Summary
In 2011, scientists in Europe managed to replace 98% of the nitrogenous base thymine contained in a set of E. coli bacteria with a synthetic alternative called 5-chlorouracil. They did this using a new automated system that puts the bacteria through a very particular and highly stressful environment. In this case, that environment contained high amounts of the 5-chlorouracil, which is in fact toxic to the bacteria in higher doses. However, the amounts of 5-chlorouracil given to the E.coli were just below the lethal amount. The bacteria with very little innate resistance to the substance died off, while the hardier bacteria lived. In this way, the scientist's experiments actually helped the bacteria build up a stronger resistance to 5-chlorouracil, so much so that, due to its extreme similarity to the base thymine, the 5-chlorouracil began to replace thymine in the bacteria's DNA over a five month period (140 days).
The relevance of this experiment to industrial uses is not yet clear, but points to the extreme adaptability of the E.coli. It could be used as a protein synthesis mechanism or in biomedical research, perhaps even gene therapy.
Relevance
This article is relevant to this unit due to the experiments we have conducted during this term regarding the transfer of DNA through plasmids using PCR, and in our recently begun unit regarding adaptation and the beginnings of evolution.
Citation
Louët, Sabine. "Rewriting E. coli's Genetic Code." The Scientist: n. pag. The Scientist. Web. 8 Jan.
2015.
<http://www.the-scientist.com/?articles.view/articleNo/31006/title/
Rewriting-E--coli-s-Genetic-Code/>
How can this be used in gene therapy?
ReplyDeleteThe selection for specific resistant genes could potentially be used because bacteria could be used to select for those genes and then those genes could be inserted into areas of the genome. However, the specific usage isn't really clear yet, as the research is still early.
DeleteWhat is considered a "stressful environment" for bacteria?
ReplyDeleteAs with any organism, a stressful environment is usually one that is extreme in temperature, or toxicity or other factors. In this case, the environment contained levels of the toxic substance 5-chlorouracil.
Delete