MCCLINTOCK, Timothy S.*; DERBY, Charles D.; ACHE, Barry W.; University of Kentucky; Georgia State University; University of Florida: PHYSIOLOGICAL GENOMICS OF LOBSTER OLFACTION

Several fundamental observations about olfaction were made first using lobsters, largely due to advantages that stem from their anatomy and a wealth of background knowledge. Investigating the molecular basis for the function of the lobster organ has also proved fruitful. Reasoning that gene products specific to, or enriched in, the olfactory organ will help identify its unique properties, we have used expression profiling strategies such as differential amplification by PCR to identify molecular markers of the olfactory sensory neurons, their auxiliary cells, secretory cells of the associated aesthetasc tegumental glands, and reactive epithelial cells critical for the remarkable ability of the organ to regenerate itself. More importantly, the identity of these markers make predictions about novel physiological processes such as glutamatergic input to the olfactory sensory neurons and the production of neuroactive biogenic amine hormones by the auxiliary cells that surround the inner dendrites of the olfactory sensory neurons. More recently, bioinformatics of ESTs from more than 5,500 cDNAs confirms the preponderance of neurons in the mature zone of the olfactory organ. To allow testing of hypotheses about which mRNAs are most closely associated with the olfactory organ and its functions, we generated a cDNA microarray. As a first test of the array, we compared olfactory organ with dactyl, a taste organ, and identified 115 gene products that discriminate between these two chemosensory tissues. We are now in position to use mRNA abundance to investigate the olfactory organ as a molecular system by observing the responses of thousands of mRNAs to experimental manipulation.