Figure 6
Overexpression of chBRD2 reduces NDV replication in DF-1 cells. A Fluorescence observation of DsRed and DsRed-BRD2 in plasmid-transfected DF-1 cells. DF-1 cells were transfected with 3.0 μg of pDsRed-C1 or pDsRed-chBRD2 to overexpress DsRed or DsRed-chBRD2. The fluorescence of DsRed and DsRed-chBRD2 was observed under an inverted fluorescence microscope at 36 hpt. DAPI was used to detect nuclei. The original magnification was 1 × 100. B The effect of DsRed or DsRed-BRD2 overexpression on the transcription of the chBRD2 gene in DF-1 cells. The transcription levels of the chBRD2 gene in pDsRed-C1- or pDsRed-chBRD2-transfected cells or non-transfected cells were detected by qRT-PCR at 36 hpt. The relative transcription levels of the chBRD2 gene were compared with those of the control GAPDH gene. Error bars represent standard deviations (mean ± SD) (***P < 0.001 compared to the value of non-transfected cells). C The growth kinetics of rSS1GFP were compared using multicycle growth curves in pDsRed-C1- or pDsRed-chBRD2-transfected cells or non-transfected cells. The cell culture supernatants were collected at the indicated time points (6, 12, 24, 36, 48, and 72 hpi), and the viral titres were titrated using TCID50 (50% tissue culture infective doses) in DF-1 cells. Error bars represent standard deviations (mean ± SD) (*P < 0.05; **P < 0.01; ***P < 0.001 compared to the value of non-transfected cells). Viral RNA synthesis corresponding to the NP and P genes (D) and viral gene transcription corresponding to the M and GFP genes (E) of rSS1GFP in pDsRed-C1- or pDsRed-chBRD2-transfected cells or non-transfected cells was detected by qRT-PCR at 6, 12 and 24 hpi. Error bars represent standard deviations (mean ± SD) (*P < 0.05; **P < 0.01; ***P < 0.001 compared to the value of non-transfected cells). F The expression levels of the M and GFP proteins in pDsRed-C1- or pDsRed-chBRD2-transfected cells or non-transfected cells were examined by western blot at 6, 12 and 24 hpi, respectively. The relative expression levels of the M and GFP proteins compared to control GAPDH expression levels were determined by densitometry using ImageJ software version 1.8.0. Error bars represent standard deviations (mean ± SD) (*P < 0.05; **P < 0.01 compared to the value of non-transfected cells).