The international team around Coufal has now also found an unexpectedly large genetic diversity in brain cells. The cells studied were unmistakably from the same individual, but differed in the repetitive DNA segments both among themselves and from heart and liver cells. The role of these sections is still unclear. Researchers believe it is important in lower organisms such as yeasts or plants, but rather insignificant for humans, although about 50 percent of human DNA consists of repetitive elements. The repetitive sequences were therefore considered as remnants of evolution similar to the cecum.
The results shed new light on the role of repetitive sequences, which are apparently more important than previously thought. In addition, the results can provide new insights into brain development and the development of neuronal diseases and aging processes. They can also provide explanations as to how the individuality of people arises. Among other things, this originates in the brain, but so far neither neurobiologists nor geneticists can say anything more precise.Nicole Coufal (Salk Institute in California) et al .: Nature, doi: 10.1038 / nature08248. ddp / wde - Martina Bisculm ad