Projects

Current Projects in the Vickers Lab Include

Neuroethology of olfactory divergence in moth species

Communication between individuals relies upon a ‘match’ between the signal emitted by the sender and the sensory capabilities of the receiver. One conundrum in the evolution of new signals is that changes in the signal may not be met by commensurate changes in the receiver. Under these conditions, communication is expected to be under strong stabilizing selection with new signals being selected against. However, in moth species, many of which use olfactory communication, it is clear that divergence of signals has occurred on a massive scale. The aim of this project has been to understand the genetic underpinnings of male behavioral responses and olfactory physiology in two closely related species of Heliothine moth, Heliothis virescens and Heliothis subflexa. These species utilize distinct pheromone blends but can be hybridized under laboratory conditions. This provides the opportunity to scrutinize the behavioral responses of hybrid and backcross males and characterize the odor blends to which they are attracted. Subsequently, we can examine the antennal and central olfactory pathways to determine their relationship with the behavior. In collaboration with Dr. Fred Gould‘s lab at North Carolina State University we have made advances in our understanding of the genetic control of some of the olfactory features that underlie male behavior.

Antennal Imaginal Disc Transplants between two moth species

The adult moth antenna and central brain structure responsible for processing odor information are derived, during metamorphosis, from a patch of tissue known as the antennal imaginal disc. Imaginal discs also give rise to other adult insect structures such as legs, wings, eyes and genitalia.For several years, we have been engaged in a collaborative effort with Dr. Charlie Linn‘s group at Cornell University wherein the imaginal discs of two different moth species are transplanted and the effects on behavioral and olfactory neurobiology are examined. These transplants provide us with a mechanism to alter the eventual inputs to the adult brain. For example, an antennal imaginal disc taken from an H. virescens male is going to develop a certain repertoire of olfactory receptors – evenif the disc is transplanted into a recipient that normally receives a completely different input.These experiments provide us with the ability to examine change the olfactory inputs to the brain and study their effects upon behavior and odor processing.