Biosafety Assessment Of Transgenic Pigs Expressing PEPCK-1

With the animal transgenic technology being used widely in creating of newbreeding materials, bioreactors, medicine, food and basic research of biology,bio-safety issues of transgenic animals is also getting more concern. However, due tothe inadequate work of science popularization of the transgenic technology, andlacking of communications to the media and public for scientists, etc, Especially theestablishment of related evaluation system, the contents, methods are not perfect,sothat people have little acquaintance with this field. For transgenic animals, people paymore and more attention on bio-safety issues including the impact of horizontal genetransfer or unintentional release of trans-genes on biodiversity, the potential risk ofgene modification on animal health, and food safety of genetically engineeredanimals.In the study, transgenic pigs of expressing PEPCK-1were the research object; theenvironmental safety was assessed by detecting the manure, the soil and the bloodDNA. The health of genetically engineered pigs was assessed by detecting thephysiological and biochemical indicators. The impacts of the milk of PEPCK-1transgenic sow on the health of piglets were also assessed.The environmental safety of genetically engineered pigs were assessed through thefollowing protocols:1）The horizontal gene transfer was detected with PCR to detectthe transgenes in microbial DNA extracts of blood or manure and soil, The resultswere negative.2）Using PCR to detect the boars in mating transgenic sows and pigletsof feeding milk of genetically modified sows whether occur to horizontal genetransfer,The results were negative.3）Analyzing nutrient element of transgenic pigsmanure or soil by physio-biochemical method. It was found that the variation ofnutrient element of soil or manure was probably caused by soil spacial difference oranimal-to-animal variation but not the transgenes. These results suggested thattransgenic pigs may be safe for the environment.In order to examine the health status of the transgenic pigs, carrying out theanalysis of growth performance, hematology, physio-biochemical analysis, immuneindexes and reproductive hormone level. The results were as follows:1)The resultsshowed that the weight and average daily gain were significantly higher than ordinarypigs in2,3months of age. Although the growth production was not significantdifference in4or5months of age, but the average body weight or average daily gainwas still higher than the control group.2) Most values of hematology were normal either for genetically engineered pigs or control ordinary pigs.only white blood cells(WBC) was significant difference in6months of age.3) For physio-biochemicalindicators, Triglyceride (TG) was significant difference between the experimentalgroup and control group in6months of age, and significantly lower than the controlgroup in3or7months of age, and relatively low in the whole test. Otherphysio-biochemical indicators had no significant difference between transgenic pigsand the control group.4) The IgG level of the experimental group at6months of agewas significantly higher than the control group.5)The level of reproductive hormoneshowed that reproductive hormone level change significantly, and the transgenic sowsof A1was in line with the law of dams reproductive hormonal changes during theestrus period. Transgenic sows of A2may be affected by external factors appeared toreproductive disorders, but the content of reproductive hormones in the normal range. Theseresults initially speculated that the exogenous gene (PEPCK-1) may not have impacton the health of pigs except the reproductive hormone.Finally, the piglets were fed with the milk of genetically modified sows andcommon milk to study the impact of the milk of genetically modified sows on piglets.The piglets were weighed once a week after the start of the experiment, and collectedthe blood samples to detect the serum physiological and biochemical at the beginningand end of the experiment. The results showed: there was no significant difference onthe weight, growth between the experimental group and the control group. We canpreliminarily conclude that the milk of genetically modified sows have no adverseeffect to the health of piglets.Based on the three aspects above, this test preliminarily demonstrates PEPCK-1gene has no adverse impact on environmental safety and the health of pigs.