At 24 hpi, the activities of SOD, CAT and LYZ in the intestine were detected to evaluate the effect of DIV1 infection on the nonspecific immunity of M. japonicus (Figures 2A–C), and the activities of α-AMS, LPS and TPS in the intestine were detected to evaluate the digestive function (Figures 2D–F). The gene discussed is CAT; the disease is infection.