The olfactory perception is the process that the olfactory receptor is activated by odorous molecules, which induce the transduction of signal in the cell and the chemical information is transduced into electrical impulses. After the changed signal is transmitted to the brain, the whole perception process completes. OR gene belongs to the multigene family. The coded olfactory receptor proteins belong to the G-protein-coupled receptor (GPCR) superfamily and therefore are invariably seven-transmembrane domain(7TM) protein. Olfactory receptor protein plays an important role in olfactory perception and signal transduction process.
Animals ; Humans ; Olfactory Receptor Neurons ; metabolism ; physiology ; Receptors, Odorant ; chemistry ; genetics ; physiology ; Signal Transduction

No abstract available.
Receptors, Odorant ; Polymorphism, Single Nucleotide ; Selection, Genetic ; Livestock ; Genomics* ; Genotype ; Olfactory Receptor Neurons

Animals ; Codon, Nonsense ; Disease ; genetics ; Drosophila ; genetics ; metabolism ; Drosophila Proteins ; genetics ; Humans ; Pseudogenes ; Receptors, Odorant ; genetics

OBJECTIVETo clone and identify olfactory receptor odorant receptor 7 (OR7) gene of Aedes albopictus and analyze its expression profile and calcium regulation function.

METHODRT-PCR was used to amplify the olfactory receptor OR7 gene of Ae. albopictus and OR7 expression was detected in different tissues and organs. The coding sequence of OR7 gene was cloned in eukaryotic expression vector pME18s, which was then transfected into HEK293 cells. The calcium callback function in response to odor molecule stimulation was analyzed by calcium imaging technique.

RESULTSThe OR7 gene of Ae. albopictus was cloned and sequence analysis showed that its coding region was 1395 bp. RT-PCR detected OR7 expression in the larvae, pupae and adult mosquitoes, especially in female mosquitos. Preliminary analysis of calcium callback function demonstrated the specific regulation of calcium absorption by OR7 in response to odor molecule stimulation.

CONCLUSIONThe OR7 gene of Ae. albopictus has been cloned successfully. OR7 is highly expressed in female mosquitos and is capable of specific recognition of the odor molecules.

Aedes ; genetics ; Animals ; Cloning, Molecular ; Female ; Gene Expression ; Genes, Insect ; HEK293 Cells ; Humans ; Larva ; Pupa ; Receptors, Odorant ; genetics

OBJECTIVETo constitute the animal model of unilateral olfactory nerve transection and observe the expression level and distribution of odorant receptors.

METHODSThirty-two rats were divided into two groups: the olfactory nerve transection group (20) and the control group (12). The former group received the operation to transect the left olfactory nerve following the left olfactory bulb was exposed under microscope and the latter group did not give any disposal. At every stage of five days, two weeks, four weeks and six weeks after the operation, five rats from the nerve transection group and three from the control group were anaesthetized simultaneously, and olfactory epithelium were taken out after transcardial perfusion, then paraffin imbedding. Coronal sections were sliced for HE staining to observe the thickness changes of the olfactory epithelium, and for in situ hybridization (ISHs) to investigate the expression of olfactory receptor genes (Olr287, Olr226, Olr1493 and Olr1654) in the epithelium, also to evaluate the changes of the expression level and location of the selected receptors during the regeneration of olfactory epithelium.

RESULTSHE staining showed that 5 days after the operation cell quantity and thickness of the olfactory epithelium decreased obviously, which increased gradually 2 or 4 weeks after operation. After 6 weeks' recovery, the thickness of the epithelium could reach the control level. The pattern of cell staining by ISH showed a specific spatial distribution along the anteroposterior (AP) and dorsoventral (DV) axis. Evidence suggested that odorant receptors were distributed in continuous and multiple overlapping bands in the normal or nerve transected-recovered epithelium rather than in the conventionally accepted three or four zones. The data also demonstrated that the distribution of sensory neuron types, as identified and defined by odorant receptor expression, was restored to normal or nearly so by 6 weeks after operation. Likewise, the numbers of probe-labeled neurons in the nerve transected-recovered had an obvious decrease 5 days after olfactory nerve transection. Reactive cells (x(-) +/- s) of Olr1493 in the operated side was (53.9 +/- 19.9), compared with (419.0 +/- 21.2) in the unoperated side, there was statistic significance between them (t = 63.960, P < 0.01). Reactive cells increased gradually according to the regeneration of the epithelium, and were nearly equivalent to the normal side 6 weeks later without significant differentiation (t = 2.600, P > 0.05), according to the absolute positive cells in the operated and unoperated side of (417.8 +/- 32.4) and (445.3 +/- 10.0) respectively.

CONCLUSIONThe regeneration of the sensory neurons and receptors, both the number and the distribution, can recover to normal after olfactory nerve transection.

Animals ; Male ; Olfactory Mucosa ; metabolism ; Olfactory Nerve ; metabolism ; surgery ; Olfactory Nerve Injuries ; Olfactory Receptor Neurons ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Odorant ; genetics ; metabolism

G protein-coupled receptors (GPCRs) are involved in all human physiological systems where they are responsible for transducing extracellular signals into cells. GPCRs signal in response to a diverse array of stimuli including light, hormones, and lipids, where these signals affect downstream cascades to impact both health and disease states. Yet, despite their importance as therapeutic targets, detailed molecular structures of only 30 GPCRs have been determined to date. A key challenge to their structure determination is adequate protein expression. Here we report the quantification of protein expression in an insect cell expression system for all 826 human GPCRs using two different fusion constructs. Expression characteristics are analyzed in aggregate and among each of the five distinct subfamilies. These data can be used to identify trends related to GPCR expression between different fusion constructs and between different GPCR families, and to prioritize lead candidates for future structure determination feasibility.
Animals ; Computational Biology ; Crystallography, X-Ray ; Gene Expression ; Humans ; Plasmids ; genetics ; metabolism ; Protein Domains ; Receptors, Adrenergic, beta-1 ; Receptors, G-Protein-Coupled ; classification ; genetics ; metabolism ; Receptors, Odorant ; metabolism ; Receptors, Purinergic P1 ; genetics ; metabolism ; Sf9 Cells ; Spodoptera

The olfactory epithelium is the main end organ for the sense of smell in humans and vertebrates. Specially differenciated neuronal cells called olfactory receptor neurons (ORNs) play a key role in the olfactory epithelium by expressing the olfactory receptors (ORs) on their apical surface membrane. The ORs are G-protein coupled receptors that transmit signals from odorants to ORNs by molecular cascades using cyclic adenosine monophosphate, calcium ions and other molecules, which result in the depolarization of ORN. Unlike other mammalian animals, only about 30% of OR genes in the human genome are expressed. The Nobel Prize was awarded to the scientists who cloned these ORs for the first time. Each ORN expresses only a single type of OR, and ORNs which express the same type of OR converge together into the same glomeruli in the olfactory bulb. A single OR recognizes multiple odorants, and a single odorant is recognized by multiple ORs with varying affinities. At the higher neurons beyond the bulb, neuronal connections are divergent. The combinatorial model of odor identification and discrimination is well established at the convergence level, but little is known about the action mechanisms of neuronal divergence for odor identification and discrimination and further study is required.
Adenosine Monophosphate ; Animals ; Awards and Prizes ; Calcium ; Clone Cells ; Discrimination (Psychology) ; Genome, Human ; GTP-Binding Proteins ; Humans ; Ions ; Membranes ; Neurons ; Nobel Prize ; Odors ; Olfactory Bulb ; Olfactory Mucosa ; Olfactory Pathways ; Olfactory Receptor Neurons ; Receptors, Odorant ; Smell* ; Vertebrates