Amazing Gene Swap Creates Microbe Makeover

Genome Transplant Described As "Breakthrough In Biological Engineering"

(AP)  Talk about identity theft: Scientists changed one species of bacteria into another by performing a complete gene swap.

It is a step in the quest to one day create artificial organisms, part of a bigger project to custom-design microbes that could produce cleaner fuels. But the way it was performed, dubbed a "genome transplant," has genetics specialists buzzing.

"This is equivalent to changing a Macintosh computer to a PC by inserting a new piece of software," declared genome-mapping pioneer J. Craig Venter, senior author of the new research published Thursday by the journal Science.

For years, scientists have moved single genes and even large chunks of DNA from one species to another. But Venter's team transplanted an entire genome, all of an organism's genes, from one bacterium into another in one fell swoop.

These were not complex bacteria, but cousins from a family of small, simple microbes known as Mycoplasma. Nor do the researchers know exactly how the transplant took hold. But somehow the new genes cleanly replaced the old and started working correctly — not very often, but in just enough cells to prove the concept.

The experiment "is a landmark in biological engineering," said Dr. Barbara Jasny, a deputy editor of Science.

Beyond pushing scientific boundaries, why would switching a goat germ into a cattle germ be useful?

That is not the real aim. It is part of a broader field called "synthetic biology" or "synthetic genomics" that aims to build new organisms that work in ways totally different than nature intended — and scientists are divided about whether the Venter approach will really play a big role.

"There are people doing some important synthetic engineering efforts with other approaches," cautioned Dr. David Relman, a microbiologist and infectious disease specialist at Stanford University. "This is a different one that is a little more daring, and perhaps dramatic."

"One could wonder whether this method will be used for more than a tiny research community," added Dr. George Church, a genetics professor at Harvard Medical School. "Most people find it easier to work with pieces" of DNA.

Church points to the most popular synthetic biology method under study, genetically modifying existing organisms, such as E. coli bacteria, to make them do such things as churn out medications.

In contrast, Venter's self-named institute in Rockville, Md., is trying to create an artificial chromosome — the structure that carries DNA — that contains industrially useful genes such as ones that could help produce alternative fuels.

That work is far from complete, but to make it work, they'd have to put the artificial chromosome into a living cell and it would have to jump-start that host. Thursday's experiment was designed just to prove an entire-genome switch is possible, with regular bacteria DNA.

The Venter team picked two Mycoplasma species, simple germs that contain a single chromosome and lack the cell walls that form barriers in other bacteria. First, they added genes to turn the donor bacteria an easy-to-spot bright blue, and to make it resist an antibiotic used to kill off any host germ that retained its own genes.

Then they stripped off the donor chromosome's proteins, to see if naked DNA alone could "reboot" a foreign cell. Blue germs appeared within days of dropping the genome into lab dishes containing the second bacteria. Not many — only about one in every 150,000 cells took up the donor genome and grew, but they bore no evidence of the original DNA.

"That's extremely inefficient," acknowledged lead scientist John Glass, a Venter Institute microbiologist. "We think we can steadily improve this."

"Synthetic genomics still remains to be proven, but now we are much closer to knowing it's actually theoretically possible," added Venter.

It's not clear that the method would work on larger, more complicated bacteria, other specialists cautioned. Nor does the work automatically mean an artificial chromosome alone could activate a living cell.

"It's going to be much more complicated to do with synthetic organisms," said Dr. Jonathan Eisen, an evolutionary biologist at the University of California, Davis. Still, "it's a great first step."

[toolmangler-2009]

Scientists changed one species of bacteria into another by performing a complete gene swap.


Wonder if that would work for those born without a sexual identity they will call their own?

[toolmangler-2009]

It use to be said "Don't believe anything you hear and only half of what you see." With the advent of Digital Photography you had to feel it to believe it. Now by cracky, you can't believe anything. Ok GOD!!! you can turn us off now, we're no further use to anyone.

[toolmangler-2009]

"This is equivalent to changing a Macintosh computer to a PC by inserting a new piece of software," declared genome-mapping pioneer J. Craig Venter,

Isn't that called 'de_evolution'? "taking something that works and making it into something that doesn't work as good"?

[rushlimpdrug]

Mom! Craig is making a mess in the kitche again.

[grazinggoat]

Monsanto creates GM corn that lives for one season, and produces no viable seeds for the next years' crop. The corn has an aggressive pollen that attacks and replaces local species, making an entire region, and gradually the world dependent on Monsanto for its corn
Posted by brianbwb

-well brianbwb, with all my respect to your point I don't agree with the extent this experiment is allowing to do. We're not into genetically modified corn or human destined food here. I understand the Monsanto case. But Nature has always won on the long run. Creating chaos in genetics (by setting up more aggressive species) will be defeated in a way or another by nature. Similarly to the erosion of Mountains by some factors that are as invisible as the wind and as soft as water. Monsanto will take a hit when it's genetic modification will be beaten by another one that is better in quantity yielding results or faster growth etc.

So was the natural selection and so will be the artificial one. I'm just not afraid, of GM food and crops. I'M afraid of what touches us Humans (modified microbes and microorganisms), that may attack us on a large scale and cause massive deaths. In that aspect I agree with you, but then Nature is there to protect us. That does mean a newly emgineered strain of bugs can kills masses of Humans, but Nature will again prevail...

[brianbwb-2009]

to grazinggoat,

You write,"Swapping genes between two step-species is not a bad idea."

So far I believe it is indeed a bad idea.

Monsanto creates GM corn that lives for one season, and produces no viable seeds for the next years' crop. The corn has an aggressive pollen that attacks and replaces local species, making an entire region, and gradually the world dependent on Monsanto for its corn.

Sound like a James Bond-like mad criminal plot? Guess what, it is already being spread, the poor guy who owned a farm next door to their experimental field was actually sued for copyright infringement when their crop cross pollinated his.

I have a problem with genetic experimentation, as it seems the goal is always to take "ownership" of that which should not be "owned", or to continue Hitler's eugenics experiments, to create ever deadlier and incurable biological weapons, or otherwise alter facets of life about which the role played is not yet fully understood.

"Because a thing can be done" is not a reason that it should be done.

Next thing you know, NASA will erect a huge platform in space, blocking out the sun, then charge continents for access to sunlight.

[grazinggoat]

Quite surprising! Well not that much, since it was well known on a smaller sacle, I mean gene transplant but not complete gene swap!

-There are vectors called Plasmid that we can modify in order to make them bear some different genetic material, by cutting with DNAse and by inserting with Polymerases some stranger piece of DNA that we take from other species as far as a bacterium or a rabbit. Once those vectors modified they are inserted into bacteriea that may acquire the newly inserted stranger material. Shock (by heat and cold or/and other chemical means) allows the cell wall to temporarily break in order to allow the insertion of the whole plasmid in the cell body.

-Venter is audacious, a bit lucky but a bit imprudent. Alien DNA is usually attacked by new host DNAse and digested, eliminated. Swapping genes between two step-species is not a bad idea. And he's pretty lucky because he inserted the alien genes into DNAse-deficient individuals (most probably).

- Just for curiosity sake, it's worth the trial, see what would happen, if further species are swapped-genes. Interesting!

Imagine this now: Fifty years from now, in a war campaign soemwherein China, with a shock wave American soldiers DNA are injected in permeablised Chinese soldiers.... in a odd of 1 in 150,000 to survive, only a new race just been created. That makes me shiver...

[amazedd]

I Sphinx, therefore I am.