• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.87-92
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• 2003

We describe here the cloning, expression and characterization of a cDNA encoding a putative chemosensory protein (CSP) from the mole cricket, Gryllotalpa orientalis. The G. orientalis chemosensory protein cDNA sequences comprised of 384 bp with 128 amino acid residues. The G. orientalis chemosensory protein showed 75.4% protein sequence identity to the Locusta migratoria CSP, Northern blot analysis revealed that signal was stronger in head than leg and cuticle, indicating that the head part containing antennae is a main site for G. orientalis chemosensory protein synthesis. The cDNA encoding G. orientalis chemosensory protein was expressed as approximately 12 kDa polypeptide in baculovirus-infected insect cells.

• BMB Reports
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• v.45 no.11
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• pp.612-622
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• 2012

Olfactory receptors (ORs) detect volatile chemicals that lead to the initial perception of smell in the brain. The olfactory receptor (OR) is the first protein that recognizes odorants in the olfactory signal pathway and it is present in over 1,000 genes in mice. It is also the largest member of the G protein-coupled receptors (GPCRs). Most ORs are extensively expressed in the nasal olfactory epithelium where they perform the appropriate physiological functions that fit their location. However, recent whole-genome sequencing shows that ORs have been found outside of the olfactory system, suggesting that ORs may play an important role in the ectopic expression of non-chemosensory tissues. The ectopic expressions of ORs and their physiological functions have attracted more attention recently since MOR23 and testicular hOR17-4 have been found to be involved in skeletal muscle development, regeneration, and human sperm chemotaxis, respectively. When identifying additional expression profiles and functions of ORs in non-olfactory tissues, there are limitations posed by the small number of antibodies available for similar OR genes. This review presents the results of a research series that identifies ectopic expressions and functions of ORs in non-chemosensory tissues to provide insight into future research directions.

• Molecules and Cells
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• v.42 no.1
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• pp.28-35
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• 2019

Animals need to be able to alter their developmental and behavioral programs in response to changing environmental conditions. This developmental and behavioral plasticity is mainly mediated by changes in gene expression. The knowledge of the mechanisms by which environmental signals are transduced and integrated to modulate changes in sensory gene expression is limited. Exposure to ascaroside pheromone has been reported to alter the expression of a subset of putative G protein-coupled chemosensory receptor genes in the ASI chemosensory neurons of C. elegans (Kim et al., 2009; Nolan et al., 2002; Peckol et al., 1999). Here we show that ascaroside pheromone reversibly represses expression of the str-3 chemoreceptor gene in the ASI neurons. Repression of str-3 expression can be initiated only at the L1 stage, but expression is restored upon removal of ascarosides at any developmental stage. Pheromone receptors including SRBC-64/66 and SRG-36/37 are required for str-3 repression. Moreover, pheromone-mediated str-3 repression is mediated by FLP-18 neuropeptide signaling via the NPR-1 neuropeptide receptor. These results suggest that environmental signals regulate chemosensory gene expression together with internal neuropeptide signals which, in turn, modulate behavior.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2002.04a
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• pp.73-73
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• 2002

No Abstract, See Full Text

• Genomics & Informatics
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• v.16 no.1
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• pp.2-9
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• 2018

Olfactory receptors (ORs) in mammals are generally considered to function as chemosensors in the olfactory organs of animals. They are membrane proteins that traverse the cytoplasmic membrane seven times and work generally by coupling to heterotrimeric G protein. The OR is a G protein-coupled receptor that binds the guanine nucleotide-binding $G{\alpha}_{olf}$ subunit and the $G{\beta}{\gamma}$ dimer to recognize a wide spectrum of organic compounds in accordance with its cognate ligand. Mammalian ORs were originally identified from the olfactory epithelium of rat. However, it has been recently reported that the expression of ORs is not limited to the olfactory organ. In recent decades, they have been found to be expressed in diverse organs or tissues and even tumors in mammals. In this review, the expression and expected function of olfactory receptors that exist throughout an organism's system are discussed.

• Development and Reproduction
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• v.10 no.3
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• pp.159-168
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• 2006

Rodents and many other mammals have two chemosensory systems that mediate responses to pheromones, the main and accessory olfactory system, MOS and AOS, respectively. The chemosensory neurons associated with the MOS are located in the main olfactory epithelium, while those associated with the AOS are located in the vomeronasal organ(VNO). Pheromonal odorants access the lumen of the VNO via canals in the roof of the mouth, and are largely thought to be nonvolatile. The main pheromone receptor proteins consist of two superfamilies, V1Rs and V2Rs, that are structurally distinct and unrelated to the olfactory receptors expressed in the main olfactory epithelium. These two type of receptors are seven transmembrane domain G-protein coupled proteins(V1R with $G_{{\alpha}i2}$, V2R with $G_{0\;{\alpha}}$). V2Rs are co-expressed with nonclassical MHC Ib genes(M10 and other 8 M1 family proteins). Other important molecular component of VNO neuron is a TrpC2, a cation channel protein of transient receptor potential(TRP) family and thought to have a crucial role in signal transduction. There are four types of pheromones in mammalian chemical communication - primers, signalers, modulators and releasers. Responses to these chemosignals can vary substantially within and between individuals. This variability can stem from the modulating effects of steroid hormones and/or non-steroid factors such as neurotransmitters on olfactory processing. Such modulation frequently augments or facilitates the effects that prevailing social and environmental conditions have on the reproductive axis. The best example is the pregnancy block effect(Bruce effect), caused by testosterone-dependent major urinary proteins(MUPs) in male mouse urine. Intriguingly, mouse GnRH neurons receive pheromone signals from both odor and pheromone relays in the brain and may also receive common odor signals. Though it is quite controversial, recent studies reveal a complex interplay between reproduction and other functions in which GnRH neurons appear to integrate information from multiple sources and modulate a variety of brain functions.