مقالات پذیرفته شده در نهمین کنگره بین المللی زیست پزشکی
Life at the Limits: Microbial Adaptation via Gene Transfer and Epigenetic Control
Life at the Limits: Microbial Adaptation via Gene Transfer and Epigenetic Control
Shirin Dehghan,1,*
1. Genetics graduate, Kharazmi University
Introduction: Extremophilic microorganisms exhibit exceptional resilience to environmental stressors, including high radiation, desiccation, extreme temperatures, and oxidative stress. This adaptability is not solely determined by their genomic content but also by dynamic epigenetic regulation, which enables rapid, reversible changes in gene expression without altering DNA sequences. Understanding these epigenetic mechanisms provides valuable insights for astrobiology, long-duration space missions, and biomedical innovations, including synthetic biology and microbiome-based therapies.
Methods: Epigenetic Plasticity in Extremophiles
Epigenetic regulation in extremophiles involves multiple layers, including DNA methylation, nucleoid-associated protein modulation, and small non-coding RNAs. These mechanisms allow cells to fine-tune stress-response pathways and optimize DNA repair processes in response to environmental challenges. For example, DNA methylation of recA and pprA loci in Deinococcus radiodurans regulates repair activity following UV or gamma radiation exposure, enabling temporary adaptation without permanent genetic change.
Synergistic Role of Horizontal Gene Transfer
While epigenetic mechanisms are central to rapid adaptation, horizontal gene transfer (HGT) can complement this process by introducing novel genes that enhance stress resilience. In extremophiles, acquired genes can be integrated into existing regulatory networks via epigenetic modulation, ensuring functional assimilation and minimizing deleterious effects. This interplay allows populations to respond efficiently to fluctuating stressors, such as those encountered during spaceflight.
Results: Applications for Space Missions
The adaptive flexibility of extremophiles has practical implications for space biology. Epigenetically tuned microorganisms can serve as components of self-sustaining life-support systems, performing bioremediation, in situ resource utilization, or biosynthesis of essential biomolecules. Radiation-resistant strains may assist in recycling waste, producing oxygen, or synthesizing pharmaceuticals on Mars or lunar habitats, thereby reducing mission payloads.
Biomedical Implications
Insights from extremophile epigenetics also inform human health applications. Understanding stress-response regulation may guide the development of radioprotective strategies, microbial therapeutics, or engineered microbiomes capable of thriving under oxidative or inflammatory conditions. These findings bridge fundamental microbial ecology with translational biomedicine.
Challenges and Future Directions
Despite the promise of epigenetic adaptability, challenges remain. Epigenetic states can be unstable over long periods or under novel extraterrestrial conditions. Ethical and biosafety considerations are crucial when deploying modified microbes beyond Earth. Integrating multi-omics analyses, predictive modeling, and high-throughput screening will be essential to designing strains with robust, controllable adaptability.
Conclusion: Epigenetic plasticity endows extremophiles with remarkable resilience, complementing genomic and horizontal gene transfer mechanisms. By elucidating these adaptive processes, researchers can design microbial platforms optimized for extreme environments, advancing both space biology and biomedical applications.