Meeting Abstract
Identifying the genetic basis of phenotypic variation within and across species is a key objective of genetic research. With the advent of inexpensive genomic sequencing and the development of bioinformatics tools, it is possible to identify candidate genes related to phenotypic variation across a wide array of organisms. However, much of this work has been limited to model systems with a plethora of tools for genetic manipulation and functional characterization. Fireflies are an excellent system for studying phenotypic variation because of their wide behavioral diversity. Many fireflies have a single species-specific flash pattern that is used for mate identification and choice, do not eat as adults, and the variety of light signal patterns is hypothesized as a primary driver of reproductive isolation and speciation. However, fireflies in the Photuris genus are aggressive mimics – females of these species mimic the flash patterns of prey species to lure males in to eat them and thus, have multiple flash patterns. Most Photuris species are known for this predatory behavior and the genetic basis for this variation has yet to be studied. To explore this, we compared selective constraint on genes between a predatory firefly, Photuris quadrifulgens, with those from a non-predatory firefly, Photuris frontalis, using publicly-available transcriptomes derived from head tissue. We identified nine gene families evolving under positive selection, including genes involved in digestion, vision, and detoxification. These results highlight the utility of comparative methods to identify candidate genes in non-model organisms, which is crucial in understanding phenotypic variation in many organisms, not only in model systems.
