Cardiac development needs more than protein-coding genes
When the human genome was sequenced, biologists were surprised to find that very little of the genome — less than 3 percent — corresponds to protein-coding genes. What, they wondered, was all the rest of that DNA doing?It turns out that much of it codes for genetic snippets known as long non-coding RNAs, or lncRNAs. In recent years, scientists have found that these molecules often help to regulate which genes get turned on or off inside a cell. However, little is known about the specific roles of the thousands of lncRNAs discovered so far. In a new study, MIT biologists have identified a critical role for a lncRNA they dubbed “Braveheart.” This lncRNA appears to stimulate stem cells to transform into heart cells during mouse embryonic stem cell (ESC) differentiation; the researchers suspect that lncRNAs may control this process in humans as well. If so, learning more about lncRNAs could...