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Magalhães-Sant'Ana M, More SJ, Morton DB, Osborne M, Hanlon A. What do European veterinary codes of conduct actually say and mean? A case study approach. Vet Rec 2015; 176:654. [PMID: 25861823 DOI: 10.1136/vr.103005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2015] [Indexed: 11/04/2022]
Abstract
Codes of Professional Conduct (CPCs) are pivotal instruments of self-regulation, providing the standards to which veterinarians should, and sometimes must, comply. Despite their importance to the training and guidance of veterinary professionals, research is lacking on the scope and emphasis of the requirements set out in veterinary CPCs. This paper provides the first systematic investigation of veterinary CPCs. It relies on a case study approach, combining content and thematic analyses of five purposively selected European CPCs: Federation of Veterinarians of Europe (FVE), Denmark, Ireland, Portugal and the UK. Eight overarching themes were identified, including 'definitions and framing concepts', 'duties to animals', 'duties to clients', 'duties to other professionals', 'duties to competent authorities', 'duties to society', 'professionalism' and 'practice-related issues'. Some differences were observed, which may be indicative of different approaches to the regulation of the veterinary profession in Europe (which is reflected in having a 'code of ethics' or a 'code of conduct'), cultural differences on the status of animals in society, and regulatory bodies' proactivity in adapting to professional needs and to societal changes regarding the status of animals. These findings will contribute to an improved understanding of the roles of CPCs in regulating the veterinary profession in Europe.
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Part CE, Kiddie JL, Hayes WA, Mills DS, Neville RF, Morton DB, Collins LM. Physiological, physical and behavioural changes in dogs (Canis familiaris) when kennelled: testing the validity of stress parameters. Physiol Behav 2014; 133:260-71. [PMID: 24866912 DOI: 10.1016/j.physbeh.2014.05.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 05/09/2014] [Accepted: 05/16/2014] [Indexed: 11/17/2022]
Abstract
Domestic dogs (Canis familiaris) housed in kennelling establishments are considered at risk of suffering poor welfare. Previous research supporting this hypothesis has typically used cortisol:creatinine ratios (C/Cr) to measure acute and chronic stress in kennelled dogs. However, the value of C/Cr as a welfare indicator has been questioned. This study aimed to test the validity of a range of physiological, physical and behavioural welfare indicators and to establish baseline values reflecting good dog welfare. Measurements were taken from 29 privately-owned dogs (14 males, 15 females), ranging in age and breed, in their own home and in a boarding kennel environment, following a within-subjects, counterbalanced design. Pairwise comparisons revealed that C/Cr and vanillylmandelic acid:creatinine ratios (VMA/Cr) were higher in the kennel than home environment (P=0.003; P=0.01, respectively) and were not associated with differences in movement/exercise between environments. Dogs' surface temperature was lower in kennels (P=0.001) and was not associated with ambient temperature. No association with age, or effects of kennel establishment, kennelling experience, sex or source were found. Dogs were generally more active in kennels, but showed considerable individual variability. C/Cr and 5-HIAA:creatinine ratios (5-HIAA/Cr) were negatively correlated with lip licking in kennels. Baseline values for each parameter are presented. The emotional valence of responses was ambiguous and no definitive evidence was found to suggest that dogs were negatively stressed by kennelling. It was concluded that C/Cr and, particularly, VMA/Cr and surface temperature provide robust indicators of psychological arousal in dogs, while spontaneous behaviour might be better used to facilitate interpretation of physiological and physical data on an individual level.
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Chang JC, Hazelett DJ, Stewart JA, Morton DB. Motor neuron expression of the voltage-gated calcium channel cacophony restores locomotion defects in a Drosophila, TDP-43 loss of function model of ALS. Brain Res 2013; 1584:39-51. [PMID: 24275199 DOI: 10.1016/j.brainres.2013.11.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Revised: 10/29/2013] [Accepted: 11/17/2013] [Indexed: 12/11/2022]
Abstract
Dysfunction of the RNA-binding protein, TDP-43, is strongly implicated as a causative event in many neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). TDP-43 is normally found in the nucleus and pathological hallmarks of ALS include the presence of cytoplasmic protein aggregates containing TDP-43 and an associated loss of TDP-43 from the nucleus. Loss of nuclear TDP-43 likely contributes to neurodegeneration. Using Drosophila melanogaster to model TDP-43 loss of function, we show that reduced levels of the voltage-gated calcium channel, cacophony, mediate some of the physiological effects of TDP-43 loss. Null mutations in the Drosophila orthologue of TDP-43, named TBPH, resulted in defective larval locomotion and reduced levels of cacophony protein in whole animals and at the neuromuscular junction. Restoring the levels of cacophony in all neurons or selectively in motor neurons rescued these locomotion defects. Using TBPH immunoprecipitation, we showed that TBPH associates with cacophony transcript, indicating that it is likely to be a direct target for TBPH. Loss of TBPH leads to reduced levels of cacophony transcript, possibly due to increased degradation. In addition, TBPH also appears to regulate the inclusion of some alternatively spliced exons of cacophony. If similar effects of cacophony or related calcium channels are found in human ALS patients, these could be targets for the development of pharmacological therapies for ALS.
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Morton DB. A Risk Assessment Approach to Severity Classification in Animal Research. Altern Lab Anim 2012; 40:P2-3. [DOI: 10.1177/026119291204000510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Morton DB. Behavioral responses to hypoxia and hyperoxia in Drosophila larvae: molecular and neuronal sensors. Fly (Austin) 2011; 5:119-25. [PMID: 21150317 DOI: 10.4161/fly.5.2.14284] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The ability to detect changes in oxygen concentration in the environment is critical to the survival of all animals. This requires cells to express a molecular oxygen sensor that can detect shifts in oxygen levels and transmit a signal that leads to the appropriate cellular response. Recent biochemical, genetic and behavioral studies have shown that the atypical soluble guanylyl cyclases function as oxygen detectors in Drosophila larvae triggering a behavioral escape response when exposed to hypoxia. These studies also identified the sensory neurons that innervate the terminal sensory cones as likely chemosensors that mediate this response. Here I summarize the data that led to these conclusions and also highlight evidence that suggests additional, as yet unidentified, proteins are also required for detecting increases and decreases in oxygen concentrations.
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Vermehren-Schmaedick A, Scudder C, Timmermans W, Morton DB. Drosophila gustatory preference behaviors require the atypical soluble guanylyl cyclases. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2011; 197:717-27. [PMID: 21350862 DOI: 10.1007/s00359-011-0634-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 02/08/2011] [Accepted: 02/13/2011] [Indexed: 11/27/2022]
Abstract
The intracellular messenger cGMP has been suggested to play a role in taste signal transduction in both vertebrates and invertebrates. In the present study, we have examined the role of the Drosophila atypical soluble guanylyl cyclases (sGCs), Gyc-89Da and Gyc-89Db, in larval and adult gustatory preference behaviors. We showed that in larvae, sucrose attraction requires Gyc-89Db and caffeine avoidance requires Gyc-89Da. In adult flies, sucrose attraction is unaffected by mutations in either gene whereas avoidance of low concentrations of caffeine is eliminated by loss of either gene. Similar defective behaviors were observed when cGMP increases were prevented by the expression of a cGMP-specific phosphodiesterase. We also showed that both genes were expressed in gustatory receptor neurons (GRNs) in larval and adult gustatory organs, primarily in a non-overlapping pattern, with the exception of a small group of cells in the adult labellum. In addition, in adults, several cells co-expressed the bitter taste receptor, Gr66a, with either Gyc-89Da or Gyc-89Db. We also showed that the electrophysiological responses of a GRN to caffeine were significantly reduced in flies mutant for the atypical sGCs, suggesting that at least part of the adult behavioral defects were due to a reduced ability to detect caffeine.
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Hawkins P, Morton DB, Burman O, Dennison N, Honess P, Jennings M, Lane S, Middleton V, Roughan JV, Wells S, Westwood K. A guide to defining and implementing protocols for the welfare assessment of laboratory animals: eleventh report of the BVAAWF/FRAME/RSPCA/UFAW Joint Working Group on Refinement. Lab Anim 2011; 45:1-13. [PMID: 21123303 DOI: 10.1258/la.2010.010031] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The refinement of husbandry and procedures to reduce animal suffering and improve welfare is an essential component of humane science. Successful refinement depends upon the ability to assess animal welfare effectively, and detect any signs of pain or distress as rapidly as possible, so that any suffering can be alleviated. This document provides practical guidance on setting up and operating effective protocols for the welfare assessment of animals used in research and testing. It sets out general principles for more objective observation of animals, recognizing and assessing indicators of pain or distress and tailoring these to individual projects. Systems for recording indicators, including score sheets, are reviewed and guidance is set out on determining practical monitoring regimes that are more likely to detect any signs of suffering. This guidance is intended for all staff required to assess or monitor animal welfare, including animal technologists and care staff, veterinarians and scientists. It will also be of use to members of ethics or animal care and use committees. A longer version of this document, with further background information and extra topics including training and information sharing, is available on the Laboratory Animals website.
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Morton DB. A commentary on the animal welfare symposium, with possible actions. JOURNAL OF VETERINARY MEDICAL EDUCATION 2010; 37:107-113. [PMID: 20378888 DOI: 10.3138/jvme.37.1.107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The author analyzes the common themes addressed by speakers at the AVMA/AAVMC conference on animal welfare, adding a few comments of his own. These themes can be summarized in the basic statement that "the veterinary profession has a responsibility to its members and to the public to provide and ensure a good education in animal welfare science, ethics, and public policy and law." Veterinarians have a special role as animals' advocates for several reasons: they have the knowledge base and the required skills and commitment to fulfill this role; they have earned the confidence and respect of the constituents they serve; they are the professionals to whom policy makers logically turn for guidance on animal health and welfare issues. Therefore, the veterinary profession has an opportunity to reassert itself as the advocate not only for animals' physical health but also for their mental health and welfare. To be successful, however, the profession's leadership and members must engage without delay in advancing educational programs, research projects, and outreach to solidify authority in this key component of veterinary medicine.
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Jennings M, Prescott MJ, Buchanan-Smith HM, Gamble MR, Gore M, Hawkins P, Hubrecht R, Hudson S, Jennings M, Keeley JR, Morris K, Morton DB, Owen S, Pearce PC, Prescott MJ, Robb D, Rumble RJ, Wolfensohn S, Buist D. Refinements in husbandry, care and common procedures for non-human primates: Ninth report of the BVAAWF/FRAME/RSPCA/UFAW Joint Working Group on Refinement. Lab Anim 2009; 43 Suppl 1:1-47. [PMID: 19286892 DOI: 10.1258/la.2008.007143] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Preface Whenever animals are used in research, minimizing pain and distress and promoting good welfare should be as important an objective as achieving the experimental results. This is important for humanitarian reasons, for good science, for economic reasons and in order to satisfy the broad legal principles in international legislation. It is possible to refine both husbandry and procedures to minimize suffering and improve welfare in a number of ways, and this can be greatly facilitated by ensuring that up-to-date information is readily available. The need to provide such information led the British Veterinary Association Animal Welfare Foundation (BVAAWF), the Fund for the Replacement of Animals in Medical Experiments (FRAME), the Royal Society for the Prevention of Cruelty to Animals (RSPCA) and the Universities Federation for Animal Welfare (UFAW) to establish a Joint Working Group on Refinement (JWGR) in the UK. The chair is Professor David Morton and the secretariat is provided by the RSPCA. This report is the ninth in the JWGR series. The RSPCA is opposed to the use of animals in experiments that cause pain, suffering, distress or lasting harm and together with FRAME has particular concerns about the continued use of non-human primates. The replacement of primate experiments is a primary goal for the RSPCA and FRAME. However, both organizations share with others in the Working Group, the common aim of replacing primate experiments wherever possible, reducing suffering and improving welfare while primate use continues. The reports of the refinement workshops are intended to help achieve these aims. This report produced by the British Veterinary Association Animal Welfare Foundation (BVAAWF)/Fund for the Replacement of Animals in Medical Experiments (FRAME)/Royal Society for the Prevention of Cruelty to Animals (RSPCA)/Universities Federation for Animal Welfare (UFAW) Joint Working Group on Refinement (JWGR) sets out practical guidance on refining the husbandry and care of non-human primates (hereinafter primates) and on minimizing the adverse effects of some common procedures. It provides a valuable resource to help understand the physical, social and behavioural characteristics and needs of individual primates, and is intended to develop and complement the existing literature and legislative guidelines. Topics covered include refinements in housing, husbandry and common procedures such as restraint, identification and sampling, with comprehensive advice on issues such as primate communication, assessing and facilitating primate wellbeing, establishing and maintaining social groups, environmental and nutritional enrichment and animal passports. The most commonly used species are the key focus of this resource, but its information and recommendations are generally applicable to other species, provided that relevant individual species characteristics are taken into account.
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Abstract
Human minisatellite probes consisting of tandem repeats of the 'core' sequence, a putative recombination signal in human DNA, cross-hybridize to multiple polymorphic fragments in dog and cat DNA to produce individual-specific DNA 'fingerprints'. Pedigree analysis shows that most of the DNA fragments detected in an individual are heterozygous, and that these fragments are derived from multiple dispersed autosomal loci. DNA fingerprints of cats and dogs should prove suitable for individual identification and for establishing family relationships. They are also suitable for rapid marker generation in large pedigrees and could be applied to linkage analysis in these animals.
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Zimmer M, Gray JM, Pokala N, Chang AJ, Karow DS, Marletta MA, Hudson ML, Morton DB, Chronis N, Bargmann CI. Neurons detect increases and decreases in oxygen levels using distinct guanylate cyclases. Neuron 2009; 61:865-79. [PMID: 19323996 DOI: 10.1016/j.neuron.2009.02.013] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 01/02/2009] [Accepted: 02/10/2009] [Indexed: 11/26/2022]
Abstract
Homeostatic sensory systems detect small deviations in temperature, water balance, pH, and energy needs to regulate adaptive behavior and physiology. In C. elegans, a homeostatic preference for intermediate oxygen (O2) levels requires cGMP signaling through soluble guanylate cyclases (sGCs), proteins that bind gases through an associated heme group. Here we use behavioral analysis, functional imaging, and genetics to show that reciprocal changes in O2 levels are encoded by sensory neurons that express alternative sets of sGCs. URX sensory neurons are activated by increases in O2 levels, and require the sGCs gcy-35 and gcy-36. BAG sensory neurons are activated by decreases in O2 levels, and require the sGCs gcy-31 and gcy-33. The sGCs are instructive O2 sensors, as forced expression of URX sGC genes causes BAG neurons to detect O2 increases. Both sGC expression and cell-intrinsic dynamics contribute to the differential roles of URX and BAG in O2-dependent behaviors.
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Morton DB, Stewart JA, Langlais KK, Clemens-Grisham RA, Vermehren A. Synaptic transmission in neurons that express the Drosophila atypical soluble guanylyl cyclases, Gyc-89Da and Gyc-89Db, is necessary for the successful completion of larval and adult ecdysis. ACTA ACUST UNITED AC 2008; 211:1645-56. [PMID: 18456892 DOI: 10.1242/jeb.014472] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Insect ecdysis is a precisely coordinated series of behavioral and hormonal events that occur at the end of each molt. A great deal is known about the hormonal events that underlie this process, although less is known about the neuronal circuitry involved. In this study we identified two populations of neurons that are required for larval and adult ecdyses in the fruit fly, Drosophila melanogaster (Meigen). These neurons were identified by using the upstream region of two genes that code for atypical soluble guanylyl cyclases to drive tetanus toxin in the neurons that express these cyclases to block their synaptic activity. Expression of tetanus toxin in neurons that express Gyc-89Da blocked adult eclosion whereas expression of tetanus toxin in neurons that express Gyc-89Db prevented the initiation of the first larval ecdysis. Expression of tetanus toxin in the Gyc-89Da neurons also resulted in about 50% lethality just prior to pupariation; however, this was probably due to suffocation in the food as lethality was prevented by stopping the larvae from burrowing deep within the food. This result is consistent with our model that the atypical soluble guanylyl cyclases can act as molecular oxygen detectors. The expression pattern of these cyclases did not overlap with any of the neurons containing peptides known to regulate ecdysis and eclosion behaviors. By using the conditional expression of tetanus toxin we were also able to demonstrate that synaptic activity in the Gyc-89Da and Gyc-89Db neurons is required during early adult development for adult eclosion.
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Morton DB. Vaccines and animal welfare. REV SCI TECH OIE 2007; 26:157-63. [PMID: 17633300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Vaccination promotes animal welfare by protecting animal health, but it also has other welfare benefits, e.g. recent investigations have looked at the potential of vaccines in immunoneutering such as immunocastration--a humane alternative to the painful traditional methods. Similarly, vaccination can be used during disease outbreaks as a viable alternative to stamping-out, thus avoiding the welfare problems that on-farm mass slaughter can cause. Protecting animal health through vaccination leads to improved animal welfare, and maintaining good welfare ensures that animals can respond successfully to vaccination (as poor welfare can lead to immunosuppression, which can affect the response to vaccination). It is clear that vaccination has tremendous advantages for animal welfare and although the possible side effects of vaccination can have a negative effect on the welfare of some individual animals, the harm caused by these unwanted effects must be weighed against the undoubted benefits for groups of animals.
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Wells DJ, Playle LC, Enser WEJ, Flecknell PA, Gardiner MA, Holland J, Howard BR, Hubrecht R, Humphreys KR, Jackson IJ, Lane N, Maconochie M, Mason G, Morton DB, Raymond R, Robinson V, Smith JA, Watt N. Assessing the welfare of genetically altered mice. Lab Anim 2006; 40:111-4. [PMID: 16600070 DOI: 10.1258/002367706776318971] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In 2003, under the auspices of the main UK funders of biological and biomedical research, a working group was established with a remit to review potential welfare issues for genetically altered (GA) mice, to summarize current practice, and to recommend contemporary best practice for welfare assessments. The working group has produced a report which makes practical recommendations for GA mouse welfare assessment and dissemination of welfare information between establishments using a 'mouse passport'. The report can be found at www.nc3rs.org.uk/GAmice and www.lal.org.uk/gaa and includes templates for the recommended welfare assessment scheme and the mouse passport. An overview is provided below.
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Vermehren A, Langlais KK, Morton DB. Oxygen-sensitive guanylyl cyclases in insects and their potential roles in oxygen detection and in feeding behaviors. JOURNAL OF INSECT PHYSIOLOGY 2006; 52:340-8. [PMID: 16427074 DOI: 10.1016/j.jinsphys.2005.12.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Revised: 11/28/2005] [Accepted: 12/05/2005] [Indexed: 05/06/2023]
Abstract
Responses to hypoxia and hyperoxia depend critically on the ability of the animal to detect changes in O2 levels. However, it has only been recently that an O2-sensing system has been identified in invertebrates. Evidence is accumulating that this molecular O2 sensor is, surprisingly, a class of soluble guanylyl cyclase (sGC) known as atypical sGCs. It has long been known that the conventional sGC alpha and beta subunits form heterodimeric enzymes that are potently activated by NO, but do not bind O2. By contrast, the Drosophila melanogaster atypical sGC subunits, Gyc-88E, Gyc-89Da and Gyc-89Db, are only slightly sensitive to NO, but are potently activated under hypoxic conditions. Here we review evidence that suggests that the atypical sGCs can function as molecular O2 sensors mediating behavioral responses to hypoxia. Sequence comparisons of other predicted O2-sensitive sGCs suggest that most, if not all, insects express two heterodimeric sGCs; an NO-sensitive isoform and a separate O2-sensitive isoform. Expression data and recent experiments that block the function of cells that express the atypical sGCs and experiments that reduce the cGMP levels in these cells also suggest a role in behavioral responses to sweet tastants.
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Morton DB, Langlais KK, Stewart JA, Vermehren A. Atypical soluble guanylyl cyclases in Drosophila as neutral oxygen sensors and their involvement in gestation. BMC Pharmacol 2005. [DOI: 10.1186/1471-2210-5-s1-s7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Morton DB, Langlais KK, Stewart JA, Vermehren A. Comparison of the properties of the five soluble guanylyl cyclase subunits in Drosophila melanogaster. JOURNAL OF INSECT SCIENCE (ONLINE) 2005; 5:12. [PMID: 16341244 PMCID: PMC1307573 DOI: 10.1093/jis/5.1.12] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Accepted: 12/05/2004] [Indexed: 05/05/2023]
Abstract
The Drosophila melanogaster genome contains 5 genes that code for soluble guanylyl cyclase subunits. Two of these genes code for subunits, Gycalpha-99B and Gycbeta-100B, which form a conventional NO-sensitive guanylyl cyclase and the other three code for atypical subunits, Gyc-88E, Gyc-89Da and Gyc-89Db. The properties and distribution of Gyc-88E and Gyc-89Db have previously been described and here Gyc-89Da is described. Gyc-89Da only forms an active guanylyl cyclase when co-expressed with Gyc-88E. The three atypical subunits probably form two different heterodimers in vivo: Gyc-88E/89Da and Gyc-88E/89Db. Both of these heterodimers were slightly stimulated by NO donors and Gyc-88E/89Da showed a greater activation by Mn2+, with an increase in Vmax and a decrease in K(m), compared to Gyc-88E/89Db. Both Gyc-88E/89Da and Gyc-88E/89Db were expressed in neurons in both the peripheral and central nervous system. Although all three heterodimeric soluble guanylyl cyclases in D. melanogaster can be activated by NO and inhibited by ODQ, the atypical enzymes can be distinguished from the conventional soluble guanylyl cyclase by their sensitivity to the NO-independent activators YC-1 and BAY 41-2272, which will only activate the conventional enzyme.
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Morton DB. Atypical soluble guanylyl cyclases in Drosophila can function as molecular oxygen sensors. J Biol Chem 2004; 279:50651-3. [PMID: 15485853 DOI: 10.1074/jbc.c400461200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Conventional soluble guanylyl cyclases are heterodimeric enzymes that synthesize cGMP and are activated by nitric oxide. Recently, a separate class of soluble guanylyl cyclases has been identified that are only slightly activated by or are insensitive to nitric oxide. These atypical guanylyl cyclases include the vertebrate beta2 subunit and examples from the invertebrates Manduca sexta, Caenorhabditis elegans, and Drosophila melanogaster. A member of this family, GCY-35 in C. elegans, was recently shown to be required for a behavioral response to low oxygen levels and may be directly regulated by oxygen (Gray, J. M., Karow, D. S., Lu, H., Chang, A. J., Chang, J. S., Ellis, R. E., Marletta, M. A., and Bargmann, C. I. (2004) Nature 430, 317-322). Drosophila contains three genes that code for atypical soluble guanylyl cyclases: Gyc-88E, Gyc-89Da, and Gyc-89Db. COS-7 cells co-transfected with Gyc-88E and Gyc-89Da or Gyc-89Db accumulate low levels of cGMP under normal atmospheric oxygen concentrations and are potently activated under anoxic conditions. The increase in activity is graded over oxygen concentrations of 0-21%, can be detected within 1 min of exposure to anoxic conditions and is blocked by the soluble guanylyl cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ). Gyc-88E and Gyc-89Db are co-expressed in a subset of sensory neurons where they would be ideally situated to act as oxygen sensors. This is the first demonstration of a soluble guanylyl cyclase that is activated in response to changing oxygen concentrations.
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Raj ABM, Leach MC, Morton DB. Carbon dioxide for euthanasia of laboratory animals. Comp Med 2004; 54:470-1. [PMID: 15575359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
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Langlais KK, Stewart JA, Morton DB. Preliminary characterization of two atypical soluble guanylyl cyclases in the central and peripheral nervous system of Drosophila melanogaster. ACTA ACUST UNITED AC 2004; 207:2323-38. [PMID: 15159437 DOI: 10.1242/jeb.01025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Conventional soluble guanylyl cyclases form alpha/beta heterodimers that are activated by nitric oxide (NO). Recently, atypical members of the soluble guanylyl cyclase family have been described that include the rat beta2 subunit and MsGC-beta3 from Manduca sexta. Predictions from the Drosophila melanogaster genome identify three atypical guanylyl cyclase subunits: Gyc-88E (formerly CG4154), Gyc-89Da (formerly CG14885) and Gyc-89Db (formerly CG14886). Preliminary data showed that transient expression of Gyc-88E in heterologous cells generated enzyme activity in the absence of additional subunits that was slightly stimulated by the NO donor sodium nitroprusside (SNP) but not the NO donor DEA-NONOate or the NO-independent activator YC-1. Gyc-89Db was inactive when expressed alone but when co-expressed with Gyc-88E enhanced the basal and SNP-stimulated activity of Gyc-88E, suggesting that they may form heterodimers in vivo. Here, we describe the localization of Gyc-88E and Gyc-89Db and show that they are expressed in the embryonic and larval central nervous systems and are colocalized in several peripheral neurons that innervate trachea, basiconical sensilla and the sensory cones in the posterior segments of the embryo. We also show that there are two splice variants of Gyc-88E that differ by seven amino acids, although no differences in biochemical properties could be determined. We have also extended our analysis of the NO activation of Gyc-88E and Gyc-89Db, showing that several structurally unrelated NO donors activate Gyc-88E when expressed alone or when co-expressed with Gyc-89Db.
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Carbone L, Baumans V, Morton DB. Report of the Workshop on Euthanasia Guidelines and Practices. Altern Lab Anim 2004; 32 Suppl 1B:445-6. [DOI: 10.1177/026119290403201s71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Determining ethical standards for laboratory animal euthanasia requires an assessment of the relative amounts of pain and distress caused by different methods. Animal behaviour data are an important indicator of pain and distress, but their interpretation can be controversial; moreover, behaviour is more easily assessed with some euthanasia methods than with others. While every euthanasia method requires careful study, CO2 inhalation has come under close scrutiny both because it is so widely used for rodent euthanasia, and because it has, until recently, long been considered relatively non-aversive.
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Morton DB. Invertebrates Yield a Plethora of Atypical Guanylyl Cyclases. Mol Neurobiol 2004; 29:97-116. [PMID: 15126679 DOI: 10.1385/mn:29:2:097] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2003] [Accepted: 08/13/2003] [Indexed: 11/11/2022]
Abstract
Invertebrate model systems have a long history of generating new insights into neuronal signaling systems. This review focuses on cyclic GMP signaling and describes recent advances in understanding the properties and functions of guanylyl cyclases in invertebrates. The sequencing of three invertebrate genomes has provided a complete catalog of the guanylyl cyclases in C. elegans, Drosophila, and the mosquito Anopheles gambiae. Using this data and that from cloned guanylyl cyclases in Manduca sexta, C. elegans, and Drosophila, plus predictions and models from vertebrate guanylyl cyclases, evidence is presented that there is a much broader array of properties for these enzymes than previously realized. In addition to the classic homodimeric receptor guanylyl cyclases, C. elegans has at least two receptor guanylyl cyclases that are predicted to require heterodimer formation for activity. Soluble guanylyl cyclases are generally recognized as being obligate heterodimers that are activated by nitric oxide (NO). Some of the soluble guanylyl cyclases in C. elegans may heterodimeric, but all appear to be insensitive to NO. The beta2 soluble guanylyl cyclase subunit in mammals and similar ones in Manduca and Drosophila are active in the absence of additional subunits and there is evidence that Drosophila and Anopheles also express an additional subunit that enhances this activity.
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Morton DB. The Welfare of Non-human Primates in Research in the EU. Altern Lab Anim 2004; 32 Suppl 1A:307. [DOI: 10.1177/026119290403201s50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This summarises a draft report of the Non-human Primate Working Group, prepared for the European Union's Scientific Committee on Animal Health and Welfare. It was formally adopted by the Scientific Committee at their meeting in December 2002, and the full text is available online at http://europa.eu.int/comm/food/fs/sc/scah/out83_en.pdf .
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50
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Johannes S, Hartinger J, Hendriksen CFM, Morton DB, Cussler K. Humane endpoints in the efficacy testing of swine erysipelas vaccines. ALTEX 2003; 20:11-5. [PMID: 12579350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
For licensing the efficacy of vaccines for veterinary use has to be demonstrated by well-controlled laboratory experiments in which vaccinated and untreated animals of the target species are challenged. Erysipelas challenge tests cause extreme suffering of the unprotected animals with high fever, apathy, large skin lesions, and even death. This paper describes a standardised procedure for the vaccination challenge test and gives due consideration to the welfare of the animals. By monitoring and using clinical signs observed during the test it is possible to minimise animal pain and distress, thus preventing unnecessary animal suffering.
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