Setting Standards

Late in 1973, Berg and 77 other molecular biologists sent a letter to the prestigious American scientific journal Science. It asked the U.S. National Academy of Sciences to look into possible dangers of recombinant DNA research and establish safety guidelines for experiments in this new field.

Other Scientists: Paul Berg (1926- )

Born on June 30, 1926, in Brooklyn, New York, Paul Berg was the son of a clothing manufacturer. His study of biochemistry at Pennsylvania State College was interrupted by World War II, in which he fought in the navy. He finally obtained his bachelor's degree in 1948. He earned a Ph.D. in biochemistry from Western Reserve University, now Case Western Reserve, in Cleveland, Ohio, in 1952. Before he came to Stanford in 1959, he taught at the Washington University School of Medicine in St. Louis.

Berg's first major research achievement, made in 1956, proved part of Francis Crick and Sydney Brenner's theory about how proteins were made. Crick and Brenner had suggested a year earlier that small molecules that they called adapter molecules towed individual amino acids into place and attached them to growing protein molecules. Berg found the first type of adapter molecule (transfer RNA) to be identified and showed that it always attached itself to an amino acid called methionine.

The work Berg was doing in 1972 and 1973 also grew out of discoveries by Watson and Crick. After the two scientists worked out the structure of DNA, they proposed that the double-stranded DNA molecule would reproduce by splitting apart. Each of the resulting single strands would then rebuild its partner strand by attracting free-floating bases in the cell. Berg demonstrated that short single strands of DNA did stick to other strands containing a complementary sequence of bases. For instance, a strand with the sequence C-A-A-T-G would bond to one with the sequence G-T-T-A-C.

Berg's planned experiment of combining virus genes and trying to make the altered viruses put the combined genes into bacteria was a first step toward introducing new genes into cells from mammals, James Watson (with Andrew Berry) writes in DNA: The Secret of Life, his history of DNA research. Eventually, Watson says, Berg hoped to use viruses to carry healthy genes into the cells of people with genetic diseases. Almost two decades later, French Anderson and others employed this same idea in developing gene therapy.

Berg won a share of the Nobel Prize in chemistry in 1980 for his pioneering work on the biochemistry of genes. He has also received other awards, including the Albert Lasker Award for basic medical research (1980) and the National Medal of Science (1985).

The scientists' call for caution went still further in a second letter, published in July 1974. Berg, Boyer, Cohen, and the other signers of the letter asked other researchers in the field to agree to a moratorium, or temporary halt, for some kinds of gene-altering research until the possible hazards of such work had been evaluated and more adequate safety precautions had been developed. The scientists were afraid that bacteria with dangerous added traits, such as the power to cause cancer or resist antibiotics, might escape from genetic engineers' laboratories and infect humans.

These safety fears resulted in a groundbreaking meeting of 140 molecular biologists at Asilomar, a retreat center in central California,

Issues: Continuing Safety Concerns

Most experts now think that the chances of a dangerous genetically modified microorganism escaping a laboratory on its own are small. Especially after the al-Qaeda attacks of September 2001, however, fear has grown that terrorists might create and release such deadly microbes deliberately. Defectors from Soviet biological warfare laboratories reported in the 1990s that the laboratories had conducted genetic engineering experiments on disease-causing bacteria, for instance.

Two experiments in the early 2000s were innocent in themselves, but they showed how easy creating a deadly microorganism could be. In the first experiment, described in February 2001, Australian scientists genetically altered the virus that causes mousepox, a disease similar to the often fatal human disease smallpox, and thereby accidentally made a virus that could kill mice vaccinated against the standard form of mousepox. Secondly, scientists at the State University of New York at Stony Brook reported in July 2002 that they had used information available on the Internet and DNA purchased through the mail to create "from scratch" a virus capable of causing the crippling disease polio. Members of Congress and even some scientists questioned whether accounts of research of this kind should be published, saying that terrorists might read them and put the methods described in the reports to terrible use.

in February 24-27, 1975. The meeting was also spurred by a second concern: the possibility that if scientists did not establish rules for this new technology, legislators would. Alarming stories about genetic engineering were beginning to appear in newspapers, radio, and television, and the public was demanding that the technology be controlled.

By the end of their argumentative meeting, the Asilomar group had devised guidelines for conducting different types of gene-splicing experiments. The National Institutes of Health (NIH), the chief research institutions sponsored by the U.S. government, used the Asilomar guidelines as a model when it drew up its own safety rules in 1976. The NIH rules were binding on all scientists receiving funding from the federal government, and most other U.S. researchers, especially those at universities, agreed to follow them as well. The NIH also established the Recombinant DNA Advisory Committee (RAC) to review future genetic engineering experiments.

These government steps quieted public fears. After several years of gene-splicing experiments passed without major problems, most of the NIH rules were dropped in 1980. The RAC, however, remains in existence. Its main job is to review experiments or drug tests in which altered genes are transferred into humans (gene therapy).

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