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Degitz SJ, Olker JH, Denny JS, Degoey PP, Hartig PC, Cardon MC, Eytcheson SA, Haselman JT, Mayasich SA, Hornung MW. In vitro screening of per- and polyfluorinated substances (PFAS) for interference with seven thyroid hormone system targets across nine assays. Toxicol In Vitro 2024; 95:105762. [PMID: 38072180 DOI: 10.1016/j.tiv.2023.105762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/31/2023] [Accepted: 12/05/2023] [Indexed: 12/30/2023]
Abstract
The US Environmental Protection Agency is evaluating the ecological and toxicological effects of per- and polyfluorinated chemicals. A number of perfluorinated chemicals have been shown to impact the thyroid axis in vivo suggesting that the thyroid hormone system is a target of these chemicals. The objective of this study was to evaluate the activity of 136 perfluorinated chemicals at seven key molecular initiating events (MIE) within the thyroid axis using nine in vitro assays. The potential MIE targets investigated are Human Iodothyronine Deiodinase 1 (hDIO1), Human Iodothyronine Deiodinase 2 (hDIO2), Human Iodothyronine Deiodinase 3 (hDIO3), Xenopus Iodothyronine Deiodinase (xDIO3); Human Iodotyrosine Deiodinase (hIYD), Xenopus Iodotyrosine Deiodinase (xIYD), Human Thyroid Peroxidase (hTPO); and the serum binding proteins Human Transthyretin (hTTR) and Human Thyroxine Binding Globulin (hTBG). Of the 136 PFAS chemicals tested, 85 had sufficient activity to produce a half-maximal effect concentration (EC50) in at least one of the nine assays. In general, most of these PFAS chemicals did not have strong potency towards the seven MIEs examined, apart from transthyretin binding, for which several PFAS had potency similar to the respective model inhibitor. These data sets identify potentially active PFAS chemicals to prioritize for further testing in orthogonal in vitro assays and at higher levels of biological organization to evaluate their capacity for altering the thyroid hormone system and causing potential adverse health and ecological effects.
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Affiliation(s)
- Sigmund J Degitz
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA.
| | - Jennifer H Olker
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Jeffery S Denny
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Philip P Degoey
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Phillip C Hartig
- US Environmental Protection Agency, Office of Research and Development Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27709, USA
| | - Mary C Cardon
- US Environmental Protection Agency, Office of Research and Development Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27709, USA
| | - Stephanie A Eytcheson
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Jonathan T Haselman
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Sally A Mayasich
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Michael W Hornung
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
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Mayasich SA, Goldsmith MR, Mattingly KZ, LaLone CA. Combining In Vitro and In Silico New Approach Methods to Investigate Type 3 Iodothyronine Deiodinase Chemical Inhibition Across Species. Environ Toxicol Chem 2023; 42:1032-1048. [PMID: 36825751 PMCID: PMC10895443 DOI: 10.1002/etc.5591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
New approach methodologies (NAMs) are being developed to reduce and replace vertebrate animal testing in support of ecotoxicology and risk assessment. The US Environmental Protection Agency's Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS) bioinformatic tool was used to evaluate amino acid sequence conservation of the type 3 iodothyronine deiodinase (DIO3) enzyme across species to demonstrate NAM applications for understanding effects of chemical interactions with a specific protein target. Existing literature was used to identify critical amino acids for thyroid hormone binding and interaction with a reducing cofactor. The SeqAPASS tool identifies whether known critical amino acids involved in ligand binding are exact, partial, or not matches across species compared with a template species based on molecular weight and side chain classification. This evaluation guided the design of variant proteins representing critical amino acid substitutions found in various species. Site-directed mutagenesis of the wild-type (WT) human DIO3 gene sequence was used to create six variant proteins expressed in cell culture, which were then tested in vitro for chemical inhibition. Significant differences in in vitro median inhibitory concentration results were observed among variants for potential competitive inhibitors. A molecular model representing the WT human DIO3 was constructed using Molecular Operating Environment (MOE) software and mutated in silico to create the six variants. The MOE Site Finder tool identified the proposed catalytic and cofactor sites and potential alternative binding sites. Virtual docking did not provide affinity scores with sufficient resolution to rank the potency of the chemical inhibitors. Chemical characteristics, function and location of substituted amino acids, and complexities of the protein target are important considerations in developing NAMs to evaluate chemical susceptibility across species. Environ Toxicol Chem 2023;42:1032-1048. © 2023 University of Wisconsin-Madison. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
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Affiliation(s)
- Sally A. Mayasich
- Aquatic Sciences Center, University of Wisconsin‐Madison, Madison, Wisconsin, USA
- Office of Research and Development, Center for Computational Toxicology and Ecology, Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - Michael R. Goldsmith
- Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina
- Congruence Therapeutics, Montreal, Quebec, Canada
| | | | - Carlie A. LaLone
- Office of Research and Development, Center for Computational Toxicology and Ecology, Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
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Clerbaux LA, Mayasich SA, Muñoz A, Soares H, Petrillo M, Albertini MC, Lanthier N, Grenga L, Amorim MJ. Gut as an Alternative Entry Route for SARS-CoV-2: Current Evidence and Uncertainties of Productive Enteric Infection in COVID-19. J Clin Med 2022; 11:5691. [PMID: 36233559 PMCID: PMC9573230 DOI: 10.3390/jcm11195691] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/17/2022] [Accepted: 09/20/2022] [Indexed: 12/15/2022] Open
Abstract
The gut has been proposed as a potential alternative entry route for SARS-CoV-2. This was mainly based on the high levels of SARS-CoV-2 receptor expressed in the gastrointestinal (GI) tract, the observations of GI disorders (such as diarrhea) in some COVID-19 patients and the detection of SARS-CoV-2 RNA in feces. However, the underlying mechanisms remain poorly understood. It has been proposed that SARS-CoV-2 can productively infect enterocytes, damaging the intestinal barrier and contributing to inflammatory response, which might lead to GI manifestations, including diarrhea. Here, we report a methodological approach to assess the evidence supporting the sequence of events driving SARS-CoV-2 enteric infection up to gut adverse outcomes. Exploring evidence permits to highlight knowledge gaps and current inconsistencies in the literature and to guide further research. Based on the current insights on SARS-CoV-2 intestinal infection and transmission, we then discuss the potential implication on clinical practice, including on long COVID. A better understanding of the GI implication in COVID-19 is still needed to improve disease management and could help identify innovative therapies or preventive actions targeting the GI tract.
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Affiliation(s)
| | - Sally A. Mayasich
- University of Wisconsin-Madison Aquatic Sciences Center at US EPA, Duluth, MN 55804, USA
| | - Amalia Muñoz
- European Commission, Joint Research Centre (JRC), 2440 Geel, Belgium
| | - Helena Soares
- Laboratory of Human Immunobiology and Pathogenesis, iNOVA4Health, Faculdade de Ciências Médicas—Nova Medical School, Universidade Nova de Lisboa, 1099-085 Lisbon, Portugal
| | | | | | - Nicolas Lanthier
- Laboratory of Hepatogastroenterology, Service d’Hépato-Gastroentérologie, Cliniques Universitaires Saint-Luc, UCLouvain, 1200 Brussels, Belgium
| | - Lucia Grenga
- Département Médicaments et Technologies pour la Santé, Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université Paris-Saclay, 91190 Paris, France
| | - Maria-Joao Amorim
- Instituto Gulbenkian de Ciência, 2780-156 Lisbon, Portugal
- Católica Biomedical Research Centre, Católica Medical School, Universidade Católica Portuguesa, 1649-023 Lisbon, Portugal
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Clerbaux LA, Amigó N, Amorim MJ, Bal-Price A, Batista Leite S, Beronius A, Bezemer GFG, Bostroem AC, Carusi A, Coecke S, Concha R, Daskalopoulos EP, De Bernardi F, Edrosa E, Edwards SW, Filipovska J, Garcia-Reyero N, Gavins FNE, Halappanavar S, Hargreaves AJ, Hogberg HT, Huynh MT, Jacobson D, Josephs-Spaulding J, Kim YJ, Kong HJ, Krebs CE, Lam A, Landesmann B, Layton A, Lee YO, Macmillan DS, Mantovani A, Margiotta-Casaluci L, Martens M, Masereeuw R, Mayasich SA, Mei LM, Mortensen H, Munoz Pineiro A, Nymark P, Ohayon E, Ojasi J, Paini A, Parissis N, Parvatam S, Pistollato F, Sachana M, Sørli JB, Sullivan KM, Sund J, Tanabe S, Tsaioun K, Vinken M, Viviani L, Waspe J, Willett C, Wittwehr C. COVID-19 through Adverse Outcome Pathways: Building networks to better understand the disease - 3rd CIAO AOP Design Workshop. ALTEX 2022; 39:322–335. [PMID: 35032963 PMCID: PMC10069302 DOI: 10.14573/altex.2112161] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 02/07/2023]
Abstract
On April 28-29, 2021, 50 scientists from different fields of expertise met for the 3rd online CIAO workshop. The CIAO project “Modelling the Pathogenesis of COVID-19 using the Adverse Outcome Pathway (AOP) framework” aims at building a holistic assembly of the available scientific knowledge on COVID-19 using the AOP framework. An individual AOP depicts the disease progression from the initial contact with the SARS-CoV-2 virus through biological key events (KE) toward an adverse outcome such as respiratory distress, anosmia or multiorgan failure. Assembling the individual AOPs into a network highlights shared KEs as central biological nodes involved in multiple outcomes observed in COVID-19 patients. During the workshop, the KEs and AOPs established so far by the CIAO members were presented and positioned on a timeline of the disease course. Modulating factors influencing the progression and severity of the disease were also addressed as well as factors beyond purely biological phenomena. CIAO relies on an interdisciplinary crowdsourcing effort, therefore, approaches to expand the CIAO network by widening the crowd and reaching stakeholders were also discussed. To conclude the workshop, it was decided that the AOPs/KEs will be further consolidated, integrating virus variants and long COVID when relevant, while an outreach campaign will be launched to broaden the CIAO scientific crowd.
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Affiliation(s)
| | | | | | - Anna Bal-Price
- European Commission, Joint Research Centre, Ispra, Italy
| | | | - Anna Beronius
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | | | | | - Sandra Coecke
- European Commission, Joint Research Centre, Ispra, Italy
| | - Rachel Concha
- Fairleigh Dickinson University, Green Neuroscience Laboratory, San Diego, CA, USA
| | | | - Francesca De Bernardi
- Division of Otorhinolaryngology, Department of Biotechnologies and Life Sciences, University of Insubria, Ospedale di Circolo e Fondazione Macchi, Varese, Italy
| | - Eizleayne Edrosa
- Green Neuroscience Laboratory, Neurolinx Research Institute, San Diego, CA, USA
| | | | | | | | - Felicity N E Gavins
- The Centre for Inflammation Research and Translational Medicine (CIRTM), Brunel University London, London, UK
| | - Sabina Halappanavar
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Alan J Hargreaves
- School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Helena T Hogberg
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Mylène T Huynh
- Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Daniel Jacobson
- Biosciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | | | - Young Jun Kim
- Korea Institute of Science and Technology Europe Forschungsgesellschaft mbH, Saarbrücken, Germany
| | - Hyun Joon Kong
- University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | | | - Ann Lam
- Green Neuroscience Laboratory, Neurolinx Research Institute, San Diego, CA, USA
| | | | | | - Yong Oh Lee
- Korea Institute of Science and Technology Europe Forschungsgesellschaft mbH, Saarbrücken, Germany
| | | | | | - Luigi Margiotta-Casaluci
- The Centre for Inflammation Research and Translational Medicine (CIRTM), Brunel University London, London, UK
| | - Marvin Martens
- Department of Bioinformatics - BiGCaT, NUTRIM, Maastricht University, Maastricht, The Netherlands
| | - Rosalinde Masereeuw
- Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - Sally A Mayasich
- University of Wisconsin-Madison Aquatic Sciences Center at US EPA, Duluth, MN, USA
| | | | | | | | - Penny Nymark
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Elan Ohayon
- Green Neuroscience Laboratory, Neurolinx Research Institute, San Diego, CA, USA
| | - Joshi Ojasi
- Hiranandani College of Pharmacy, Mumbai, India
| | - Alicia Paini
- European Commission, Joint Research Centre, Ispra, Italy
| | | | - Surat Parvatam
- Centre for Predictive Human Model Systems Atal Incubation Centre - Centre for Cellular and Molecular Biology Habsiguda, Hyderabad, India
| | | | - Magdalini Sachana
- Environment Health and Safety Division, Environment Directorate, Organisation for Economic Cooperation and Development (OECD), Paris, France
| | | | | | - Jukka Sund
- European Commission, Joint Research Centre, Ispra, Italy
| | - Shihori Tanabe
- Division of Risk Assessment, Center for Biological Safety and Research, National Institute of Health Sciences, Kawasaki, Japan
| | - Katya Tsaioun
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Mathieu Vinken
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
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Mayasich SA, Korte JJ, Denny JS, Hartig PC, Olker JH, DeGoey P, O'Flanagan J, Degitz SJ, Hornung MW. Xenopus laevis and human type 3 iodothyronine deiodinase enzyme cross-species sensitivity to inhibition by ToxCast chemicals. Toxicol In Vitro 2021; 73:105141. [PMID: 33713820 DOI: 10.1016/j.tiv.2021.105141] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/12/2021] [Accepted: 03/08/2021] [Indexed: 11/15/2022]
Abstract
Deiodinase enzymes are critical for tissue-specific and temporal control of activation or inactivation of thyroid hormones during vertebrate development, including amphibian metamorphosis. We previously screened ToxCast chemicals for inhibitory activity toward human recombinant Type 3 iodothyronine deiodinase enzyme (hDIO3) and subsequently produced Xenopus laevis recombinant dio3 enzyme (Xldio3) with the goals to identify specific chemical inhibitors of Xldio3, to evaluate cross-species sensitivity and explore whether the human assay results are predictive of the amphibian. We identified a subset of 356 chemicals screened against hDIO3 to test against Xldio3, initially at a single concentration (200 μM), and further tested 79 in concentration-response mode. Most chemicals had IC50 values lower for hDIO3 than for Xldio3 and many had steep Hill slopes (a potential indication of non-specific inhibition). However, eight of the most potent chemicals are likely specific inhibitors, with IC50 values of 14 μM or less, Hill slopes near -1 and curves not significantly different between species likely due to conservation of catalytically active amino acids. Controlling for assay conditions, human in vitro screening results can be predictive of activity in the amphibian assay. This study lays the groundwork for future studies using recombinant non-mammalian proteins to test cross-species sensitivity to chemicals. DISCLAIMER: The views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
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Affiliation(s)
- Sally A Mayasich
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA; Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Joseph J Korte
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Jeffrey S Denny
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Phillip C Hartig
- Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jennifer H Olker
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Philip DeGoey
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Joseph O'Flanagan
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA; Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Sigmund J Degitz
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA
| | - Michael W Hornung
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, MN, USA.
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Mayasich SA, Clarke BL. Vasotocin and the origins of the vasopressin/oxytocin receptor gene family. Vitamins and Hormones 2020; 113:1-27. [DOI: 10.1016/bs.vh.2019.08.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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Mayasich SA, Clarke BL. The emergence of the vasopressin and oxytocin hormone receptor gene family lineage: Clues from the characterization of vasotocin receptors in the sea lamprey (Petromyzon marinus). Gen Comp Endocrinol 2016; 226:88-101. [PMID: 26764211 DOI: 10.1016/j.ygcen.2016.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 12/31/2015] [Accepted: 01/02/2016] [Indexed: 01/01/2023]
Abstract
The sea lamprey (Petromyzon marinus) is a jawless vertebrate at an evolutionary nexus between invertebrates and jawed vertebrates. Lampreys are known to possess the arginine vasotocin (AVT) hormone utilized by all non-mammalian vertebrates. We postulated that the lamprey would possess AVT receptor orthologs of predecessors to the arginine vasopressin (AVP)/oxytocin (OXT) family of G protein-coupled receptors found in mammals, providing insights into the origins of the mammalian V1A, V1B, V2 and OXT receptors. Among the earliest animals to diverge from the vertebrate lineage in which these receptors are characterized is the jawed, cartilaginous elephant shark, which has genes orthologous to all four mammalian receptor types. Therefore, our work was aimed at helping resolve the critical gap concerning the outcomes of hypothesized large-scale (whole-genome) duplication events. We sequenced one partial and four full-length putative lamprey AVT receptor genes and determined their mRNA expression patterns in 15 distinct tissues. Phylogenetically, three of the full-coding genes possess structural characteristics of the V1 clade containing the V1A, V1B and OXT receptors. Another full-length coding gene and the partial sequence are part of the V2 clade and appear to be most closely related to the newly established V2B and V2C receptor subtypes. Our synteny analysis also utilizing the Japanese lamprey (Lethenteron japonicum) genome supports the recent proposal that jawless and jawed vertebrates shared one-round (1R) of WGD as the most likely scenario.
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Affiliation(s)
- Sally A Mayasich
- Department of Biomedical Sciences, School of Medicine, University of Minnesota-Duluth, 1035 University Drive, Duluth, MN 55812, USA.
| | - Benjamin L Clarke
- Department of Biomedical Sciences, School of Medicine, University of Minnesota-Duluth, 1035 University Drive, Duluth, MN 55812, USA.
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Mayasich SA, Smucker RA. Role ofCristispira sp. and other bacteria in the chitinase and chitobiase activities of the crystalline style ofCrassostrea virginica (Gmelin). Microb Ecol 1987; 14:157-166. [PMID: 24202643 DOI: 10.1007/bf02013020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Activity was found for chitinase and chitobiase in the crystalline styles of American oysters (Crassostrea virginica Gmelin) collected from the Chesapeake Bay (Maryland, USA). The oysters were maintained in tanks on natural food from a constant flow of unfiltered estuarine water. Chitinase and chitobiase specific activities were compared with total, viable, and chitinoclastic bacterial counts andCristispira counts. Regression analyses revealed that one correlation, chitobiase vsCristispira, was significant (P < 0.05). Several oysters were fed chitin in the presence or absence of chloramphenicol. Although no chitinoclasts were present in the antibiotic-treated oysters, the treatment means did not differ significantly (P > 0.05) for either chitinase or chitobiase activity. In several cases with both chitin-fed and naturally fed oysters, enzyme activity was found when noCristispira were present. The results of the investigations suggest that the oyster produces chitinase and chitobiase endogenously.
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Affiliation(s)
- S A Mayasich
- Chesapeake Biological Laboratory, University of Maryland, P.O. Box 38, 20688, Solomons, Maryland, USA
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