Related Experiment Video
Updated: Feb 7, 2026
12:32
Quantification of Plasmid-Mediated Antibiotic Resistance in an Experimental Evolution Approach
Published on: December 14, 2019
14.7K
Experimental evolution of UV resistance in a phage
Eric F Tom1, Ian J Molineux2, Matthew L Paff1
1Department of Integrative Biology, University of Texas, Austin, TX, USA.
Peerj
|July 18, 2018
Summary
Researchers evolved bacteriophages (viruses that infect bacteria) to resist ultraviolet (UV) light. While survival improved 50-fold, genetic changes suggest limited potential for UV protection in phage therapy applications.
Area of Science:
- Microbiology
- Molecular Biology
- Evolutionary Biology
Background:
- Bacteriophages are viruses that infect bacteria and are being explored for therapeutic applications.
- Ultraviolet (UV) radiation poses a significant challenge to the efficacy of phage therapy due to DNA damage.
- Understanding phage resistance mechanisms is crucial for optimizing phage therapy.
Purpose of the Study:
- To investigate the genetic basis of UV resistance in double-stranded DNA (dsDNA) bacteriophage T7.
- To assess the potential for artificial evolution of UV-protective phages for applications like plant protection.
Main Methods:
- Subjecting bacteriophage T7 to 30 cycles of lethal UV irradiation for selection.
- Analyzing the genome of the evolved population for high-frequency genetic changes.
- Quantifying the survival improvement of the selected phage population.
Main Results:
- A 50-fold increase in UV survival was observed after 30 selection cycles.
- Key genetic alterations included a 2.1 kb deletion in early genes and three substitutions in structural genes.
- The deletion contributed minimally to survival, suggesting an error-catastrophe mechanism for reduced mutation rate.
- No significant changes were found in DNA metabolism genes.
Conclusions:
- The evolved UV resistance in bacteriophage T7 was modest compared to other radiation-resistant organisms.
- The identified genetic changes provide insights into phage adaptation to UV stress.
- While phage therapy for plants may benefit from UV protection, alternative strategies like UV-blocking materials might be more effective.
Related Concept Videos
02:55The Evidence for Evolution
48.3K
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.
48.3K
01:54Convergent Evolution
33.0K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
33.0K
01:24Eukaryotic Evolution
42.1K
The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria.
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
42.1K
02:31Synteny and Evolution
3.8K
John H. Renwick first coined the term “synteny” in 1971, which refers to the genes present on the same chromosomes, even if they are not genetically linked. The species with common ancestry tend to show conserved syntenic regions. Therefore, the concept of synteny is nowadays used to describe the evolutionary relationship between species.
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral...
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral...
3.8K
01:30UV–Vis Spectrum
2.1K
When light passes through a substance, a portion of the light is absorbed while the remaining light is reflected or transmitted. If the molecule absorbs light between the wavelengths of 180–400 nm range, the UV spectrum is obtained, and if it absorbs light in the 400–780 nm wavelength range, the visible spectrum is obtained.
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar...
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar...
2.1K
03:21Genome Size and the Evolution of New Genes
9.2K
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.
9.2K