In 2015, Jens Rister was watching a Jets-Bills game on TV. As the green-clad Jets lined up against the red-uniformed Bills, he had a sinking feeling. Rister wasn’t thinking about the score – he was wondering about the 13 million Americans who are red/green colorblind. For those viewers, the brightly colored uniforms looked identical, and even matched the bright green of the turf. For them, the game was totally incomprehensible.
Rister, an assistant professor of biology at UMass Boston, researches how color vision develops, using the fly eye as a model. While fly eyes are very different from our own, there are some striking similarities to human eyes. Flies and humans both have a random arrangement of color-sensing photoreceptors that are used to see color.
Humans have three different types of color photoreceptors: blue, green, and red cones. In order to properly see color, all three kinds of cones have to be present. During development, each photoreceptor is dedicated to a specific color and maintains this dedication until the end of our lives. If a photoreceptor fails to develop into one of the three kinds of receptors, or tries to be a blue and green receptor at the same time, color vision won’t work.
“We still have a lot to learn about how the different types of photoreceptors develop so that there is no confusion, and blue and green don’t end up in the same cell,” Rister said. “Our brain has to rely on the photoreceptors to be correct in order to see color. These sensors have to be stable for a long time, and they have to be unambiguous to the brain.”
Rister’s research focuses on how genetic pathways regulate the development of these photoreceptors. Rister, along with collaborators from New York University and the Cincinnati Children’s Hospital Medical Center, focused on the Hippo pathway, which is known to regulate growth and prevent tumors. This pathway, Rister discovered, is repurposed to regulate the development of photoreceptors in the fly eye.
“Nature likes to reuse the same pathways for different functions,” Rister said. “When the pathway is mutated, the fly will end up with all blue, but no green photoreceptors.”
The Hippo pathway is also involved in human cancers. Now, Rister’s team can study this genetic pathway to identify genes that are required for both eye development and tumor suppression.
Rister’s research is supported by three-year R00 Pathway to Independence Award from the National Eye Institute of the National Institutes of Health. His lab supports both undergraduate and graduate researchers, who get hands-on experience with complex procedures.
“We can satisfy the diverse academic interests of our students – whether they want to study neurobiology or signaling pathways relevant for human disease,” Rister said.