Evolution is based on heredity, changes to the genetic material (mutation), and the natural selection of those organisms that are best suited to the given environmental conditions.
An international team led by Rupert Mutzel at the Freie Universität of Berlin has now successfully emulated one particular evolutionary process in the laboratory. As the researchers report in the journal Angewandte Chemie, they were able to generate a bacterial strain whose genetic material contains an artificial building block in place of a natural one. Their success results from a special automated cultivation technique.
DNA, the carrier of the genetic information of all cells, is based on a code consisting of four “letters”, the bases adenine, cytosine, guanine, and thymine. Thanks to their new artificial evolution process, the scientists have now been able to grow bacteria in which the thymine of DNA has been replaced with an analogue, the base 5-chlorouracil. This synthetic component is poisonous to other organisms.
The researchers started with a genetically modified strain of the bacterium Escherichia coli that is no longer capable of producing thymine. These microorganisms were cultivated over many generations in the presence of increasing amounts of chlorouracil in a specially built apparatus. Whenever the size of the population sank below a certain level, the bacteria were given a brief dose of a chlorouracil-free, thymine-containing medium to give them a chance to recover. The concentration of chlorouracil was automatically increased whenever genetic variants of the bacteria that better tolerated this substance were produced. In this way, the cells were always exposed to a quantity of chlorouracil that was just barely tolerable. After about 1000 generations, the microorganisms had adapted to the altered environmental conditions, that is, the presence of chlorouracil instead of thymine. They were able to build up their DNA with chlorouracil in place of thymine. Analysis of the genome showed that the process of adaptation resulted in many changes to the genetic material of the bacteria.
“Our results demonstrate the success of our evolutionary cultivation strategy,” says Mutzel. “In this way it should be possible to develop microorganisms that can convert chemical intermediates to pharmaceuticals or break down environmental pollutants.” Microorganisms that have DNA with synthetic building blocks may also be useful in hindering the spread of purposely or accidentally released modified cells in the environment. Such microorganisms would also be incapable of exchanging genes with their natural relatives.Author: Rupert Mutzel, Freie Universität Berlin (Germany), http://www.biologie.fu-berlin.de/arbeitsgruppen/mikrobiologie/ag_
mutzel/personen/professoren/rupert_mutzel/index.htmlTitle: Chemical Evolution of a Bacterium's Genome
The original article is available from our online pressroom at http://pressroom.angewandte.org
Rupert Mutzel | Angewandte Chemie
More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn
How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy