A multi-target dsRNA for simultaneous inhibition of yellow head virus and white spot syndrome virus in shrimp.

Outbreaks of diseases caused by yellow head virus (YHV) and white spot syndrome virus (WSSV) infection in shrimp have resulted in economic losses worldwide. DsRNA-mediated RNAi has been used to control these viruses, and the best target genes for efficient inhibition of YHV and WSSV are the protease and ribonuleotide reductase small subunit (rr2), respectively. However, one dsRNA can suppress only one virus, and therefore the production of multi-target dsRNA to effectively inhibit both YHV and WSSV is needed. In this study, plasmids pETpro-rr2_one stem and pETpro-rr2_two stems were constructed to produce two different forms of multi-target dsRNA in E. coli, which were designed specifically to both YHV protease and WSSV rr2 genes. The potency of each dsRNA in inhibiting YHV and WSSV and reducing shrimp death were investigated in L. vannamei. Shrimp were injected with the dsRNAs into the hemolymph before challenge with YHV or WSSV. The results showed that both dsRNAs could inhibit the viruses, however the one stem construct was more effective than the two stems construct when shrimp were infected with WSSV. This study establishes a potential strategy for dual inhibition of YHV and WSSV for further application in shrimp aquaculture.