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GENETIC ENGINEERING

Frankenstein and the Miracle

Perhaps more than any other issue, genetic engineering or recombinant DNA captures both the hopefulness and the unease that characterized feelings about science in the 1970s. It held out the hope of fantastic health benefits, promising to make drugs easy to synthesize and diseases treatable. Yet it also threatened the specter of Frankenstein: artificial life escaping from the lab and unleashing new diseases on the world. In 1974 scientists concerned about such a scenario called a halt to genetic engineering work. By the end of the decade environmental activists and much of the general public were deeply worried by these experiments, but most biologists were convinced they could control it. Entrepreneurial companies like Genentech, formed in 1976, were looking for ways to exploit the commercial potential of genetic engineering. The U.S. government, after first imposing strict guidelines on recombinant DNA research, ultimately relaxed restrictions.

The Idea

DNA, or deoxyribonucleic acid, is one of the most basic building blocks of life, found in every organism. DNA molecules are composed of chains of meaningful information, commonly referred to as genes, encoded by combinations of four amino acids. Each gene produces a different effect in a cell: telling it to grow bone, for example. In 1972 microbiologists found that they could take a fragment of DNA from one organism and splice it together with DNA from another. This allowed them to do two kinds of experiments. First, they were able to tell what genes did by implanting them in a different kind of cell. If, for example, a genetically modified bacterium suddenly began producing a human hormone, then researchers would know that they had found the DNA segment that coded for that hormone. Similarly, researchers and commercial labs were interested in whether hormones such as insulin, commonly used by diabetics, could be produced easily and cheaply using simple organisms as manufacturers.

The Technique

The technique developed steadily over the decade. The first landmark was to develop a tool that would cut DNA. Since DNA is far too small for even the steadiest hand to slice with a mechanical tool without smashing it, the technique developed in 1970 to cut it was the use of a restriction enzyme, a protein that would fragment the DNA at a specific site. DNA is a double molecule, two chains joined together and wound into a double helix. Some restriction enzymes cut both sides, but at slightly different sites, leaving the end of one hanging off. Since each of the four amino acid bases can be mated to only one of the other four, a strip beginning with the same sequence of bases as the one just separated would be sticky; it would tend to attach itself to the DNA fragment. The enzyme ligase (from the Latin ligare, to tie) helps make these sticky fragments attach themselves firmly. The result is recombinant DNA, a kind of DNA not found in nature: part belonging to one organism, part to another. The recombinant DNA is placed in a host cell, usually a bacterium.

Controversy

Scientists first became concerned about the impact of these procedures in 1973 when researcher Paul Berg proposed experiments that involved using bacteria commonly found in humans, E. coli, to carry a virus that caused cancer tumors. The experiment was canceled, but scientists who discussed it at two important meetings that year felt it symbolized the dangerous potential recombinant DNA possessed. Following the decision to halt most further research in this area or conduct it under the most stringent guidelines, the press exploded with a discussion of its dangers and potential benefits. Laypeople and environmental activists, such as Friends of the Earth, participated in a public debate that would have been unimaginable two decades earlier about the direction scientific research ought to pursue. When the government relaxed its genetic engineering guidelines in 1979, persuaded by biologists' arguments that the lab strains of E. coli used in genetic research were so weakened that they could never survive in the wild to carry deadly genetic material, Friends of the Earth filed suit. They succeeded in delaying implementation of the new guidelines, insisting that federal regulators were required to conduct an environmental-impact study on the effect of creating new, unpredictable organisms. Some scientists, like geneticist James Watson, one of the early opponents of genetic engineering, grew bitter about the unprecedented public oversight of scientific priorities. Some activists, on the other hand, initially encouraged by signs of social concern by scientists over the impact of new technologies, felt betrayed by the ultimate refusal of the scientific community and regulators to listen to their concerns. In the 1980s biotechnology became a rapidly growing industry, and the federal government quietly began funding gene research on a scale matched only by the Apollo project.