The young rhesus, named ANDi, which is backwards for "inserted DNA," is the closest animal yet to humans that has been genetically modified – that is, the first transgenic nonhuman primate. He received the extra gene, a marker used in laboratory research, while he still was an unfertilized egg.
Scientists typically use mice carrying a human gene to study human diseases and potential treatments for them. But an animal more closely related to humans could possibly speed the process. Rhesus monkeys and humans share 95 percent of their DNA, versus 85 percent for mice and humans, according to the National Institutes of Health.
ANDi was born Oct. 2 at Oregon Regional Primate Research Center at Oregon Health Sciences University in Portland. Details of ANDi will be published Thursday in the journal Science.
"ANDi is robust and plays normally with his two roommates," said co-author Gerald Schatten. Last year, Schatten and his colleagues created the first cloned monkey, a female named Tetra, by splitting an embryo.
Schatten said ANDi's modified DNA has just a simple green fluorescent marker gene from the jellyfish that glows, so it should in theory be easy to identify in his genetic blueprint.
However, the same method the scientists used to modify his DNA could lead to other laboratory animals that can carry genes associated with specific medical conditions, including cancers and Parkinson's disease.
"We could just as easily introduce, for example, an Alzheimer's gene to accelerate the development of a vaccine for that disease," said Schatten.
"We hope to bridge the scientific gap between transgenic mice and humans," Schatten said. "We could also get better answers with fewer animals, while accelerating the discovery of cures through molecular medicine.
"Monkeys like ANDi and Tetra, a cloned monkey, will quickly but safely help us determine if innovative therapies are safe and effective." He said it soon might be possible to introduce genetic markers that can be monitored by magnetic resonance imaging, for example, to discover how heart disease or mental illness develop.
Ronald Desrosiers, director of Harvard Medical School's New England Regional Primate Research Center in Southboro, Mass., said transgenic monkeys could be particularly useful in studying human genetic disorders.
"One problem with studying mice is that they are mice, and they are pretty far from humans," Desrosiers told United Press International. "But monkeys have systems much closer to humans for studying genetic diseases."
However, it will take some time before transgenic monkeys can be bred with the same degree of efficiency and ease as transgenic mice, he said.
Breeding ANDi was no modest task. The Oregon scientists genetically modified and fertilized 224 eggs. They first added the jellyfish DNA directly to a mother monkey's egg, using a modified virus, and then injected a male monkey's sperm into the modified eggs. That resulted in 40 embryos, which were transferred into 20 surrogate mothers.
Five pregnancies resulted, from which there were three live male births; two monkeys were stillborn. Of the healthy infants, only ANDi had the jellyfish gene successfully integrated into his genetic makeup.
However, the gene does not yet show fluorescence. The researchers said that might be because it is present in such small amounts in his body, or because it won't be expressed until he is older.
In a news story accompanying the research article, Schatten and bioethicist LeRoy Walters of Georgetown University's Kennedy Institute of Ethics will note they don't expect transgenic monkeys to be common research tools. There are ethical and expense issues.
"I don't see any immediate therapeutic application," Walters was quoted as saying in the article.
Reproductive biologist Ted Golos of Wisconsin Regional Primate Research Center in Madison said in the news article that transgenic primates could be helpful in examining human processes such as aging, immunology and behavior that are difficult to study in rodents.
Copyright 2000 by United Press International. All rights reserved.