Tatsuya Morisaki, a research scientist at Colorado State University, and Tim Stasevich, an associate professor in the university’s department of biochemistry and molecular biology, are the creators of a method of visualizing genes live during translation. While they created this imaging system in 2016, scientists around the world have begun using the technology to look at translation in a variety of increasingly complicated model organisms.
In October, Maëlle Bellec at the Max Planck Institute for Heart and Lung Research released research that demonstrated how her team crossed into visualizing translation in vertebrates by observing it in zebrafish.
RNA translation is the process in which “DNA makes RNA, which makes protein,” Morisaki said. This means that in humans — as well as most other organisms — different structures of DNA or genes can influence the proteins each cell can create. Proteins perform numerous important functions, including giving the body energy, fighting infections and helping cells divide. Certain proteins are naturally fluorescent, which can be used to visualize translation.
The problem, Morisaki said, is fluorescent proteins take time to fold and mature. By the time scientists can observe the fluorescence, “the translation event has already happened.” By introducing repeats of epitope tags into the protein of interest, the tags begin fluorescing as soon as the protein is translated, creating amplification.
“So we don’t need to wait for maturation or folding,” Morisaki said.
With this technology, scientists can look at individual molecules, while before they could only look at an organism as a whole.
“You can say a gene is on,” Morisaki said. “But does that mean that it was actually translated?” The uncertainty of past observations created a perfect niche for single-molecule imaging.
Scientists visualized DNA transcription years before this research, but the next step of translation was not captured visually until Stasevich, Morisaki and others developed the technique in 2016. After this initial breakthrough, researchers around the world used the technique on increasingly complicated model organisms. Stasevich said his and Morisaki’s work started small.
“We were imaging in a single cell,” Stasevich said.
The next step was Caenorhabditis elegans, a small translucent roundworm.
“Then there was a science paper in, like, 2022 or 23, where they did our translation imaging in a fruit fly, another very common model organism,” Stasevich said. “Now Maëlle has taken it to the next level in a developing animal to actually see gene expression.”
With each increasingly complex organism, more precision and magnification are necessary to clearly visualize translation.
Bellec expanded on Stasevich and Morisaki’s research using a hardy species of popular aquarium fish. Zebrafish are becoming increasingly popular for biomedical research, and they are translucent during development, meaning it would be easier to visualize what is happening inside the fish — in this case, translation. The key difference between this and past research is the presence of a spinal column.
“Maybe someday it’ll be humans,” Stasevich said. “It’s incredible to see. It takes about a decade to go from a single cell to something like a vertebrate.”
One of the main future applications of this work is cancer research, in particular researching genes that make different organisms more or less susceptible to cancer. Tumor suppressor genes are a primary focus. When these genes are mutated or “turned off,” cancerous cells can grow and spread more easily. The p53 gene is one of the most commonly occurring tumor-suppressing genes and is of specific interest to Stasevich and Morisaki.
“In elephants, they have double the copy of p53, which might explain why they don’t get cancer that often,” Stasevich said. He went on to explain the big question in their area of cancer research is about gene regulation.
Currently, they can image active genes and see an individual gene live at single-molecule resolution. This means they can see what turns the gene on and off. According to Stasevich, their long-term goal is to “understand how tumor suppressors get turned off.”
While the path to their goal is in sight, obstacles remain. One of the biggest is time.
“Right now, give me one gene and wait six months, maybe a year, and then I might start some experiments on it,” Stasevich said.
Their solution is to cut down the time cost of studying one gene. Ideally, they want to be able to screen entire genomes, testing “hundreds of thousands of different compounds and seeing what’s really turning things on or off,” Stasevich said. Once they accomplish this, other scientists would be better able to use the method in their own research.
Reach Maya Hanner at science@collegian.com or on social media @RMCollegian.
