Eyeing The Details 

Ann Morris is studying zebra fish for answers to retinal regeneration 

by Robin Roenker
photos by Mark Cornelison

Unlike humans, when zebra fish suffer damage to their retinas, they are able to regenerate them. Biologist Ann Morris, who joined UK’s faculty this year as an assistant professor, is working to understand how that happens.

For Morris, the approach only makes sense.

“If you want to improve health and treatments for disease,” she explains, “look at situations where the desired outcome occurs naturally. I’m interested from a basic science point of view in how these things happen. But I’m also aware of the implications for what I might learn for human health. I like to keep both of those things in my mind at the same time.”

Looking to nature to understand desired outcomes has been a theme of Morris’s work since her doctoral research at Emory University, where she studied a phenomenon called maternal fetal tolerance—why it is that a pregnant mother does not reject her fetus, which is only 50 percent genetically identical to her. Understanding that process may one day lead to better means of preventing graft rejection in organ transplant patients.

Her first postdoctoral position, from 2001-2002, was a stay at the Institute of Human Genetics in Montpellier, France, where Morris’s dual undergraduate degrees in French and biochemistry came in handy.

It was during her postdoctoral position at Florida State University from 2002-2009 that Morris turned her attention to the eye, and began working on zebra fish retinal regeneration.

“I love working on the eye,” Morris says. “The retina is just a beautiful tissue. The architecture of the retina, when you observe it under a high-power microscope, is really beautiful. Each cell has its place, and its own distinct shape and it occupies a distinct position. So it’s really aesthetically pleasing.”

Currently, Morris’s research uses lines of zebra fish that are genetically engineered to develop a specific retinal mutation. In one genetic line, the fishes’ rod photoreceptors die. These photoreceptors are responsible for mediating vision in dim light. In another, the fishes’ cone photoreceptors also die—these mediate daytime and color vision. In both cases, stem cells already present within the fishes’ retinas are activated to replace the rods or cones that have been lost.

By extracting RNA from the fishes’ retinal tissue and using microarray analysis and by surveying retinal tissue on a high-power, fluorescent microscope, Morris is working to identify new genes that haven’t yet been identified as playing a role in the regeneration process.

Down the line, her work may help inform therapies for inherited retinal degenerative diseases in humans, like retinitis pigmentosa, which leads to permanent blindness and for which there is currently no treatment or cure.

“There’s still so much to be learned,” Morris says. “Right now we’re focusing on gene discovery, and then once we have identified these genes, we’ll need to test them.  We’ll need to figure out what their function is. We’ll have to understand how they’re interacting with other genes that have been identified before. So there’s a lot of work still to be done.”

Morris foresees working on her zebra fish project for some time to come. And she’s excited to be doing her work in at UK.

The University of Kentucky is a great place to be,” she says. “I’m really excited to be part of the growing research community here.”