NSF PRFB FY 2023: Unlocking the genetic basis of structural coloration

Karin, Benjamin R, Berkeley CA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. This research investigates the genetic basis of animal coloration, which is an ideal trait for studying evolution. Animal coloration is divided into pigments and structural colors. Pigments, often red and yellow, are small particles that directly absorb and reflect light of different colors. Structural colors, often blue, are caused by the interaction of light reflecting off different cellular layers inside the tissue. Pigment colors often have simple genetic control mechanisms, but the genetic basis of structural colors is only beginning to be understood. This research will leverage unique species of lizards and snakes that independently evolved variation in blue structural vs. red or yellow pigment color to unlock their genetic basis. The fellow will actively recruit, train, and mentor undergraduates from underrepresented groups in science, focusing on genetic lab techniques and other practical topics such as coding skills, reading primary literature, and career development. The fellow will work in elementary schools to teach evolutionary biology and develop a teaching module using colorful lizard models. The primary objectives of this research are to 1) understand the genomic basis of structural color and associated regulatory and cellular changes, and 2) test for conserved changes across increasing phylogenetic scales. This research will first focus on Plestiodon gilberti skink lizards in California which display red pigmentary and blue structural tail color variation and recently had a high-quality genome sequenced. The fellow will compare more than 100 genomes to pinpoint the genomic regions that underlie structural color, then investigate associated gene expression changes and corresponding cellular anatomy of color-producing cells. As individuals age they lose their color and converge on the same adult phenotype, which the fellow will leverage to assess if ontogenetic color change is controlled by the same regulatory pathways as polymorphism. Next, the fellow will investigate if conserved genomic regions underlie structural color polymorphism using whole genome sequencing on replicated color polymorphic systems at increasing phylogenetic scales across lizards and snakes. Finally, the fellow will compare genomes in public databases to test if candidate loci from genomic sequencing predict the presence or absence of bright structural colors. This research develops an understanding of the repeatability of evolution and provides a framework to predict the genetic basis of complex traits that can be applied to important problems in human medicine and animal conservation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.