MicroRNA Regulatory Mechanisms in Aquatic Organisms

MicroRNAs (miRNAs) are small non-coding RNAs of approximately 18–25 nucleotides that fine-tune gene expression at the post-transcriptional level. In aquatic organisms, they govern crucial processes including development, tissue differentiation, metabolism and immune defence. Biogenesis of miRNAs involves transcription by RNA polymerase II, processing by Drosha and Dicer enzymes, and assembly into the RNA-induced silencing complex (RISC), which guides target recognition. In teleost fish and invertebrates, miRNAs control organogenesis, stress adaptation and host–pathogen interactions by targeting mRNAs in key signalling cascades such as Toll-like receptor, MAPK and NF-κB pathways. Environmental factors—temperature shifts, dietary components and pathogen exposure—modify miRNA expression profiles, with long-term effects on physiology and population resilience. In aquaculture, miRNA signatures have emerged as biomarkers for disease diagnosis, indicators of environmental stress and tools for selective breeding. Recent advances in high-throughput sequencing and multi-omics integration have expanded our understanding of miRNA networks, paving the way for novel strategies to enhance health, growth and sustainability in aquatic farming systems.

Research from Nature Portfolio

Studies have revealed that a virus-induced host miRNA in teleost fish can act as a molecular facilitator for viral replication. Investigation of megalocytivirus infection in Japanese flounder demonstrated that induction of a specific miRNA concurrently suppresses interferon regulatory factor 7 (IRF7) and p53, thereby dampening type I interferon responses and apoptosis. This dual repression enables early viral propagation by evading innate immunity. Mechanistic assays confirmed direct targeting of the 3′ untranslated regions of both IRF7 and p53 transcripts, while overexpression of these proteins reversed the miRNA’s proviral effects. This work exemplifies how host-derived miRNAs may be co-opted by pathogens to subvert antiviral barriers in aquatic organisms.

MicroRNA Regulatory Mechanisms in Aquatic Organisms publication trend

The graph below shows the total number of articles in microrna regulatory mechanisms in aquatic organisms across all publications each year (not limited to Nature Index journals).

Technical terms

microRNA (miRNA): A short non-coding RNA molecule that binds complementary sequences in target mRNAs to repress translation or induce degradation.

RNA-induced silencing complex (RISC): A multiprotein complex that incorporates a mature miRNA to guide sequence-specific recognition and silencing of target mRNAs.

Post-transcriptional regulation: Control of gene expression after transcription, including mRNA splicing, transport, stability and translation, often mediated by miRNAs and RNA-binding proteins.

Non-coding RNA: Any RNA molecule that is not translated into protein but may have regulatory or structural functions within the cell.

References

1. Multiomics analysis revealed miRNAs as potential regulators of the immune response in Carassius auratus gills to Aeromonas hydrophila infection. Frontiers in Immunology (2023).
2. MicroRNA Regulation in Infectious Diseases and Its Potential as a Biosensor in Future Aquaculture Industry: A Review. Molecules (2023).
3. MiR-181a Negatively Regulates Claudin-3 to Facilitate Lateolabrax maculatus Iridovirus Replication in Lateolabrax maculatus Astroglia Cells. Viruses (2024).
4. pol-miR-731, a teleost miRNA upregulated by megalocytivirus, negatively regulates virus-induced type I interferon response, apoptosis and cell cycle arrest. Scientific Reports (2016).