Similar to virus that replicated in a Se-deficient host, virus isolated from GPx-1–knockout mice that developed myocarditis also had viral genome changes. Virus isolated from GPx-1–knockout hearts that developed myocarditis had the same six mutations as were found in virus isolated from Se-deficient mice. In addition, another nucleotide change occurred: Nt 2690: G → A. The changes in the genome were associated with the increased virulence of the virus, because viruses isolated from GPx-1–knockout mice that did not develop myocarditis were identical to the input strain.
Thus, both a deficiency in Se as well as a specific deficiency in GPx-1 activity lead to viral genome changes, which suggests that increased oxidative stress of the host can affect a viral genome.