CAMBRIDGE, MA -- 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 so far the methods that are used to perturb gene expression don't even get close to those dynamics. To understand the functional impact of those gene-expression changes better, we have to be able to match the naturally occurring dynamics as closely as possible," says Silvana Konermann, an MIT graduate student in brain and cognitive sciences.
The ability to precisely control the timing and duration of gene expression should make it much easier to figure out the roles of particular genes, especially those involved in learning and memory. The new system can also be used to study epigenetic modifications chemical alterations of the proteins that surround DNA which are also believed to play an important role in learning and memory.
Konermann and Mark Brigham, a graduate student at Harvard University, are the lead authors of a paper describing the technique in the July 22 online edition of Nature. The paper's senior author is Feng Zhang, the W.M. Keck Assistant Professor in Biomedical Engineering at MIT and a core
|Contact: Sarah McDonnell|
Massachusetts Institute of Technology