TINKERING WITH LIFE

It is one of the lowliest of nature's creatures, a rod-shaped beastie less than a ten-thousandth of an inch long. Its normal habitat is the intestine. Its functions there are still basically unknown. Yet this tiny parcel of protoplasm has now become the center of a stormy controversy that has divided the scientific community, stirred fears--often farfetched--about tampering with nature, and raised the prospect of unprecedented federal and local controls on basic scientific research. Last week the bacterium known to scientists as Escherichia coli* (E. coli, for short) even became a preoccupation at the highest levels of government.

Appearing before a Senate subcommittee on behalf of the Carter Administration, HEW Secretary Joseph Califano asked Congress to impose federal restrictions on recombinant DNA research, a new form of genetic inquiry involving E. coli. The urgency of Califano's request underlined the remarkable fact that a longtime dream of science, genetic engineering, is at hand --and, some fear, already out of hand. In laboratories across the nation, scientists are combining segments of E. coli's DNA with the DNA of plants, animals and other bacteria. By this process, they may well be creating forms of life different from any that exist on earth.

That this exciting new research holds great promise but could also pose some peril was stressed in the day-long testimony before Senator Edward Kennedy's health subcommittee. Califano called recombinant DNA "a scientific tool of enormous potential." He also warned about possible--though unknown--hazards and concluded: "There is no reasonable alternative to regulation under law." Massachusetts Governor Michael Dukakis, involved in the controversy over genetic-engineering projects at Harvard and M.I.T., argued for the public right to regulate the research. Said he: "Genetic manipulation to create new forms of life places biologists at a threshold similar to that which physicists reached when they first split the atom. I think it is fair to say that the genie is out of the bottle."

The issue, stated simply, is whether that genie is good or evil. Proponents of this research in DNA--the master molecule of life--are convinced that it can help point the way toward a new promised land--of understanding and perhaps curing cancer and such inherited diseases as diabetes and hemophilia; of inexpensive new vaccines; of plants that draw their nitrogen directly from the air rather than from costly fertilizers; of a vastly improved knowledge of the genetics of all plants and animals, including eventually even humans (TIME special section, April 19, 1971).

Opponents of the new research acknowledge its likely bounty, but fear that those benefits might be outweighed by unforeseeable risks. What would happen, they ask, if by accident or design, one variety of re-engineered E. coli proved dangerous? By escaping from the lab and multiplying, their scenario goes, it could find its way into human intestines and cause baffling diseases. Beyond any immediate danger, others say, there are vast unknowns and moral implications. Do not intervene in evolution, they warn in effect, because "it's not nice to fool Mother Nature." Caltech's biology chairman, Robert Sinsheimer, concludes: "Biologists have become, without wanting it, the custodians of great and terrible power. It is idle to pretend otherwise."

The scientific community is bitterly divided about the unknown risks of genetic engineering. The wrangling has been public, and traditional scientific courtesy has all but vanished. Infuriated by unreasoning opposition to the new discoveries, James Watson--who, with Francis Crick, won a Nobel Prize for determining the double-helix structure of the DNA (for deoxyribonucleic acid) molecule--has labeled the critics "kooks," "shits" and "incompetents." One of his targets is fellow Nobel Laureate George Wald, who has supported efforts to ban recombinant DNA research at Harvard and M.I.T. Wald contends that instead of trying to find the roots of cancer, for example, through genetic research, society can fight the disease more effectively by taking carcinogens out of the environment.

The concern of Caltech's Sinsheimer is partly philosophical --some might even say mystical. He fears the unpredictable consequences of breaching what he calls nature's "evolutionary barrier" between different kinds of creatures--the genetic incompatibility that in most cases prevents one species from breeding with another. In the same vein, retired Columbia Biochemist Erwin Chargaff asks: "Have we the right to counteract, irreversibly, the evolutionary wisdom of millions of years in order to satisfy the ambition and the curiosity of a few scientists?"

For every salvo from the critics, though, a return round comes from defenders of recombinant DNA research. Bernard Davis, a Harvard Medical School microbiologist, is so sure the new technique is safe that he has publicly offered to drink recombinant DNA. He insists that those who worry about infections are totally ignorant of medicine's long history of safely handling highly contagious bacteria and viruses. Nor, he says, do they understand how difficult it is for a microbe to become pathogenic. He adds: "Those who claim we are letting loose an Andromeda strain are either hysterics or are trying to wreck a whole new field of research." Less acerbically, Chemist John Abelson pointed out in last week's Science that in five years of work with recombinant DNA there has not been a single reported case of infection. The evidence so far suggests that virulent combinations of genes are highly unlikely; the host bacteria simply reject the unwanted genes or die. "Thus," he concludes, "it is probably not possible to create a strain that would overgrow the laboratory and head for the town, as depicted in movies of the 1950s."

Brushing off Chargaffs fears of violating "evolutionary wisdom," Molecular Biologist Stanley Cohen, at the Stanford University School of Medicine, notes that man has been intervening in the natural order for centuries--by breeding animals and cultivating hybrid plants and, more recently, by the use of vaccines and antibiotics. With undisguised sarcasm, Cohen adds that it was Chargaffs "evolutionary wisdom that gave us the gene combinations for bubonic plague, smallpox, yellow fever, typhoid, polio and cancer."

The DNA furor has already intruded on the free exchange of information so vital to scientists. Longtime associates are no longer talking to each other. Fearful of losing out on tenure or research grants by taking the "wrong" stand on the issue, some junior researchers are lapsing into monklike silence. At Harvard, at least one graduate student has been disowned by her thesis adviser for getting into the fray. Says Microbiologist Richard Goldstein of the Harvard Medical School: "The level of animosity is unbelievable. There have been character assassinations left and right." Sometimes the argument has sounded like a replay of old Vietnik protests. At a forum of the National Academy of Sciences in Washington last month, unruly opponents of genetic research, chanting "We shall not be cloned," took over the stage and unfurled a banner reading: WE WILL CREATE THE PERFECT RACE--ADOLF HITLER.

Scientists clearly do not have any diabolical intent, but their emotional and unusually public debate over DNA has made ordinary citizens sit up and take notice. Newspaper and magazine articles have carried such chilling headlines as: NEW STRAINS OF LIFE--OR DEATH, SCIENCE THAT FRIGHTENS SCIENTISTS and MAN-MADE BACTERIA COULD RAVAGE EARTH. The Public Broadcasting Service (PBS) produced a special hour-long show, "The Gene Engineers," for its Nova series. Taking the genetics fuss as his cue, Columnist Russell Baker recently wrote of a plan by depilatory makers to combine the genes of man and ape. Their goal: to produce more hirsute customers.

Art Buchwald also got into the act. He described a visit to a futuristic "people" lab, where he asks the white-coated salesman if there have been any accidents. Yes, the salesman replies. "Someone once accidentally mixed the genes of Jack the Ripper with a donkey ..." "What was the result?" "We reproduced Idi Amin." Hollywood, too, is aware of the box office value of converting re-engineered cells into celluloid. In the new film, Demon Seed, a scientist's wife (Julie Christie) is "ravished" by his supersmart computer, which somehow manages to combine its "genes" with hers. The fruit of that union: an offspring that appears at first to be--well, a miniature knight in armor.

Science is not interested in pursuing such bizarre fantasies; the real advances are exciting enough. About five years ago, California scientists learned how to combine genes from different organisms, regardless of how low or high they are on the evolutionary scale. Though the researchers added only one or two new genes to a bacterium's collection of thousands of genes, the creation of such hybrid molecules was a stunning feat. The accomplishment seemed to breach one of nature's more inviolable barriers. Even primates as closely related as gorilla and man are so different genetically that they cannot produce offspring. Thus it was not size alone that made King Kong and his ladylove a mismatch. The real species barrier is in the genes.

Molecular biology's wizards have managed to cross that obstacle in their work with bacteria. Unlike higher organisms, bacteria are single-celled creatures that usually reproduce not by sexual mating but by simply dividing. Thus their ability to acquire new and possibly advantageous genes would seem to be highly limited. But the tiny creatures have devised a cunning alternative. Besides their single, large, ringed chromosome (which is the repository of most of their genes), they possess much smaller closed loops of DNA, called plasmids--which consist of only a few genes. This extra bit of DNA--genetic small change, as it has been dubbed--serves a highly useful purpose. When two bacteria brush against each other, they sometimes form a connecting bridge. During such a "conjugation," a plasmid from one bacterium may be passed into the other.

These natural transfers can be crucial to the survival of the bacterium. It is through new plasmids, for example, that bacteria like Staphylococcus aureus have become resistant to penicillin. The plasmid acquired by the staph bug contained a gene that directs the production of a penicillinase, an enzyme that cracks apart invading penicillin molecules, making them ineffective. Different plasmids, sometimes passed from one bacterium to another, can order up still another kind of chemical weapon, a so-called restriction enzyme, which can sever the DNA of an invading virus, say, at a predetermined point.

Observing these bacterial tricks, molecular biologists began isolating various restriction enzymes. They had already discovered another type of bacterial enzyme, called a ligase (from the Latin word meaning to bind), which acted as a form of genetic glue that could reattach severed snatches of DNA. Using their new biochemical tools, the scientists embarked upon some remarkable experiments. As usual, they turned to their favorite guinea pig, a lab strain of E. coli, and soon they had learned to insert with exquisite precision new genetic material from other, widely differing organisms into the bacteria (see diagram).

E. coli did not merely accept the hybrid plasmids. When the bacteria reproduced--by dividing and thus doubling--at a rate of about once every 30 minutes, they created carbon copies of themselves, new plasmids and all. In only a day, one bacterium could make billions of duplicates of a transplanted gene.

The tremendous potential of these recombination techniques was not lost on the scientists. They reasoned that if the appropriate genes could be successfully inserted into E. coli, they could turn the bacteria into miniature pharmaceutical factories. The tiny creatures could churn out great quantities of insulin for diabetics (now obtained from the pancreases of pigs and other animals), clotting factor for hemophiliacs (currently both scarce and expensive), vitamins and antibiotics.

Re-engineered bacteria could have many other tasks. Scientists are already considering creation of special nitrogen-fixing bacteria, which would live in roots of crops that now do not have them, thus making it unnecessary to fertilize fields. A General Electric researcher has already added plasmids to create an experimental bug that produces enzymes capable of degrading a wide range of hydrocarbons; an organism engineered by recombinant DNA might some day be used to clean up oil spills. (Even this scheme alarms some opponents of the new research. They fear that a bug designed to gobble up oil spills might get into a pipeline or the fuel tanks of a jet in flight. Jokes one observer: "Some day you may have to worry about your car being infected.")

Most important, recombinant techniques are of enormous help to scientists in mapping the positions of genes and learning their fundamental nature. Stanley Falkow, a University of Washington microbiologist, recently used the method to isolate two toxin-producing bacterial genes that cause diarrhea in humans and livestock. This discovery may lead, in time, to a vaccine against the disorder. But far greater biological bonanzas are in the offing. After three decades of intense study, only one-third of E. coli's 3,000 to 4,000 separate genes have been identified. Higher organisms are much more complex. Humans, for example, have hundreds of thousands of genes. Trying to find out what each of them does has stymied scientists. But if human genes could be transplanted, one at a time, into E. coli and replicated in wholesale amounts, researchers would for the first time have great enough quantities of genes and their products to analyze them fully. Eventually, the genes on all 46 human chromosomes could be precisely located and studied. Not the least of the benefits might be a vastly increased understanding of the molecular basis of disease --especially cancer, which seems to occur when the cell's genetic machinery goes awry.

No one has given more thought to Andromeda-strain scenarios than the scientists who most strongly support the new research. Indeed, it was their own caution that first brought these possibilities before the public. In the summer of 1971, while lecturing on the safe handling of cancer viruses at James Watson's Cold Spring Harbor Laboratory on Long Island, a young cancer researcher named Robert Pollack learned from a visiting scientist that her boss at Stanford Medical Center planned a novel experiment. He hoped to insert a monkey virus, SV40, into E. coli. Although the virus seems harmless enough in its original hosts, it can cause tumors when injected into lab animals; it also turns laboratory cultures of human cells cancerous, although there is no evidence that it can cause cancer in people.

Highly concerned about the uncertainties of infecting laboratory bacteria similar to those in man with known cancer genes. Pollack immediately called Stanford and raised his doubts. The experimenter, Biochemist Paul Berg, listened politely but saw no reason for alarm. He knew that SV40 had been handled without ill effects by countless laboratory workers and had even been inadvertently included in some of the first batches of oral polio vaccine without doing any apparent harm. Indeed, Berg felt that the experiment was not only safe but extremely important. SV40's appeal lies in the fact that it has only a few genes, one of which apparently has the ability to turn normal cells into cancerous ones. If anyone could unlock the mysteries of this lethal gene--a goal of laboratories around the world (and the kind of discovery that might well win a Nobel Prize) --he would have taken a major step toward understanding the elusive mechanism of cancer.

When Berg asked his colleagues about the experiment, some of them also expressed misgivings. What if an altered E. coli, carrying SV40 genes, planted a slow-ticking cancer time bomb in the human gut? Nagged by such questions, Berg canceled his experiment. But even while Berg was agonizing over the decision, scientists made two dramatic discoveries that would vastly simplify recombinant work.

At the University of California at San Francisco, Herbert Boyer and his colleagues found an exceptional new cutting enzyme. Unlike available restriction enzymes, it did not break apart the twin-stranded DNA with a simple slice. Instead, it caused an overlapping, mortise-type break that automatically left a bit of '"sticky" single-stranded DNA at each end, to which new mate rial could be readily attached. Previously, Berg and others who worked in the field had to create such sticky tails synthetically.

The other breakthrough came when Stanley Cohen and his team, working in a Stanford lab two floors below Berg's, found a remarkable plasmid, which was promptly dubbed pSC (Cohen's initials) 101. It had the uncanny ability to take on a new gene and to slip into E. coli. Word of Cohen's miraculous little gene conveyor spread rapidly, and experimenters from all over the world besieged him for samples. Usually, scientists are more than willing to oblige such requests. But because pSC 101. in conjunction with Boyer's new enzymatic scalpel, made the creation of novel gene combinations so easy, Cohen was hesitant about distributing the material.

Up to this point, little news of these developments had passed outside the tightly knit community of molecular biologists. Any reports that did appear were in scientific journals, in a language virtually incomprehensible to laymen. But as molecular biologists scrambled to isolate other useful plasmids and enzymes for recombinant work, it became increasingly clear to Berg, Cohen and others that the emerging science needed some controls--at least until the risks, if any, were explored. Nowhere was this more apparent than at a private meeting of some 140 leading molecular biologists in New Hampshire during the summer of 1973. When Cohen described his latest work, the scientists were electrified. As the meeting's cochairman, Maxine Singer, a DNA specialist at the National Institutes of Health (NIH) recalls: "Here was someone talking about putting any two kinds of DNA together." Before the meeting broke up, the scientists voted to ask the National Academy of Sciences to examine the new technique for risks. They also agreed to voice their concern in a public letter to Science, the foremost U.S. science journal.

The academy bounced the problem right back to the molecular biologists by forming an investigatory committee and choosing Berg as its head. As far as Berg and Cohen were concerned, the action came none too soon. Some of the requests for plasmids had been sent by scientists planning precisely the same type of tumor virus implant that Berg had voluntarily forsworn two years earlier. "I was really shocked," Berg recalls. At a meeting of his special committee at M.I.T. in April 1974, the other members promptly agreed to a highly unusual move. They asked all researchers to honor a temporary ban on certain types of recombinant DNA experiments deemed potentially the most dangerous: those involving animal tumor viruses, and those increasing drug resistance or toxicity in bacteria. This time they published their appeal in both Science and the British journal Nature. Not since 1939--when a handful of physicists asked their colleagues to stop publishing atomic data to prevent the information from falling into German hands--had scientists tried such self-policing.

The moratorium, however, was only a stopgap. In February 1975, at Berg's invitation, 134 scientists, including many leading molecular biologists, plus a handful of lawyers and 18 interested reporters, assembled at the picturesque Asilomar retreat among the pines and redwoods of California's Monterey Peninsula. The serenity of the setting was shattered by four lawyers, led by Daniel Singer, Maxine's husband, who lectured the scientists on their legal responsibilities. If an accident did occur during recombinant work, they pointed out, a technician might sue the lab chief. And if a dangerous bug escaped and infected people outside, the lawyers warned, the situation could turn into a legal--to say nothing of a medical--disaster.

The calculated shock treatment worked. Toiling through the night, Berg and his committee drafted recommendations that the conferees readily accepted before their departure the next day. They voted not only to continue the ban on the worrisome experiments, but also to press NIH to establish levels of safety that should be required for different experiments. In addition, they decided that precautions to keep research organisms from escaping from laboratories had to include "biological containment." This required the creation of mutated strains of E. coli so disabled that they could live nowhere but in a test tube. If they did escape their special broth and enter the atmosphere--or human gut--they would die almost instantly (see box).

Although the scientists left Asilomar thinking that they had allayed public fear about their work, they had only managed to fan it. Newspapers, which had until then paid scant attention to the story of recombinant DNA, erupted with scare headlines, alarming the nation with exaggerated doomsday prophecies. Two months later, Ted Kennedy held his first hearings on the new genetics. Some scientists, joined by politicians, began questioning whether the molecular biologists should do their own policing. Said one: "This is probably the first time in history that the incendiaries formed their own fire brigade."

The gibe seemed aimed particularly at another Stanford scientist, David Hogness, who was leading the way in a new form of genetic roulette, appropriately called "shotgun" experiments. Hogness was using enzymes to fragment the DNA of fruit flies and then was inserting the gene material piecemeal into bacteria. That way he could reproduce the inserted genes in vast quantities and discover their functions. The technique seems to be working. To date, he has managed to isolate and identify 36 of the thousands of the fruit fly's genes. But critics fear that because the nature of many of the genes is totally unknown beforehand, the host bacteria might be endowed with some dangerous new characteristic. What irritated the opponents of recombinant DNA even more was the fact that Hogness was in charge of a subcommittee appointed by the National Institutes of Health to draft the guidelines. That, said M.I.T.'s Jonathan King, leading member of the radical Science for the People organization, was like "having the chairman of General Motors write the specifications for safety belts."

Despite the sniping, the NIH group by last summer managed to turn Asilomar's directive into concrete rules. The guidelines continue the ban against the potentially most dangerous experiments. They also provide two principal lines of defense against lesser hypothetical risks. They establish four levels of physical containment; these range from standard laboratory precautions (dubbed "P-l") for experiments in the lowest-risk category--say, injecting harmless bacterial genes into E. coli--to ultrasecure laboratories ("P-4") for work with animal tumor viruses or primate cells. At present, two new P-4 facilities are almost ready. One is a gleaming white trailer parked behind a bar bed-wire fence on the grounds of the National Institutes of Health in Bethesda, Md. It has a totally sealed environment, airlocks, decontamination systems, showers for workers after experiments, and sealed cabinets accessible only through attached gloves. Some "worst case" experiments, involving animal tumor viruses, will begin in the trailer this summer. NIH is also converting some of the abandoned germ-warfare labs at Maryland's Fort Detrick into similar super-containment facilities. In addition to the labs, the guidelines require the use of the self-destructing, escape-proof microbes for certain higher-risk experiments.

Most researchers, eager to continue their work in cracking various genetic riddles, welcomed the guidelines. Numerous universities across the country had already begun work on new P-3 labs, which have a lower and less costly level of containment (air locks, limited access, safety cabinets with curtains of flowing air) than P-4 facilities. Not everyone, though, was pleased.

Egged on by Wald and his biologist wife, Ruth Hubbard, Cambridge's Mayor Alfred Velluci used the escalating DNA furor to badger his old foe, Harvard. He convened the city council in an effort to halt DNA research at the school. Said Velluci: "Something could crawl out of the laboratory, such as a Frankenstein." At the council's request, Harvard and M.I.T. agreed to a moratorium on P-3 research while an eight-member citizens' review board studied the issue. In February, the council overrode Velluci and passed an ordinance permitting recombinant DNA work to be resumed in Cambridge--under standards only slightly more strict than the NIH guidelines.

Most scientists breathed a sigh of relief; the specter of local governments proclaiming a hodgepodge of crippling restrictions on the freedom of inquiry had faded--at least temporarily. Local politicians now may go along with the impending federal legislation, which is expected to impose restraints on all researchers--including those at previously unregulated industry labs. Still, scientists remain concerned over any political controls on their work. At last week's Senate hearing, these fears were voiced by Norton Zinder, a molecular geneticist at Rockefeller University. Said he: "We are moving into a precedent-making area --the regulation of an area of scientific research--and I must plead that this be done with extreme care and without haste. The record of past attempts of authoritative bodies, either church or state, to control intellectual thought and work have led to some of the sorriest chapters in human history."

Zinder has reason for worry. But he and other scientists should find reassurance in the experience of Cambridge. There, citizens patiently ignored political demagoguery, perceived the false notes in the voices of doom, mastered the complex issues and then cast their votes for the continuation--with reasonable restraints--of free scientific inquiry. Congress should do no less.

* Named for its discoverer, the German pediatrician Theodor Escherich, who isolated it from feces in 1885, and for its habitat, the colon.

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