Swine PPAR-γ2/MyoD Expression Up-regulated In Skeletal Muscle Of Transgenic Mouse Via Swine Myoz1/Myf6 Gene Promoter

The purpose of transgenic animal is to transfer the exogenous genes into host cells and make it stable in the host genome. What’s more, the foreign genes could pass on to the next generation steadily. We could study the expression level of exogenous genes in vivo through transgenic animal, and finally obtain the ideal characters. Our study linearized the existing muscle specific promoter plasmids, p GL3-Myoz1-PPAR-γ2his-Basic and p SV40-Myf6-Myo DEGFP-N1. The linearized plasmids were microinjected into pronuclei of fertilized FVB/NJ mouse embryos and get PPAR-γ2 and Myo D transgenic(TG) animals. Our study was to study the copy number of foreign gene, the tissue specificity of promoter, phenotypic traits and so on. Our purpose was to get the usefull promoter for the transgenic pig. The main research results are as follows:1. In our study, PPAR-γ2 and Myo D transgenic mouse were identified by PCR technology. what’s more, the copy number was also selected by PCR technology, and result showed that the foreign gene could passed to next generation. We used real-time fluorescence quantification PCR, immunohistochemistry and Western blot to test the swine muscle-specific promoter Myoz1 and Myf6 were indeed up-regulated PPAR-γ2 and Myo D expression. Moreover, the target genes of PPAR-γ2, such as fatty acid-binding protein 4(FABP4) and lipoprotein lipase(LPL), were also over expressed.2. We used frozen section and the oil red O staining to test the lipid droplets in the skeletal muscle section, and the result showed that the lipid droplets were much more in TG mice muscle than that in WT mice muscle. We also test the triacylglycerol content in skeletal muscle, the result showed that the triacylglycerol content in skeletal muscle of TG mice was significantly increased(p < 0.01).3. We used the real-time fluorescence quantification technique to test the Myo D expression level of TG mouse different tissues, such as heart, liver, spleen, lungs, kidney, brain, muscle and fat. The result showed that Myo D gene got specific high expression in muscle tissue.4. We also examined the growth conditions of muscle fiber by HE stain of muscle section, which showed that the muscle fiber diameter and area of TG mouse were both greater than that of WT mouse in significance level(p<0.01), and the muscle fiber number in unit area of TG mouse was less than that of WT mouse in significance level(p<0.01).In conclusion, swine Myoz1 and Myf6 promoter could up-regulateed the exogenous gene expression, and influence intramuscular fat content and the growth of muscle fibers. At last, our study could provide an effective promoter for future preparation of transgenic pig to improve the pork quality.