Olfaction, taste, and pheromone perception
Our lab studies the molecules, cells and circuits that underlie olfaction, taste, and pheromone recognition. We use Drosophila, whose chemosensory systems can be conveniently studied with molecular, genetic, electrophysiological, behavioral, and computational analysis. We also study mosquitoes that are vectors of global disease. One current project concerns the mechanisms underlying olfactory adaptation. We have recently found a surprising role for RNA in modulating olfactory sensitivity. In a related project, we found an unexpected response of Drosophila to certain wasps: the flies begin mating quickly. Surprisingly, the sight of wasps induces the dramatic regulation in the fly nervous system of a 41 amino-acid micropeptide, which is essential to the change in mating behavior. One of the most ancient and fundamental problems in biology is how an animal identifies a suitable mating partner. We identified a cluster of four receptor genes, IR52a,b,c, and d, which act in this process in Drosophila. Some of the neurons in which they are expressed are activated by exposure to members of the same species, but not by a closely related species. Optogenetic activation of some of these neurons drives males over the species barrier to show sexual behavior towards a distantly related species. We are now exploring mechanisms by which these receptors, and the neurons and circuits they define, act in mate detection. Another project concerns adaptation of the taste system. Drosophila can taste a great diversity of organic molecules. We are studying how the receptors, neurons and circuits of the taste system allow the animal to make feeding decisions, and how the system evolves to allow species to adapt to new environments. We are also interested in how mosquitoes and tsetse flies use their chemosensory systems to detect and locate human hosts. The work may lead to new means of controlling the transmission of global infectious diseases that afflict hundreds of millions of people each year.
John Carlson received an AB from Harvard and a PhD from Stanford. Following postdoctoral work at Stanford he joined the Yale faculty as an Assistant Professor. He enjoys teaching a large undergraduate class, and serves on the Committee on Human Rights of the National Academies. Besides science he enjoys shinrin-yoku and French novels.