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Does a DNA-less cellular organism exist on Earth?
Akira Hiyoshi1, Kohji Miyahara, Chiaki Kato
1Department of Applied Life Science, Sojo University, Ikeda, Kumamoto city, Japan.
Genes to Cells : Devoted to Molecular & Cellular Mechanisms
|November 19, 2011
Summary
Researchers explored the possibility of DNA-less microorganisms, which could possess RNA genomes. Despite developing new methods, all tested samples ultimately showed DNA, though the search for these elusive organisms continues.
Area of Science:
- Microbiology
- Molecular Biology
- Astrobiology
Background:
- All known self-reproducing organisms utilize Deoxyribonucleic acid (DNA) as their genetic material.
- The existence of RNA viruses and the RNA world hypothesis suggest the theoretical possibility of DNA-less organisms.
- The vast, unexplored microbial diversity presents a potential niche for such life forms.
Purpose of the Study:
- To develop and apply experimental methods for detecting DNA-less microorganisms.
- To investigate the possibility of RNA-based genomes in unculturable or novel microbial life.
- To contribute to the understanding of early life evolution and the boundaries of life.
Main Methods:
- Cultivation of microbial samples using drugs that inhibit DNA replication and expression.
- Detection of Deoxyribonucleic acid (DNA) in microbial colonies using fluorescent dyes.
- Cellular-level double staining techniques to differentiate between DNA and Ribonucleic acid (RNA).
Main Results:
- Initial screening identified several colonies and cells that appeared DNA-less.
- Subsequent isolation and re-cultivation confirmed that all apparently DNA-less colonies were, in fact, DNA-positive.
- No definitive evidence of DNA-less microorganisms was found in the tested environmental samples.
Conclusions:
- The experimental search for DNA-less microorganisms, while yielding no positive results to date, utilized novel methodologies.
- The possibility of DNA-less organisms remains plausible due to cultivation challenges and the vastness of microbial diversity.
- Further refinement of detection techniques and cultivation strategies may be necessary to discover such organisms in the future.
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