Cold Spring Harbor, N.Y. As the body ages, the physical effects are notable; wrinkles in the skin appear, physical exertion becomes harder. But there are also less visible processes going on. Inside aging brains there is another phenomenon at work, which may contribute to age-related brain defects.
In a paper [http://dx.doi.org/10.1038/nn.3368] published in the journal Nature Neuroscience CSHL Associate Professor Joshua Dubnau [http://www.cshl.edu/Faculty/dubnau-joshua.html] and colleagues show that so-called "jumping genes," or transposons, increase in abundance and activity in the brains of fruit flies as they age.
Originally discovered at CSHL by Professor Barbara McClintock while working on maize (corn) in the 1940s, transposons are typically repeat DNA sequences that insert themselves into the DNA of an animal or plant.
The moniker "jumping genes" comes from the fact that when activated they can reinsert themselves, or transpose, into another part of the genome. In the course of doing so they are thought to either provide variations in genetic function or, especially in the germline, induce potentially fatal disruptive defects.
Jumping genes in the brains of fruit flies
The lifespan of a fruit fly can be measured in days. The average fly lives for somewhere between 40-50 days. But they provide a powerful model with which to get at the genetics of things like aging and brain function, including memory.
Dubnau's interest was piqued by an experiment in which his team showed that when the activity of a protein called Ago2 (Argonaute 2) was perturbed, so was long-term memorywhich was tested using a trained Pavolvian response to smell. "This is a neurodegenerative defect that gets profoundly more apparent with age of the flies," notes Dubnau.
|Contact: Edward Brydon|
Cold Spring Harbor Laboratory