INTERNATIONAL CONGRESS OF
CancerGenetics
Bacterial Small RNAs Analogous to microRNAs: Roles in Stress Resistance and Extraterrestrial Survival
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Shirin Dehghan,1,*
1. Genetics graduate, Kharazmi University
- Introduction: Bacterial small RNAs (sRNAs), functionally analogous to eukaryotic microRNAs (miRNAs), have emerged as pivotal regulators of gene expression in response to environmental stress. These molecules, typically 50–250 nucleotides in length, modulate mRNA stability, translation, and regulatory networks, thereby orchestrating adaptive responses critical for survival under extreme conditions. The study of sRNAs in extremophilic bacteria provides a compelling framework for understanding microbial resilience in space environments and offers translational insights for synthetic biology, astrobiology, and biotechnology. sRNAs mediate stress resistance through diverse mechanisms, including post-transcriptional repression of target mRNAs, modulation of transcription factors, and interaction with RNA-binding proteins. In Deinococcus radiodurans, known for its remarkable radiation resistance, sRNAs such as Dsr1 and Dsr2 regulate genes involved in DNA repair, oxidative stress mitigation, and protein quality control, thereby enhancing cellular recovery after gamma irradiation or desiccation. Similarly, in thermophilic and halophilic bacteria, sRNAs coordinate responses to temperature extremes, osmotic pressure, and nutrient limitation, allowing rapid physiological adjustments without the need for permanent genomic alterations.
- Methods: The functional analogy between bacterial sRNAs and eukaryotic miRNAs extends beyond mere size and regulatory roles; both classes of RNAs establish fine-tuned networks that can propagate epigenetic-like effects. In bacteria, sRNAs often interact with RNA chaperones such as Hfq and ProQ to stabilize interactions with multiple targets, thereby integrating multiple stress-response pathways. This regulatory versatility underlies bacterial epigenetic plasticity, enabling populations to transiently adapt to fluctuating or extreme environments, including those encountered in spaceflight conditions such as microgravity, ionizing radiation, and desiccation. sRNAs also contribute to horizontal gene transfer (HGT) dynamics, indirectly shaping microbial adaptability. By modulating the expression of mobile element-encoded genes or stress-inducible recombination pathways, sRNAs facilitate the assimilation of beneficial genetic material acquired through plasmids, phages, or transposons. This mechanism is particularly relevant for extremophiles in extraterrestrial analog habitats, where HGT can confer resistance to radiation or oxidative damage, complementing the intrinsic stress-protective functions of sRNAs.
- Results: Applications in astrobiology and space biotechnology are increasingly evident. sRNA-mediated regulation can be leveraged to engineer extremophiles with enhanced tolerance to space-relevant stressors, supporting in situ resource utilization, bioremediation, and biosynthesis of essential compounds during long-duration missions. For example, sRNA-controlled gene circuits could enable the adaptive production of antioxidants, DNA repair proteins, or biopolymers under variable radiation or nutrient conditions, providing self-regulating microbial systems for habitat maintenance or pharmaceutical synthesis. Despite these opportunities, several challenges must be addressed. Functional characterization of sRNAs in extremophiles remains incomplete, with many small transcripts unannotated or lacking experimentally validated targets. Extraterrestrial environmental factors may alter RNA stability, folding, or protein interactions, necessitating robust in vitro and in situ modeling. Ethical and biosafety considerations are paramount when deploying engineered microbes in space habitats, emphasizing the need for controllable, reversible, and well-characterized regulatory systems.
- Conclusion: In conclusion, bacterial sRNAs analogous to eukaryotic miRNAs are central to the survival strategies of extremophiles, mediating stress resistance, adaptive plasticity, and integration of horizontally acquired traits. Their study informs both fundamental microbial ecology and practical applications in space missions and biotechnology. Advancing our understanding of sRNA networks, combined with synthetic biology and computational modeling, will enable the rational design of microbial systems capable of thriving under extraterrestrial conditions while supporting translational biomedicine and astrobiology initiatives.
- Keywords: Bacterial Small RNAs (sRNAs), microRNA Analogs, Stress Resistance, DNA Repair Regulation
