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Basakis P, Khaderi A, Lom B. Xenopus retinal ganglion cell axon extension is unaffected by 5-HT 1B/D receptor activation during visual system development. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.001076. [PMID: 38116474 PMCID: PMC10728752 DOI: 10.17912/micropub.biology.001076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 11/27/2023] [Accepted: 11/30/2023] [Indexed: 12/21/2023]
Abstract
Activating 5-HT 1B/D receptors with the agonist Zolmitriptan was previously shown to facilitate Xenopus retinal ganglion cell (RGC) axon extension from ectopic eye primordia transplanted to the ventral fin. To determine if 5-HT 1B/D receptor activation influenced entopic RGC axonal outgrowth toward the optic tectum during typical visual system development, we reared embryos in 50 μΜ Zolmitriptan then visualized optic tracts with anterograde HRP labeling. Zolmitriptan did not significantly alter entopic RGC extension in the contralateral brain. Consequently, RGC axon extension in ectopic but not entopic locations is influenced by altering serotonergic signaling .
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Affiliation(s)
- Petros Basakis
- Biology & Neuroscience, Davidson College, Davidson, North Carolina, United States
| | - Aalim Khaderi
- Biology & Neuroscience, Davidson College, Davidson, North Carolina, United States
- Systems Biology, Harvard Medical School, Harvard University, Cambridge, Massachusetts, United States
| | - Barbara Lom
- Biology & Neuroscience, Davidson College, Davidson, North Carolina, United States
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2
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A Focal Impact Model of Traumatic Brain Injury in Xenopus Tadpoles Reveals Behavioral Alterations, Neuroinflammation, and an Astroglial Response. Int J Mol Sci 2022; 23:ijms23147578. [PMID: 35886924 PMCID: PMC9323330 DOI: 10.3390/ijms23147578] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Traumatic Brain Injury (TBI) is a global driver of disability, and we currently lack effective therapies to promote neural repair and recovery. TBI is characterized by an initial insult, followed by a secondary injury cascade, including inflammation, excitotoxicity, and glial cellular response. This cascade incorporates molecular mechanisms that represent potential targets of therapeutic intervention. In this study, we investigate the response to focal impact injury to the optic tectum of Xenopus laevis tadpoles. This injury disrupts the blood-brain barrier, causing edema, and produces deficits in visually-driven behaviors which are resolved within one week. Within 3 h, injured brains show a dramatic transcriptional activation of inflammatory cytokines, upregulation of genes associated with inflammation, and recruitment of microglia to the injury site and surrounding tissue. Shortly afterward, astrocytes undergo morphological alterations and accumulate near the injury site, and these changes persist for at least 48 h following injury. Genes associated with astrocyte reactivity and neuroprotective functions also show elevated levels of expression following injury. Since our results demonstrate that the response to focal impact injury in Xenopus resembles the cellular alterations observed in rodents and other mammalian models, the Xenopus tadpole offers a new, scalable vertebrate model for TBI.
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Ismail V, Zachariassen LG, Godwin A, Sahakian M, Ellard S, Stals KL, Baple E, Brown KT, Foulds N, Wheway G, Parker MO, Lyngby SM, Pedersen MG, Desir J, Bayat A, Musgaard M, Guille M, Kristensen AS, Baralle D. Identification and functional evaluation of GRIA1 missense and truncation variants in individuals with ID: An emerging neurodevelopmental syndrome. Am J Hum Genet 2022; 109:1217-1241. [PMID: 35675825 PMCID: PMC9300760 DOI: 10.1016/j.ajhg.2022.05.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/11/2022] [Indexed: 12/02/2022] Open
Abstract
GRIA1 encodes the GluA1 subunit of α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors, which are ligand-gated ion channels that act as excitatory receptors for the neurotransmitter L-glutamate (Glu). AMPA receptors (AMPARs) are homo- or heteromeric protein complexes with four subunits, each encoded by different genes, GRIA1 to GRIA4. Although GluA1-containing AMPARs have a crucial role in brain function, the human phenotype associated with deleterious GRIA1 sequence variants has not been established. Subjects with de novo missense and nonsense GRIA1 variants were identified through international collaboration. Detailed phenotypic and genetic assessments of the subjects were carried out and the pathogenicity of the variants was evaluated in vitro to characterize changes in AMPAR function and expression. In addition, two Xenopus gria1 CRISPR-Cas9 F0 models were established to characterize the in vivo consequences. Seven unrelated individuals with rare GRIA1 variants were identified. One individual carried a homozygous nonsense variant (p.Arg377Ter), and six had heterozygous missense variations (p.Arg345Gln, p.Ala636Thr, p.Ile627Thr, and p.Gly745Asp), of which the p.Ala636Thr variant was recurrent in three individuals. The cohort revealed subjects to have a recurrent neurodevelopmental disorder mostly affecting cognition and speech. Functional evaluation of major GluA1-containing AMPAR subtypes carrying the GRIA1 variant mutations showed that three of the four missense variants profoundly perturb receptor function. The homozygous stop-gain variant completely destroys the expression of GluA1-containing AMPARs. The Xenopus gria1 models show transient motor deficits, an intermittent seizure phenotype, and a significant impairment to working memory in mutants. These data support a developmental disorder caused by both heterozygous and homozygous variants in GRIA1 affecting AMPAR function.
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Affiliation(s)
- Vardha Ismail
- Wessex Clinical Genetics Service, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Coxford Rd, Southampton SO165YA, UK
| | - Linda G Zachariassen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Annie Godwin
- European Xenopus Resource Centre, School of Biological Sciences, King Henry Building, King Henry I Street, Portsmouth PO1 2DY, UK
| | - Mane Sahakian
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Sian Ellard
- Exeter Genomics Laboratory, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter EX2 5DW, UK; University of Exeter Medical School, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter EX2 5DW, UK
| | - Karen L Stals
- Exeter Genomics Laboratory, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter EX2 5DW, UK
| | - Emma Baple
- Exeter Genomics Laboratory, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter EX2 5DW, UK; University of Exeter Medical School, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter EX2 5DW, UK
| | - Kate Tatton Brown
- South-West Thames Clinical Genetics Service, St George's University of London, Cranmer Terrace, London SW17 0RE, UK
| | - Nicola Foulds
- Wessex Clinical Genetics Service, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Coxford Rd, Southampton SO165YA, UK
| | - Gabrielle Wheway
- Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK
| | - Matthew O Parker
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, Old St Michael's Building, White Swan Road, Portsmouth PO1 2DT, UK
| | - Signe M Lyngby
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Miriam G Pedersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Julie Desir
- Département de Génétique Clinique - Institut de Pathologie et de Génétique, Institut de Pathologie et de Génétique, Avenue Georges Lemaître, 25 6041 Gosselies, Belgium
| | - Allan Bayat
- Danish Epilepsy Centre, Department of Epilepsy Genetics and Personalized Medicine, 4293 Dianalund, Denmark; Department of Regional Health Research, University of Southern Denmark, 5230 Odense, Denmark
| | - Maria Musgaard
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 75 Laurier Ave E, Ottawa, ON K1N 6N5, Canada
| | - Matthew Guille
- European Xenopus Resource Centre, School of Biological Sciences, King Henry Building, King Henry I Street, Portsmouth PO1 2DY, UK
| | - Anders S Kristensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
| | - Diana Baralle
- Wessex Clinical Genetics Service, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Coxford Rd, Southampton SO165YA, UK; Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK.
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Lombard-Banek C, Li J, Portero EP, Onjiko RM, Singer CD, Plotnick DO, Al Shabeeb RQ, Nemes P. In Vivo Subcellular Mass Spectrometry Enables Proteo-Metabolomic Single-Cell Systems Biology in a Chordate Embryo Developing to a Normally Behaving Tadpole (X. laevis)*. Angew Chem Int Ed Engl 2021; 60:12852-12858. [PMID: 33682213 PMCID: PMC8176382 DOI: 10.1002/anie.202100923] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Indexed: 01/05/2023]
Abstract
We report the development of in vivo subcellular high-resolution mass spectrometry (HRMS) for proteo-metabolomic molecular systems biology in complex tissues. With light microscopy, we identified the left-dorsal and left-ventral animal cells in cleavage-stage non-sentient Xenopus laevis embryos. Using precision-translated fabricated microcapillaries, the subcellular content of each cell was double-probed, each time swiftly (<5 s/event) aspirating <5 % of cell volume (≈10 nL). The proteins and metabolites were analyzed by home-built ultrasensitive capillary electrophoresis electrospray ionization employing orbitrap or time-of-flight HRMS. Label-free detection of ≈150 metabolites (57 identified) and 738 proteins found proteo-metabolomic networks with differential quantitative activities between the cell types. With spatially and temporally scalable sampling, the technology preserved the integrity of the analyzed cells, the neighboring cells, and the embryo. 95 % of the analyzed embryos developed into sentient tadpoles that were indistinguishable from their wild-type siblings based on anatomy and visual function in a background color preference assay.
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Affiliation(s)
- Camille Lombard-Banek
- Department of Chemistry & Biochemistry, University of Maryland, 0107 Chemistry Building, 8051 Regents Drive, College Park, MD 20742 (USA)
| | - Jie Li
- Department of Chemistry & Biochemistry, University of Maryland, 0107 Chemistry Building, 8051 Regents Drive, College Park, MD 20742 (USA)
| | - Erika P. Portero
- Department of Chemistry & Biochemistry, University of Maryland, 0107 Chemistry Building, 8051 Regents Drive, College Park, MD 20742 (USA)
| | - Rosemary M. Onjiko
- Department of Chemistry, The George Washington University, 800 22nd St NW, Washington, DC 20052 (USA)
| | - Chase D. Singer
- Department of Chemistry & Biochemistry, University of Maryland, 0107 Chemistry Building, 8051 Regents Drive, College Park, MD 20742 (USA)
| | - David O. Plotnick
- Department of Chemistry, The George Washington University, 800 22nd St NW, Washington, DC 20052 (USA)
| | - Reem Q. Al Shabeeb
- Department of Chemistry, The George Washington University, 800 22nd St NW, Washington, DC 20052 (USA)
| | - Peter Nemes
- Department of Chemistry & Biochemistry, University of Maryland, 0107 Chemistry Building, 8051 Regents Drive, College Park, MD 20742 (USA)
- Department of Chemistry, The George Washington University, 800 22nd St NW, Washington, DC 20052 (USA)
- Department of Anatomy & Cell Biology, School of Medicine and Health Sciences, The George Washington University, 2300 I Street NW, Washington, DC 20037 (USA)
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Viet J, Reboutier D, Hardy S, Lachke SA, Paillard L, Gautier-Courteille C. Modeling ocular lens disease in Xenopus. Dev Dyn 2020; 249:610-621. [PMID: 31872467 PMCID: PMC7759097 DOI: 10.1002/dvdy.147] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 12/18/2019] [Accepted: 12/20/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Ocular lens clouding is termed as cataract, which depending on the onset, is classified as congenital or age-related. Developing new cataract treatments requires new models. Thus far, Xenopus embryos have not been evaluated as a system for studying cataract. RESULTS We characterized the developmental process of lens formation in Xenopus laevis tailbuds and tadpoles, and we disrupted the orthologues of three mammalian cataract-linked genes in F0 by CRISPR/Cas9. We assessed the consequences of gene inactivation by combining external examination with histochemical analyses and functional vision assays. Inactivating the key metazoan eye development transcription factor gene pax6 produces a strong eye phenotype including an absence of eye tissue. Inactivating the genes for gap-junction protein and a nuclease, gja8 and dnase2b, produces lens defects that share several features of human cataracts, including impaired vision acuity, nuclei retention in lens fiber cells, and actin fibers disorganization. We tested the potential improvement of the visual acuity of gja8 crispant tadpoles upon treatment with the molecular chaperone 4-phenylbutyrate. CONCLUSION Xenopus is a valuable model organism to understand the molecular pathology of congenital eye defects, including cataracts, and to screen molecules with a potential to prevent or reverse cataracts.
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Affiliation(s)
- Justine Viet
- Univ Rennes, CNRS, IGDR-UMR 6290, F-35000 Rennes, France
| | | | - Serge Hardy
- Univ Rennes, CNRS, IGDR-UMR 6290, F-35000 Rennes, France
| | - Salil A. Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Luc Paillard
- Univ Rennes, CNRS, IGDR-UMR 6290, F-35000 Rennes, France
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Corradi E, Dalla Costa I, Gavoci A, Iyer A, Roccuzzo M, Otto TA, Oliani E, Bridi S, Strohbuecker S, Santos-Rodriguez G, Valdembri D, Serini G, Abreu-Goodger C, Baudet ML. Axonal precursor miRNAs hitchhike on endosomes and locally regulate the development of neural circuits. EMBO J 2020; 39:e102513. [PMID: 32073171 PMCID: PMC7073465 DOI: 10.15252/embj.2019102513] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 12/24/2019] [Accepted: 01/17/2020] [Indexed: 12/22/2022] Open
Abstract
Various species of non‐coding RNAs (ncRNAs) are enriched in specific subcellular compartments, but the mechanisms orchestrating their localization and their local functions remain largely unknown. We investigated both aspects using the elongating retinal ganglion cell axon and its tip, the growth cone, as models. We reveal that specific endogenous precursor microRNAs (pre‐miRNAs) are actively trafficked to distal axons by hitchhiking primarily on late endosomes/lysosomes. Upon exposure to the axon guidance cue semaphorin 3A (Sema3A), pre‐miRNAs are processed specifically within axons into newly generated miRNAs, one of which, in turn, silences the basal translation of tubulin beta 3 class III (TUBB3), but not amyloid beta precursor protein (APP). At the organismal level, these mature miRNAs are required for growth cone steering and a fully functional visual system. Overall, our results uncover a novel mode of ncRNA transport from one cytosolic compartment to another within polarized cells. They also reveal that newly generated miRNAs are critical components of a ncRNA‐based signaling pathway that transduces environmental signals into the structural remodeling of subcellular compartments.
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Affiliation(s)
- Eloina Corradi
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Irene Dalla Costa
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Antoneta Gavoci
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Archana Iyer
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Michela Roccuzzo
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Tegan A Otto
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Eleonora Oliani
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Simone Bridi
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Stephanie Strohbuecker
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | | | - Donatella Valdembri
- Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Torino, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Guido Serini
- Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Torino, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | | | - Marie-Laure Baudet
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
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7
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Fainsod A, Kot-Leibovich H. Xenopus embryos to study fetal alcohol syndrome, a model for environmental teratogenesis. Biochem Cell Biol 2018; 96:77-87. [DOI: 10.1139/bcb-2017-0219] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Vertebrate model systems are central to characterize the outcomes of ethanol exposure and the etiology of fetal alcohol spectrum disorder (FASD), taking advantage of their genetic and morphological closeness and similarity to humans. We discuss the contribution of amphibian embryos to FASD research, focusing on Xenopus embryos. The Xenopus experimental system is characterized by external development and accessibility throughout embryogenesis, large clutch sizes, gene and protein activity manipulation, transgenesis and genome editing, convenient chemical treatment, explants and conjugates, and many other experimental approaches. Taking advantage of these methods, many insights regarding FASD have been obtained. These studies characterized the malformations induced by ethanol including quantitative analysis of craniofacial malformations, induction of fetal growth restriction, delay in gut maturation, and defects in the differentiation of the neural crest. Mechanistic, biochemical, and molecular studies in Xenopus embryos identified early gastrula as the high alcohol sensitivity window, targeting the embryonic organizer and inducing a delay in gastrulation movements. Frog embryos have also served to demonstrate the involvement of reduced retinoic acid production and an increase in reactive oxygen species in FASD. Amphibian embryos have helped pave the way for our mechanistic, molecular, and biochemical understanding of the etiology and pathophysiology of FASD.
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Affiliation(s)
- Abraham Fainsod
- Department of Cellular Biochemistry and Cancer Research, Institute for Medical Research Israel–Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
- Department of Cellular Biochemistry and Cancer Research, Institute for Medical Research Israel–Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Hadas Kot-Leibovich
- Department of Cellular Biochemistry and Cancer Research, Institute for Medical Research Israel–Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
- Department of Cellular Biochemistry and Cancer Research, Institute for Medical Research Israel–Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
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8
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Kha CX, Tseng KAS. Developmental dependence for functional eye regrowth in Xenopus laevis. Neural Regen Res 2018; 13:1735-1737. [PMID: 30136686 PMCID: PMC6128050 DOI: 10.4103/1673-5374.238611] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Cindy X Kha
- School of Life Sciences, University of Nevada, Las Vegas, NV, USA
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Sun J, Tang S, Peng H, Saunders DMV, Doering JA, Hecker M, Jones PD, Giesy JP, Wiseman S. Combined Transcriptomic and Proteomic Approach to Identify Toxicity Pathways in Early Life Stages of Japanese Medaka (Oryzias latipes) Exposed to 1,2,5,6-Tetrabromocyclooctane (TBCO). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:7781-90. [PMID: 27322799 DOI: 10.1021/acs.est.6b01249] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Currently, the novel brominated flame retardant 1,2,5,6-tetrabromocyclooctane (TBCO) is considered a potential replacement for hexabromocyclododecane (HBCD). Therefore, use of TBCO could increase in the near future. To assess potential toxicological risks to aquatic organisms, embryos of Japanese medaka (Oryzias latipes) were exposed to 10, 100, or 1000 μg/L TBCO from 2 h postfertilization until 1 day post-hatch. TBCO accumulated in embryos in the order of 0.43-1.3 × 10(4)-fold, and the rate constant of accumulation was 1.7-1.8 per day. The number of days to hatch and the hatching success of embryos exposed to the medium and the greatest concentrations of TBCO were impaired. Responses of the transcriptome (RNA-seq) and proteome were characterized in embryos exposed to 100 μg/L TBCO because this was the least concentration of TBCO that caused an effect on hatching. Consistent with effects on hatching, proteins whose abundances were reduced by exposure to TBCO were enriched in embryo development and hatching pathways. Also, on the basis of the responses of transcriptome and proteome, it was predicted that TBCO might impair vision and contraction of cardiac muscle, respectively, and these effects were confirmed by targeted bioassays. This study provided a comprehensive understanding of effects of TBCO on medaka at early life stages and illustrated the power of "omics" to explain and predict phenotypic responses to chemicals.
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Affiliation(s)
- Jianxian Sun
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Song Tang
- School of Environment and Sustainability, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C8, Canada
| | - Hui Peng
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Jon A Doering
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C8, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C8, Canada
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
- Department of Veterinary Biomedical Sciences, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B4, Canada
- Zoology Department, Center for Integrative Toxicology, Michigan State University , East Lansing, Michigan 48824, United States
- School of Biological Sciences, University of Hong Kong , Hong Kong Special Administrative Region 999077, People's Republic of China
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210093, People's Republic of China
| | - Steve Wiseman
- Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
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10
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Rothman GR, Blackiston DJ, Levin M. Color and intensity discrimination in Xenopus laevis tadpoles. Anim Cogn 2016; 19:911-9. [PMID: 27146661 DOI: 10.1007/s10071-016-0990-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 04/19/2016] [Accepted: 04/25/2016] [Indexed: 12/12/2022]
Abstract
Investigations into the physiology of Xenopus laevis have the potential to greatly accelerate biomedical research, especially concerning neural plasticity and sensory systems, but are limited by the lack of available information on behavioral learning in this species. Here, we attempt to lay the foundations for a behavioral assay in Xenopus that can be used in conjunction with biological manipulations. We tested cohorts of Xenopus tadpoles across four light-mediated active-avoidance experiments, using either wavelength or intensity as the salient discriminative cue. In the wavelength task, we determine a baseline learning rate and characterize retention of learning, identifying active extinction effects as far more potent than the passage of time in the loss of behavior. In the intensity task, we examine the effects of varying differences between the discriminative stimuli on acquisition and extinction and identify a critical range of intensity differences where learning changes. The results of our experiments demonstrate that Xenopus is a tractable model organism for cognitive research and can learn a variety of associative tasks in the laboratory settings. These data reveal new aspects of the Xenopus larval visual processing system and facilitate future research between cognitive methods and biological/chemical manipulations to study mechanisms of brain structure and function.
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Affiliation(s)
- Gabriel R Rothman
- Department of Biology, Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA, 02155, USA
| | - Douglas J Blackiston
- Department of Biology, Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA, 02155, USA
| | - Michael Levin
- Department of Biology, Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA, 02155, USA.
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11
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Martinez-De Luna RI, Ku RY, Aruck AM, Santiago F, Viczian AS, San Mauro D, Zuber ME. Müller glia reactivity follows retinal injury despite the absence of the glial fibrillary acidic protein gene in Xenopus. Dev Biol 2016; 426:219-235. [PMID: 26996101 DOI: 10.1016/j.ydbio.2016.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/02/2016] [Accepted: 03/02/2016] [Indexed: 01/02/2023]
Abstract
Intermediate filament proteins are structural components of the cellular cytoskeleton with cell-type specific expression and function. Glial fibrillary acidic protein (GFAP) is a type III intermediate filament protein and is up-regulated in glia of the nervous system in response to injury and during neurodegenerative diseases. In the retina, GFAP levels are dramatically increased in Müller glia and are thought to play a role in the extensive structural changes resulting in Müller cell hypertrophy and glial scar formation. In spite of similar changes to the morphology of Xenopus Müller cells following injury, we found that Xenopus lack a gfap gene. Other type III intermediate filament proteins were, however, significantly induced following rod photoreceptor ablation and retinal ganglion cell axotomy. The recently available X. tropicalis and X. laevis genomes indicate a small deletion most likely resulted in the loss of the gfap gene during anuran evolution. Lastly, a survey of representative species from all three extant amphibian orders including the Anura (frogs, toads), Caudata (salamanders, newts), and Gymnophiona (caecilians) suggests that deletion of the gfap locus occurred in the ancestor of all Anura after its divergence from the Caudata ancestor around 290 million years ago. Our results demonstrate that extensive changes in Müller cell morphology following retinal injury do not require GFAP in Xenopus, and other type III intermediate filament proteins may be involved in the gliotic response.
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Affiliation(s)
- Reyna I Martinez-De Luna
- Departments of Ophthalmology, Biochemistry & Molecular Biology, Neuroscience & Physiology, The Center for Vision Research and SUNY Eye Institute, Upstate Medical University, Syracuse 13210, NY, USA
| | - Ray Y Ku
- Departments of Ophthalmology, Biochemistry & Molecular Biology, Neuroscience & Physiology, The Center for Vision Research and SUNY Eye Institute, Upstate Medical University, Syracuse 13210, NY, USA
| | - Alexandria M Aruck
- Departments of Ophthalmology, Biochemistry & Molecular Biology, Neuroscience & Physiology, The Center for Vision Research and SUNY Eye Institute, Upstate Medical University, Syracuse 13210, NY, USA
| | - Francesca Santiago
- Departments of Ophthalmology, Biochemistry & Molecular Biology, Neuroscience & Physiology, The Center for Vision Research and SUNY Eye Institute, Upstate Medical University, Syracuse 13210, NY, USA
| | - Andrea S Viczian
- Departments of Ophthalmology, Biochemistry & Molecular Biology, Neuroscience & Physiology, The Center for Vision Research and SUNY Eye Institute, Upstate Medical University, Syracuse 13210, NY, USA
| | - Diego San Mauro
- Department of Zoology & Physical Anthropology, Faculty of Biological Sciences, Complutense University, Madrid 28040, Spain
| | - Michael E Zuber
- Departments of Ophthalmology, Biochemistry & Molecular Biology, Neuroscience & Physiology, The Center for Vision Research and SUNY Eye Institute, Upstate Medical University, Syracuse 13210, NY, USA.
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Wong KA, Trembley M, Abd Wahab S, Viczian AS. Efficient retina formation requires suppression of both Activin and BMP signaling pathways in pluripotent cells. Biol Open 2015; 4:573-83. [PMID: 25750435 PMCID: PMC4400599 DOI: 10.1242/bio.20149977] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Retina formation requires the correct spatiotemporal patterning of key regulatory factors. While it is known that repression of several signaling pathways lead to specification of retinal fates, addition of only Noggin, a known BMP antagonist, can convert pluripotent Xenopus laevis animal cap cells to functional retinal cells. The aim of this study is to determine the intracellular molecular events that occur during this conversion. Surprisingly, blocking BMP signaling alone failed to mimic Noggin treatment. Overexpressing Noggin in pluripotent cells resulted in a concentration-dependent suppression of both Smad1 and Smad2 phosphorylation, which act downstream of BMP and Activin signaling, respectively. This caused a decrease in downstream targets: endothelial marker, xk81, and mesodermal marker, xbra. We treated pluripotent cells with dominant-negative receptors or the chemical inhibitors, dorsomorphin and SB431542, which each target either the BMP or Activin signaling pathway. We determined the effect of these treatments on retina formation using the Animal Cap Transplant (ACT) assay; in which treated pluripotent cells were transplanted into the eye field of host embryos. We found that inhibition of Activin signaling, in the presence of BMP signaling inhibition, promotes efficient retinal specification in Xenopus tissue, mimicking the affect of adding Noggin alone. In whole embryos, we found that the eye field marker, rax, expanded when adding both dominant-negative Smad1 and Smad2, as did treating the cells with both dorsomorphin and SB431542. Future studies could translate these findings to a mammalian culture assay, in order to more efficiently produce retinal cells in culture.
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Affiliation(s)
- Kimberly A Wong
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA The Center for Vision Research, SUNY Eye Institute, Upstate Medical University, Syracuse, NY 13210, USA
| | - Michael Trembley
- Department of Pharmacology and Physiology, Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Syafiq Abd Wahab
- Department of Molecular Biology, Weill Cornell Graduate School of Medical Sciences, New York, NY 10021, USA
| | - Andrea S Viczian
- Department of Ophthalmology, SUNY Upstate Medical University, Syracuse, NY 13210, USA Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA The Center for Vision Research, SUNY Eye Institute, Upstate Medical University, Syracuse, NY 13210, USA
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