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Mechanotransduction channel Piezo is widely expressed in the spider, Cupiennius salei, mechanosensory neurons and central nervous system. Sci Rep 2021; 11:7994. [PMID: 33846502 PMCID: PMC8042031 DOI: 10.1038/s41598-021-87202-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 03/25/2021] [Indexed: 01/01/2023] Open
Abstract
Mechanosensory neurons use mechanotransduction (MET) ion channels to detect mechanical forces and displacements. Proteins that function as MET channels have appeared multiple times during evolution and occur in at least four different families: the DEG/ENaC and TRP channels, as well as the TMC and Piezo proteins. We found twelve putative members of MET channel families in two spider transcriptomes, but detected only one, the Piezo protein, by in situ hybridization in their mechanosensory neurons. In contrast, probes for orthologs of TRP, ENaC or TMC genes that code MET channels in other species did not produce any signals in these cells. An antibody against C. salei Piezo detected the protein in all parts of their mechanosensory cells and in many neurons of the CNS. Unspecific blockers of MET channels, Ruthenium Red and GsMTx4, had no effect on the mechanically activated currents of the mechanosensory VS-3 neurons, but the latter toxin reduced action potential firing when these cells were stimulated electrically. The Piezo protein is expressed throughout the spider nervous system including the mechanosensory neurons. It is possible that it contributes to mechanosensory transduction in spider mechanosensilla, but it must have other functions in peripheral and central neurons.
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Short S, Robinson A, Lahive E, Green Etxabe A, Hernádi S, Pereira MG, Kille P, Spurgeon DJ. Off-Target Stoichiometric Binding Identified from Toxicogenomics Explains Why Some Species Are More Sensitive than Others to a Widely Used Neonicotinoid. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3059-3069. [PMID: 33559465 DOI: 10.1021/acs.est.0c05125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Neonicotinoids are currently licensed for use in 120 countries, making accurate nontarget species sensitivity predictions critical. Unfortunately, such predictions are fraught with uncertainty, as sensitivity is extrapolated from only a few test species and neonicotinoid sensitivities can differ greatly between closely related taxa. Combining classical toxicology with de novo toxicogenomics could greatly improve sensitivity predictions and identify unexpectedly susceptible species. We show that there is a >30-fold differential species sensitivity (DSS) for the neonicotinoid imidacloprid between five earthworm species, a critical nontarget taxon. This variation could not be explained by differential toxicokinetics. Furthermore, comparing key motif expression in subunit genes of the classical nicotinic acetylcholine receptor (nAChR) target predicts only minor differences in the ligand binding domains (LBDs). In contrast, predicted dissimilarities in LBDs do occur in the highly expressed but nonclassical targets, acetylcholine binding proteins (AChBPs). Critically, the predicted AChBP divergence is capable of explaining DSS. We propose that high expression levels of putative nonsynaptic AChBPs with high imidacloprid affinities reduce imidacloprid binding to critical nAChRs involved in vital synaptic neurotransmission. This study provides a clear example of how pragmatic interrogation of key motif expression in complex multisubunit receptors can predict observed DSS, thereby informing sensitivity predictions for essential nontarget species.
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Affiliation(s)
- Stephen Short
- UK Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom
- Cardiff School of Biosciences, BIOSI 1, University of Cardiff, P.O. Box 915, Cardiff, CF10 3TL, United Kingdom
| | - Alex Robinson
- UK Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom
| | - Elma Lahive
- UK Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom
| | - Amaia Green Etxabe
- UK Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom
| | - Szabolcs Hernádi
- Cardiff School of Biosciences, BIOSI 1, University of Cardiff, P.O. Box 915, Cardiff, CF10 3TL, United Kingdom
| | - M Glória Pereira
- UK Centre for Ecology and Hydrology, Library Avenue, Bailrigg, Lancaster LA1 4AP, United Kingdom
| | - Peter Kille
- Cardiff School of Biosciences, BIOSI 1, University of Cardiff, P.O. Box 915, Cardiff, CF10 3TL, United Kingdom
| | - David J Spurgeon
- UK Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom
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Sukumar V, Liu H, Meisner S, French AS, Torkkeli PH. Multiple Biogenic Amine Receptor Types Modulate Spider, Cupiennius salei, Mechanosensory Neurons. Front Physiol 2018; 9:857. [PMID: 30050453 PMCID: PMC6052906 DOI: 10.3389/fphys.2018.00857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/15/2018] [Indexed: 12/02/2022] Open
Abstract
The biogenic amines octopamine (OA), tyramine (TA), dopamine (DA), serotonin (5-HT), and histamine (HA) affect diverse physiological and behavioral processes in invertebrates, but recent findings indicate that an additional adrenergic system exists in at least some invertebrates. Transcriptome analysis has made it possible to identify biogenic amine receptor genes in a wide variety of species whose genomes have not yet been sequenced. This approach provides new sequences for research into the evolutionary history of biogenic amine receptors and allows them to be studied in experimentally accessible animal models. The Central American Wandering spider, Cupiennius salei, is an experimental model for neurophysiological, developmental and behavioral research. We identified ten different biogenic amine receptors in C. salei transcriptomes. Phylogenetic analysis indicated that, in addition to the typical receptors for OA, TA, DA, and 5-HT in protostome invertebrates, spiders also have α1- and α2-adrenergic receptors, but lack TAR2 receptors and one invertebrate specific DA receptor type. In situ hybridization revealed four types of biogenic amine receptors expressed in C. salei mechanosensory neurons. We used intracellular electrophysiological experiments and pharmacological tools to determine how each receptor type contributes to modulation of these neurons. We show that arachnids have similar groups of biogenic amine receptors to other protostome invertebrates, but they lack two clades. We also clarify that arachnids and many other invertebrates have both α1- and α2-adrenergic, likely OA receptors. Our results indicate that in addition to an OAβ-receptor that regulates rapid and large changes in sensitivity via a Gs-protein activating a cAMP mediated pathway, the C. salei mechanosensory neurons have a constitutively active TAR1 and/or α2-adrenergic receptor type that adjusts the baseline sensitivity to a level appropriate for the behavioral state of the animal by a Gq-protein that mobilizes Ca2+.
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Affiliation(s)
- Vaishnavi Sukumar
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Hongxia Liu
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Shannon Meisner
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Andrew S French
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Päivi H Torkkeli
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
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Bao H, Meng X, Liu Z. Spider acetylcholine binding proteins: An alternative model to study the interaction between insect nAChRs and neonicotinoids. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 90:82-89. [PMID: 28993249 DOI: 10.1016/j.ibmb.2017.09.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/27/2017] [Accepted: 09/27/2017] [Indexed: 06/07/2023]
Abstract
Acetylcholine binding proteins (AChBPs) are homologs of extracellular domains of nicotinic acetylcholine receptors (nAChRs) and serve as models for studies on nAChRs. Particularly, studies on invertebrate nAChRs that are limited due to difficulties in their heterologous expression have benefitted from the discovery of AChBPs. Thus far, AChBPs have been characterized only in aquatic mollusks, which have shown low sensitivity to neonicotinoids, the insecticides targeting insect nAChRs. However, AChBPs were also found in spiders based on the sequence and tissue expression analysis. Here, we report five AChBP subunits in Pardosa pseudoannulata, a predator enemy against rice insect pests. Spider AChBP subunits shared higher sequence similarities with nAChR subunits of both insects and mammals compared with mollusk AChBP subunits. The AChBP1 subunit of P. pseudoannulata (Pp-AChBP) was then expressed in Sf9 cells. The Ls-AChBP from Lymnaea stagnalis was also expressed for comparison. In both AChBPs, one ligand site per subunit was present at each interface between two adjacent subunits. Neonicotinoids had higher affinities (7.9-18.4 times based on Kd or Ki values) for Pp-AChBP than for Ls-AChBP, although epibatidine and α-bungarotoxin showed higher affinities for Ls-AChBP. These results indicate that spider AChBP could be used as an alternative model to study the interaction between insect nAChRs and neonicotinoids.
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Affiliation(s)
- Haibo Bao
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, China
| | - Xiangkun Meng
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Zewen Liu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, China.
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Fabian-Fine R, Anderson CM, Roush MA, Johnson JAG, Liu H, French AS, Torkkeli PH. The distribution of cholinergic neurons and their co-localization with FMRFamide, in central and peripheral neurons of the spider Cupiennius salei. Cell Tissue Res 2017; 370:71-88. [PMID: 28687927 DOI: 10.1007/s00441-017-2652-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 05/23/2017] [Indexed: 12/21/2022]
Abstract
The spider Cupiennius salei is a well-established model for investigating information processing in arthropod sensory systems. Immunohistochemistry has shown that several neurotransmitters exist in the C. salei nervous system, including GABA, glutamate, histamine, octopamine and FMRFamide, while electrophysiology has found functional roles for some of these transmitters. There is also evidence that acetylcholine (ACh) is present in some C. salei neurons but information about the distribution of cholinergic neurons in spider nervous systems is limited. Here, we identify C. salei genes that encode enzymes essential for cholinergic transmission: choline ACh transferase (ChAT) and vesicular ACh transporter (VAChT). We used in-situ hybridization with an mRNA probe for C. salei ChAT gene to locate somata of cholinergic neurons in the central nervous system and immunohistochemistry with antisera against ChAT and VAChT to locate these proteins in cholinergic neurons. All three markers labeled similar, mostly small neurons, plus a few mid-sized neurons, in most ganglia. In the subesophageal ganglia, labeled neurons are putative efferent, motor or interneurons but the largest motor and interneurons were unlabeled. Groups of anti-ChAT labeled small neurons also connect the optic neuropils in the spider protocerebrum. Differences in individual cell labeling intensities were common, suggesting a range of ACh expression levels. Double-labeling found a subpopulation of anti-VAChT-labeled central and mechanosensory neurons that were also immunoreactive to antiserum against FMRFamide-like peptides. Our findings suggest that ACh is an important neurotransmitter in the C. salei central and peripheral nervous systems.
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Affiliation(s)
- Ruth Fabian-Fine
- Department of Biology, Saint Michael's College, One Winooski Park, Box 283, Colchester, VT, 05439, USA.
| | - Carly M Anderson
- Department of Biology, Saint Michael's College, One Winooski Park, Box 283, Colchester, VT, 05439, USA
| | - Molly A Roush
- Department of Biology, Saint Michael's College, One Winooski Park, Box 283, Colchester, VT, 05439, USA
| | - Jessica A G Johnson
- Department of Physiology and Biophysics, Dalhousie University, PO Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Hongxia Liu
- Department of Physiology and Biophysics, Dalhousie University, PO Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Andrew S French
- Department of Physiology and Biophysics, Dalhousie University, PO Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Päivi H Torkkeli
- Department of Physiology and Biophysics, Dalhousie University, PO Box 15000, Halifax, NS, B3H 4R2, Canada
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