miR-9875 functions in antiviral immunity by targeting PDCD6 in mud crab ().

Programmed cell death 6 (PDCD6) is a well-known apoptosis regulator that is involved in the immunity of mammals. However, the effects of miRNA-mediated regulation of PDCD6 expression on apoptosis and virus infection in organisms, especially in marine invertebrates, have not been extensively explored. In this study, PDCD6 of mud crab () (-PDCD6) was characterized. The results showed that -PDCD6 contains five EF-hands domains and could suppress virus infection apoptosis promotion. It also presented that -PDCD6 was directly targeted by miR-9875 and , miR-9875 served as a positive regulator during the virus invasion. The findings indicated that the miR-9875-PDCD6 pathway possessed fundamental effects on the immune response to virus infection in mud crab. Therefore, our research provided a novel insight into the roles of both miR-9875 and PDCD6 in the regulation of apoptosis and virus defense in mud crab.