FIG 6.

Effect of deleting genes encoding nonessential VTPs on CyHV-3 virulence. The virulence of the indicated recombinant viruses was tested in carp (triplicate groups each consisting of 15 subjects; average weight, 1.90 ± 0.68 g, and average age, 3 months old). On day 0, fish were infected for 2 h by immersion in water containing 800 PFU/ml or mock infected. Survival rate was measured over a period of 30 days. The nine upper panels show the survival curves observed for replicates. The lower panel shows the mean survival curves based on the three replicates.