Identification and characterization of lncRNAs and the interaction of lncRNA-mRNA in Epinephelus coioides induced with Singapore grouper iridovirus infection.

Singapore grouper iridovirus (SGIV) is a highly pathogenic double-stranded DNA virus, and the fatality rate of SGIV-infected grouper is more than 90%. Up to now, there is no effective methods to control the disease. Long non-coding RNAs (lncRNAs) might play an important role in individual growth and development, immune regulation and other life processes. In this study, lncRNAs were identified in Epinephelus coioides, an important economic aquaculture marine fish in China and Southeast Asia, and the regulatory relationships of lncRNAs and mRNA response to SGIV infection were analyzed. A total of 11,678 lncRNAs were identified and classified from the spleen and GS (grouper spleen) cells. 105 differentially expressed lncRNAs (DElncRNAs) were detected during SGIV infection. The lncRNAs and the regulated mRNAs were analyzed using co-expression network, lncRNA target gene annotation and GO enrichment. At 24 and 48 h after SGIV infection, 118 and 339 lncRNA-mRNA pairs in GS cells were detected, and 728 and 688 differentially expressed lncRNA-mRNA pairs in spleen were obtained, respectively. GO and KEGG were used to predict the DE lncRNAs' target genes, and deduce the DE lncRNAs-affected signaling pathways. In GS cells, lncRNAs might participate in cell part, binding and catalytic activity; and lncRNAs might be involved in immune system process and transcription factor activity in spleen. These data demonstrated that lncRNAs could regulate the expression of immune-related genes response to viral infection, and providing a new insight into understanding the complexity of immune regulatory networks mediated by lncRNAs during viral infection in teleost fish.