The Study Of Somatotropic Efficacies Of Gene Medicine Of Ghrelin Of Pig In Mice

Total RNA had been extracted from tissue of pig, 450bp fragment had been obtained by RT-PCR and had been cloned to pMD 18-T. This construction was digested with the same enzymes (Mlu1 and XhoⅠ) and ligated the PCI vector. The recombination plasmid was identified with PCR, digestion of internal restriction enzyme, and sequencing. The result suggest that the nucleotide sequence isolated from the recombinant plasmid PCI-Ghrelin-28aa was the same as the expected. We here studied the effect of PCI-Ghrelin-28aa on body weight gain in mice in twenty-five days. Intramuscular administration (1microg/kg BW) of PCI-ghrelin-28aa to mice significantly stimulated body weight gain. ADG on the five days was greater by the PCI-Ghrelin-28aa than by control mice (0.93±0.33 vs. 0.84±0.29g, respectively; P＜0.05), and after days ,more mice in PCI-Ghrelin-28aa treatment were observed growing ompared with control mice(P＜0.05), especially from 10 to 15 days. Conclusion: The successful construction of recombinant plasmid PCI-ghrelin-28aa will be benefit to further study in gene vaccine.The sequence of fusion gene have been designed on the basis of many reference, and synthesized this fusion gene. It was 233bp in length including signal peptide sequence and two restriction enzymic sites (Xho1 and Mlu1). Synthesized gene DNA was ligated with prepared fragments of PCI(Xho1E and Mlu1E), then transformed to DH5_α. We selected and identified the positive clones by PCR and digestion with XholE and MlulE. Sequencing result showed that expression vector of fusion gene has constructed successfully. Intramuscular administration (1microg/kg BW) of PCI-Ghrelin/GHRH to mice can get more ADG from 0 to 25 days compared with control treatment.Injectable sustained release PCI-Ghrelin-28aa were prepared by double emulsion-in liquid evaporation process, using biodegrable poly lactic acid as-carrier. The result oftransfection in vivo showed that after 25 days, accumulative increased body weights on the group injected with PCI-Ghrelin-28aa microspheres was higher than those group injected with naked plasmid(14.3%), saline(27.9%) respectively. In conclusion, PCI-Ghrelin-28aa microspheres have a controlled release effect and tendency to enhance absorb and expression of PCI-Ghrelin-28aa.In conclusion: PCI-ghrelin-28aa can significantly stimulate body weight gain of mice. PCI-Ghrelin/GHRH can stimulate growth of mice for a short time, and its Somatotropic Efficacies inferior to PCI-Ghrelin-28aa. PCI-Ghrelin-28aa microspheres have a controlled release effect and tendency to enhance absorb and expression of PCI-Ghrelin-28aa.