This included the identification of a Drosophila transcriptional feedback loop, now known to be central to the clocks of plants, cyanobacteria, Neurospora , and mammals. All six known fly clock genes have orthologues known or suspected to be important for circadian timekeeping in mammals. Biochemical, anatomical and genetic approaches are utilized not only to identify and understand clock components but also to uncover components of the input and output pathways. These studies have identified a few key central nervous system cells that contain input and output molecules as well as the central pacemaker. This in vivo neurobiological focus will allow a more detailed understanding of the connections between the circadian pacemaker and biological processes within the living animal.
Reproductive behavior is robust.
A number of aspects of these behaviors are stereotypical and therefore easily quantified, but significant plasticity exists to allow the animals to adapt to novel situations. Drosophila provides a genetically tractable system in which to investigate the molecular basis of behavior. The Hall lab uses behavioral and genetic approaches to understand how the sexual identity of the nervous system and its output is specified. Courtship learning, the ability of a male fly to modify its behavior after exposure to a mate female, is being used by the Griffith lab to dissect the biochemical events underlying memory formation. Anatomical circuits responsible for courtship plasticity have been defined using cell-specific expression of these transgenes.