Cloning And Differently Expression Of FABP4, ADIPOQ And CFD Genes Of Altay Sheep

Object: Altay sheep is a fat-tail sheep breed, its unique fat-tail plays an important role in maintaining the metabolic and body temperature through the tail fat deposition and metabolism. And it is an ideal model in the study of fat deposition and metabolism. Recent studies suggested that FABP4,ADIPOQ and CFD genes are involved in the physiology process of glucose and lipid metabolism and and adipocyte differentiation,preliminary infers that these three genes are closely related to the fat deposition and metabolism. With Altay sheep as objects,investigated the effects of these three genes on fat deposition and metabolism of Altay sheep. Methods: 1.The construction of animal models:The starvation tests of Altay sheep were conducted through simulating the way their fat deposition and metabolism under the natural physiological state, fat deposits during the summer and autumn months and lipolysis during spring and winter. 2.The sheep FABP4,ADIPOQ and CFD genes was amplified from tail fat of Altay sheep by using RT-PCR techniques. 3.Semi-quantitative RT-PCR was employed to investigate their expression profiles in different organizations of sheep. 4.Real-time RT-PCR method was used to detected FABP4,ADIPOQ and CFD genes m RNA expression changes in the no-starvation and continuous starvation groups respectively. Results: 1. After two weeks gradually limited feeding and fasting for 4 weeks(free water), the sheep from continuous starvation groups acted more anxious;the fat tail presented a "flat thin" phenotype, the skin of fat tail became saggy;the volume of tail fat tissue decreased by a third; the body weight decreased significantly. 2.The CDS of FABP4,ADIPOQ and CFD genes were cloned, which encoded 132,239,261 amino acid residues respectively.The FABP4 nucleotide sequences and amino acid sequences from sheep, goat,cow, yak and wapiti were appeared to be highly similarity(90%); The similarity of sheep ADIPOQ nucleotide sequences and amino acid sequences with those three genes in cow, mice, rat,pig and human was more than 75%,the highest similarity(85%) presented between sheep and cow;the similarity of sheep CFD nucleotide sequences and amino acid sequences with that in cow(ruminant animals)was more than 96.9%. 3.The results of semi-quantitative PCR indicated that FABP4 gene expressed in all the examined tissues,but most strongly in the mesenteric adipose tissues and tail fat;ADIPOQ gene was only highly expressed in the tail fat;CFD gene expressed in heart,liver,spleen,lung, muscle tissue and tail fat,but had the high expression in the tail fat. 4.The results of real-time PCR analysis revealed that there was no significant differences in FABP4 m RNA between no-starvation and continuous starvation groups(P>0.05); On the contrary, the expression level of ADIPOQ and CFD gene were significantly higher in the tail fat of continuous starvation groups(P<0.01). Conclusion:All these results suggested that FABP4,ADIPOQ and CFD genes play a role in the process of regulating metabolism in Altay sheep tail fat deposition, which can be used as candidacy functional genes to regulate the processes of growth of mammalian adipose tissue.