FIG. 4.
Characterization of the nsp9 genetic components of MHVp15-1 and MHVp15-3. Shown is a comparison of MHV (black circle and solid line), the attenuated parent virus MHV9/10 (black square and solid line), MHVQ4319T (black triangle and dotted line), MHVK4298R (black square and dotted line), and MHV9/10K4298R (black circle and dotted line). Growth curves were performed on DBT cell monolayers infected at an MOI of 0.05 PFU/cell. Supernatants were sampled for replicating virus at 0, 6, 12, 18, and 24 hpi, and titers were determined by plaque assay. Data points represent the average of three replicate experiments, and error bars show the standard deviation. The limit of detection (lod) is represented by a horizontal dashed line at 1.7 log10 PFU/ml.