NASA Scientists Insert a 500-million-year-old Gene in Modern Bacteria

 

          

 

It’s a project 500 million years in the making: Using a process called paleo-experimental evolution, Georgia Tech researchers have resurrected a 500-million-year-old gene from bacteria and inserted it into modern-day Escherichia coli(E. coli) bacteria. This bacterium has now been growing for more than 1,000 generations, giving the scientists a front row seat to observe evolution in action.

“This is as close as we can get to rewinding and replaying the molecular tape of life,” said scientist Betül Kaçar, a NASA astrobiology postdoctoral fellow in Georgia Tech’s NASA Center for Ribosomal Origins and Evolution. “The ability to observe an ancient gene in a modern organism as it evolves within a modern cell allows us to see whether the evolutionary trajectory once taken will repeat itself or whether a life will adapt following a different path.”

In 2008, Associate Professor of Biology Eric Gaucher, successfully determined the ancient genetic sequence of Elongation Factor-Tu (EF-Tu), an essential protein in E. coli. EFs are one of the most abundant proteins in bacteria, found in all known cellular life and required for bacteria to survive. That vital role made it a perfect protein for the scientists to answer questions about evolution.

After achieving the difficult task of placing the ancient gene in the correct chromosomal order and position in place of the modern gene within E. coli, Kaçar produced eight identical bacterial strains and allowed “ancient life” to re-evolve. This chimeric bacteria composed of both modern and ancient genes survived, but grew about two times slower than its counterpart composed of only modern genes.

“The altered organism wasn’t as healthy or fit as its modern-day version, at least initially,” said Gaucher, “and this created a perfect scenario that would allow the altered organism to adapt and become more fit as it accumulated mutations with each passing day.”

The growth rate eventually increased and, after the first 500 generations, the scientists sequenced the genomes of all eight lineages to determine how the bacteria adapted. Not only did the fitness levels increase to nearly modern-day levels, but also some of the altered lineages actually became healthier than their modern counterpart.

When the researchers looked closer, they noticed that every EF-Tu gene did not accumulate mutations. Instead, the modern proteins that interact with the ancient EF-Tu inside of the bacteria had mutated and these mutations were responsible for the rapid adaptation that increased the bacteria’s fitness. In short, the ancient gene has not yet mutated to become more similar to its modern form, but rather, the bacteria found a new evolutionary trajectory to adapt.

These results were presented at the recent NASA International Astrobiology Science Conference. The scientists will continue to study new generations, waiting to see if the protein will follow its historical path or whether it will adopt via a novel path altogether.

“We think that this process will allow us to address several longstanding questions in evolutionary and molecular biology,” said Kaçar. “Among them, we want to know if an organism’s history limits its future and if evolution always leads to a single, defined point or whether evolution has multiple solutions to a given problem.”

The sheer number of interacting genes in protein synthesis means that random mutations are more likely to hit one of EF-Tu's partners than EF-Tu itself. Eventually, though, EF-Tu may begin to evolve - either following the same path it began 500 million years ago or not. We'll have to wait for the final results.

The Daily Galaxy viahttp://www.gatech.edu

Image credit: publicdomainpictures.net

 

Comments

[YittiNitti]

lol they better be careful, they gonna end up creating some earth destroying creature lol.

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[Joe]

anyone else think this is a bad idea?

[WTF lol]

Woah woah woah woah. Evolution isn't possible the earth is only 6000 years old and jesus put us here idiots.............

Naw I'm kidding it's 2012 how can anyone be that ignorant ;)

[josh]

Well its not truly known what direction the bacteria will take. But perhaps this modern bacteria paired with a supposed ancient bacteria is the outcome of past generations evolving to form a new lifeform. If the bacteria does survive and take an opposite track then it should prove evolution. It it takes the same similar path of its modern counterpart it doesn't really prove anything but that it can adapt. But be careful to jump the gun to say the second idea i suggest more correct than the first. So i predict the ancient bacteria will follow its counterpart.

[matto]

Kind of agree with josh... it will only prove it can adapt... but keep in mind that they just inserted ONE GENE in the bacteria.

I think the focus here will be more on the evolution of that particular gene (deletions, permutations, mutations on its bases) than on the organism per se... but im not a native english speaker so i may have misunderstood the article :S

[Geri Rowley]

the altered lineages actually became healthier than their modern counterpart.

[iain carstairs]

Are they still obsessed with random mutations? If all evolutionary development were random, how can anyone become an expert in it?

James Shapiro's new book "Evolution: a view from the 21st century" comes from 44 years in the field, has 1300 references, and conclusively shows that the genome is an area of intelligence, something long observed from lab studies. If we refuse to accept reality, it's hardly surprising that our GM, antibiotic and anti-cancer researchers continue to be outwitted.

[tiago]

in a sense, evolution IS adaptation, over several hundreds of generations.. so showing signs of adaptation is an awesome start. the fact that it's becoming healthier than it's modern counterpart is remarkable. we're able to watch evolution happen in a lab now. need more proof? given that there are so many species in earth, each able to survive in its own habitat, I think ghats proof enough that Darwin was right and that evolution may seem random but it really favors those able to adapt.

[anonymous]

Isnt this how aids was created!??

[J]

Just fyi to the editors, you can't really "resurrect" a gene. It's not really a living organism by itself.

[matto]

Comment on post by Geri Rowley: Evolution by natural selection is not random, although it has a random component to it (which is mainly the material in which natural selection presses on).

[Charles Isbell]

And where has this 500-million (500,000,000) year old Gene
been since it "first began"? Before Earth was created? Before .......?

[Singaporistu]

next step, bring back the dinosaurs, lol .... that will be the best reason to go visit the zoo

[anonymous]

"next step, bring back the dinosaurs, lol .... that will be the best reason to go visit the zoo"

...they already tried that. http://www.imdb.com/title/tt0107290/

[sokobanz]

Jurassic Park.

[Eddie]

BAD Idea,,, It could just WIPE Us Out ,,