Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Evolution writ small

Abstract:
Rice study measures physical effects of evolution at molecular scale

Evolution writ small

Houston, TX | Posted on August 26th, 2010

A unique experiment at Rice University that forces bacteria into a head-to-head competition for evolutionary dominance has yielded new insights about the way Darwinian selection plays out at the molecular level. An exacting new analysis of the experiment has revealed precisely how specific genetic mutations impart a physical edge in the competition for survival.

The new research, which could lead to more effective strategies to combat antibiotic drug resistance, was the most downloaded article this month in the journal Molecular Systems Biology.

The research builds upon an ingenious 2005 study involving bacteria called "thermophiles," which thrive at high temperatures. Researchers in the laboratory of Rice biochemist Yousif Shamoo "knocked out" a key gene that allowed the thermophiles to make energy at high temperatures. These crippled versions of the bacteria were then grown inside fermentors for several weeks. Each day, the temperature of the fermentors was increased. As a result, the bacteria were forced to either starve or adapt to survive at high temperature.

Of the hundreds of possible mutations, only five proved successful in allowing the cells to adapt and survive at high temperature. Each of these had mutations in a gene that creates a key enzyme that helps make energy at high temperature. Each of the five made a slightly different version of the enzyme.

"One of these five eventually won out entirely and drove all the others to extinction," said Shamoo, associate professor of biochemistry and cell biology and director of Rice's Institute of Biosciences and Bioengineering. "The question is what physical advantage did that particular mutant have? What were the precise physical changes to the enzyme that allowed that strain to outcompete its cousins?"

Finding the answer to that question was painstaking. While the genetic mutations were known from the earlier study, it fell to graduate student Matt Peña to find out how small changes in the DNA structure of the bacteria translated into specific enzymatic changes. He found that adaptation depended critically on simultaneously keeping the enzyme working while also increasing its resistance to inactivation as the temperatures increased.

He found that versions of the enzyme -- which is a specific kind of protein -- that became inactive were also subject to protein misfolding. In humans, an inability to maintain properly folded and active proteins has been linked to several human diseases, including Alzheimer's.

"Studies like this can help us understand the physical basis for these kinds of diseases, and they can give us a better understanding for the molecular basis for adaptation," Shamoo said. "For example, what we learn from these thermophiles carries over into our work on drug-resistant bacteria because the principles of adaptation are the same no matter whether you're studying temperature, pH, antibiotic resistance or whatever," he said.

Shamoo's lab won funding from the National Institutes of Health in 2009 to study how bacteria evolve antibiotic resistance. One of the ultimate goals of the project is to predict how evolution will play out so that drugmakers can head off resistance before it arises.

"With the thermophile study we've shown that it is possible to build a fitness function -- a mathematical expression -- that translates enzyme performance into a specific measure of competitive advantage," Shamoo said. "That's important because if you can't do that for one protein of interest, then there's no way you're going to be able to do it for a more complicated problem like antibiotic resistance, which involves simultaneous mutations to more than one gene."

Co-authors of the new research paper include Milya Davlieva, research scientist; Matthew Bennett, assistant professor of biochemistry and cell biology; and John Olson, the Ralph and Dorothy Looney Professor of Biochemistry and Cell Biology at Rice. The research was funded by the National Science Foundation, the National Institutes of Health and the Welch Foundation.

####

About Rice University
Located in Houston, Rice University is consistently ranked one of America's best teaching and research universities. Known for its "unconventional wisdom," Rice is distinguished by its: size -- 3,279 undergraduates and 2,277 graduate students; selectivity -- 12 applicants for each place in the freshman class; resources -- an undergraduate student-to-faculty ratio of 5-to-1; sixth largest endowment per student among American private research universities; residential college system, which builds communities that are both close-knit and diverse; and collaborative culture, which crosses disciplines, integrates teaching and research, and intermingles undergraduate and graduate work.

For more information, please click here

Contacts:
Jade Boyd
713-348-6778

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Global Nano-Enabled Packaging Market For Food and Beverages Will Reach $15.0 billion in 2020 May 26th, 2015

Dr.Theivasanthi Slashes the Price of Graphene Heavily: World first & lowest price – Nano-price (30 USD / kg) of graphene by nanotechnologist May 26th, 2015

Fine-tuned molecular orientation is key to more efficient solar cells May 26th, 2015

DNA Double Helix Does Double Duty in Assembling Arrays of Nanoparticles: Synthetic pieces of biological molecule form framework and glue for making nanoparticle clusters and arrays May 25th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Researchers find the 'key' to quantum network solution May 25th, 2015

One step closer to a single-molecule device: Columbia Engineering researchers first to create a single-molecule diode -- the ultimate in miniaturization for electronic devices -- with potential for real-world applications May 25th, 2015

DNA Double Helix Does Double Duty in Assembling Arrays of Nanoparticles: Synthetic pieces of biological molecule form framework and glue for making nanoparticle clusters and arrays May 25th, 2015

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

Academic/Education

SUNY Poly CNSE and NIOSH Launch Federal Nano Health and Safety Consortium: May 20th, 2015

New JEOL E-Beam Lithography System to Enhance Quantum NanoFab Capabilities May 6th, 2015

FEI Partners With the George Washington University to Equip New Science & Engineering Hall: Suite of new high-performance microscopes will be used for cutting-edge experiments at GW’s new research facility April 29th, 2015

Renishaw Raman systems used to study 2D materials at Boston University, Massachusetts, USA. April 28th, 2015

Announcements

Global Nano-Enabled Packaging Market For Food and Beverages Will Reach $15.0 billion in 2020 May 26th, 2015

Dr.Theivasanthi Slashes the Price of Graphene Heavily: World first & lowest price – Nano-price (30 USD / kg) of graphene by nanotechnologist May 26th, 2015

Fine-tuned molecular orientation is key to more efficient solar cells May 26th, 2015

DNA Double Helix Does Double Duty in Assembling Arrays of Nanoparticles: Synthetic pieces of biological molecule form framework and glue for making nanoparticle clusters and arrays May 25th, 2015

Nanobiotechnology

DNA Double Helix Does Double Duty in Assembling Arrays of Nanoparticles: Synthetic pieces of biological molecule form framework and glue for making nanoparticle clusters and arrays May 25th, 2015

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Supercomputer unlocks secrets of plant cells to pave the way for more resilient crops: IBM partners with University of Melbourne and UQ May 21st, 2015

Research partnerships

Supercomputer unlocks secrets of plant cells to pave the way for more resilient crops: IBM partners with University of Melbourne and UQ May 21st, 2015

Taking control of light emission: Researchers find a way of tuning light waves by pairing 2 exotic 2-D materials May 20th, 2015

Efficiency record for black silicon solar cells jumps to 22.1 percent: Aalto University's researchers improved their previous record by over 3 absolute percents in cooperation with Universitat Politècnica de Catalunya May 18th, 2015

Organic nanoparticles, more lethal to tumors: Carbon-based nanoparticles could be used to sensitize cancerous tumors to proton radiotherapy and induce more focused destruction of cancer cells, a new study shows May 18th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project