(A) Virus growth kinetics. DF1 cells are infected with the layer strain JL08CH3-1 and prototype strain HPRS103 at an MOI of 0.01, which are harvested and quantified using a TCID50 assay at 1, 2, 3, 4, 5, 6, and 7 dpi. (B) RT assay. DF1 cells are infected with the layer strain JL08CH3-1 or HPRS103 at an MOI of 0.01, which are harvested and quantified using a colorimetric reverse transcriptase assay at 1, 2, 3, 4, 5, 6, and 7 dpi. (C) Western blotting. The recombinant viruses rHPRS/JL3-1 and rHPRS103 are detected with p27 monoclonal antibody 2E5. (D) IFA assay. DF-1 cells are infected with the recombinant viruses rHPRS/JL3-1 and rHPRS103 for 72 h, and then detected with the 4A3 monoclonal antibody and analyzed using a fluorescence microscope. Scale bar: 400 μm. (E) Virus growth kinetics. DF1 cells are infected with 0.01 MOI rHPRS/JL3-1 and rHPRS103, which are harvested and quantified using a TCID50 assay at 1, 2, 3, 4, 5, 6, and 7 dpi. (F) RT assay. DF1 cells are infected with 0.01 MOI rHPRS/JL3-1 or rHPRS103, which are harvested and quantified using a colorimetric reverse transcriptase assay at 1, 2, 3, 4, 5, 6, and 7 dpi. dpi, days post-inoculation; IFA, immunofluorescence; MOI, multiplicity of infection; TCID50, 50% infective dose of tissue culture.