From the half-man, half-horse centaur of mythology to the bug-headed man of the sci-fi classic The Fly, the idea of somehow combining people with animals has long fueled human imagination.
Now, geneticists are mixing human, animal, and even plant species, promising major advances in medicine. But others worry about unforeseen consequences, as Wyatt Andrews reports in an Eye on America report.
A goat farm in rural Massachusetts may not look like the frontier of biomedicine--until you hear how they breed the animals. They are splicing a gene from human beings into the goats.
Reseachers say by splicing the gene, it reproduces a protein, which is a potential drug for people.
A similar technology is used to make tobacco plants in a California greenhouse. Human genes are instructing these plants to make medicine.
Mich Hein of the biomedicine company EPIcyte says, "This plant is a mixture of man and tobacco. We have put a human gene, actually two human genes, in that particular plant."
Welcome to the world of transgenic medicine, a species-bending technology that could change the way drugs are made. Because scientists now know the genetic source of dozens of human antibodies--the proteins that fight disease--they are splicing those human genes into a variety of plants and animals.
Steve Parkinson of TranXenoGen says, "Basically it's the idea of taking a human gene and putting it into a chicken."
At a recent biotech convention, companies from around the world boasted about using this technology. Insulin harvested from transgenic chickens. Heart disease antibodies from transgenic mice.
Jim Cornett of Medarex says, "It makes human antibodies instead of mouse antibodies."
The advantage here is volume.
As Hein says, "We have almost a limitless supply of antibodies that we can go out there and capture that occur naturally."
Hein's company, EPIcyte, is using corn and tobacco to grow antibodies for herpes and Crohn's disease.
"We could make these things of fields of corn or rice or in other crops so that we could make literally metric tons of preventatives or therapeutics," says Hein.
Thom Newberry of Genzyme Transgenics says, "You can make very large quantities of proteins in a relatively effective way."
Newberry says his company picked goats because it's easy to harvest pure protein from goat milk.
As impressive as this technology seems, it does raise an ethical question. Does it cross some boundary of nature to cross genes from human beings with plants and animals?
"We need healthy skepticism," says Professor Sheldon Krimsky, a bioethicist at Tufts University. He sees no problem putting one human gene in a goat, but he worries that there are no rules governing the mixed-species future.
Bioethicist Sheldon Krimsky says, "No one is looking at the general question of transgenic animals and society." He adds, "There is a point, and I'm not sure where it is, where we sholdn't be putting in large segments of human genes into animals."
Approval for transgenic medicine is still years away but the raw biology exists now. For the biopharmaceutical industry, corn that grows insulin or goats growing vaccines for cancer may well become high-tech drug factories programmed by the genetic code of man.
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