heterochromatin tagged posts

An artistic rendering of the mechanism responsible for relocalization of heterochromatic repair sites during homologous recombination. A nuclear myosin walks along a dynamic nuclear actin filament, carrying broken DNA for repair. Credit: Yekaterina Kadyshevskaya, USC

‘Walking molecules’ haul away damaged DNA to the cell’s emergency room. Amid the rise of CRISPR and genome editing, scientists are still learning more about DNA repair and its significance in aging and diseases such as cancer. The cell has its own paramedic team and emergency room to aid and repair damaged DNA, a new USC Dornsife study reveals.

The findings are timely, as scientists are delving into the potential of genome editing with the DNA-cutting enzyme, CRISPR-Cas9, to treat diseases or to advance scientific knowledge ab...

Activity with age. Fluorescence in the fat body of fruit flies tracks the activity of transposable elements of DNA. It increases markedly with age. Credit: Jason Wood/Brown University

A new study increases and strengthens the links that have led scientists to propose the “transposon theory of aging.” Transposons are rogue elements of DNA that break free in aging cells and rewrite themselves elsewhere in the genome, potentially creating lifespan-shortening chaos in the genetic makeups of tissues. As cells get older, prior studies have shown, tightly wound heterochromatin wrapping that typically imprisons transposons becomes looser, allowing them to slip out of their positions in chromosomes and move to new ones, disrupting normal cell function...