达,发现其在大脑、肝脏、肾脏、卵巢、精巢、垂体、胰腺、皮肤、脂肪、肺、十二指肠、空肠、回肠、盲肠、直肠等组织中有表达,其中,在肝脏、肾脏、盲肠和精巢的表达量较高,在胰腺、皮肤、脂肪和肺组织中仅有微量表达。本研究为进一步探究cGPR119b基因在家鸡中的生理功能奠定了基础。

G protein-coupled receptor 119（ GPR119） is a member of class A（ rhodopsin-type） G protein-coupled receptor family. In mammals,GPR119 gene is found to be highly expressed in pancreatic islet β cells,PP cells and intestine endocrine L cells involving in insulin secretion. In this study,we cloned a chicken GPR119-like gene（ named cGPR119 b）from intestine and examined its expression in chicken tissues. The results showed that the full-length cDNA of cGPR119 b was 954 bp in length and encoding a precursor protein of 317 amino acids. Sequence analysis revealed that chicken GPR119 b had high amino acid sequence identity with that of Anas platyrhynchos（ 79. 9%）,Chelonia mydas（ 61. 0%）,Chrysemys picta bellii（ 62. 3%）,and Meleagris gallopavo（ 95. 5%）. 5＇-RACE PCR assay revealed that the 5＇-UTR of cGPR119 b is 678 bp. Quantitative real-time PCR assay showed that cGPR119 b gene was widely expressed in various chicken tissues including the brain,liver,kidney,intestine,ovary,testis,pituitary,pancreas,skin,fat,lung,duodenum,jejunum,ileum,cecum and rectum. cGPR119 b gene was highly expressed in liver,kidneys,cecum and testes,whereas weakly expressed in the pancreas,skin,fat and lung. The present study provided a basis to uncover the physiological roles of cGPR119 b gene in chickens.