RESUMO
The copy numbers of exogenous gene in transgenic animals is always regarded as an important information of transgenic animals.Thus,simple and sensitive methods are required for the detection of the copy numbers of exogenous gene.Three kinds of transgenic Shanbei white cashmere goats,containing Tβ4-GFP,FGF5s-GFP and VEGF164-GFP,has been obtained by using PiggyBac(PB) transposon system.Fluorescence quantitative PCR was carried out to detect the copy numbers of copGFP.Using Gluc as reference gene,the double standard curves of exogenous gene and reference gene were mapped and the genomic DNA of transgenic goats were analysized by real-time fluorescence quantitative PCR.Moreover,the copGFP/Gluc ratio in the samples was calculated as the copy numbers of copGFP.In addition,Tβ4-GFP transgenic cashmere goats were selected to detect the integration sites by using the genomic walking kit.The results showed that the standard curve equation of copGFP was y=-3.230 6x+39.216 (R2 =0.998 8) and the standard curve equation of Gluc was y=-3.564 8x+38.440 (R2 =0.996 0).The copy numbers of exogenous gene in the transgenic cashmere goats were obtained and the numbers of integration sites in the selected Tβ4-GFP transgenic goats were consistent with the copy numbers of copGFP.As a conclusion,the high throughput,fast and sensitive real-time fluorescence quantitative PCR is an efficient and convenient method for the copy number of exogenous gene in transgenic cashmere goats.
RESUMO
The induced pluripotent stem cells (iPSCs), derived by ectopic expression of reprogramming factors in somatic cells, can potentially provide unlimited autologous cells for regenerative medicine. In theory, the autologous cells derived from patient iPSCs should be immune tolerant by the host without any immune rejections. However, our recent studies have found that even syngeneic iPSC-derived cells can be immunogenic in syngeneic hosts by using a teratoma transplantation model (Nature 474:212-215, 2011). Recently two research groups differentiated the iPSCs into different germ layers or cells, transplanted those cells to the syngeneic hosts, and evaluated the immunogenicity of those cells. Both of the two studies support our conclusions that some certain but not all tissues derived from iPSCs can be immunogenic, although they claimed either "negligible" or "lack of" immunogenicity in iPSC derivatives (Nature 494:100-104, 2013; Cell Stem Cell 12:407-412, 2013). To test the immunogenicity of clinically valuable cells differentiated from human iPSCs are emergently required for translation of iPSC technology to clinics.