MicroRNA transcriptome analysis for elucidating the immune mechanism of the redclaw crayfish Cherax quadricarinatus under Decapod iridescent virus 1 infection

Redclaw crayfish (Cherax quadricarinatus) is a large, tropical freshwater crustacean species with considerable potential of commercial production. In recent years, infection with DIV1 in redclaw crayfish is being reported in aquaculture industries, causing high mortality and huge economic losses. However, many characteristics of this virus, including pathogenesis, transmission mechanism, and host immunity, remain largely unknown.MicroRNAs are known to play important roles in numerous biological processes, and many microRNAs are reported to be involved in the regulation of immune responses. In this study, nine-small RNA libraries were constructed using hemocytes of redclaw crayfish to characterize the differentially expressed miRNAs (DE-miRNAs) at 24 and 48 h postinfection (hpi). A total of 14 and 22 DE-miRNAs were identified in response to DIV1 infection at 24 and 48 hpi, respectively. Further, functional annotation of the predicted host target genes using GO and KEGG pathway enrichment analyses indicated that relevant biological processes and signal pathways underwent miRNAmediated regulation after DIV1 infection. Our results enhanced the understanding of the mechanisms of miRNA-mediated regulation of immune responses under DIV1 infection in crustaceans.

Automated summary

This study constructed small RNA libraries using redclaw crayfish hemocytes to investigate the differential expression and regulation mechanism of miRNAs after DIV1 virus infection. The results showed that 14 and 22 differentially expressed miRNAs were identified at 24 and 48 hours postinfection, respectively. Functional annotation analysis revealed that miRNA-mediated regulation was involved in relevant biological processes and signal pathways.