earticle

영어

The production of transgenic animals using somatic cell nuclear transfer (SCNT) has been widely described. A critical problem in the production of transgenic animals is the uncontrolled constitutive expression of the foreign gene which occasionally results in serious physiological disorders in the transgenic animal. In this study, we designed three different expression vectors that express the hEPO gene. hEPO is a hormone produced by the kidney that promotes the formation of red blood cells by the bone marrow. For the in vitro production of transgenic embryos, the different expression vectors were transduced into holstein ear fibroblast cells, respectively, and GFP expressed donor cells were transferred into enucleated oocytes, and then the reconstructed SCNT embryos were developed into pre-implantation stage. From three replicates, GFP expressed 112 transgenic SCNT embryos were produced. When their cleavage rate and blastocyst rate were compared with non-transgenic SCNT embryos, the results were presented into 73.2% vs. 76.9% and 26.8% vs. 30.6%, respectively, there were no differences. Also, total cell number and ICM cell numbers of day 8 blastocysts were statistically not different between the transgenic SCNT groups (120.6±7.9 and 31.4±8.2) and control SCNT group (128.3±4.8 and 35.3±4.0). The GFP expression levels were presented consecutively high during the culture of transgenic SCNT embryos. By analysis of semi-quantitative RT-PCR, the relative expression levels of hEPO mRNA and pluripotent gene were determined. These results demonstrated that the hEPO expressed transgenic bovine embryos can be efficiently produced in vitro by SCNT technique, while their potential of cloned animal production have to be examined in further study.