Synthetic DNA Soon to Yield Artificial Life
By Rick Weiss
Washington Post, December 17, 2007
Edited by Andy Ross
Scientists in Maryland have built the world's first entirely handcrafted
chromosome -- a large looping strand of DNA made from scratch in a laboratory,
containing all the instructions a microbe needs to live and reproduce. In 2008,
they hope to transplant it into a cell, where it is expected to "boot itself up"
and take over the cell.
Some companies are already gaining monopoly control over the core "operating
system" for artificial life and are poised to become the Microsofts of synthetic
biology.
"We're heading into an era where people will be writing DNA programs like the
early days of computer programming, but who will own these programs?" asked Drew
Endy, a scientist at MIT.
At the core of synthetic biology's new ascendance are high-speed DNA
synthesizers that can produce very long strands of genetic material from basic
chemical building blocks: sugars, nitrogen-based compounds and phosphates.
Today a scientist can write a long genetic program on a computer, then use a
synthesizer to convert that digital code into actual DNA. Experiments indicate
that when a chromosome is put into a cell, it will direct the destruction of the
cell's old DNA and become its new "brain" -- telling the cell to start making a
valuable chemical, for example, or a medicine or a toxin, or a bio-based
gasoline substitute.
Unlike conventional biotechnology, in which scientists induce modest genetic
changes in cells to make them serve industrial purposes, synthetic biology
involves the large-scale rewriting of genetic codes to create metabolic machines
with singular purposes.
"I see a cell as a chassis and power supply for the artificial systems we are
putting together," said Tom Knight of MIT. Knight and colleagues have started a
collection of hundreds of interchangeable genetic components they call
BioBricks, which students and others are already popping into cells like Lego
pieces.
So far, synthetic biology is still semi-synthetic, involving single-cell
organisms such as bacteria and yeast that have a blend of natural and synthetic
DNA. The cells can reproduce, but in many cases that urge has been genetically
suppressed, along with some other biological functions, to maximize
productivity.
J. Craig Venter, chief executive of Synthetic Genomics in Rockville, wants his
cells to make ethanol, hydrogen and other exotic fuels for vehicles, to fill a
market estimated to be worth $1 trillion.
In a big step toward that goal, Venter has now built the first fully artificial
chromosome, a strand of DNA many times longer than anything made by others and
laden with all the genetic components a microbe needs to get by. Venter has
already shown that he can insert a "natural" chromosome into a cell and bring it
to life. If a synthetic chromosome works the same way, the first living cells
with fully artificial genomes could be growing in dishes by the end of 2008.
The plan is to mass-produce a plain genetic platform able to direct the basic
functions of life, then attach custom DNA modules to make synthetic fuels or
other products.
It will be a challenge to cultivate fuel-spewing microbes, Venter acknowledged.
Among other problems, he said, is that unless the fuel is constantly removed,
"the bugs will basically pickle themselves."
Another application is in medicine, where synthetic DNA is allowing bacteria and
yeast to produce the malaria drug artemisinin far more efficiently than it is
made in plants, its natural source.
Bugs such as these will seem quaint once fully synthetic organisms are brought
on line to work on tasks from industrial production to chemical cleanups. But
the prospect of a flourishing synbio economy has many wondering who will own the
valuable rights to that life.
In the past year, the U.S. Patent and Trademark Office has been flooded with
aggressive synthetic-biology claims. Some of Venter's applications "are
breathtaking in their scope," said Knight. And with Venter's company openly
hoping to develop "an operating system for biologically-based software," some
fear it is seeking synthetic hegemony.
"Ultimately synthetic biology means cheaper and widely accessible tools to build
bioweapons, virulent pathogens and artificial organisms that could pose grave
threats to people and the planet," concluded a recent report by the Ottawa-based
ETC Group.
Many scientists say the threat has been overblown. Venter notes that his
synthetic genomes are spiked with special genes that make the microbes dependent
on a rare nutrient not available in nature. And DuPont says the company's bugs
are too spoiled to survive outdoors.
But the technology is quickly becoming so simple that it will not be long before
"bio hackers" working in garages will be downloading genetic programs and making
them into novel life forms.
AR: This story will run and run.
