Christmas has come early to scientists at the University of Virginia School of Medicine. They’ve developed a technology that allows you to watch how individual genes move and interact in living cells. You can think of it as Facebook’s live streaming meets the adventurous Ms. Frizzle and her Magic School Bus.
Using a gene editing system called CRISPR/Cas9, the team tagged genes of interest with fluorescent proteins that light up under a microscope – allowing them to watch in real time where these genes are in a cell’s nucleus and how they interact with other genes in the genome. This research, which was funded in part by a CIRM Research Leadership award, was published in the journal Nature Communications.
Watching genes in living cells
Traditional methods for observing the locations of genes within cells, such as fluorescent in situ hybridization (FISH), kill the cells – giving scientists only a snapshot of the complex interactions between genes. With this new technology, scientists can track genes in living cells and generate a 3D map of where genes are located within chromatin (the DNA/protein complex that makes up our chromosomes) during the different stages of a cell’s existence. They can also use these maps to understand changes in gene interactions caused by diseases like cancer.
Senior author on the study, Dr. Mazhar Adli, explained in a news release:
“This has been a dream for a long time. We are able to image basically any region in the genome that we want, in real time, in living cells. It works beautifully. With the traditional method, which is the gold standard, basically you will never be able to get this kind of data, because you have to kill the cells to get the imaging. But here we are doing it in live cells and in real time.”
Additionally, this new technique helps scientists conceptualize the position of genes in a 3D rather than in a linear fashion.
“We have two meters of DNA folded into a nucleus that is so tiny that 10,000 of them will fit onto the tip of a needle,” Adli explained. “We know that DNA is not linear but forms these loops, these large, three-dimensional loops. We want to basically image those kind of interactions and get an idea of how the genome is organized in three-dimensional space, because that’s functionally important.”
Not only can this CRISPR technology light up specific genes of interest, but it can also turn their activity on or off, allowing the scientists to observe the effects of one gene’s activity on others. The flexibility of this approach for visualizing genes in live cells is something that the research world currently lacks.
“We were told we would never be able to do this. There are some approaches that let you look at three-dimensional organization. But you do that experiment on hundreds of millions of cells, and you have to kill them to do it. Here, we can look at the single-cell level, and the cell is still alive, and we can take movies of what’s happening inside.”
This is a pretty nifty imaging tool for scientists that allows them to watch where genes are located and how they move as a cell develops and matures. Live-streaming the components of the genetic engine that keeps a cell running could also provide new insights into why certain genetic diseases occur and potentially open doors for developing better treatments.