The Expression Of Ghrelin And Slc22a5in Gastrointestinal Tract In Lambs

To explore the gene expression patterns during the development of thegstrointestinal tract and accumulate data for the further study of the molecularregulation of gastrointestinal development. In this study, bioinformatics and molecularbiology techniques were used to isolate and identify two genes associated with thelamb gastrointestinal development in sheep, and made some preliminary predictionand research. The results which we achieved were as follows：1. Sheep Ghrelin and Slc22a5were isolated and identified by comparativegenomics and, and the abomasums RNA of7-day-aged lambs were employed astemplate. The whole and partial CDS of Slc22a5were obtained, and the fragmentslength were409bp and995bp respectively. The amplified Ghrelin was409bp,including a complete coding sequence, which was351bp in size, encoded116aminoacids. The sheep Ghrelin was12975.74D in molecular weight,4.70in isoelectricpoint. The protein of Ghrelin had one signal peptide between site1and23, and thewhole peptide showed the characterisitic of hydrophobicity, which was atransmembrane protein. The secondary structure of Ghrelin showed that it mainlyConstituted of α-helix and coils, and it may play an important role in immuneresponse, stress response and transcription regulation in extracellular.2. The gastrointestinal tract(rumen, reticulum, omasum, abomasums, duodenum,jejunum, ileum) cDNA of7-day-aged lambs were employed as template to analyse thetissue specificity of Ghrelin and Slc22a5gene, and validate it by real-time PCR. Theresults revealed that Ghrelin and Slc22a5existed in all the above tissues, it wassignificantly higher in abomasums and ileum than in other tissues respectively.3. The development changes of abomasums Ghrelin expression in0~56daylambs was analyzed by. The results showed that the expression of abomasums Ghrelinin lambs increased with the addition of age, it reached a plateau at the age of49d,however, got a slightly decrease at the age of56d. 4．The relationship between the expression of Ghrelin and abomasums weightshowed that it was in a liner manner: Y=17.342x+18.109(n=9, R2=0.647, P=0.009),both of them increased with the addition of age.5. The effects of42-day weaning on Ghrelin expression in lamb abomasums wasresearched by real-time PCR. The results indicated that the expression of abomasumsGhrelin mRNA of the treatment group were high significantly or significantly lowerthan the controlled group(P<0.05or P<0.01), the Ghrelin mRNA expression of thetwo treatments reached a maximum at the age of49d, and both have a tendency offirst increased then decreased.The study of the above suggested that Ghrelin gene may play an important rolein the development of lamb abomasums while Slc22a5gene in the growth of ileum,but the mechanism of these needs further research.