PRRSV genomic variant spectra. (A) Note that the read depth is plotted on a log scale. The black solid curve depicts the coverage of the mapped Olot/91. The green bars show the locations of the Olot/91's variants when compared to the reference LV genome while the red bars are mixed variants in the viral population. Darker bars are variants that led to non-synonymous changes. (B) Genomic organisation of PRRSV. B- and T-cell epitopes distributed across the ORFs were represented with black horizontal bars.