title: Expression analysis of the 3 G-protein subunits, Galpha, Gbeta, and Ggamma, in the olfactory receptor organs of adult Drosophila melanogaster.
abstract: In many species, olfactory transduction is triggered by odorant molecules that interact with olfactory receptors coupled to heterotrimeric G-proteins. The role of G-protein-linked transduction in the olfaction of Drosophila is currently under study. Here, we supply a thorough description of the expression in the olfactory receptor organs (antennae and maxillary palps) of all known Drosophila melanogaster genes that encode for G-proteins. Using RT-polymerase chain reaction, we analyzed 6 Galpha (G(s), G(i), G(q), G(o), G(f), and concertina), 3 Gbeta (G(beta5), G(beta13F), and G(beta76C)), and 2 Ggamma genes (G(gamma1) and G(gamma30A)). We found that all Galpha protein-encoding genes showed expression in both olfactory organs, but G(f) mRNA was not detected in palps. Moreover, all the Gbeta and Ggamma genes are expressed in antennae and palps, except for G(beta76C). To gain insight into the hypothesis of different G-protein subunits mediating differential signaling in olfactory receptor neurons (ORNs), we performed immunohistochemical studies to observe the expression of several Galpha and Gbeta proteins. We found that Gs, Gi, Gq, and G(beta13F) subunits displayed generalized expression in the antennal tissue, including ORNs support cells and glial cells. Finally, complete coexpression was found between Gi and Gq, which are mediators of the cyclic adenosine monophosphate and IP3 transduction cascades, respectively.
authors.affiliation: Department of Functional Biology, Faculty of Medicine, University of Oviedo, Julian Claveria s/n, 33006 Oviedo, Spain.
authors.forename: Tamara
authors.initials: T
authors.lastname: Boto
authors.forename: Carolina
authors.initials: C
authors.lastname: Gomez-Diaz
authors.forename: Esther
authors.initials: E
authors.lastname: Alcorta
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D044385:GTP-Binding Protein alpha Subunits / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D044387:GTP-Binding Protein beta Subunits / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D044388:GTP-Binding Protein gamma Subunits / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D007150:Immunohistochemistry; D018034:Olfactory Receptor Neurons / Q000378:metabolism
chemical_list: D044385:GTP-Binding Protein alpha Subunits; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits