RNAi-Based Therapy: Combating Shrimp Viral Diseases

Abstract

Shrimp aquaculture has become a vital industry, meeting the growing global demand for seafood. Shrimp viral diseases have posed significant challenges to the aquaculture industry, causing major economic losses worldwide. Conventional treatment methods have proven to be ineffective in controlling these diseases. However, recent advances in RNA interference (RNAi) technology have opened new possibilities for combating shrimp viral diseases. This cutting-edge technology uses cellular machinery to silence specific viral genes, preventing viral replication and spread. Numerous studies have shown the effectiveness of RNAi-based therapies in various model organisms, paving the way for their use in shrimp health. By precisely targeting viral pathogens, RNAi has the potential to provide a sustainable and environmentally friendly solution to combat viral diseases in shrimp aquaculture. This review paper provides an overview of RNAi-based therapy and its potential as a game-changer for shrimp viral diseases. We discuss the principles of RNAi, its application in combating viral infections, and the current progress made in RNAi-based therapy for shrimp viral diseases. We also address the challenges and prospects of this innovative approach.

Keywords: dsRNA; innate immune response; penaeid shrimp; post-transcriptional gene silencing; shrimp viral diseases; siRNA; therapeutics.

Figure 1

Schematic illustration of RNAi pathway (endogenous and exogenous). The siRNA and miRNA pathways are denoted by solid and dotted arrows, respectively. In the siRNA pathway, Dicer cleaves dsRNA to produce siRNAs in the cytoplasm. These siRNAs are integrated into the RISC complex and then unwound into two single-stranded RNAs known as the passenger and guide strand. The guide strand stays inside the RISC to control the sequence-specific decay of complementary mRNA while the exonucleases break down the passenger strand. On the other hand, the miRNA pathway starts with endogenously encoded pri-miRNAs, which are then transcribed by RNA polymerase II and trimmed by Drosha to produce pre-miRNAs. These precursors are subsequently transported to the cytosol where Dicer cleaves them to create miRNAs. Similar to the siRNA pathway, the miRNA duplex unwinds and one of the strands, the so-called mature miRNA, assembles into RISC, causing either mRNA breakage or translation inhibition, depending on the degree of similarity between the miRNA and the mRNA target. Exogenous RNAi triggers (pink dashed arrows), such as vector-based shRNAs and synthetic dsRNAs, siRNAs, and miRNAs, may also induce RNAi.

Figure 2

Potential delivery methods of RNAi molecule in shrimp to combat viral diseases.