Finding the future of eye care with frogs

Some of the most “ribbiting” research happening on campus stems from regeneration – the science of reforming, repairing, or regrowing lost tissue. This is the prerogative of researchers in the Tseng Lab, which recently observed that certain frog larvae can regrow their eyeballs.

“We’re building a blueprint for eye tissue regeneration,” said Kelly Tseng, professor in the School of Life Sciences. “Having knowledge about how other vertebrates regrow their eyes is going to help us improve human eye therapeutics.”

Cataracts. Optic nerve damage. Glaucoma and other degenerative eye diseases. Their days may be numbered, as Tseng says this research could alleviate these medical problems. The ongoing study intends to identify the mechanisms that stimulate the frog’s regenerative qualities, and discover the genes specifically required for regeneration to take place.

“We’re connecting what we learned from the frogs to what we know about human eye health, and making links between them,” said Tseng. “We have a new model that has not been studied or identified previously, so any new result is extremely exciting and can contribute to the field. This research is a bit of a blank canvas.”

Her amphibian of choice is the African clawed frog (Xenopus laevis), an established biomedical model for research with high regenerability. From larval stages to adulthood, it can regenerate limbs, retinas, and even optic nerves. 

“How do these animals know to repair a lost tissue or organ, and why can some animals do this at all?” she said. “Frogs are a very classic model for understanding developmental biology, and our hope is that they’ll see us through to the finish line with answers.”

Ponds and Pupils

Just as it takes more than one frog to make a pond, it requires more than a single researcher to make a lab. Tseng attributes much of the ongoing study’s success to her pupils who have been at the forefront of each new advancement and discovery.

“They are the most exciting part of walking into the lab every day,” said Tseng. “The ideas and dedication they have to the science – they’re integral.”

Belen Gutierrez is a graduate researcher currently using machine learning in the lab, which helps her turn frog samples into 3D objects on a computer. This provides a closer look at how regeneration affects nearby body structures at no consequence to the frog.

“Modern equipment lets me observe the impacts each trial has on the optic nerve and brain from the computer modeling,” said Gutierrez, who has worked in the lab for six years. “My interest in regeneration started back in high school, and to now be making my own mark in this research feels unreal.”

Her colleague Madison Frederick has her own unique focus: lineage tracing, or observing where individual cells go during the development of a new eye. Together, they’re looking for similarities between tail regrowth in tadpoles and eye regeneration in the larva, seeking shared mechanisms between the regeneration of two different types of tissues.

“Almost everyone I know has a problem with their eyes, and inevitably as we get older, we’re going to have issues,” said Frederick, currently in her second year of graduate school. “I think it is a field of research that can touch so many lives and be really impactful.”

Understanding regeneration, what contributes to it, and building a pathway to replicate it for human benefit is the immediate goal. And that ambition has made her time as a graduate researcher unforgettable. 

“I think it’s kind of fulfilling a dream to be in graduate school, getting to do research as part of my education – and then what we’re studying is novel,” she said. “We’re the first people to make this observation in the lab, so getting to answer questions that no one’s asked before is such a unique opportunity I’m really grateful for.”