PDGFC and infection: In this study, after virulent DY197 infection, the mRNA expression of platelet-derived growth factor C (VEGFC), platelet-derived growth factor receptor subunit B (PDGFB), integrin alpha-2 (ITGA2), myosin regulatory light polypeptide 9b (MYL9), myosin light chain kinase (MYLK) genes involved in focal adhesion and regulation of actin cytoskeleton pathways were significantly downregulated in the spleen, which may cause cell proliferation and migration disorders that are important for repairing of tissue damage.