FIG 2 .

Virulence of SARS-CoV viroporin-defective mutants. Groups of five 16-week-old BALB/c mice were subjected to mock infection (PBS, gray filled circles) or infected with 100,000 PFU of either the parental virus (wt, black filled circles) or genetically engineered viruses missing E protein (ΔE, blue filled squares), 3a protein (Δ3a, red filled circles), or 8a protein (Δ8a, green filled diamonds). Mean levels of weight loss (left graph) and survival (right graph) through 10 dpi are shown for each group. Data summarize two replicate experiments with equivalent results. Error bars represent the standard deviations of mouse weight data.