共查询到20条相似文献,搜索用时 15 毫秒
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Single cocaine exposure does not alter striatal pre‐synaptic dopamine function in mice: an [18F]‐FDOPA PET study 下载免费PDF全文
David R Bonsall Michelle Kokkinou Mattia Veronese Christopher Coello Lisa A. Wells Oliver D. Howes 《Journal of neurochemistry》2017,143(5):551-560
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Frauke van Bebber Alexander Hruscha Michael Willem Bettina Schmid Christian Haass 《Journal of neurochemistry》2013,127(4):471-481
Alzheimer's disease is the most frequent dementia. Pathologically, Alzheimer's disease is characterized by the accumulation of senile plaques composed of amyloid β‐peptide (Aβ). Two proteases, β‐ and γ‐secretase proteolytically generate Aβ from its precursor, the ß‐amyloid precursor protein (APP). Inhibition of β‐secretase, also referred to as b eta‐site A PP c leaving e nzyme (BACE1) or γ‐secretase is therefore of prime interest for the development of amyloid‐lowering drugs. To assess the in vivo function of zebrafish Bace1 (zBace1), we generated zBace1 knock out fish by zinc finger nuclease‐mediated genome editing. bace1 mutants (bace1?/?) are hypomyelinated in the PNS while the CNS is not affected. Moreover, the number of mechanosensory neuromasts is elevated in bace1?/?. Mutations in zebrafish Bace2 (zBace2) revealed a distinct melanocyte migration phenotype, which is not observed in bace1?/?. Double homozygous bace1?/?; bace2?/? fish do not enhance the single mutant phenotypes indicating non‐redundant distinct physiological functions. Single homozygous bace1 mutants as well as double homozygous bace1 and bace2 mutants are viable and fertile suggesting that Bace1 is a promising drug target without major side effects. The identification of a specific bace2 ?/? associated phenotype further allows improving selective Bace1 inhibitors and to distinguish between Bace 1 and Bace 2 inhibition in vivo.
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David S. Goldstein Patti Sullivan Courtney Holmes Gary W. Miller Shawn Alter Randy Strong Deborah C. Mash Irwin J. Kopin Yehonatan Sharabi 《Journal of neurochemistry》2013,126(5):591-603
Intra‐neuronal metabolism of dopamine (DA) begins with production of 3,4‐dihydroxyphenylacetaldehyde (DOPAL), which is toxic. According to the ‘catecholaldehyde hypothesis,’ DOPAL destroys nigrostriatal DA terminals and contributes to the profound putamen DA deficiency that characterizes Parkinson's disease (PD). We tested the feasibility of using post‐mortem patterns of putamen tissue catechols to examine contributions of altered activities of the type 2 vesicular monoamine transporter (VMAT2) and aldehyde dehydrogenase (ALDH) to the increased DOPAL levels found in PD. Theoretically, the DA : DOPA concentration ratio indicates vesicular uptake, and the 3,4‐dihydroxyphenylacetic acid : DOPAL ratio indicates ALDH activity. We validated these indices in transgenic mice with very low vesicular uptake (VMAT2‐Lo) or with knockouts of the genes encoding ALDH1A1 and ALDH2 (ALDH1A1,2 KO), applied these indices in PD putamen, and estimated the percent decreases in vesicular uptake and ALDH activity in PD. VMAT2‐Lo mice had markedly decreased DA:DOPA (50 vs. 1377, p < 0.0001), and ALDH1A1,2 KO mice had decreased 3,4‐dihydroxyphenylacetic acid:DOPAL (1.0 vs. 11.2, p < 0.0001). In PD putamen, vesicular uptake was estimated to be decreased by 89% and ALDH activity by 70%. Elevated DOPAL levels in PD putamen reflect a combination of decreased vesicular uptake of cytosolic DA and decreased DOPAL detoxification by ALDH.
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We estimated local and metapopulation effective sizes ( and meta‐) for three coexisting salmonid species (Salmo salar, Salvelinus fontinalis, Salvelinus alpinus) inhabiting a freshwater system comprising seven interconnected lakes. First, we hypothesized that might be inversely related to within‐species population divergence as reported in an earlier study (i.e., FST: S. salar> S. fontinalis> S. alpinus). Using the approximate Bayesian computation method implemented in ONeSAMP, we found significant differences in () between species, consistent with a hierarchy of adult population sizes (). Using another method based on a measure of linkage disequilibrium (LDNE: ), we found more finite values for S. salar than for the other two salmonids, in line with the results above that indicate that S. salar exhibits the lowest among the three species. Considering subpopulations as open to migration (i.e., removing putative immigrants) led to only marginal and non‐significant changes in , suggesting that migration may be at equilibrium between genetically similar sources. Second, we hypothesized that meta‐ might be significantly smaller than the sum of local s (null model) if gene flow is asymmetric, varies among subpopulations, and is driven by common landscape features such as waterfalls. One ‘bottom‐up’ or numerical approach that explicitly incorporates variable and asymmetric migration rates showed this very pattern, while a number of analytical models provided meta‐ estimates that were not significantly different from the null model or from each other. Our study of three species inhabiting a shared environment highlights the importance and utility of differentiating species‐specific and landscape effects, not only on dispersal but also in the demography of wild populations as assessed through local s and meta‐s and their relevance in ecology, evolution and conservation. 相似文献
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Genetic removal of eIF2α kinase PERK in mice enables hippocampal L‐LTP independent of mTORC1 activity 下载免费PDF全文
Brenna C. Beckelman Nicole P. Kasica Xueyan Zhou Lucas Dufresne Galli Alexey G. Ryazanov Tao Ma 《Journal of neurochemistry》2018,146(2):133-144
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Corticosterone primes the neuroinflammatory response to DFP in mice: potential animal model of Gulf War Illness 下载免费PDF全文
James P. O'Callaghan Kimberly A. Kelly Alicia R. Locker Diane B. Miller Steve M. Lasley 《Journal of neurochemistry》2015,133(5):708-721
Gulf War Illness (GWI) is a multi‐symptom disorder with features characteristic of persistent sickness behavior. Among conditions encountered in the Gulf War (GW) theater were physiological stressors (e.g., heat/cold/physical activity/sleep deprivation), prophylactic treatment with the reversible AChE inhibitor, pyridostigmine bromide (PB), the insect repellent, N,N‐diethyl‐meta‐toluamide (DEET), and potentially the nerve agent, sarin. Prior exposure to the anti‐inflammatory glucocorticoid, corticosterone (CORT), at levels associated with high physiological stress, can paradoxically prime the CNS to produce a robust proinflammatory response to neurotoxicants and systemic inflammation; such neuroinflammatory effects can be associated with sickness behavior. Here, we examined whether CORT primed the CNS to mount neuroinflammatory responses to GW exposures as a potential model of GWI. Male C57BL/6 mice were treated with chronic (14 days) PB/ DEET, subchronic (7–14 days) CORT, and acute exposure (day 15) to diisopropyl fluorophosphate (DFP), a sarin surrogate and irreversible AChE inhibitor. DFP alone caused marked brain‐wide neuroinflammation assessed by qPCR of tumor necrosis factor‐α, IL6, chemokine (C‐C motif) ligand 2, IL‐1β, leukemia inhibitory factor, and oncostatin M. Pre‐treatment with high physiological levels of CORT greatly augmented (up to 300‐fold) the neuroinflammatory responses to DFP. Anti‐inflammatory pre‐treatment with minocycline suppressed many proinflammatory responses to CORT+DFP. Our findings are suggestive of a possible critical, yet unrecognized interaction between the stressor/environment of the GW theater and agent exposure(s) unique to this war. Such exposures may in fact prime the CNS to amplify future neuroinflammatory responses to pathogens, injury, or toxicity. Such occurrences could potentially result in the prolonged episodes of sickness behavior observed in GWI.
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Agronomic nitrogen‐use efficiency of rice can be increased by driving OsNRT2.1 expression with the OsNAR2.1 promoter 下载免费PDF全文
Jingguang Chen Yong Zhang Yawen Tan Min Zhang Longlong Zhu Guohua Xu Xiaorong Fan 《Plant biotechnology journal》2016,14(8):1705-1715
The importance of the nitrate () transporter for yield and nitrogen‐use efficiency (NUE) in rice was previously demonstrated using map‐based cloning. In this study, we enhanced the expression of the OsNRT2.1 gene, which encodes a high‐affinity transporter, using a ubiquitin (Ubi) promoter and the ‐inducible promoter of the OsNAR2.1 gene to drive OsNRT2.1 expression in transgenic rice plants. Transgenic lines expressing pUbi:OsNRT2.1 or pOsNAR2.1:OsNRT2.1 constructs exhibited the increased total biomass including yields of approximately 21% and 38% compared with wild‐type (WT) plants. The agricultural NUE (ANUE) of the pUbi:OsNRT2.1 lines decreased to 83% of that of the WT plants, while the ANUE of the pOsNAR2.1:OsNRT2.1 lines increased to 128% of that of the WT plants. The dry matter transfer into grain decreased by 68% in the pUbi:OsNRT2.1 lines and increased by 46% in the pOsNAR2.1:OsNRT2.1 lines relative to the WT. The expression of OsNRT2.1 in shoot and grain showed that Ubi enhanced OsNRT2.1 expression by 7.5‐fold averagely and OsNAR2.1 promoters increased by about 80% higher than the WT. Interestingly, we found that the OsNAR2.1 was expressed higher in all the organs of pUbi:OsNRT2.1 lines; however, for pOsNAR2.1:OsNRT2.1 lines, OsNAR2.1 expression was only increased in root, leaf sheaths and internodes. We show that increased expression of OsNRT2.1, especially driven by OsNAR2.1 promoter, can improve the yield and NUE in rice. 相似文献
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Donna Crabtree Matthew Dodson Xiaosen Ouyang Michaël Boyer‐Guittaut Qiuli Liang Mary E. Ballestas Naomi Fineberg Jianhua Zhang 《Journal of neurochemistry》2014,128(6):950-961
Parkinson's disease is a neurodegenerative movement disorder. The histopathology of Parkinson's disease comprises proteinaceous inclusions known as Lewy bodies, which contains aggregated α‐synuclein. Cathepsin D (CD) is a lysosomal protease previously demonstrated to cleave α‐synuclein and decrease its toxicity in both cell lines and mouse brains in vivo. Here, we show that pharmacological inhibition of CD, or introduction of catalytically inactive mutant CD, resulted in decreased CD activity and increased cathepsin B activity, suggesting a possible compensatory response to inhibition of CD activity. However, this increased cathepsin B activity was not sufficient to maintain α‐synuclein degradation, as evidenced by the accumulation of endogenous α‐synuclein. Interestingly, the levels of LC3, LAMP1, and LAMP2, proteins involved in autophagy‐lysosomal activities, as well as total lysosomal mass as assessed by LysoTracker flow cytometry, were unchanged. Neither autophagic flux nor proteasomal activities differs between cells over‐expressing wild‐type versus mutant CD. These observations point to a critical regulatory role for that endogenous CD activity in dopaminergic cells in α‐synuclein homeostasis which cannot be compensated for by increased Cathepsin B. These data support the potential need to enhance CD function in order to attenuate α‐synuclein accumulation as a therapeutic strategy against development of synucleinopathy.
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Joanna Kucharska Patricia del Río Blanca Arango‐Gonzalez Matteo Gorza Annette Feuchtinger Marius Ueffing 《Journal of neurochemistry》2014,130(2):227-240
Subretinal injections with glial cell line‐derived neurotrophic factor (GDNF) rescue morphology as well as function of rod cells in mouse and rat animal models of retinitis pigmentosa. At the same time, it is postulated that this effect is indirect, mediated by activation of retinal Müller glial (RMG) cells. Here, we show that Cyr61/CCN1, one of the secreted proteins up‐regulated in primary RMG after glial cell line‐derived neurotrophic factor stimulation, provides neuroprotective and pro‐survival capacities: Recombinant Cyr61 significantly reduced photoreceptor (PR) cells death in organotypic cultures of Pde6brd1 retinas. To identify stimulated pathways in the retina, we treated Pde6brd1 retinal explants with Cyr61 and observed an overall increase in activated Erk1/2 and Stat3 signalling molecules characterized by activation‐site‐specific phosphorylation. To identify Cyr61 retinal target cells, we isolated primary porcine PR, RMG and retinal pigment epithelium (RPE) cells and exposed them separately to Cyr61. Here, RMG as well as RPE cells responded with induced phosphorylation of Erk1/2, Stat3 and Akt. In PR, no increase in phosphorylation in any of the studied proteins was detected, suggesting an indirect neuroprotective effect of Cyr61. Cyr61 may thus act as an endogenous pro‐survival factor for PR, contributing to the complex repertoire of neuroprotective activities generated by RMG and RPE cells.
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Dao‐Zhong Jin Ming‐Lei Guo Bing Xue Li‐Min Mao John Q. Wang 《Journal of neurochemistry》2013,127(5):620-631
Two glutamate receptors, metabotropic glutamate receptor 5 (mGluR5), and ionotropic NMDA receptors (NMDAR), functionally interact with each other to regulate excitatory synaptic transmission in the mammalian brain. In exploring molecular mechanisms underlying their interactions, we found that Ca2+/calmodulin‐dependent protein kinase IIα (CaMKIIα) may play a central role. The synapse‐enriched CaMKIIα directly binds to the proximal region of intracellular C terminal tails of mGluR5 in vitro. This binding is state‐dependent: inactive CaMKIIα binds to mGluR5 at a high level whereas the active form of the kinase (following Ca2+/calmodulin binding and activation) loses its affinity for the receptor. Ca2+ also promotes calmodulin to bind to mGluR5 at a region overlapping with the CaMKIIα‐binding site, resulting in a competitive inhibition of CaMKIIα binding to mGluR5. In rat striatal neurons, inactive CaMKIIα constitutively binds to mGluR5. Activation of mGluR5 Ca2+‐dependently dissociates CaMKIIα from the receptor and simultaneously promotes CaMKIIα to bind to the adjacent NMDAR GluN2B subunit, which enables CaMKIIα to phosphorylate GluN2B at a CaMKIIα‐sensitive site. Together, the long intracellular C‐terminal tail of mGluR5 seems to serve as a scaffolding domain to recruit and store CaMKIIα within synapses. The mGluR5‐dependent Ca2+ transients differentially regulate CaMKIIα interactions with mGluR5 and GluN2B in striatal neurons, which may contribute to cross‐talk between the two receptors.
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Ye Jin Koichi Sato Ayaka Tobo Chihiro Mogi Masayuki Tobo Naoya Murata Satoshi Ishii Dong‐Soon Im Fumikazu Okajima 《Journal of neurochemistry》2014,129(4):683-695
Interleukin‐1β (IL‐1β) is released from activated microglia and involved in the neurodegeneration of acute and chronic brain disorders, such as stroke and Alzheimer's disease, in which extracellular acidification has been shown to occur. Here, we examined the extracellular acidic pH regulation of IL‐1β production, especially focusing on TDAG8, a major proton‐sensing G‐protein‐coupled receptor, in mouse microglia. Extracellular acidification inhibited lipopolysaccharide ‐induced IL‐1β production, which was associated with the inhibition of IL‐1β cytoplasmic precursor and mRNA expression. The IL‐1β mRNA and protein responses were significantly, though not completely, attenuated in microglia derived from TDAG8‐deficient mice compared with those from wild‐type mice. The acidic pH also stimulated cellular cAMP accumulation, which was completely inhibited by TDAG8 deficiency. Forskolin and a cAMP derivative, which specifically stimulates protein kinase A (PKA), mimicked the proton actions, and PKA inhibitors reversed the acidic pH‐induced IL‐1β mRNA expression. The acidic pH‐induced inhibitory IL‐1β responses were accompanied by the inhibition of extracellular signal‐related kinase and c‐Jun N‐terminal kinase activities. The inhibitory enzyme activities in response to acidic pH were reversed by the PKA inhibitor and TDAG8 deficiency. We conclude that extracellular acidic pH inhibits lipopolysaccharide‐induced IL‐1β production, at least partly, through the TDAG8/cAMP/PKA pathway, by inhibiting extracellular signal‐related kinase and c‐Jun N‐terminal kinase activities, in mouse microglia.
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Hearing vulnerability after noise exposure in a mouse model of reactive oxygen species overproduction 下载免费PDF全文
Shigefumi Morioka Hirofumi Sakaguchi Taro Yamaguchi Yuzuru Ninoyu Hiroaki Mohri Takashi Nakamura Yasuo Hisa Kiyokazu Ogita Naoaki Saito Takehiko Ueyama 《Journal of neurochemistry》2018,146(4):459-473
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Expression of the purine biosynthetic enzyme phosphoribosyl formylglycinamidine synthase in neurons 下载免费PDF全文
Colleen A. Mangold Pamela J. Yao Mei Du Willard M. Freeman Stephen J. Benkovic Moriah L. Szpara 《Journal of neurochemistry》2018,144(6):723-735
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Ruoli L. Chen O. O. Ogunshola Karkheng K. Yeoh Anant Jani Michalis Papadakis Simon Nagel Alastair M. Buchan 《Journal of neurochemistry》2014,131(2):177-189
This study investigated the effects of 2‐(1‐chloro‐4‐hydroxyisoquinoline‐3‐carboxamido) acetic acid (IOX3), a selective small molecule inhibitor of hypoxia‐inducible factor (HIF) prolyl hydroxylases, on mouse brains subject to transient focal cerebral ischaemia. Male, 8‐ to 12‐week‐old C57/B6 mice were subjected to 45 min of middle cerebral artery occlusion (MCAO) either immediately or 24 h after receiving IOX3. Mice receiving IOX3 at 20 mg/kg 24 h prior to the MCAO had better neuroscores and smaller blood–brain barrier (BBB) disruption and infarct volumes than mice receiving the vehicle, whereas those having IOX3 at 60 mg/kg showed no significant changes. IOX3 treatment immediately before MCAO was not neuroprotective. IOX3 up‐regulated HIF‐1α, and increased EPO expression in mouse brains. In an in vitro BBB model (RBE4 cell line), IOX3 up‐regulated HIF‐1α and delocalized ZO‐1. Pre‐treating IOX3 on RBE4 cells 24 h before oxygen–glucose deprivation had a protective effect on endothelial barrier preservation with ZO‐1 being better localized, while immediate IOX3 treatment did not. Our study suggests that HIF stabilization with IOX3 before cerebral ischaemia is neuroprotective partially because of BBB protection, while immediate application could be detrimental. These results provide information for studies aimed at the therapeutic activation of HIF pathway for neurovascular protection from cerebral ischaemia.
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Vaishnavi Sunil Jadhav Karl‐Heinz Krause Sunit K. Singh 《Journal of neurochemistry》2014,131(6):803-815
HIV‐1 invades CNS in the early course of infection, which can lead to the cascade of neuroinflammation. NADPH oxidases (NOXs) are the major producers of reactive oxygen species (ROS), which play important roles during pathogenic insults. The molecular mechanism of ROS generation via microRNA‐mediated pathway in human microglial cells in response to HIV‐1 Tat protein has been demonstrated in this study. Over‐expression and knockdown of microRNAs, luciferase reporter assay, and site‐directed mutagenesis are main molecular techniques used in this study. A significant reduction in miR‐17 levels and increased NOX2, NOX4 expression levels along with ROS production were observed in human microglial cells upon HIV‐1 Tat C exposure. The validation of NOX2 and NOX4 as direct targets of miR‐17 was done by luciferase reporter assay. The over‐expression and knockdown of miR‐17 in human microglial cells showed the direct role of miR‐17 in regulation of NOX2, NOX4 expression and intracellular ROS generation. We demonstrated the regulatory role of cellular miR‐17 in ROS generation through over‐expression and knockdown of miR‐17 in human microglial cells exposed to HIV‐1 Tat C protein.
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Proteomic profiling of patient‐derived glioblastoma xenografts identifies a subset with activated EGFR: implications for drug development 下载免费PDF全文
Kristine E. Brown Gustavo Chagoya Shawn G. Kwatra Timothy Yen Stephen T. Keir Mary Cooter Katherine A. Hoadley Ahmed Rasheed Eric S. Lipp Roger Mclendon Francis Ali‐Osman Darell D. Bigner John H. Sampson Madan M. Kwatra 《Journal of neurochemistry》2015,133(5):730-738
The development of drugs to inhibit glioblastoma (GBM) growth requires reliable pre‐clinical models. To date, proteomic level validation of widely used patient‐derived glioblastoma xenografts (PDGX) has not been performed. In the present study, we characterized 20 PDGX models according to subtype classification based on The Cancer Genome Atlas criteria, TP53, PTEN, IDH 1/2, and TERT promoter genetic analysis, EGFR amplification status, and examined their proteomic profiles against those of their parent tumors. The 20 PDGXs belonged to three of four The Cancer Genome Atlas subtypes: eight classical, eight mesenchymal, and four proneural; none neural. Amplification of EGFR gene was observed in 9 of 20 xenografts, and of these, 3 harbored the EGFRvIII mutation. We then performed proteomic profiling of PDGX, analyzing expression/activity of several proteins including EGFR. Levels of EGFR phosphorylated at Y1068 vary considerably between PDGX samples, and this pattern was also seen in primary GBM. Partitioning of 20 PDGX into high (n = 5) and low (n = 15) groups identified a panel of proteins associated with high EGFR activity. Thus, PDGX with high EGFR activity represent an excellent pre‐clinical model to develop therapies for a subset of GBM patients whose tumors are characterized by high EGFR activity. Further, the proteins found to be associated with high EGFR activity can be monitored to assess the effectiveness of targeting EGFR.
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Yi‐Xiang Qi Ren‐Ying Xia Ya‐Su Wu David Stanley Jia Huang Gong‐Yin Ye 《Journal of neurochemistry》2014,131(6):767-777
The biogenic amine serotonin ( 5‐hydroxytryptamine, 5‐HT) is a neurotransmitter in vertebrates and invertebrates. It acts in regulation and modulation of many physiological and behavioral processes through G‐protein‐coupled receptors. Five 5‐HT receptor subtypes have been reported in Drosophila that share high similarity with mammalian 5‐HT1A, 5‐HT1B, 5‐HT2A, 5‐HT2B, and 5‐HT7 receptors. We isolated a cDNA (Pr5‐HT8) from larval Pieris rapae, which shares relatively low similarity to the known 5‐HT receptor classes. After heterologous expression in HEK293 cells, Pr5‐HT8 mediated increased [Ca2+]i in response to low concentrations (< 10 nM) of 5‐HT. The receptor did not affect [cAMP]i even at high concentrations (> 10 μM) of 5‐HT. Dopamine, octopamine, and tyramine did not influence receptor signaling. Pr5‐HT8 was also activated by various 5‐HT receptor agonists including 5‐methoxytryptamine, (±)‐8‐Hydroxy‐2‐(dipropylamino) tetralin, and 5‐carboxamidotryptamine. Methiothepin, a non‐selective 5‐HT receptor antagonist, activated Pr5‐HT8. WAY 10635, a 5‐HT1A antagonist, but not SB‐269970, SB‐216641, or RS‐127445, inhibited 5‐HT‐induced [Ca2+]i increases. We infer that Pr5‐HT8 represents the first recognized member of a novel 5‐HT receptor class with a unique pharmacological profile. We found orthologs of Pr5‐HT8 in some insect pests and vectors such as beetles and mosquitoes, but not in the genomes of honeybee or parasitoid wasps. This is likely to be an invertebrate‐specific receptor because there were no similar receptors in mammals.