White Spot Syndrome Virus (WSSV) poses a significant threat to shrimp aquaculture worldwide. Developing effective antiviral strategies is crucial to mitigating the economic impact of WSSV outbreaks. RNA interference (RNAi), a naturally occurring cellular process, has emerged as a promising approach to controlling viral infections.
Scientists Soon Joo Hong and Ki Hong Kim from the Department of Aquatic Life Medicine at Pukyong National University (South Korea) evaluated the protective efficacy and duration of protection provided by a single administration of various doses of long dsRNA targeting the ribonucleotide reductase 2 (rr2) of WSSV in whiteleg shrimp Litopenaeus vannamei.
The Power of dsRNA Against WSSV
Recent advances in RNA interference (RNAi) technology have opened new possibilities for combating viral diseases in shrimp. This cutting-edge technology uses the cellular machinery to silence specific viral genes, preventing viral replication and spread (Alam et al., 2023).
Previous studies like Joo and Hong (2023) have demonstrated that long double-stranded RNAs (dsRNA) targeting essential WSSV genes can induce a sequence-specific RNAi response in shrimp, leading to viral suppression. This antiviral mechanism offers a potential solution for combating WSSV infections.
Optimizing dsRNA Dosage and Duration of Protection
To establish RNAi as a practical antiviral measure, it is essential to determine the optimal dsRNA dose and the duration of protection provided. The study, published in the journal Diseases of Aquatic Organisms, aimed to evaluate the protective efficacy and longevity of a single administration of various doses of dsRNA targeting the ribonucleotide reductase 2 (rr2) of WSSV in whiteleg shrimp.
Key Findings
- Effectiveness at Low Doses: The protective efficacy of dsRNA targeting WSSV rr2 was not compromised even when the dose was reduced to 100 ng g-1 of body weight. This suggests that a relatively low dose can effectively induce an RNAi response in shrimp.
- Long-term Protection: Shrimp were well-protected against WSSV challenges up to 4 weeks after the administration of rr2-targeting dsRNA. Although the protective effect waned by 6 weeks, these results indicate that dsRNA can provide protection for at least 1 month.
Implications for Shrimp Aquaculture
The findings of this study have significant implications for shrimp aquaculture:
- Monthly Administration: Monthly administration of dsRNA targeting WSSV could serve as a long-term protective strategy against WSSV infections.
- Cost-effective Approach: The ability to use relatively low doses of dsRNA makes RNAi-mediated antiviral methods potentially cost-effective.
- Sustainable Aquaculture: RNAi-based strategies offer a sustainable and environmentally friendly approach to managing viral diseases in shrimp farming.
Future Directions
While this study provides valuable insights into the potential of RNAi for WSSV control, further research is needed to:
- Explore Other Target Genes: Identifying additional WSSV genes suitable for dsRNA-mediated targeting could enhance the efficacy of this approach.
- Evaluate Long-term Effects: Long-term studies are needed to assess the potential impacts of repeated dsRNA administration on shrimp health and the environment.
- Develop Delivery Methods: Developing efficient and cost-effective methods for delivering dsRNA to shrimp could facilitate its widespread application in aquaculture.
Conclusion
In conclusion, RNAi is a highly promising tool for combating WSSV infections in shrimp. The findings of this study demonstrate the potential of dsRNA to provide effective and long-lasting protection against this devastating viral disease.
As research continues to advance, RNAi-mediated methods may become a valuable component of sustainable shrimp aquaculture practices.
Contact
Ki Hong Kim
Department of Aquatic Life Medicine, Pukyong National University
Busan 48513, South Korea
Email: khkim@pknu.ac.kr
Reference
Hong SJ, Kim KH (2024) RNA interference targeting WSSV ribonucleotide reductase 2 provides long-term protection against infection in Litopenaeus vannamei. Dis Aquat Org 159:71-78. https://doi.org/10.3354/dao03805
Other references
Alam, M. S., Islam, M. N., Das, M., Islam, S. F., Rabbane, M. G., Karim, E., Roy, A., Alam, M. S., Ahmed, R., & Md. Kibria, A. S. (2023). RNAi-Based Therapy: Combating Shrimp Viral Diseases. Viruses, 15(10). https://doi.org/10.3390/v15102050
Joo Hong, S., & Hong Kim, K. (2023). Effects of length and sequence of long double-stranded RNAs targeting ribonucleotide reductase 2 of white spot syndrome virus (WSSV) on protective efficacy against WSSV. Journal of Invertebrate Pathology, 196, 107869. https://doi.org/10.1016/j.jip.2022.107869
