Abstract：microRNA has an important regulatory role in cell proliferation and differentiation. The microRNA-378-1 precursor was amplified by PCR from Large White(Sus scrofa) genomic DNA and was digested by XhoⅠ and then ligated into XhoⅠ digested vector pEGP-miR to produce the recombinant vector pEGP-miR-378-1. This vector was transfected to porcine fetal fibroblasts cells (PEF, porcine embryo fibroblast) and its transfection efficiency and expression were detected by fluorescence observation and RT-PCR, respectively. The results showed that pEGP-miR-378-1 vector was constructed successfully with high transfection efficiency. Further RT-PCR results showed that the expression of microRNA-378-1 was increased significantly compared with control groups(P<0.01). This will provide technological platform for producing transgenic animals to further study the function of microRNA-378-1
