The MRE11 opposes white spot syndrome virus infection through the IRF and Dorsal mediated antiviral pathways in shrimp.

Meiotic recombination 11 (MRE11), a key component of the MRE11-RAD50-NBS1 (MRN) complex, plays important roles in damaged DNA repair and immune response. In this study, we described the molecular cloning of a new member of MRE11 from Litopenaeus vannamei named as LvMRE11. The full length of LvMRE11 was 2999 bp, including a 1947 bp open reading frame (ORF) that encoded a putative protein of 648 amino acids with a calculated molecular weight of ∼73.2 kDa LvMRE11 was universally expressed in all tested tissues and its expression in intestine was responsive to the challenge of white spot syndrome virus (WSSV), poly (I: C), poly [dA:dT], CpG-ODN 2006 and IFN stimulatory DNA (ISD). The dsRNA-mediated knockdown of LvMRE11 enhanced the susceptibility of shrimps to WSSV infection, as manifested by a higher mortality and viral loads observed in LvMRE11 silenced shrimps. Besides, silencing of LvMRE11 resulted in decreased expression levels of IRF-Vago-JAK/STAT pathway components, and Dorsal but not the Relish, as well as several antimicrobial peptides (AMPs). In conclusion, we provided some evidences that the involvement of LvMRE11 in innate immune against virus infection probably through regulating the IRF and Dorsal mediated antiviral pathways.