C05: Evolutionary and Structural Adaptations in the Eye Lens of the Freeze-Tolerant North American Wood Frog (Rana sylvatica)

My general research area is evolutionary biology and bioinformatics. My project is working with the North American wood frog (Rana sylvatica) to study stability and adaptability in lens crystallin proteins. Instability and aggregation of lens crystallins can cause cataracts, which are the leading cause of blindness worldwide. The wood frog is a cold-adapted vertebrate that freezes solid during the winter, demonstrating extremely stable crystallins. Thus we can use the wood frog to learn what in the amino acid sequence of crystallins imparts stability. As crystallins are fairly conserved across vertebrates, what we learn about lens stability in the wood frog can be applied to humans and potentially drive innovative treatments for cataracts. For this project, lenses were sampled from the wood frog (following Miami University and IACUC protocols) and the expressed RNAs were isolated. The cDNAs that were obtained from the RNAs were sequenced and assembled de novo with Trinity from OmicsBox. We then made sequence alignments and Maximum Likelihood phylogenetic trees with the cDNAs from the wood frog and other related species, using the IQtree package. The phylogenetic trees show relationships between the sequences and how closely they are related. For example yN crystallins are unique among y crystallins and are more closely related to each other than to other y crystallins. The next step will be to use IMPACT_S, a bioinformatic tool, to identify amino acid residues under positive evolutionary selection, evaluate their biochemical properties, and determine how those properties affect protein stability. Working on this project has given me hands-on experience with bioinformatic research and helped inform me of what I would like to pursue as a career. Along with working on the project, I have also had the opportunity to present my research and learned valuable communication and presentation skills.

Author(s): Jayden Tharp, Biochemistry and Premedical Studies Major
Advisor(s): Andor Kiss, Department of Biology