Named ANDi, backwards for “inserted DNA,” the active, healthy rhesus monkey received an extra gene while he was still an unfertilized egg, according to a paper published in the January 12 issue of the journal, Science.

Born on October 2, 2000, “ANDi is robust and plays normally with his two roommates,” says Gerald Schatten of the Oregon Regional Primate Research Center at the Oregon Health Sciences University in Portland, Oregon.

ANDi’s modified DNA consists only of a simple marker gene, designed to be easily identified within his genetic blueprint. But the same modification method should lead to other laboratory animals carrying genes associated with specific medical conditions, Schatten says.

“We could just as easily introduce, for example, an Alzheimer’s gene, to accelerate the development of a vaccine for that disease. In this way, we hope to bridge the scientific gap between transgenic mice and humans. We could also get better answers from fewer animals, while accelerating the discovery of cures through molecular medicine,” Schatten says.

ANDi is the product of an experiment that involved some 224 mother monkey eggs.

The Oregon team—including K.Y. Chong, C. Martinovich, and C. Simerly—added a marker gene directly to each egg using a technique that is already used in human gene therapy investigations.

The modified eggs were fertilized by injection with a father monkey’s sperm, producing 40 embryos. After the embryos were transferred to 20 surrogates, five pregnancies resulted. Three healthy male babies were born, two infants were stillborn, and another pregnancy didn’t develop.

Of the healthy infants, only ANDi demonstrated successful transgene integration.

Stem cells and gene therapy show promise for eradicating many devastating diseases, says Schatten. “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 may soon be possible to introduce markers monitored by non-invasive techniques, such as MRI [magnetic resonance imaging] or PET [positron emission tomography], to discover the developmental events that lead to diseases like diabetes, heart disease and even mental illnesses.”