Chemical Senses Advance Access originally published online on September 12, 2008
Chemical Senses 2009 34(1):37-48; doi:10.1093/chemse/bjn053
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Comparing Peripheral Olfactory Coding with Host Preference in the Rhagoletis Species Complex
1 Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans Knöll Strasse 8, Jena, Germany 2 Department of Entomology, Barton Laboratory, New York Agricultural Experiment Station, Cornell University, Geneva, NY, USA 3 Department of Biological Sciences, Galvin Life Science Center, University of Notre Dame, PO Box 369, Notre Dame, IN, USA 4 Department of Entomology, University of Illinois, 320 Morrill Hall, 505 South Goodwin Avenue, Urbana, IL, USA
Correspondence to be sent to: Shannon Olsson, Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans Knöll Strasse 8, D-07745 Jena, Germany. e-mail: solsson{at}ice.mpg.de
| Abstract |
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Recent studies have shown that flies from sympatric populations of Rhagoletis pomonella infesting hawthorn, apple, and flowering dogwood fruit can distinguish among unique volatile blends identified from each host. Analysis of peripheral chemoreception in Rhagoletis flies suggests that changes in receptor specificity and/or receptor neuron sensitivity could impact olfactory preference among the host populations and their hybrids. In an attempt to validate these claims, we have combined flight tunnel analyses and single sensillum electrophysiology in F2 and backcross hybrids displaying a variety of behavioral phenotypes. Results show that differences in peripheral chemoreception among second-generation adults do not provide a direct correlation between peripheral coding and olfactory behavior. We conclude that either the plasticity of the central nervous system in Rhagoletis can compensate for significant alterations in peripheral coding or that peripheral changes present subtle effects on behavior not easily detectable with current techniques. The results of this study imply that the basis for olfactory behavior in Rhagoletis has a complicated genetic and neuronal basis, even for populations with a recent divergence in preference.
Key words: coding, flight tunnel, hybrid, single sensillum electrophysiology, speciation, ORN
Accepted 4 August 2008