Controlling genes with light
Although human cells have an estimated 20,000 genes, only a fraction of those are turned on at any given time, depending on the cell’s needs — which can change by the minute or hour. To find out what those genes are doing, researchers need tools that can manipulate their status on similarly short timescales.That is now possible, thanks to a new technology developed at MIT and the Broad Institute that can rapidly start or halt the expression of any gene of interest simply by shining light on the cells. The work is based on a technique known as optogenetics, which uses proteins that change their function in response to light. In this case, the researchers adapted the light-sensitive proteins to either stimulate or suppress the expression of a specific target gene almost immediately after the light comes on.“Cells have very dynamic gene expression happening on a fairly short timescale, but...