Diversity in neuronal DNA

Human neurons: bits of DNA are shown in red

Salk Institute Human neurons: bits of DNA are shown in redSalk Institute

About half of healthy neurons contain large chunks of DNA that are inserted into genomes or deleted from them, a conclusion that runs counter to the principle that every cell contains the same genetic material. The findings are part of a recent study coordinated by researchers from the Salk Institute, in California (Nature Neuroscience, September 12, 2016). One of the sources of these variations are so-called jumping genes, or L1s, which are known to be small pieces of DNA that copy and paste themselves throughout the genome. It has now been found that L1s not only cause insertions but can also cause deletions of stretches of the genome. “This recent study reveals a new and surprising form of variation that will help us understand the role of L1s, not only in healthy brains but in those affected by schizophrenia and autism,” said Fred Gage, of the Salk Institute. Three Brazilians collaborated in the study: Apuã Paquola, also with the Salk Institute; Francisco Alves, with the University of São Paulo (USP); and Alysson Muotri, with the University of California, San Diego.