Editor's Summary
16 June 2005
A change of mind
Vive la difference seems fair comment when it comes to the organization of the vertebrate brain and mind. The basic kit of parts can achieve considerable variation between individuals. A source of variability in the neuronal genome that might explain some of the differences is reported this week: retrotransposition by LINE-1 regulatory elements. In adult rat neuronal stem cells, and in vivo in brains of transgenic mice, an engineered human LINE-1 is shown to produce DNA from RNA by reverse transcription. Similar retrotranspositions have been seen previously in germ cells or in early embryogenesis, before the cells had adopted a distinct (neuronal, say) lineage. But this new work suggests that mobile genetic elements might alter the neuronal genome — and neuronal circuits — at a much later stage.
News and Views: Genetics: LINEs in mind
At least half the human genome consists of mobile elements, such as LINEs, some of which can jump around the genome. These elements have been crucial in genome evolution, but they may also contribute to human diversity.
Eric M. Ostertag and Haig H. Kazazian, Jr
doi: 10.1038/435890a
Article: Somatic mosaicism in neuronal precursor cells mediated by L1 retrotransposition
Alysson R. Muotri, Vi T. Chu, Maria C. N. Marchetto, Wei Deng, John V. Moran and Fred H. Gage
doi: 10.1038/nature03663
Abstract | Full Text | PDF (496K) | Supplementary information