The nucleocytoplasmic distribution characterization of VP1 protein in CHO-K1 and MDCC-MSB1 cells. To realize the subcellular distribution of VP1, the full-length VP1 gene included the fused whole EGFP gene at the 5′-terminus to generate the EGFP-VP1 expressing plasmid pEGFP-VP1 as illustrated in a schematic diagram (a). After 48 h post-transfection with the above plasmid in CHO-K1 cells (b) and MDCC-MSB1 cells (c), both cell types were fixed and stained with DAPI to reveal the nuclei. The subcellular localization of VP1 was determined by green fluorescence detection through confocal fluorescence microscopy