Genetic variability of immunomodulatory genes in ectromelia virus isolates detected by denaturing high-performance liquid chromatography.

The genetic variability of nine genes in 12 isolates and strains of ectromelia virus, which causes a smallpox-like disease (mousepox) in mice, was determined and allows for classification of ectromelia viruses. The low genetic variability suggests that evolutionary pressure maintains the activity of immunomodulatory genes in natural poxvirus infections.