EXOSC8 and infection: Moreover, despite the 100% mortality induced by rYY-rVP3 infection, discernible differences in survival curves were still observed between the rYY-rVP3 and rZW-mP9 infection groups, reinforcing the previous conclusion that P9-rep sequence recombination, rather than the sole P9 promoter replacement, contributes to the virulence enhancement of rMDPV.