'Jumping Genes' Create Diversity In Human Brain Cells, Offering Clues To Evolutionary And Neurological Disease
ScienceDaily (Aug. 6, 2009) — Rather than sticking to a single DNA script, human brain cells harbor astonishing genomic variability, according to scientists at the Salk Institute for Biological Studies. The findings, to be published in the Aug. 5, 2009, advance online edition of Nature, could help explain brain development and individuality, as well as lead to a better understanding of neurological disease.
The team, led by Fred Gage, Ph.D., a professor in the Salk's Laboratory of Genetics and holder of the Vi and John Adler Chair for Research on Age-Related Neurodegenerative Diseases, found that human brain cells contain an unexpected number of so-called mobile elements—extraordinary pieces of DNA that insert extra copies of themselves throughout the genome using a "copy and paste" mechanism.
"This is a potential mechanism to create the neural diversity that makes each person unique," says Gage. "The brain has 100 billion neurons with 100 trillion connections, but mobile pieces of DNA could give individual neurons a slightly different capacity from each other."
The only other human cells known to remodel their genome are the cells of the immune system. There the genes coding for antibodies are shuffled to create the necessary variety of antibodies capable of recognizing an infinite number of distinct antigens.
