NSF Postdoctoral Fellowship in Biology FY 2021: Inference of the repeated evolution of prothoracic defensive glands in the Tenebrionidae (Coleoptera)

Rork, Adam M, State College PA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2021, 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. Insects use chemical secretions for many reasons, including to find food, mates, and defend against predators. Chemical secretions from glands are especially important for self-defense. However, our understanding of how glands evolve to produce specific chemicals from specific body regions is limited. Studying gland function and evolution is essential to understanding the evolution of insect chemical defenses, insect communication, and insects as a whole. The Fellow will use darkling beetles and their thoracic defensive glands as a model system for testing hypotheses about mechanisms of insect gland evolution. The outcomes of this research will also aid the development of educational materials for public outreach and K-12 students from diverse backgrounds. This research primarily aims to address whether prothoracic defensive glands (PDGs) of darkling beetles (Coleoptera: Tenebrionidae), have evolved via parallel or convergent evolution. Specifically, this research aims to examine 1) the genes and gene regulatory networks involved in PDG development across Tenebrionidae, 2) the anatomically homologous features of Tenebrionidae PDGs, and 3) life history traits correlated with PDG evolution. Comparative transcriptomics will be used to compare the gene expression profiles of developing PDGs and glandless body tissue in five representative taxa to identify candidate genes and gene regulatory networks involved in gland development. Morphological investigations examining gland origin points, musculature, locality, gross structure, and ultrastructure will be carried out to examine whether they are derived from homologous or non-homologous tissues. Examining correlations between PDG evolution and life history traits will be carried out using gland occurrence and life history data mined from literature and placed in the context of the latest phylogenetic hypotheses for Tenebrionidae. The Fellow hypothesizes that the PDGs of Tenebrionidae have evolved through parallel evolution (i.e., develop through the co-option of homologous gene regulatory networks and prothoracic tissues), but are not correlated with known life history traits. In addition to collaboration with professional educators, this project will also provide excellent research, training, and scientific communication opportunities for the Fellow as well as for graduate and undergraduate students interested in insect morphology, bioinformatics, and phylogenetics. 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.