LSU Professor Secures NSF Grant to Unravel Mysteries of Vision Evolution

Baton Rouge, LA – Dr. Patricia Schneider, an Assistant Professor in LSU’s Department of Biological Sciences, has been awarded a nearly million-dollar grant from the National Science Foundation (NSF) to investigate the complex mechanisms underlying the development and evolution of visual perception.

Her research focuses on the unique adaptations of the four-eyed fish, a species found along the coast of South and Central America. This fish possesses a remarkable innovation: a partially duplicated eye that allows it to see both above and below water.

Dr. Schneider aims to uncover the genetic and developmental processes that led to this evolutionary novelty, providing insights into how vision has evolved and how the brain processes visual information.

“There are many intriguing questions about adaptation and diversification that evolutionary developmental biology can help answer, but they aren't always easily accessible. The four-eyed fish is a prime example of nature's innovation that is readily available, making them an excellent model organism,” said Schneider.

Schneider joined LSU in 2021, bringing her team and ongoing projects from the University of Para in Brazil, where she continues to collaborate. She has since successfully established an LSU colony of four-eyed fish by leveraging their widespread availability in the pet trade.

The project will delve into the genetic programs controlling eye development in the four-eyed fish, investigating how these programs have been modified to create the unique duplicated eye structure.

“When an embryo is developing, there's a genetic blueprint that tells the body how to form all its organs, including the eyes. This process is fairly conserved in many animals, such as humans, birds, and other fish. However, in the four-eyed fish, something unusual happens that causes the cornea and pupils to duplicate. Our team’s expertise in developmental biology together with our experience in working with non-model species place us in the ideal position to investigate the cellular and molecular mechanisms underlying innovations to the visual system in the Anableps” Schneider explained.

The research has already revealed that the fish’s duplicated cornea is not a simple replication but a highly specialized structure with distinct genetic and functional properties. The portion of the cornea exposed to air shares genetic similarities with land-dwelling animals, showing a remarkable resemblance to the human cornea.

The team will also investigate how the four-eyed fish sees things differently from other fish. Equipped with a partially duplicated retina—the organ converting light into neural signals—this species has evolved specialized functions for each retinal half. Schneider's preliminary data shows that each half contains distinct photoreceptors, allowing them to process different wavelengths of light. This adaptation likely enhances the fish's overall visual perception, as the submerged retina is adapted to low-light, murky conditions while the exposed retina functions optimally in brighter environments. The team will now identify the genes and regulatory elements governing the development and function of these specialized retinal halves.

Finally, to understand how the brain processes visual information from the duplicated eyes, Schneider's team will map the neural pathways connecting both retinal halves to specific brain regions. One question they will address is whether the fish perceives two distinct images or a single unified one. This neural mapping will provide critical insights into the fish's unique visual system and may uncover novel neural circuits involved in complex visual processing.

To achieve this comprehensive understanding, Schneider will employ cutting-edge in-house spatial transcriptomics coupled with imaging. This technique analyzes gene expression at the cellular level without disrupting the tissue, allowing researchers to precisely map cell locations and gene activity within the organ. 

"In combination with existing data from other species, our results will enable the identification of a common genetic program that can help explain plasticity and evolution of gene expression and point to shared conserved elements that may play a role in development or disease," said Schneider. 

This research will also enable the integration of existing collaboration with research institutions in Brazil and will foster inclusive opportunities for US-based trainees from underrepresented backgrounds providing funding support and training.