The Western blot results showed that the protein expression levels of cleaved caspase 3 were 1.3 ± 0.099 and 1.0 ± 0.22 at four and six weeks after infection, which were significantly higher than those of the uninfected group (0.12 ± 0.083) (F = 54.01, p < 0.01). This evidence concerns the gene CASP3 and infection.