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Neuroethology of olfaction in Drosophila

evolution and specialization

Ibba, Irene (2010). Neuroethology of olfaction in Drosophila. Diss. (sammanfattning/summary) Alnarp : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2010:17
ISBN 978-91-576-7494-4
[Doctoral thesis]

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In insects olfaction is a primary sensory modality. As a result changes in the animal’s ecology are often paralleled by modifications in the olfactory system. Using a comparative approach between the generalist Drosophila melanogaster and its sibling specialist D. sechellia, I looked at the coding properties of the olfactory system. Using electrophysiology, neuroanatomy, and behavioral assays we demonstrate how the olfactory system of adults of specialist fruitfly Drosophila sechellia has evolved to accommodate its unique preference for Morinda citrifolia fruit. We show that the fly has expanded the number of one antennal sensillum type inhabited by two neurons sensitive to Morinda volatiles. The numerical increased has caused the formation of a macro glomerular complex tuned to fruit volatiles. Accordingly, the olfactory preference of the species for these odors and combinations thereof has radically changed. We subsequently show that also larvae of this species changed their olfactory preference. With such a simple olfactory circuitry, consisting of only 21 olfactory neurons, the identification of the factor underlying the switch is especially promising. Finally, we looked what olfactory information is conveyed to the brain of the fruitfly via an evolutionarily old olfactory subsystem, that of coeloconic sensory neurons. These neurons express ionotropic receptors (Irs) instead of conventional olfactory receptors (Ors), and natural ligand for this set of receptors have been poorly investigated. We identified three new ligands biologically active for coeloconic neurons, and investigate the significance of these compounds in odor coding and in fly attraction.

Authors/Creators:Ibba, Irene
Title:Neuroethology of olfaction in Drosophila
Subtitle:evolution and specialization
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2010
Number of Pages:45
ALLI Dekker, T., Ibba, I., Siju, K.P., Stensmyr, M., and Hansson, B. S. 2006. Olfactory shifts parallel superspecialism for toxic fruit in Drosophila melanogaster sibling, D. sechellia. Current Biology 16, 101-109. II Ibba, I., Angioy A.M., Hansson, B. S., Dekker, T. A macroglomerular complex for fruit odors radically changes blend preference in Drosophila. Submitted. III Ibba I., Hansson B.S., Birgersson G., Dekker T. Angioy A.M. Identification of natural ligands for OSNs in the coeloconic sensilla of Drosophila melanogaster. Manuscript. IV Ibba I., Hansson B. S., Hill S. R., Angioy A. M., Dekker T. Olfactory specialisation of Drosophila sechellia larvae. Manuscript.
Place of Publication:Alnarp
ISBN for printed version:978-91-576-7494-4
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:H Protection of plants and stored products > H10 Pests of plants
Subjects:Not in use, please see Agris categories
Agrovoc terms:drosophila, morinda citrisfolia, neurophysiology, animal behaviour, larvae, parents, evolution
Keywords:olfactory system, Drosophila, specialization, Morinda citrifolia, behavior, adult, larva
Permanent URL:
ID Code:2229
Department:(LTJ, LTV) > Department of Plant Protection Biology
Deposited By: Irene Ibba
Deposited On:11 Feb 2010 00:00
Metadata Last Modified:02 Dec 2014 10:17

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