Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Evolvability could be a driving force in drug resistance

10.08.2004


Not only has life evolved, but life has evolved to evolve.



That’s the conclusion drawn by two Rice University scientists who have designed a computer simulation to test the idea that evolvability -- the likelihood of genetic mutation -- is a trait that can itself be favored or disfavored through the process of natural selection.

The results of the study appear in the Aug. 10 issue of Proceedings of the National Academy of Sciences.


Researchers Michael Deem, the John W. Cox Professor of Bioengineering and professor of physics and astronomy, and David Earl, Deem’s post-doctoral research fellow, drew their conclusions from a sophisticated computer simulation that recorded how much and how rapidly proteins mutated based on external changes in their environment. As the researchers ramped up the frequency and severity of environmental changes -- imagine rapid shifts between heat waves and cold snaps or heavy rains and droughts -- they saw an increased likelihood of survival among proteins that mutated more frequently.

"Selection for evolvability would help explain a growing body of experimental results including the evolution of drug resistance in bacteria, the fact that some immune system cells mutate much more rapidly than other cells in our bodies, as well as why some bacteria and higher-order organisms have a tendency to transpose or swap relatively long sequences of DNA," said Deem.

Traditionally, a significant number of evolutionary biologists have discounted the idea that evolvability is subject to natural selection, in part because the idea that evolution acts upon the mechanism that causes evolution seems to violate the basic scientific principle that an event cannot precede its own cause.

But Deem and Earl argue that causal violations need not occur. For one thing, there are several different ways that genetic mutations occur. Random changes along the DNA chain are now understood to be only one way that organisms evolve. Mutations also occur based on genetic recombination, genetic transposition and horizontal gene transfer. With these mechanisms, relatively large chunks of genetic code are shuffled or substituted for one another along the DNA chain.

Deem and Earl’s argument centers on the idea that the ability to reorder genes or to cause large-scale genetic change are themselves genetic traits, traits that are subject to selection like any others.

The upshot of this is that many observations within evolutionary biology that were heretofore considered evolutionary happenstance or accidents, may in fact be explained by selection for evolvability.

Two primary examples of this can be found in the escalating "arms race" that has been documented between pathogens and the immune systems in people and other higher-order vertebrates. Deem and Earl argue that wide variation among bacteria and other antigens has put selective pressure on our immune systems to rapidly adapt methods of identifying and attacking invaders. Similar observations on the rapid mutability among flu viruses and other invading pathogens provide additional evidence, they said.

"The implication is that the drugs we have developed to fight invading pathogens also confer selective pressure on the evolvability of the pathogens themselves," Earl said. "In drug design, it is important to consider this and to look for ways to minimize or counteract this driving force for drug resistence."

Jade Boyd | EurekAlert!
Further information:
http://www.rice.edu

More articles from Health and Medicine:

nachricht Penn vet research identifies new target for taming Ebola
12.01.2017 | University of Pennsylvania

nachricht The strange double life of Dab2
10.01.2017 | University of Miami Miller School of Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>