Glowing monkeys raise ethics concerns
Altered gene traits were passed to babies in study
WASHINGTON - Scientists have created the first genetically modified monkeys that can pass their new genetic attributes to their offspring, an advance designed to give researchers new tools for studying human disease but one that raises a host of thorny ethical questions.
In this case, the Japanese researchers added genes that caused the animals to glow green under a fluorescent light and beget offspring with the same ability in order to test a technique they hope to use to produce animals with Parkinson's, Huntington's, and other diseases.
The work, described in today's issue of the journal Nature, was hailed by some researchers as a long-sought milestone that could lead to crucial insights into a host of ailments and provide invaluable ways to test new treatments.
But the research was condemned by animal rights proponents, who said it paves the way for producing colonies of primates conceived expressly to suffer a plethora of illnesses and undergo potentially painful and dangerous medical experiments.
Because the work marks the first time a species so closely related to humans has been genetically altered in this way, some also worried the same techniques would be used on chimps or other primates even closer to humans or to try to endow people with desirable genetic traits.
"It's hard to put your finger on what is it about this research that is likely to stimulate ethical debate besides the sort of gut feeling that this is not the right thing to do," said Mark Rothstein, a bioethicist at the University of Louisville. "But I think we'd better contemplate where this research is going and develop policies to deal with it before it slaps us in the face."
Scientists have genetically engineered many other species to be research tools. Mice in particular have been created with a wide assortment of characteristics and diseases that mimic human ailments. But because mice are so genetically different from humans, scientists have long sought to breed primates to provide better disease "models." Although scientists have been able to genetically modify individual monkeys, they had never before succeeded in getting the new traits to pass down through generations - a crucial step for creating large enough numbers for research.
In the new work, Erika Sasakim of the Central Institute for Experimental Animals in Kawasaki, and her colleagues conducted a series of experiments using marmosets, a small monkey common in South America that matures and reproduces quickly.
The researchers modified a virus called a lentivirus to carry a jellyfish gene known as GFP (for green fluorescent protein) into the genetic material of the marmosets' cells. The gene is used commonly in research because it is easy to track - cells where the gene is active glow green when exposed to fluorescent light.
The researchers used the genetically engineered virus to insert the jellyfish gene into 80 marmoset embryos, which they then transferred into the wombs of 50 females. Seven pregnancies resulted in five offspring, four of which showed signs of the jellyfish gene in their hair roots, skin, blood cells, and other tissues. Under fluorescent light, the skin on the soles of their feet glowed.
Most importantly, eggs from one of the females and sperm from one of the males had the gene, and the researchers reported that male's sperm was used to produce at least one offspring with the gene - a male named Kouichi whose skin glowed green under the light.
In a telephone briefing for reporters, the researchers said they had since produced four offspring - two from the male and two from the female - three of which glowed green.
Some other researchers said the work marked a crucial landmark. But others criticized the work.
"These nonhuman primates already suffer in laboratories when we infect them with diseases and when we use them in toxicology tests," said Eric Kleiman of In Defense of Animals.
