The School of Molecular and Cellular Biology at the University of Illinois at Urbana-Champaign

Have you ever wondered how we know a rose from its scent, or smell the difference between cinnamon and thyme? Our ability to recognize and discriminate diverse odors depends not only on having olfactory neurons that are "tuned" to specific odorants, but also on their precise connections with the correct synaptic targets (glomeruli) in the brain (Figure A). This precise wiring pattern arises during development because olfactory axons are genetically programmed to project to specific glomeruli. The long-term goal of our lab is to understand the molecular and genetic basis by which olfactory axons pathfind to their targets using Drosophila as a model system. The following provides a brief description our research program. For more detailed information about our lab and research activities please visit our website (www.life.uiuc.edu/hing).

The Drosophila antennal system offers a unique opportunity for dissecting the development of smell (Figure B). First, its anatomy and development bear a close resemblance to those of ours. The fly's olfactory bulb contain only ~40 types of antennal axons matched with an equal number of uniquely identifiable glomeruli (Figure C and D). Second, powerful genetic and molecular tools in Drosophila permit manipulation of single genes and single cells in vivo.

We have recently discovered a number of signaling genes that function to steer antennal axons to their glomeruli: Nrg (encoding a transmembrane receptor) and Pak (encoding a kinase). We hypothesize that their gene products form a biochemical pathway that transmits signals from the extracellular environment to the actin cytoskeleton allowing olfactory axon to navigate precisely. Our current research is focused on finding answers to the following questions. What are the extracellular signals that steer antennal axons? What are the receptors that bind to these signals? How do the receptors signal to the cytoskeleton thus regulating motility? We are applying a number of tools to tackle these questions:

1. Genetic screens to identify novel genes.
2. Molecular biology and transgenic technologies to alter genes in vivo.
3. Live imaging, single-cell visualization techniques, and immunocytochemistry to study mutant antennal axons in vivo.

Collaborative Projects:

My lab has exciting collaboration with the labs of Professors Akira Chiba on a variety of technological issues, and of Professor Hugh Robertson on the expression and function of olfactory receptors in mosquitos and moths.