UCI biologists turn up the heat on bacteria, discover mutation pattern

February 3, 2012

UCI biologists who spent a year growing 115 populations into 2,000 generations of E. coli at high heat discovered that the bacteria quickly adapted at the genetic level in two markedly different ways. The findings appear in the current issue of the journal Science.

The team included Brandon Gaut, chair of the Department of Ecology & Evolutionary Biology; Albert Bennett, dean of the School of Biological Sciences; and Anthony Long, professor of ecology & evolutionary biology.

"Temperature is a complex challenge for an organism to respond to because it can affect so many parts of the cellular process," Gaut said.

They chose to apply heat (108 F, 42 C) rather than cold because Bennett had previously done so with smaller populations.

"We knew it would work, but we wanted to do it on a much grander scale so we could see genetic patterns emerging," Gaut explained.

In the populations that survived, the team identified 1,331 mutations affecting more than 600 sites in the bacterial DNA. Few of the mutations were shared from to population, suggesting little overlap among their evolutionary paths.

But when the scientists stepped back and analyzed the mutations at the level of functional gene groups, they were surprised to find a strong pattern: E. coli populations adapted to the heat by mutating one of two pathways, but rarely both.

Long said the findings could - among other applications - aid in the development of microbes for better ethanol and other biofuels, as well as bugs designed to clean up various environments.

Explore further: Ready, set, mutate... and may the best microbe win

Related Stories

Ready, set, mutate... and may the best microbe win

May 18, 2006

Even with modern genomic tools, it's a daunting task to find a smoking gun for Darwinian evolution. The problem lies in being able to say not just when and how a specific gene mutated but also how that one genetic change ...

Mutations: When benefits level off

June 8, 2011

Beneficial mutations within a bacterial population accumulate during evolution, but performance tends to reach a plateau. Consequently, theoretical evolutionary models need to take into account a "braking effect" in expected ...

Recommended for you

A better way to read the genome

October 9, 2015

UConn researchers have sequenced the RNA of the most complicated gene known in nature, using a hand-held sequencer no bigger than a cell phone.

Threat posed by 'pollen thief' bees uncovered

October 9, 2015

A new University of Stirling study has uncovered the secrets of 'pollen thief' bees - which take pollen from flowers but fail to act as effective pollinators - and the threat they pose to certain plant species.

Most EU nations seek to bar GM crops

October 4, 2015

Nineteen of the 28 EU member states have applied to keep genetically modified crops out of all or part of their territory, the bloc's executive arm said Sunday, the deadline for opting out of new European legislation on GM ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

5 / 5 (1) Feb 05, 2012
2 flavors of beneficial mutations to environmental stressors. Bookmarked as ammo against creationists (who should be along shortly)

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.