Synonymous SNPs of viral genes facilitate virus to escape host antiviral RNAi immunity

RNAi-Based Therapy: Combating Shrimp Viral Diseases

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.

Split light up aptamers as a probing tool for nucleic acids

Aptamers that bind non-fluorescent dyes and increase their fluorescence can be converted to fluorescent sensors. Here, we discuss and provide guidance for the design of split (binary) light up aptameric sensors (SLAS) for nucleic acid analysis. SLAS consist of two RNA or DNA strands and a fluorogenic organic dye added as a buffer component. The two strands hybridize to the analyzed DNA or RNA sequence and form a dye-binding pocket, followed by dye binding, and increase in its fluorescence. SLAS can detect nucleic acids in a cost-efficient label-free format since it does not require conjugation of organic dyes with nucleic acids. SLAS design is preferable over monolith fluorescent sensors due to simpler assay optimization and improved selectivity. RNA-based SLAS can be expressed in cells and used for intracellular monitoring and imaging biological molecules.

Roles of host small RNAs in the evolution and host tropism of coronaviruses

Human coronaviruses (CoVs) can cause respiratory infection epidemics that sometimes expand into globally relevant pandemics. All human CoVs have sister strains isolated from animal hosts and seem to have an animal origin, yet the process of host jumping is largely unknown. RNA interference (RNAi) is an ancient mechanism in many eukaryotes to defend against viral infections through the hybridization of host endogenous small RNAs (miRNAs) with target sites in invading RNAs. Here, we developed a method to identify potential RNAi-sensitive sites in the viral genome and discovered that human-adapted coronavirus strains had deleted some of their sites targeted by miRNAs in human lungs when compared to their close zoonic relatives. We further confirmed using a phylogenetic analysis that the loss of RNAi-sensitive target sites could be a major driver of the host-jumping process, and adaptive mutations that lead to the loss-of-target might be as simple as point mutation. Up-to-date genomic data of severe acute respiratory syndrome coronavirus 2 and Middle-East respiratory syndromes-CoV strains demonstrate that the stress from host miRNA milieus sustained even after their epidemics in humans. Thus, this study illustrates a new mechanism about coronavirus to explain its host-jumping process and provides a novel avenue for pathogenesis research, epidemiological modeling, and development of drugs and vaccines against coronavirus, taking into consideration these findings.

RNAi-based antiviral immunity of shrimp

As a kind of important economic marine crustaceans in aquaculture, shrimp can be infected by more than 20 viruses. To fight against the virus invasion, shrimp have developed the innate immunity, including RNA interference (RNAi). RNAi, mediated by short interfering RNAs (siRNAs) or microRNAs (miRNAs), plays important roles in virus-host interactions. At present, RNAi is considered to be an efficient antiviral response of shrimp. The siRNA-based RNAi, first recognized as an antiviral response of animals to resist RNA viruses, has emerged in animals as an efficient antiviral strategy against the invasion of DNA viruses and RNA viruses. In shrimp, as well as in other animals, siRNA contains a seed region (2nd-7th nt) and a supplementary region (12th-17th nt). Based on the findings in shrimp and other animals, miRNAs are essential regulators of virus-host interactions, such as virus infection/latency, and host apoptosis, autophagy and phagocytosis. Except for the seed sequence (2nd-7th), the complementary bases (to the target mRNA sequence) of a miRNA 9th-18th non-seed sequence are essential for the miRNA targeting. So far, rapidly growing evidences have supported the existence of functional RNAi machinery in shrimp. In this review, we summarize the progress of RNAi in the antiviral immune response of shrimp. The potential applications of RNAi to control shrimp diseases were also summarized.