Jan. 25 (Bloomberg) — Scientists at the J. Craig Venter
Institute, a research group thats trying to create artificial
life, moved one step closer to their goal by synthesizing the
complete set of genes of a bacterium.
The researchers built the longest artificial genome ever
made using four chemicals that make up DNA, according to the
study published yesterday by the journal Science. Comparisons of
the sequences of the four bases — adenine, cytosine, guanine
and thymine — are used to identify genetic differences among
living creatures from bacteria to humans.
The goal is to use artificial genomes to create bacteria
designed to take on specific jobs, such as converting
underground coal into a more easily extracted gas. The
scientists previously inserted the genes of one type of bacteria
into the cells of another. If they can use that method to insert
the artificial genome into a cell, theyll have created the
first new life form controlled by man-made DNA.
A genome “is the operating system of the cell, said
Hamilton Smith, the author and a Nobel Prize-winning researcher,
in an audio interview published by Science. As with computers,
“You have an operating system which by itself doesnt do
anything, but when you install it on a computer, then you have a
working computer system. Its the same with the genome. The two
together make a living, reproducing cell.
New Technique
The new technique may help to construct even bigger DNA
molecules from chemically created pieces, according to the
report. The scientists designed bits of DNA to build 101
segments of 5,000 to 7,000 base pairs, the molecules that form
the rungs of the DNA ladder. They connected the segments into
four strands, which they inserted into yeast for the final
connections.
The final chromosome was then checked against the sequence
of the natural DNA to confirm that it was an accurate replica.
The bacterial genome uses 582,970 base pairs. The longest
previous stretch of artificial DNA was 32,000 base pairs.
“Scientists are one step closer to constructing a living,
synthetic organism that has the potential for social, economic,
and ecological disruption — and society is not at all prepared
for that, said Kathy Jo Wetter, a Carrboro, North Carolina-
based researcher with ETC Group, an environmental advocacy group
in Ottawa.
Venter, 61, founded Synthetic Genomics Inc. in 2005 to find
ways to use artificial genes to build new organisms that could
turn sunlight and plant matter into fuel, clean up industrial
waste, or monitor patients for the first signs of disease.
The Venter Institute, which engages in a wide range of
genetic research, has made virus genomes, which are much
smaller, in previous studies. The Rockville, Maryland-based lab
was originally named the Institute for Genomic Research.
`Wonderful Breakthrough
“Its a wonderful breakthrough that could change the way
we think about gene therapy, said David Magnus, co-director of
Stanford Universitys Center for Biomedical Ethics. “It would
allow us potentially to create chromosomes exactly the same as a
patients chromosome but with genes that have been corrected.
This could be a future treatment for disease.
The potential to profit from creating so-called designer
organisms like this is sparking both excitement and debate among
scientists and venture capital investors.
“Venter is claiming bragging rights to the worlds longest
length of synthetic DNA, but size isnt everything, said Jim
Thomas, a program manager at ETC Group, in an e-mail. “The
important question isnt `How long? but `How wise?
Already, scientists are producing strings of man-made DNA,
short for deoxyribonucleic acid, which directs the functions of
all living cells. They then splice the manufactured DNA into the
genes of existing organisms, reprogramming bacteria to act like
microscopic factories churning out biofuels.
No Regulatory Oversight
Venters experiments are taking synthetic biology a step
further by building new organisms from the ground up with wholly
artificial genes. The ETC Group called for “a moratorium on the
release and commercialization of synthetic organisms,
according to a statement released on its Web site yesterday.
“Regulatory oversight is stalled, and there has been no
meaningful or inclusive discussion on how to govern synthetic
biology in a safe and just way, ETC Groups Thomas said.
Venter, who rocked the scientific world in 2000 by
designing a new way to map the collection of human genes in
record time, is no stranger to big ideas, or controversy.
In 2002, he was ousted as president of Foster City,
California-based Celera Genomics, which he helped start to
decode the human genome, after the board decided to concentrate
on drug development instead of selling genetic data. Later that
year, Venter revealed on CBSs 60 Minutes II that his own genes
made up most of Celeras database.
Re-engineered microorganisms may inherit all sorts of jobs.
For now, top gene researchers are particularly excited about the
potential for energy-producing microbes that may become single-
celled refineries for ethanol, biodiesel or other petroleum
substitutes without using food crops such as corn.
Synthetic biology builds on the more than three decades of
genetic engineering behind trailblazing biotechnology companies
such as Amgen Inc. and Genentech Inc.
