The Molecular Evolution of Insect Opsin Genes

Opsins are part of the superfamily of G-coupled receptor proteins and together with chromophores, are responsible for initiating the signal transduction cascade responsible for animal vision. Since opsins have a critical role on visual perception these genes are crucial for a myriad of adaptive traits and behaviors and should show diverse signs of natural selection at the molecular level. Understanding the evolution of opsins across the wide diversity of insect groups will allow us to better understand the evolutionary pressure on insect opsins and serve as a model for both other gene systems and other taxonomic groups of animals that are more difficult to study.

Our goal is to expand our sampling of insect opsins and then use these new data to explore and better understand patterns of evolution and diversity of these crucial genes. I will use the data generated during my thesis project for three specific aims: (1) create a more densely sampled gene phylogeny of opsins across the class Insecta; (2) analyze evolution of the insect opsins looking for signs of selection on protein regions and on the entire gene in different orders of insects; (3) perform a spatial localization of opsin expression in the compound eye of a species of praying mantis native to the Rio Grande Valley, Stagmomantis carolina.

Our study is significantly innovative since an inspection of insect opsins has not previously taken place at the class and ordinal levels and will expand the current knowledge of opsins in the insects and beyond.