Synthetic DNA Soon to Yield Artificial Life
Washington Post, December 17, 2007
Edited by Andy Ross
Scientists in Maryland have built the world's first entirely handcrafted
chromosome. It is 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 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
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 take over,
telling the cell to start making a valuable chemical, for example, or a
medicine or a toxin, or a bio-based gasoline substitute.
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.
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
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.
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."
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
But the technology is quickly becoming so simple that it
will not be long before biohackers working in garages will be downloading
genetic programs and making them into novel life forms.