Genetically modified organisms, such as tomatoes and rice, have been around for several decades now, although the controversies surrounding this technology are still unresolved. The engineering behind genetically modified foods involves the manipulation or transfer of individual genes from one species to another. For example, so-called “golden rice” was created to boost the nutritional value of standard rice by inserting three genes that increase the production of beta carotene, which in our bodies is converted into Vitamin A. The emerging field of “synthetic biology” takes this genetic manipulation to a whole new level. The goal of synthetic biology is not to splice in one gene, or even a handful, but to assemble novel genomes from a set of standardized genetic parts, starting with microbes. This assembly of a synthetic genome would, in effect, create artificial life.
A major step toward this science fiction-like goal occurred last year. In June 2007, in an article in the journal Science, scientists at the J. Craig Venter Institute (JCVI) in Rockville, Maryland, reported that they had transplanted an entire bacterial genome, or set of genes, into cells of a closely related bacterial species. The scientists were able to identify the successfully “reprogrammed” recipient cells by their newfound antibiotic resistance and blue color, both characteristics introduced by the donor DNA. This was a milestone achievement because this was the first time that a complete set of genetic instructions consisting of more than a million “letters” of DNA had been transplanted, and it effectively transformed one species of bacterium into another.
Creating Artifical Life?
The ability to transfer an entire genome paves the way for the eventual creation of an entirely artificial chromosome, or DNA strand, and its transplantation into a cell which could give rise to the first artificial life form. A group of scientists at JCVI is rumored to have already constructed an entirely synthetic chromosome consisting of 381 genes and 580,000 “letters” of genetic code. If true, this would be another significant accomplishment– the first of its kind (an official announcement is expected any day now). The DNA sequence is based on the bacterium Mycoplasma genitalium which the team stripped down to the bare essentials needed to support life, and have named their creation (oh, those funny scientists)– Mycoplasma laboratorium. If this synthetic chromosome is successfully transplanted into, and “reprograms” living bacterial cells, these cells could represent the first artificial life form. The existing molecular machinery of the recipient cells would be natural, but it would be commandeered for the purposes of making proteins from artificial DNA.
Facing the Issues
Of course, the prospect of creating the first artificial life form will force the scientists performing this research, the government, and society as a whole to start contemplating a variety of unprecedented legal, safety, and ethical issues. Can you patent and own the legal rights to a new life form? What would happen if these artificial life forms make it into the wrong hands, or into the environment? Are these scientists playing “God”? J. Craig Venter has already filed a patent on the genome of the bacterium Mycoplasma laboratorium, and while no decision has been made yet on the status of this patent, just the filing of this patent has caused a stir. Many objections have been raised against this patent ranging from the practical to the ethical. For example, the ETC Group, a Canadian bioethics organization, claims that the patent is too far-reaching in its scope. Dr. Venter ultimately hopes to use synthetic biology to produce ethanol, hydrogen and other exotic fuels for vehicles, to fill a market that has been estimated to be worth $1 trillion. In his patent, he would like to reserve the right to any method of hydrogen or ethanol production that uses a synthetic organism such as his. Open discussions will need to be held in order to address the complex philosophical issues that accompany these scientific advances.
Also, it is clear that regulations need to be implemented for the field of synthetic biology and guidelines adhered to because of the potential of accidental or intentional misuse of synthetic organisms. As a precaution, safeguards are included in the artificially created genome in case these microbes are ever released into the environment. For example, the JCVI’s synthetic microbes contain genes that will not allow these organisms to survive outside of the laboratory because of their dependence on a supplied nutrient. To keep synthetic organisms out of the hands of people who might want to use them for bio-terrorism, comprehensive rules and records will need to be maintained.
Applications of Synthetic Biology
There are several other groups that are researching additional applications of synthetic biology, such as in manufacturing textiles and medicine. At a DuPont plant in Tennessee, engineers have created “semi-synthetic” E. coli bacteria to produce the chemical 1,3 propanediol, or PDO. PDO is spun and woven into high-tech fabrics, and the chemical is also made into laminates and adhesives. A group headed by Dr. Jay Keasling at the University of California at Berkeley, is using synthetic DNA to allow bacteria and yeast to produce the malaria drug artemisinin, an antimalarial drug that is currently too expensive for the parts of the developing world that need it most. Artemisinin is produced naturally by the sweet wormwood plant, but synthetic biology allows the drug to be produced more efficiently and cost-effectively.
The field of synthetic biology is just beginning to be explored, and as with all areas of uncharted territory, it is clear that the field’s enormous potential for innovation must be pursued cautiously and thoughtfully.
–Denise Chun, Harvard Medical School
For More Information:
Recent article in the Washington Post on current status of field of synthetic biology:
< http://www.washingtonpost.com/wp-dyn/content/article/2007/12/16/AR2007121601900.html >
New York Times article discussing the JCVI’s bacterial genome transplant:
< http://www.nytimes.com/2007/06/29/science/29cells.html?pagewanted=1 >
Science 3 August 2007:Vol. 317. no. 5838, pp. 632 – 638