The night gardeners: Immune cells rewire, repair brain while we sleep

Science tells us that a lot of good things happen in our brains while we sleep—learning and memories are consolidated and waste is removed, among other things. New research shows for the first time that important immune cells called microglia—which play an important role in reorganizing the connections between nerve cells, fighting infections, and repairing damage—are also primarily active while we sleep.

Search-and-replace genome editing without double-strand breaks or donor DNA

Here we describe prime editing, a versatile and precise genome editing method that directly writes new genetic information into a specified DNA site using a catalytically impaired Cas9 fused to an engineered reverse transcriptase, programmed with a prime editing guide RNA (pegRNA) that both specifies the target site and encodes the desired edit.