Exclusive Genomic Pathway Analysis for Groupers Infected by Different Iridovirus

Grouper is one of the most important aquaculture fish in the world. Due to high density of grouper farming, the aquaculture industry is threatened by iridovirus infections in recent years. In this study, we used next-generation sequencing technologies to analyze gene differential expression of groupers infected by two different types of iridoviruses, including Grouper Iridovirus of Taiwan (TGIV) of Megalocytivirus and Grouper Iridovirus (GIV) of Ranavirus. Zebra fish (Danio rerio) was selected as the reference model for gene functional annotations and pathway analyses. According to different fold change levels and identified associated KEGG pathways from defined gene sets, we found exclusive biological characteristics of groupers infected by two different iridoviruses. The results have shown that two specific gene sets, including the first set of PSMB2, CASP3, and U2AF2 for TGIV and the second set of PTGES, PDE3, and THBS1 for GIV were significantly and exclusively expressed. Furthermore, we also found two important pathways, Proteasome and ECM-receptor interaction pathways, were identified by employing gene set/pathway enrichment analysis. These results could facilitate biologists realizing comprehensive gene regulation of groupers infected by different iridoviruses and developing specific vaccines for grouper aquaculture.