Molecular Biology: Applications to Espionage, Intelligence, and Security

views updated

Molecular Biology: Applications to Espionage, Intelligence, and Security

█ BRIAN HOYLE

Molecular biology involves the use of techniques to determine or rearrange the sequence of the components of deoxyribonucleic acid (DNA).

In the mid-1970s, it became possible, using what came to be called recombinant DNA technology, to splice a specific region of DNA from one organism into the DNA of another to express the protein that the insert coded for.

Molecular biology and "weaponizing"

During the Cold War of the 1950s and 1960s, the consensus in the intelligence community was that the Soviet Union explored the use of recombinant DNA technology to engineer more lethal microorganisms for use as weapons. For example, one project attempted to insert the genetic coding for cobra and scorpion venom into the DNA of a bacteria that could enter the body.

Genetic engineering of bacteria, especially spore-forming types that are resistant to all known antibiotics, is another aspect of molecular biology that has been recognized as a military and national security threat. The infections caused by the engineered bacteria would be virtually impossible to treat. As well, genes that code for toxins could be transferred to spore forming bacteria such as Bacillus anthracis or Clostridium botulinum. Because the spores can survive for months, even years, in conditions that would kill the actively growing bacteria, the toxins would be more likely to harm an enemy.

To date, however, all indications are that such engineered bacteria do not exist. This may be because, for example, antibiotic resistance is typically not due to the expression of a single gene. Rather, many genes need to be expressed, with their products operating coordinately, to bestow the resistance. Thus, the alteration of one or a few genes is, as of late 2002, unlikely to produce the resistant "superbug." As well, genetically engineered bacteria do not tend to survive well in the environment because there is an energy cost to the bacteria to express the inserted genetic material.

The military use of molecular biology to design biological weapons was banned by the 1972 Biological Warfare Convention. The signatory nations agreed in the 1980 and 1986 reviews of the convention that the ban applies to genetically engineered microorganisms. In the U.S., the Biological Weapons and Anti-Terrorist Act (1989) and the Antiterrorism and Effective Death Penalty Act (1996) prohibit the manufacture of biological weapons and the use of molecular techniques in these processes.

Rogue states and terrorist groups are unaffected by any such agreement. Thus, it has long been viewed as prudent to use molecular biological techniques to devise protective measures against genetically engineered microorganisms, and to conduct basic research on nonengineered, disease-causing microorganisms in order to devise vaccines or other treatments (i.e., rapid detection tests). The U.S. Army has utilized molecular biological techniques to study a variety of harmful bacteria and viruses since 1982 at their Fort Detrick, Maryland, laboratories (the Biological Defense Research Program). Other organizations have research programs as well (i.e., the Unconventional Pathogen Countermeasures Program run by the Defence Advanced Research Projects Agency; DARPA). The studies have involved determining the genetic basis of the infectious capability of microorganisms as well as the involvement of other components of the cell such as surface proteins.

Molecular biology as an identification tool. Since the 1970s, the techniques to extract target DNA (i.e. bacterial DNA) from the background DNA of all the other organisms in a sample has become refined and efficient. The ability to sequence even large segments of DNA can now be accomplished very quickly, largely because of the technology and computational power developed to allow the sequencing of the human genome. Finally, the DNA sequences of microorganisms that are serious health threats and are potential targets of bioterrorists have been determined (e.g., Bacillus anthracis, the bacterium that causes anthrax, and variola virus, which causes smallpox).

These developments make it possible to detect DNA sequences from certain bacteria and viruses. The technique known as the polymerase chain reaction (PCR) is critical to this aim. PCR enables a stretch of DNA to be amplified millions of times, to quantities that are detectable on electrophoretic gels or using DNA microchip technology, where the binding of a sequence of DNA that is a mirror image of the target sequence can be visualized.

The molecular approach can be used to distinguish one species of bacteria from another, even closely related species (i.e., Bacillus anthracis from Bacillus subtilis ). A variety of enzymes exist that are capable of recognizing certain nucleotide sequences within the DNA and cutting the DNA apart at the sites where the sequence occurs. The result is fragments of differently sized DNA. The fragments can be separated according to their size using the technique of gel electrophoresis. The pattern of bands for one sample of bacteria that appears in the gel can be compared to the pattern given by another type of bacteria. If the patterns are identical, then the bacteria are the same species.

The enzyme digest technique can be combined with PCR to reveal even very small differences in DNA sequence. This allows sequences that are unique to a given bacterium to be detected. For example, this technique can identify Bacillus anthracis and Yersinia pestis, the bacterium that causes plague.

Molecular biology allows investigators to probe the cause of a disease outbreak. Learning the identity of the microorganism responsible for the outbreak can provide useful information as to the biological warfare capability of another country. For example, in 1979 an anthrax out-break in the Soviet Union killed over 60 people. The cause was suspected of being the inhalation of anthrax spores that had been accidentally released from a military research facility. A team from the Los Alamos National Laboratory analyzed the DNA in preserved tissues of victims. At least five different types of Bacillus anthracis were found. A natural outbreak typically involves a single strain. The molecular evidence all but ruled out a natural outbreak.

Another area of active research is the development of molecular techniques to detect bacteria that can contaminate food. Naturally occurring bacteria such as Salmonella typhosa, Campylobacter jejuni, and Escherichia coli cause an estimated seven to 30 million cases of foodborne illness and up to 9,000 deaths every year in the United States alone. The economic losses and strain on the health care infrastructure have been identified as national security concerns.

Molecular biology as an intelligence tool. Molecular biology could potentially be used to encode information in DNA. Scientists have shown that by assigning letters of the alphabet and grammatical symbols to triplets of nucleotide bases, and then constructing a sequence within a DNA molecule, the sequence can yield a message when decoded by the recipient. In one study, DNA containing the coded message was spotted onto a period in a sentence of a letter and then sent through the mail. The recipient, aware of which symbol contained the DNA, extracted the DNA for sequencing, and from the sequence determined the hidden message. Only someone with knowledge of the existence of the DNA spot in the letter could receive the message.

Thus, molecular biology is poised to become an important means of transmitting information.

█ FURTHER READING:

BOOKS:

Alberts, Bruce, Alexander Johnson, Julian Lewis, et al., eds. Molecular Biology of the Cell. New York: Garland Publishing, 2002.

PERIODICALS:

Clellenad, C.T., V. Risca, and C. Bancroft. "Hiding messages in DNA microdots." Nature no. 399 (1999): 533–534.

ELECTRONIC:

Los Alamos National Laboratory. "Tracing Biothreats with Molecular Signatures." Research Quarterly. Fall 2002. <http://www.damtp.cam.ac.uk/user/gr/public/gal_milky.htm> (December 7, 2002).