A biologist at The University of Texas at Arlington has received a national funding for a project which uses frogs as a model to investigate how differences in habitat such as living above or below ground affect the functions and development of the eye.
Results from the research will be exhibited in the Smithsonian National Museum of Natural History and the Natural History Museum in London - the two most-visited natural history museums in the world, with over 13 million combined annual visitors. The project will also generate a free interactive E-book for a general audience on the integrative nature of biodiversity research with a specific focus on vision biology.
"As the interface between the environment and the organism, the eye plays an important role in modulating an individual's responses to visual cues," said Matthew Fujita, UTA assistant professor of biology and principal investigator on the $714,992 National Science Foundation Division of Environmental Biology grant.
"Because environments can vary immensely across the world, including terrestrial, aquatic, above ground, and below ground habitats, eyes have evolved a multitude of ways to adapt to these distinct conditions," he added.
Rayna Bell, a research zoologist in the Department of Vertebrate Zoology at the Smithsonian Institution in Washington, D.C., and Jeffrey Streicher, a curator of amphibians in the Department of Life Sciences at the Natural History Museum in London, are co-principal investigators of the study. Streicher received his doctorate from UTA in 2012 and was a postdoctoral researcher in Fujita's lab in 2012-13.
Fujita and his colleagues hope the study's results will provide "deep insight into the constraints and opportunities of vision systems to evolving novel solutions to new life history modes and behaviors, a topic of primary importance in understanding drivers of diversification throughout the tree of life."
"This project aims to understand the evolution of the frog eye using genomic, morphological, physiological, and spectrophotometric or light absorbance data," Fujita said. "The diversity of life history strategies of frogs - which include nocturnal, diurnal, arboreal (living in trees), and fossorial (living underground) lifestyles - provides an excellent opportunity to investigate how differences in habitat and behavior affect the functions of the eye."
One example, Fujita says, is frogs that live underground tend to have small eyes because of their reduced environmental complexity compared to visual signals experienced by frogs living above ground. While these frogs exhibit the morphological reduction in eyes, do they also have a reduction in the genetic machinery that allow eyes to function? Fujita hopes that this is one of many questions the project will answer.
"Frogs are thus an excellent system to understand how the eye evolves in the face of vast differences in life history that reflect adaptations to distinct habitats," Fujita said. "Our integrative approach will provide detailed and comprehensive insight into vision evolution across life history transitions in frogs and addresses a central gap in our overall understanding of vertebrate vision evolution."
In order to understand vision systems at a broad scale first, the researchers will collect data across 27 families to generate a comprehensive appreciation of vision diversity and evolution in frogs. Molecular evolutionary studies will provide a genomic perspective on vision evolution with the expectation that visually-oriented frogs exhibit greater levels of natural selection, gene duplication, and retention of vision genes.
Characterizing the physiology and molecular underpinnings of vision in species with aquatic tadpoles and terrestrial adults will reveal how the visual system adapts to distinct visual environments during metamorphosis. These broad studies will provide a framework for more focused investigations that target transitions in sexual dichromatism - the difference in coloration of sexes within a given species - and fossoriality.
The NSF grant will also support several graduate research assistants in Fujita's lab, including T.J. Firneno, who will help establish a data management plan to consolidate all of the different data types that the project will utilize. Fujita and his students have already started collecting frog and toad specimens from Texas. They plan to continue collecting specimens in the United States and in Gabon this fall, and in Brazil, Australia and Ecuador over the next year.
The project will provide graduate, undergraduate and high school students with research experience that includes fieldwork, morphological measurements of specimens, molecular lab procedures including sequencing at UTA's Genomics Core Facility, and computational analysis, Fujita said.
Clay Clark, professor and chair of the UTA Department of Biology, said the project has the potential to fill in significant gaps in scientists' knowledge about the effects of evolutionary processes on vision, and also furthers the University's goal to do important research in data-driven discovery, one of the main pillars of its Strategic Plan 2020: Bold Solutions | Global Impact.
"With this project, Dr. Fujita and his collaborators could answer some key questions about how changes in vision are influenced by the habitat in which an animal lives," Clark said. "The fact that he is leading this project which includes scientists from two of the pre-eminent research museums in the world speaks volumes about Dr. Fujita's skills as a researcher and about the caliber of work being done in the College of Science."
Fujita came to UTA in 2012. He received a Ph.D. in Integrative Biology from the University of California at Berkeley in 2009. His research focuses on genomics, systematics, and herpetology. The goal of his lab group is to understand patterns and processes that generate the tremendous biodiversity found in reptiles and amphibians at multiple phylogenetic, geographic, and genomic scales.