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
Gene therapy shows promise for treating Niemann-Pick disease type C1
27.10.2016 | NIH/National Human Genome Research Institute
'Neighbor maps' reveal the genome's 3-D shape
27.10.2016 | International School of Advanced Studies (SISSA)
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
27.10.2016 | Life Sciences
27.10.2016 | Life Sciences
27.10.2016 | Power and Electrical Engineering