Original story from the University of New South Wales (Sydney). Researchers have revealed that so-called ‘junk DNA’ contains powerful switches that help control brain cells linked to Alzheimer’s disease. When people picture DNA, they often imagine a set of genes that shape our physical traits, influence behavior and help keep our cells and organs functioning. But genes make up only a small slice of our genetic code. Just around 2% of DNA contains our 20,000-odd genes. The other 98% has long been labelled the non-coding genome, or so-called ‘junk’ DNA. This larger portion includes many of the control switches that determine when genes turn on and how strongly they act. Astrocytes and hidden DNA switches in the brain Researchers from UNSW Sydney have now pinpointed DNA switches that help regulate astrocytes. Astrocytes are brain cells that support neurons, and they are known to be involved in Alzheimer’s disease. In a recent study, a team from UNSW’s School of Biotechnology & Biomolecular Sciences reported that they tested nearly 1000 possible switches in lab-grown human astrocytes. These switches are strings of DNA called enhancers. Enhancers can sit far from the genes they influence, sometimes separated by hundreds of thousands of DNA letters, which makes them difficult to investigate. A micron-resolution map for navigating tissue fiber networks A new method has revolutionized our ability to map tissue fiber orientation and organization across tissues, diseases and sample preparations. Testing nearly 1000 enhancers at once To tackle that problem, the researchers combined CRISPRi with single-cell…
