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
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy