Figure 8. Viral DNA replication and mRNA expression analysis of WT HSV-1 and its derived recombinant viruses. (A) DNA replication analysis of WT HSV-1 and its derived recombinant viruses. HEK293T cells were mock-infected or infected with WT HSV-1 (vUL2) and its derived recombinant viruses (vUL2Del, vUL2Mu and vUL2Rev) at an MOI of 1 for 24 h. Then, total cellular DNA was purified and PCR was performed with the primers specific for UL54 (IE gene), UL42 (E gene) and UL3 (L gene) to quantify DNA levels. To ensure that an equal amount of DNA was used from each sample, the DNA of each sample was normalized with GAPDH. (B) mRNA expression analysis of WT HSV-1 and its derived recombinant viruses. HEK293T cells were mock-infected or infected with WT HSV-1 (vUL2) and its derived recombinant viruses (vUL2Del, vUL2Mu and vUL2Rev) at an MOI of 1 for 24 h. Then, total RNA was isolated, and the mRNA expression levels of UL54, UL42, UL3 and GAPDH were assessed by RT-PCR. GAPDH was served as an internal control. Densitometry of UL54, UL42 and UL3 bands were normalized to the control GAPDH. Data were expressed as means ± SD from three independent experiments. Statistical analysis was performed using student’s t test, and * indicates P < 0.05, ** indicates P < 0.01, *** indicates P < 0.001.