The Zonal Organization of Odorant Receptor Gene Choice in the Main Olfactory Epithelium of the Mouse

Abstract Independent origins of sociality in bees and ants are associated with independent expansions of particular odorant receptor (OR) gene subfamilies. In ants, one clade within the OR gene family, the 9-exon subfamily, has dramatically expanded. These receptors detect cuticular hydrocarbons (CHCs), key social signaling molecules in insects. It is unclear to what extent 9-exon OR subfamily expansion is associated with the independent evolution of sociality across Hymenoptera, warranting studies of taxa with independently derived social behavior. Here we describe odorant receptor gene family evolution in the northern paper wasp, Polistes fuscatus, and compare it to four additional paper wasp species spanning ∼40 million years of evolutionary divergence. We find 200 putatively functional OR genes in P. fuscatus, matching predictions from neuroanatomy, and more than half of these are in the 9-exon subfamily. Most OR gene expansions are tandemly arrayed at orthologous loci in Polistes genomes, and microsynteny analysis shows species-specific gain and loss of 9-exon ORs within tandem arrays. There is evidence of episodic positive diversifying selection shaping ORs in expanded subfamilies. Values of omega (d N/dS) are higher among 9-exon ORs compared to other OR subfamilies. Within the Polistes OR gene tree, branches in the 9-exon OR clade experience relaxed negative (purifying) selection relative to other branches in the tree. Patterns of OR evolution within Polistes are consistent with 9-exon OR function in CHC perception by combinatorial coding, with both natural selection and neutral drift contributing to interspecies differences in gene copy number and sequence.

Download Full-text

Extinction reverses olfactory fear-conditioned increases in neuron number and glomerular size

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1505068112 ◽

2015 ◽

Vol 112 (41) ◽

pp. 12846-12851 ◽

Cited By ~ 24

Author(s):

Filomene G. Morrison ◽

Brian G. Dias ◽

Kerry J. Ressler

Keyword(s):

Olfactory Bulb ◽

Learning And Memory ◽

Olfactory Epithelium ◽

Olfactory System ◽

Structural Changes ◽

Freezing Behavior ◽

Extinction Training ◽

Odor Stimulus ◽

Main Olfactory Epithelium ◽

Odor Learning

Although much work has investigated the contribution of brain regions such as the amygdala, hippocampus, and prefrontal cortex to the processing of fear learning and memory, fewer studies have examined the role of sensory systems, in particular the olfactory system, in the detection and perception of cues involved in learning and memory. The primary sensory receptive field maps of the olfactory system are exquisitely organized and respond dynamically to cues in the environment, remaining plastic from development through adulthood. We have previously demonstrated that olfactory fear conditioning leads to increased odorant-specific receptor representation in the main olfactory epithelium and in glomeruli within the olfactory bulb. We now demonstrate that olfactory extinction training specific to the conditioned odor stimulus reverses the conditioning-associated freezing behavior and odor learning-induced structural changes in the olfactory epithelium and olfactory bulb in an odorant ligand-specific manner. These data suggest that learning-induced freezing behavior, structural alterations, and enhanced neural sensory representation can be reversed in adult mice following extinction training.

Download Full-text

Detection of pup odors by non-canonical adult vomeronasal neurons expressing an odorant receptor gene is influenced by sex and parenting status

BMC Biology ◽

10.1186/s12915-016-0234-9 ◽

2016 ◽

Vol 14 (1) ◽

Cited By ~ 11

Author(s):

Thiago S. Nakahara ◽

Leonardo M. Cardozo ◽

Ximena Ibarra-Soria ◽

Andrew D. Bard ◽

Vinicius M. A. Carvalho ◽

...

Keyword(s):

Odorant Receptor ◽

Receptor Gene

Download Full-text

Repellency Mechanism of Natural Guar Gum-Based Film Incorporated with Citral against Brown Planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae)

International Journal of Molecular Sciences ◽

10.3390/ijms23020758 ◽

2022 ◽

Vol 23 (2) ◽

pp. 758

Author(s):

Xiubing Gao ◽

Xianfeng Hu ◽

Feixu Mo ◽

Yi Ding ◽

Ming Li ◽

...

Keyword(s):

Differential Expression ◽

Guar Gum ◽

Defense Mechanism ◽

Insect Pests ◽

Odorant Receptor ◽

Receptor Gene ◽

Insect Pest ◽

Brown Planthopper ◽

Sequencing Analysis ◽

Or Gene

Using of plant essential oil that coevolved as a defense mechanism against agriculture insects is an alternative means of controlling many insect pests. In order to repel brown planthoppers (BPHs), the most notorious rice insect pest, a new film based on guar gum incorporated with citral (GC film) was formulated, which was effective while being environmentally friendly. In this paper, the effect and mechanism of GC film repellency against BPHs were determined. Repellent activity test and olfactory reaction analysis showed that GC film had repellency effect against BPHs, with repellency of 60.00% and 73.93%, respectively. The result of olfactory reaction indicated that GC film repellency against BPHs relied on smell. EPG analysis showed the proportion and mean duration of np waveform were significantly higher than in CK and increased following the treatment concentration, which indicated that GC film affected the recognition of BPHs to rice. Further analysis by RNA sequencing analysis showed a total of 679 genes were significantly upregulated and 284 genes were significantly downregulated in the BPHs fed on the rice sprayed with GC film compared to control. Odorant-binding protein (OBP) gene 797 and gustatory receptor gene (GR)/odorant receptor (OR) gene 13110 showed a significant decrease in differential expression and significant increase in differential expression, respectively. There were 0.66 and 2.55 differential expression multiples between treated BPHs and control, respectively. According to the results described above, we reasoned that GC film repellency against BPHs due to smell, by release of citral, caused the recognition difficulties for BPHs to rice, and OBP gene 797 and GR/OR gene 13110 appeared to be the crucial candidate genes for GC film repellency against BPHs. The present study depicted a clear and consistent repellency effect for GC film against BPHs and preliminarily clarified the mechanism of GC film as a repellent against BPHs, which might offer an alternative approach for control of BPHs in the near future. Our results could also help in the development and improvement of GC films.

Download Full-text