Fig. 6

The mutation of amino acid 78 from serine to alanine could inhibit viral sgmRNA transcription. A: BHK-21 cells were transfected with 2 μg PRRSV infected clones. At 18hpi, the samples were collected. The relative viral RNA level, compared with XH-GD, was determined. B-C: Marc-145 cells were infected with the PRRSV at an MOI of 0.5, and the cells were collected at 8 hpi and 12 hpi. The relative viral RNA level, compared with XH-GD, was determined. The data shown represent the mean ± SD (n = 3). (*, P < 0.05; **, P < 0.01; ***, P < 0.001 in comparison with the XH-GD group)