Medical world banks on this <I>desi</I> monkey with a tiny twist in its DNA

Medical world banks on this desi monkey with a tiny twist in its DNA
PALLAVA BAGLA

NEW DELHI, JAN 12: A baby monkey carrying an extra bit of DNA may suggest a way to speed new treatments for a host of disabling and fatal human conditions, from diabetes and breast cancer to Parkinson's and HIV.

Named ANDi, backwards for ``inserted DNA,'' the active, healthy Rhesus monkey received an extra gene while he was still an unfertilized egg, making him the world's first genetically modified non-human primate.

Rhesus monkeys were exported in the hundereds from India and are the ``guinea pigs'' for all primate studies in the West. US labs breed a huge colony of these monkeys of Indian origin to keep a steady supply for biomedical researchers.

Appropriately born on October 2, 2000, the birthday of Mahatma Gandhi, ``ANDi is robust and plays normally with his two roommates,'' reports the forthcoming issue of Science. Incidentally, the Mahatma's three monkeys which signified ``hear no evil, say no evil, see no evil,'' were all Rhesus monkeys.

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

``We could just as easily introduce, for example, an Alzheimer's gene, to accelerate the development of a vaccine for that disease,'' say the researchers, led by Anthony Chan at the Oregon Regional Primate Research Centre in Portland, USA. ``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''.

Chan's experiment was no easy task: Scientists added a ``marker gene'' directly to the mother monkey's egg. Over 200 eggs were then fertilized with the father monkey's sperm, producing 40 embryos. After the embryos were transferred to 20 surrogates, five pregnancies resulted. Three healthy male babies were born, while two 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, according to the researchers. ``Monkeys like ANDi will quickly but safely help us determine if innovative therapies are safe and effective,'' a scientist of the research team 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''.