Scientists have taken their control over genes one step further by developing a technology to turn on or off a gene in the adult nervous system whenever and wherever they want. Scientists at the University of Rochester report in the January issue of Nature Biotechnology on the first demonstration of the technology: permanently turning on in adult mice the gene for nerve growth factor (NGF), a substance that has been difficult for scientists to study because it's so difficult to manipulate.
Investigators believe the method will make possible important studies into the way our nervous system works. "This technology gives us an unprecedented opportunity to study the function of nearly any gene in the nervous system," says principal investigator Howard Federoff, M.D./Ph.D., chief of the University of Rochester's Division of Molecular Medicine and Gene Therapy.
"The most ideal way to study a gene is to have the ability to turn on or off that gene at any time that you wish, at any place that you wish. This new approach allows us this level of control."
Graduate student Andrew Brooks is first author of the paper. Also contributing were scientist Nariman Panahian, research associate Bhaskar Muhkerjee, and Professor Deborah Cory-Slechta, Ph.D. Brooks presented the work, which is funded by the National Science Foundation, at last month's Society for Neuroscience meeting in Washington.
The Rochester team used a new type of genetic surgery to carry out the experiment. First they created a special strain of mice by inserting extra NGF genes into their DNA, along with a "stop" DNA sequence that kept the genes turned off. Then, when the mice were several months old, scientists injected a viral vector that shuttled into the cells an enzyme that snipped out the "stop" sequence, activating the extra genes to produce NGF. The team believes this is the first permanent genetic modification in the central nervous system of an adult mammal.