Abstract：Growth hormone (GH) is the main hormone which can control the growth of animals. GH release is controled by growth hormone releasing factor(GRF) and somatostatin(SS). SS is one of important negative factors regulating GH release, reducing somatostatin receptor Ⅱ (SSTR2) expression thereby decreased the inhibition of SS. In this study, According to pig (Sus scrofa) SSTR2 gene deposited in GenBank, three short hairpin RNAs (shRNA) were designed and synthesized, after annealing in vitro, the three shRNA were cloned into the pshRNA-copGFP lentivector (LV-shRNA). Then LV-shRNA and pcDNA3.1(-)-SSTR2 recombinant plasmid were established, transient-transfection into Chinese hamster(Cricetulus griseus) ovary cell (CHO). The results showed, both SSTR2 mRNA and protein levels down-regulated significantly (P<0.05) at 48 h post-transfection detected by the fluorescent observation, Real-time PCR, and Enzyme-linked imunosorbent assay (ELISA). Expression of shRNAs in CHO cells reduced SSTR2 mRNA level by 90.4% 28.3% and 86.3% respectively. Among which, LV-shRNA1 showed the highest silencing efficiency, SSTR2 mRNA reduced 90.4 % (P<0.05) and SSTR2 protein reduced 33.3% (P<0.05) when the transfection efficiency was 80%. The LV-shRNA vector which down-regulated the pig SSTR2 gene expression was constructed successfully, and can facilitate further study on the transgenic pig.
