Australian scientists have published a study in the journal Nature Neuroscience representing the first of its kind. The researchers have identified more than 100 DNA segments which control gene activity by switching on genes in the brain. Prior research has focused on identifying DNA segments that contain blue prints for producing cell proteins.
“Our study provides a unique resource of information on gene function in the human brain which could help reveal the basis of autism and related neurological disorders,” said lead author UNSW’s Dr Irina Voineagu.
“The rest of the DNA is not just a lot of junk. Some segments of it — the enhancers — control when, and in which parts of the body, the genes become active,” said Dr Voineagu, of the UNSW School of Biotechnology and Biomolecular Sciences.
The study consisted of searching for RNA molecules (markers), produced by DNA enhancers and identifying specific enhancers and which genes were being switched on and off. Enhancers have been linked to disease causing mutations playing an important role in inherited neurodevelopmental and neuropsychiatric disorders. The final step consisted of analyzing whether any of the enhancers contained genetic changes already linked to a range of disorders including, attention deficit disorder, depression, bipolar disorder, schizophrenia and autism. The results were conclusively positive for autism.
“Our study is the first to investigate how the activity of enhancers and genes are coordinated in the human brain, and the first to show that brain enhancers are linked to autism,” said Dr Voineagu.
Irina Voineagu et al. Coexpression networks identify brain region–specific enhancer RNAs in the human brain. Nature Neuroscience, July 2015 DOI: 10.1038/nn.4063