Transcriptional basis of the acclimation to high environmental temperature at the olfactory receptor organs of Drosophila melanogaster

Abstract

BackgroundEnvironmental temperature directly affects the concentrations of chemicals in the gas phase. Therefore, if the olfactory system does not physiologically adapt to environmental conditions, it may provide inadequate information about the distance to or direction of odor sources. Previous reports have shown at the behavioral level that temperature induces changes in olfactory sensitivity in Drosophila melanogaster. These changes are initiated in the main olfactory receptor organs, the antennae. In this work, we attempted to identify the particular genes responsible for olfactory adaptation to increasing temperatures in these organs based on current knowledge of the molecular basis of olfactory reception.ResultsWhole-genome transcriptional responses to transitory temperature shifts from 21-30°C were analyzed in the third antennal segments of Drosophila. More than 53% of the genome was expressed in these organs; this percentage increased slightly (55%) after heat treatment. However, the expression levels increased for 26%, decreased for 21% and remained constant for 53% of the expressed genes. Analysis of the changes produced in 389 genes related to heat response and olfactory reception, according to the current functional annotations of the Drosophila gene set, showed significant differences in 95 of these genes, which are involved in the heat response (23), perireceptor events in olfaction (50), olfactory and gustatory receptors (18) and G-proteins and transduction cascades (4).ConclusionsGene expression was altered in response to environmental heat in the antennae of Drosophila by increasing or decreasing expression. Different acclimation patterns emerged for reception through the basiconic, trichoid and coeloconic sensilla. Changes in genes with a central role in olfactory reception, such as orco, may account for part of the acclimation reported at the behavioral level.

Identification and preliminary characterization of chemosensory perception-associated proteins in the melon fly Bactrocera cucurbitae using RNA-seq

“… 42 . For the melon fly, the number of IR sequences we identified is higher than those previously reported for other species 43 44 . This larger number may reflect the ecological specificities of the melon fly species, which feeds only on decaying or damaged fruits 45 .…”

Chemosensory genes in the antennal transcriptome of two syrphid species, Episyrphus balteatus and Eupeodes corollae (Diptera: Syrphidae)

“…We identified 154 candidate chemosensory genes (51 ORs, 32 IRs, 14 GRs, 49 OBPs, 6 CSPs and 2 SNMPs) in E. balteatus and 134 (42 ORs, 23 IRs, 16 GRs, 44 OBPs, 7 CSPs and 2 SNMPs) were identified in E. corollae , numbers slightly different compared with those of other Dipteran species [ 50 , 73 , 75 , 76 ]. Such differences could be due to sequencing methods, coverage and/or depth.…”

Gene set of chemosensory receptors in the polyembryonic endoparasitoid Macrocentrus cingulum

“…Open reading frames were predicted using ESTScan 3.0 project. Gene expression levels were estimated by RSEM software 83 , and differential expression analysis of two groups was performed using the DESeq R package (1.10.1) 84 . P-value was adjusted using q-value 85 and q-value < 0.005 and log 2 (fold_change) >1 was set as the threshold for significantly differential expression.…”