by Susan V. Seligson

To the swelling chorus of people who oppose mammalian cloning, scientists like James Robl have already gone too far. Never mind the audacity of churning out genetically indistinguishable rabbits and cows. If Robl and his colleagues in the University’s Department of Veterinary and Animal Sciences can incorporate human DNA into the egg cells of cows, what’s to stop them from riding the slippery slope to a world menaced by human-bovine monsters or a soulless society that clones babies for racial purity, cannon fodder or spare parts?

Moral and scientific integrity, for starters. In the company of the modest, sedately focused Robl, these alarmist cries seem misplaced, even hysterical. Not only, as Oprah might say, do these researchers have no intention of “going there,” but such diabolical notions remain as scientifically fanciful as his daughter Leah’s half-pig half-cow chimera portraits which adorn the walls of Robl’s Paige Laboratory office. And when Robl speaks of his work, it is with nothing less than reverence for the mysteries of life that evade even the biologist as he literally cuts, splices and otherwise tampers with the genetic material essential for life to exist.

“Sometimes I think the question isn’t, why don’t we succeed more often,” says Robl, describing the delicate but relatively crude process of poking a host cell membrane until it annexes the chromosome-packed nucleus of a donor cell, “but why we succeed at all.” A kind of miracle happens, even in the laboratory.

"Sometimes I think the question isn’t, why don’t we succeed more often, but why we succeed at all.”
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Professor Robl of Vet & Animal Sciences

Thanks to memorable scenarios about pod people, the petri-dish rebirths of Hitler or velociraptors, and Woody Allen’s slapstick efforts to clone Sleeper’s Fearless Leader from his steamroller-flattened nose, the word cloning hits a familiar, often raw nerve. Once again scientists are accused of “playing God.” Like Darwin’s theory of evolution or early in-vitro fertilization, cloning has pitted science against theology. Professional glory and potential corporate gain are cited as threats to traditional individual rights. (See sidebar, page 11.) But, like cases of summarily banned books their detractors don’t even bother to read, the uproar over cloning obscures the fact that few lay people have a clear understanding of what cloning is. Despite the noisy 1997 debut of Dolly the sheep, most people would be startled to know that cloning dates back to the sixties, when an adult frog was “copied” by replacing the DNA of a frog embryo. And most are unaware that without genetic engineering, the cloning process would be of little clinical or commercial value.

At its most basic, cloning means copying, which is why critics view laboratories like Robl’s as ghoulish assembly lines. A clone – from the Greek klwn, meaning twig — is the offspring derived from a single ancestor, either an organism or a cell, with genes identical to that ancestor or that cell. Robl’s cows are clones as the result of the delicate substitution of one nucleus for another, but some tumors are also clones, as are animals like corals, which reproduce without sex. We’re cloning every time we cultivate a house plant with a cutting. Identical twins are clones, as well as being comforting reminders of the role external factors play in shaping what makes each of us unique. Even if it were possible to clone adult humans (no one knows for sure), a “copy” of Hitler could turn out to be an ordinary Joe, making a living selling his inferior oil paintings.

Cloning a mammal, any mammal, is a huge leap from cloning a chrysanthemum. The illustrious Dolly emerged after about 300 attempts, and Robl himself has been working with mammalian cloning for the last 15 years. No one’s had much success cloning mice, Robl’s first foray into the field. Robl and his associates cloned their first cow after 12 years of trying. Because cloning eliminates the role of sperm, the researchers had to start from scratch with freshly ovulated eggs. “We had to look at what mediates the egg’s response to the sperm, and figure out what the optimum stage is to replace the egg’s genetic material with the donor material,” Robl explains. Talk about microsurgery. Robl reaches for a series of micrographs showing the donor nucleus, packed with chromosomes, being poked close to the egg cell membrane, then pinched “like a pulling a marble out from inside a balloon,” says Robl. After years of manipulating these cells and nuclei Robl says he can feel what needs to be done almost as if he were working with his actual fingers. A high voltage electrical shock is used to stimulate the nucleus to “melt into” the cytoplasm of the recipient egg after a few minutes, and another pulse activates the start of cell division. Various experiments over the years resulted in about 20 genetically identical rabbits, “nice normal bunnies” which department people adopted as pets, says Robl.