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Yue Z, Li Y, Yu B, Xu Y, Chen L, Chitturi J, Meng J, Wang Y, Tian Y, Mouridi SE, Zhang C, Zhen M, Boulin T, Gao S. A leak K + channel TWK-40 sustains the rhythmic motor program. PNAS NEXUS 2024; 3:pgae234. [PMID: 38957449 PMCID: PMC11217676 DOI: 10.1093/pnasnexus/pgae234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 06/05/2024] [Indexed: 07/04/2024]
Abstract
Leak potassium (K+) currents, conducted by two-pore domain K+ (K2P) channels, are critical for the stabilization of the membrane potential. The effect of K2P channels on motor rhythm remains enigmatic. We show here that the K2P TWK-40 contributes to the rhythmic defecation motor program (DMP) in Caenorhabditis elegans. Disrupting TWK-40 suppresses the expulsion defects of nlp-40 and aex-2 mutants. By contrast, a gain-of-function (gf) mutant of twk-40 significantly reduces the expulsion frequency per DMP cycle. In situ whole-cell patch clamping demonstrates that TWK-40 forms an outward current that hyperpolarize the resting membrane potential of dorsorectal ganglion ventral process B (DVB), an excitatory GABAergic motor neuron that activates expulsion muscle contraction. In addition, TWK-40 substantially contributes to the rhythmic activity of DVB. Specifically, DVB Ca2+ oscillations exhibit obvious defects in loss-of-function (lf) mutant of twk-40. Expression of TWK-40(gf) in DVB recapitulates the expulsion deficiency of the twk-40(gf) mutant, and inhibits DVB Ca2+ oscillations in both wild-type and twk-40(lf) animals. Moreover, DVB innervated enteric muscles also exhibit rhythmic Ca2+ defects in twk-40 mutants. In summary, these findings establish TWK-40 as a crucial neuronal stabilizer of DMP, linking leak K2P channels with rhythmic motor activity.
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Affiliation(s)
- Zhongpu Yue
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yi Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Bin Yu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yueqing Xu
- College of Biomedical Engineering, South-Central University for Nationalities, Wuhan 430074, China
| | - Lili Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jyothsna Chitturi
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Jun Meng
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Ying Wang
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Yuhang Tian
- Department of Geriatrics, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Sonia El Mouridi
- Univ Lyon, Université Claude Bernard Lyon 1, MeLiS, CNRS UMR 5284, INSERM U1314, Institut NeuroMyoGène, Lyon 69008, France
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Sciences and Engineering Division (BESE), Thuwal 23955–6900, Kingdom of Saudi Arabia
| | - Cuntai Zhang
- Department of Geriatrics, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Thomas Boulin
- Univ Lyon, Université Claude Bernard Lyon 1, MeLiS, CNRS UMR 5284, INSERM U1314, Institut NeuroMyoGène, Lyon 69008, France
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
- Department of Geriatrics, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Li S, Li Z, Ke X, Wisawapipat W, Christie P, Wu L. Cadmium toxicity to and accumulation in a soil collembolan (Folsomia candida): major factors and prediction using a back-propagation neural network model. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:23790-23801. [PMID: 38429592 DOI: 10.1007/s11356-024-32638-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 02/21/2024] [Indexed: 03/03/2024]
Abstract
Accurate prediction of cadmium (Cd) ecotoxicity to and accumulation in soil biota is important in soil health. However, very limited information on Cd ecotoxicity on naturally contaminated soils. Herein, we investigated soil Cd ecotoxicity using Folsomia candida, a standard single-species test animal, in 28 naturally Cd-contaminated soils, and the back-propagation neural network (BPNN) model was used to predict Cd ecotoxicity to and accumulation in F. candida. Soil total Cd and pH were the primary soil properties affecting Cd toxicity. However, soil pH was the main factor when the total Cd concentration was < 3 mg kg-1. Interestingly, correlation analysis and the K-spiked test confirmed nutrient potassium (K) was essential for Cd accumulation, highlighting the significance of studying K in Cd accumulation. The BPNN model showed greater prediction accuracy of collembolan survival rate (R2 = 0.797), reproduction inhibitory rate (R2 = 0.827), body Cd concentration (R2 = 0.961), and Cd bioaccumulation factor (R2 = 0.964) than multiple linear regression models. Then the developed BPNN model was used to predict Cd ecological risks in 57 soils in southern China. Compared to multiple linear regression models, the BPNN models can better identify high-risk regions. This study highlights the potential of BPNN as a novel and rapid tool for the evaluation and monitoring of Cd ecotoxicity in naturally contaminated soils.
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Affiliation(s)
- Simin Li
- Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhu Li
- Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Xin Ke
- Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Worachart Wisawapipat
- Soil Chemistry and Biogeochemistry Group, Department of Soil Science, Faculty of Agriculture, Kasetsart University, Bangkok, 10900, Thailand
| | - Peter Christie
- Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Longhua Wu
- Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
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Zhou C, Zhou Q, He X, He Y, Wang X, Zhu X, Zhang Y, Ma L. Differential modulation of C. elegans motor behavior by NALCN and two-pore domain potassium channels. PLoS Genet 2022; 18:e1010126. [PMID: 35482723 PMCID: PMC9049526 DOI: 10.1371/journal.pgen.1010126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 02/28/2022] [Indexed: 11/18/2022] Open
Abstract
Two-pore domain potassium channels (K2P) are a large family of “background” channels that allow outward “leak” of potassium ions. The NALCN/UNC80/UNC79 complex is a non-selective channel that allows inward flow of sodium and other cations. It is unclear how K2Ps and NALCN differentially modulate animal behavior. Here, we found that loss of function (lf) in the K2P gene twk-40 suppressed the reduced body curvatures of C. elegans NALCN(lf) mutants. twk-40(lf) caused a deep body curvature and extended backward locomotion, and these phenotypes appeared to be associated with neuron-specific expression of twk-40 and distinct twk-40 transcript isoforms. To survey the functions of other less studied K2P channels, we examined loss-of-function mutants of 13 additional twk genes expressed in the motor circuit and detected defective body curvature and/or locomotion in mutants of twk-2, twk-17, twk-30, twk-48, unc-58, and the previously reported twk-7. We generated presumptive gain-of-function (gf) mutations in twk-40, twk-2, twk-7, and unc-58 and found that they caused paralysis. Further analyses detected variable genetic interactions between twk-40 and other twk genes, an interdependence between twk-40 and twk-2, and opposite behavioral effects between NALCN and twk-2, twk-7, or unc-58. Finally, we found that the hydrophobicity/hydrophilicity property of TWK-40 residue 159 could affect the channel activity. Together, our study identified twk-40 as a novel modulator of the motor behavior, uncovered potential behavioral effects of five other K2P genes and suggests that NALCN and some K2Ps can oppositely affect C. elegans behavior.
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Affiliation(s)
- Chuanman Zhou
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Qian Zhou
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Xiaohui He
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yunxia He
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Xiaoqin Wang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Xiaowei Zhu
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yujia Zhang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Long Ma
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Molecular Precision Medicine, Central South University, Changsha, Hunan, China
- * E-mail:
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Rawsthorne-Manning H, Calahorro F, G. Izquierdo P, Tardy P, Boulin T, Holden-Dye L, O’Connor V, Dillon J. Confounds of using the unc-58 selection marker highlights the importance of genotyping co-CRISPR genes. PLoS One 2022; 17:e0253351. [PMID: 35041685 PMCID: PMC8765651 DOI: 10.1371/journal.pone.0253351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/29/2021] [Indexed: 11/19/2022] Open
Abstract
Multiple advances have been made to increase the efficiency of CRISPR/Cas9 editing using the model genetic organism Caenorhabditis elegans (C. elegans). Here we report on the use of co-CRISPR ‘marker’ genes: worms in which co-CRISPR events have occurred have overt, visible phenotypes which facilitates the selection of worms that harbour CRISPR events in the target gene. Mutation in the co-CRISPR gene is then removed by outcrossing to wild type but this can be challenging if the CRISPR and co-CRISPR gene are hard to segregate. However, segregating away the co-CRISPR modified gene can be less challenging if the worms selected appear wild type and are selected from a jackpot brood. These are broods in which a high proportion of the progeny of a single injected worm display the co-CRISPR phenotype suggesting high CRISPR efficiency. This can deliver worms that harbour the desired mutation in the target gene locus without the co-CRISPR mutation. We have successfully generated a discrete mutation in the C. elegans nlg-1 gene using this method. However, in the process of sequencing to authenticate editing in the nlg-1 gene we discovered genomic rearrangements that arise at the co-CRISPR gene unc-58 that by visual observation were phenotypically silent but nonetheless resulted in a significant reduction in motility scored by thrashing behaviour. This highlights that careful consideration of the hidden consequences of co-CRISPR mediated genetic changes should be taken before downstream analysis of gene function. Given this, we suggest sequencing of co-CRISPR genes following CRISPR procedures that utilise phenotypic selection as part of the pipeline.
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Affiliation(s)
| | - Fernando Calahorro
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Patricia G. Izquierdo
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Philippe Tardy
- Institut NeuroMyoGène, Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U1217, Lyon, France
| | - Thomas Boulin
- Institut NeuroMyoGène, Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U1217, Lyon, France
| | - Lindy Holden-Dye
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Vincent O’Connor
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - James Dillon
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
- * E-mail:
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Gaur AV, Agarwal R. Risperidone induced alterations in feeding and locomotion behavior of Caenorhabditis elegans. Curr Res Toxicol 2021; 2:367-374. [PMID: 34806037 PMCID: PMC8585583 DOI: 10.1016/j.crtox.2021.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/14/2021] [Accepted: 10/14/2021] [Indexed: 11/19/2022] Open
Abstract
Antipsychotic drugs (APDs) are prescribed for the treatment of psychiatric illness. However, these drugs can also contribute to several developmental and behavioral disorders. Contemporary studies to evaluate the toxic effects of numerous atypical antipsychotics are reported to cause behavioral alteration at variable doses in mammals and nematodes. Risperidone, the second most prescribed drug in India, requires more exploration of its adverse effects on humans. Here, we explore effects on feeding behavior and locomotion patterns due to risperidone exposure in C. elegans model. The study targets to work out the toxic effects of risperidone exposure on feeding and locomotion behavior in addition to the expected pharmacological effects. N2 wild type strain was exposed in liquid culture assay for 2, 4, 6, 8, 10, and 12 hours with fixed 50 µM concentration. Feeding behavior was depleted due to inhibition in pharyngeal pumping varying from 11.05% - 45.67% in a time-dependent manner. Results of locomotion assay also show time-varying increase in reversals (4.9%-34.03%) and omega bends (26.23%-62.17%) with reduction in turn counts (29.07%- 42.2%) and peristaltic speed (31.38%-42.22%) amongst exposed groups as to control. The present work shows behavioral alterations due to risperidone exposure (50 µM) in C. elegans is in a time-dependent manner. The study concludes that risperidone exposure in C. elegans produces toxic effects with time, possibly caused by antagonizing other receptors apart from serotonin (5-H2T) and dopamine (D2) adding to its expected pharmacological effects.
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Key Words
- 5-H2T
- 5-HT, 5-hydroxytryptamine
- ADF, Amphid Neuron
- APDs, Antipsychotic drugs
- Antipsychotic drugs
- Behavioral alteration
- C, Control Group
- C-0h, Control Group at 0 h
- C-10h, Control Group at 10 h
- C-12h, Control Group at 12 h. E-2h, Exposure Group at 2 h
- C-2h, Control Group at 2 h
- C-4h, Control Group at 4 h
- C-6h, Control Group at 6 h
- C-8h, Control Group at 8 h
- C. elegans
- C. elegans, Caenorhabditis elegans
- D2
- D2, Dopamine Receptor 2
- E, Exposed Group
- E-10h, Exposure Group at ten
- E-12h, Exposure Group at 12 h
- E-4h, Exposure Group at 4 h
- E-6h, Exposure Group at 6 h
- E-8h, Exposure Group at 8 h
- E. coli, Escherichia coli BOD-Biochemical Oxygen Demand
- GPR, G coupled Protein Receptor
- HSN, Hermaphrodite Specific Neuron
- Min., Minutes
- N2 Wild type
- NSM, Neurosecretory Motor Neuron
- Peristaltic speed
- Pharyngeal pumping
- Reversals
- Risperidone
- SD, Standard Deviation
- SDA, Serotonin Dopamine Antagonist
- Turn counts
- omega bends
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Affiliation(s)
- Aaditya Vikram Gaur
- Laboratory of Analytical & Molecular Toxicology (Forensic Chemistry & Toxicology Laboratory), School of Forensic Science, National Forensic Sciences University, Sector 09, Gandhinagar 382007, Gujarat, India
- Forensic Science Laboratory, Kirumampakkam, Puducherry 607402, India
| | - Rakhi Agarwal
- Laboratory of Analytical & Molecular Toxicology (Forensic Chemistry & Toxicology Laboratory), School of Forensic Science, National Forensic Sciences University, Sector 09, Gandhinagar 382007, Gujarat, India
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Iqbal F, Thompson AJ, Riaz S, Pehar M, Rice T, Syed NI. Anesthetics: from modes of action to unconsciousness and neurotoxicity. J Neurophysiol 2019; 122:760-787. [PMID: 31242059 DOI: 10.1152/jn.00210.2019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Modern anesthetic compounds and advanced monitoring tools have revolutionized the field of medicine, allowing for complex surgical procedures to occur safely and effectively. Faster induction times and quicker recovery periods of current anesthetic agents have also helped reduce health care costs significantly. Moreover, extensive research has allowed for a better understanding of anesthetic modes of action, thus facilitating the development of more effective and safer compounds. Notwithstanding the realization that anesthetics are a prerequisite to all surgical procedures, evidence is emerging to support the notion that exposure of the developing brain to certain anesthetics may impact future brain development and function. Whereas the data in support of this postulate from human studies is equivocal, the vast majority of animal research strongly suggests that anesthetics are indeed cytotoxic at multiple brain structure and function levels. In this review, we first highlight various modes of anesthetic action and then debate the evidence of harm from both basic science and clinical studies perspectives. We present evidence from animal and human studies vis-à-vis the possible detrimental effects of anesthetic agents on both the young developing and the elderly aging brain while discussing potential ways to mitigate these effects. We hope that this review will, on the one hand, invoke debate vis-à-vis the evidence of anesthetic harm in young children and the elderly, and on the other hand, incentivize the search for better and less toxic anesthetic compounds.
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Affiliation(s)
- Fahad Iqbal
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Andrew J Thompson
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Neuroscience, Faculty of Science, University of Calgary, Calgary, Alberta, Canada
| | - Saba Riaz
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Marcus Pehar
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Tiffany Rice
- Department of Anesthesiology, Perioperative and Pain Medicine, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Naweed I Syed
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Denham JE, Ranner T, Cohen N. Signatures of proprioceptive control in Caenorhabditis elegans locomotion. Philos Trans R Soc Lond B Biol Sci 2018; 373:rstb.2018.0208. [PMID: 30201846 DOI: 10.1098/rstb.2018.0208] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2018] [Indexed: 12/20/2022] Open
Abstract
Animal neuromechanics describes the coordinated self-propelled movement of a body, subject to the combined effects of internal neural control and mechanical forces. Here we use a computational model to identify effects of neural and mechanical modulation on undulatory forward locomotion of Caenorhabditis elegans, with a focus on proprioceptively driven neural control. We reveal a fundamental relationship between body elasticity and environmental drag in determining the dynamics of the body and demonstrate the manifestation of this relationship in the context of proprioceptively driven control. By considering characteristics unique to proprioceptive neurons, we predict the signatures of internal gait modulation that contrast with the known signatures of externally or biomechanically modulated gait. We further show that proprioceptive feedback can suppress neuromechanical phase lags during undulatory locomotion, contrasting with well studied advancing phase lags that have long been a signature of centrally generated, feed-forward control.This article is part of a discussion meeting issue 'Connectome to behaviour: modelling C. elegans at cellular resolution'.
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Affiliation(s)
- Jack E Denham
- School of Computing, University of Leeds, Leeds LS2 9JT, UK
| | - Thomas Ranner
- School of Computing, University of Leeds, Leeds LS2 9JT, UK
| | - Netta Cohen
- School of Computing, University of Leeds, Leeds LS2 9JT, UK
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Villa S, Di Nica V, Pescatore T, Bellamoli F, Miari F, Finizio A, Lencioni V. Comparison of the behavioural effects of pharmaceuticals and pesticides on Diamesa zernyi larvae (Chironomidae). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 238:130-139. [PMID: 29554561 DOI: 10.1016/j.envpol.2018.03.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/09/2018] [Accepted: 03/10/2018] [Indexed: 05/20/2023]
Abstract
Several studies have indicated the presence of contaminants in Alpine aquatic ecosystems. Even if measured concentrations are far below those that cause acute effects, continuous exposure to sub-lethal concentrations may have detrimental effects on the aquatic species present in these remote environments. This may lead to a cascade of indirect effects at higher levels of the ecological hierarchy (i.e., the community). To improve the determination of ecologically relevant risk endpoints, behavioural alterations in organisms due to pollutants are increasingly studied in ecotoxicology. In fact, behaviour links physiological function with ecological processes, and can be very sensitive to environmental stimuli and chemical exposure. This is the first study on behavioural alteration in a wild population of an Alpine species. In the present study, a video tracking system was standardized and subsequently used to identify contaminant-induced behavioural alterations in Diamesa zernyi larvae (Diptera, Chironomidae). Diamesa zernyi larvae, collected in an Italian Alpine stream (Rio Presena, Trentino Region), were acclimated for 24 h and successively exposed to several aquatic contaminants (pesticides: chlorpyrifos, metolachlor, boscalid, captan; pharmaceuticals: ibuprofen, furosemide, trimethoprim) at concentrations corresponding to their Lowest Observed Effect Concentration (LOEC). After 24, 48, 72, and 96 h of exposure, changes in the distance moved, the average speed, and the frequency of body bends were taken to reflect contaminant- and time-dependent effects on larval behaviour. In general, metolachlor, captan, and trimethoprim tended to reduce all the endpoints under consideration, whereas chlorpyrifos, boscalid, ibuprofen, and furosemide seemed to increase the distances moved by the larvae. This could be related to the different mechanisms of action of the investigated chemicals. Independently of the contaminant, after 72 h a general slowing down of all the behavioural activities occurred. Finally, we propose a behavioural stress indicator to compare the overall behavioural effects induced by the various contaminants.
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Affiliation(s)
- Sara Villa
- Department of Earth and Environmental Sciences, University of Milano Bicocca, Piazza della Scienza 1, 20126 Milano, Italy
| | - Valeria Di Nica
- Department of Earth and Environmental Sciences, University of Milano Bicocca, Piazza della Scienza 1, 20126 Milano, Italy.
| | - Tanita Pescatore
- Water Research Institute, National Research Council (IRSA-CNR), Via Salaria km 29.300, Monterotondo, 00015 Rome, Italy
| | - Francesco Bellamoli
- Section of Invertebrate Zoology and Hydrobiology, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122 Trento, Italy
| | - Francesco Miari
- Section of Invertebrate Zoology and Hydrobiology, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122 Trento, Italy
| | - Antonio Finizio
- Department of Earth and Environmental Sciences, University of Milano Bicocca, Piazza della Scienza 1, 20126 Milano, Italy
| | - Valeria Lencioni
- Section of Invertebrate Zoology and Hydrobiology, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122 Trento, Italy.
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Locomotion Behavior Is Affected by the Gα S Pathway and the Two-Pore-Domain K + Channel TWK-7 Interacting in GABAergic Motor Neurons in Caenorhabditis elegans. Genetics 2017; 206:283-297. [PMID: 28341653 DOI: 10.1534/genetics.116.195669] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 03/19/2017] [Indexed: 01/03/2023] Open
Abstract
Adjusting the efficiency of movement in response to environmental cues is an essential integrative characteristic of adaptive locomotion behavior across species. However, the modulatory molecules and the pathways involved are largely unknown. Recently, we demonstrated that in Caenorhabditis elegans, a loss-of-function of the two-pore-domain potassium (K2P) channel TWK-7 causes a fast, coordinated, and persistent forward crawling behavior in which five central aspects of stimulated locomotion-velocity, direction, wave parameters, duration, and straightness-are affected. Here, we isolated the reduction-of-function allele cau1 of the C. elegans gene kin-2 in a forward genetic screen and showed that it phenocopies the locomotor activity and locomotion behavior of twk-7(null) animals. Kin-2 encodes the negative regulatory subunit of protein kinase A (KIN-1/PKA). Consistently, we found that other gain-of-function mutants of the GαS-KIN-1/PKA pathway resemble kin-2(cau1) and twk-7(null) in locomotion phenotype. Using the powerful genetics of the C. elegans system in combination with cell type-specific approaches and detailed locomotion analyses, we identified TWK-7 as a putative downstream target of the GαS-KIN-1/PKA pathway at the level of the γ-aminobutyric acid (GABA)ergic D-type motor neurons. Due to this epistatic interaction, we suggest that KIN-1/PKA and TWK-7 may share a common pathway that is probably involved in the modulation of both locomotor activity and locomotion behavior during forward crawling.
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