Our research interests are in the areas of molecular endocrinology, neurobiology and behavior with a primary focus on the mechanisms and evolution of animal behavior and sexuality. I am particularly interested in applying neurobiological and genomic approaches to problems in behavioral biology and behavioral evolution. My primary models have been fishes with some work on lizards and mammals.
My students and I are currently pursuing several projects. The first examines the neuroendocrinology and functional genomics of sex- and role-change in a coral reef fish (the bluehead wrasse, Thalassoma bifasciatum). Bluehead wrasses exhibit socially controlled functional sex change and discrete alternate male phenotypes. We have been studying the neuroendocrinology of sex and role change in bluehead wrasses for some time and our work has demonstrated a critical and controlling role for the neuropeptide arginine vasotocin, key roles for estrogen synthesis mediated by the enzyme aromatase, and that the behavioral components of sex change can occur when females become behaviorally dominant even if they lack gonads (i.e., have been experimentally gonadectomized). More recently, we have begun collaborating with Dr. Neil Gemmell of the the University of Otago to use RNAseq methods and characterize gene expression changes in the brain and gonads as wrasses change sex. Our behavioral and sex change work is primarily carried out on the reef at field sites in Florida and Belize. This field-based approach and the amenability of the bluehead wrasse system to it allows our experimental social manipulations and their consequences to be studied in full complexity of nature.
A second project examines the neural and functional genomic bases of anxiety-related behavior and stress responsiveness using domestic and wild-derived zebrafish (Danio rerio). Zebrafish are valuable models for a variety of reasons including having a sequenced genome and the availability of a variety of approaches for manipulative tests of the role of differentially expressed genes in anxiety-related behaviors.
The laboratory is also participating in a NSF-funded IGERT program at NCSU focused on the possibility of genetic approaches to controlling invasive rodents on islands (please see program webpage here). This is of interest from a conservation standpoint islands are biodiversity hotspots where invasive rodents do tremendous ecological damage and have endangered and caused the extinction of many species (see an in-depth consideration of this issue and options by IGERT students here). We are also interested because release from predation in some island settings may have produced unintentional, but very informative ”experiments” with which we can learn about the neural and genetic bases of fear and anxiety-related behaviors using well studied rat and mouse species that have been evolving in natural settings either with or without strong predation pressure.
Finally, my laboratory participates in work related to developing southern flounder, Paralichthys lethostigma, as an aquaculture cultivar with a focus on sex determination and developing stocks consisting of only the faster growing females.