Elements of Olfactory Reception in Adult Drosophila melanogaster

Abstract

The olfactory system of Drosophila has become an attractive and simple model to investigate olfaction because it follows the same organizational principles of vertebrates, and the results can be directly applied to other insects with economic and sanitary relevance. Here, we review the structural elements of the Drosophila olfactory reception organs at the level of the cells and molecules involved. This article is intended to reflect the structural basis underlying the functional variability of the detection of an olfactory universe composed of thousands of odors. At the genetic level, we further detail the genes and transcription factors (TF) that determine the structural variability. The fly's olfactory receptor organs are the third antennal segments and the maxillary palps, which are covered with sensory hairs called sensilla. These sensilla house the odorant receptor neurons (ORNs) that express one or few odorant receptors in a stereotyped pattern regulated by combinations of TF. Also, perireceptor events, such as odor molecules transport to their receptors, are carried out by odorant binding proteins. In addition, the rapid odorant inactivation to preclude saturation of the system occurs by biotransformation and detoxification enzymes. These additional events take place in the lymph that surrounds the ORNs. We include some data on ionotropic and metabotropic olfactory transduction, although this issue is still under debate in Drosophila.

Drosophila Chemoreceptors: A Molecular Interface Between the Chemical World and the Brain

“…Most olfactory sensilla fall into three morphological classes [2, 5, 6]. Basiconic sensilla are located on the antenna and maxillary palp, and detect many food odors, including esters, alcohols, and aldehydes.…”

Function Clustering Self-Organization Maps (FCSOMs) for mining differentially expressed genes in Drosophila and its correlation with the growth medium

“…The former 25 groups did not contain the olfactory and gustatory function clusters. This implied that the use of both the tomato and ethanol media for larval affects the gustatory development of D. melanogaster (Inoshita and Tanimura, 2006;Bai et al, 2009;Miller and Carlson, 2010;Adachi et al, 2012;Martin et al, 2013), and the differences between these did not appear to be significant.…”

Olfactory Signaling in Insects

“…37,38 Various models of OR function have been extensively discussed. [39][40][41][42][43] The odorant specificity is determined by the OrX partner. 9,44 An exchange of only a few amino acids can lead to a shift in agonist specificity as observed for Or22a in Drosophila melanogaster versus Drosophila sechellia.…”