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Zhang K, Liu C, Sadagurski M, Sun Q. Editorial: Environmental stressors and metabolic disease. Front Endocrinol (Lausanne) 2023; 14:1298687. [PMID: 37867520 PMCID: PMC10588619 DOI: 10.3389/fendo.2023.1298687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/24/2023] Open
Affiliation(s)
- Kezhong Zhang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, United States
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Cuiqing Liu
- School of Public Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Marianna Sadagurski
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, United States
- Department of Biological Sciences, Integrative Biosciences Center, Wayne State University, Detroit, MI, United States
| | - Qinghua Sun
- School of Public Health, Zhejiang Chinese Medical University, Hangzhou, China
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Adegboye OA, Alele FO, Castellanos ME, Pak A, Emeto TI. Editorial: Environmental stressors, multi-hazards and their impact on health. Front Public Health 2023; 11:1231955. [PMID: 37497031 PMCID: PMC10368457 DOI: 10.3389/fpubh.2023.1231955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 06/30/2023] [Indexed: 07/28/2023] Open
Affiliation(s)
- Oyelola A. Adegboye
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
- Public Health and Tropical Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- World Health Organization Collaborating Center for Vector-Borne and Neglected Tropical Diseases, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD, Australia
| | - Faith O. Alele
- Public Health and Tropical Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD, Australia
| | - Maru E. Castellanos
- Public Health and Tropical Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- World Health Organization Collaborating Center for Vector-Borne and Neglected Tropical Diseases, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD, Australia
| | - Anton Pak
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD, Australia
- Centre for the Business and Economics of Health, The University of Queensland, Brisbane, QLD, Australia
| | - Theophilus I. Emeto
- Public Health and Tropical Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- World Health Organization Collaborating Center for Vector-Borne and Neglected Tropical Diseases, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD, Australia
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Paula JR, Wang X, Xu C, Moreira DC. Editorial: The defense responses of aquatic animals to the environment. Front Physiol 2023; 14:1231014. [PMID: 37362435 PMCID: PMC10285698 DOI: 10.3389/fphys.2023.1231014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 06/01/2023] [Indexed: 06/28/2023] Open
Affiliation(s)
- José Ricardo Paula
- MARE—Marine and Environmental Sciences Centre and ARNET—Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências, Universidade de Lisboa, Cascais, Portugal
- Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
- Hawaiʻi Institute of Marine Biology, University of Hawai’i at Mānoa, Kaneohe, HI, United States
| | - Xiaodan Wang
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| | - Chang Xu
- Department of Aquaculture, College of Marine Sciences, Hainan University, Haikou, Hainan, China
| | - Daniel C. Moreira
- Research Center in Morphology and Applied Immunology, Faculty of Medicine, University of Brasília, Brasília, Brazil
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Yamaguchi K, Imai T, Yatsutani H, Goto K. A Combined Hot and Hypoxic Environment during Maximal Cycling Sprints Reduced Muscle Oxygen Saturation: A Pilot Study. J Sports Sci Med 2021; 20:684-689. [PMID: 35321130 PMCID: PMC8488822 DOI: 10.52082/jssm.2021.684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 02/15/2021] [Accepted: 07/05/2021] [Indexed: 06/14/2023]
Abstract
The present study investigated the effects of a combined hot and hypoxic environment on muscle oxygenation during repeated 15-s maximal cycling sprints. In a single-blind, cross-over study, nine trained sprinters performed three 15-s maximal cycling sprints interspersed with 7-min passive recovery in normoxic (NOR; 23℃, 50%, FiO2 20.9%), normobaric hypoxic (HYP; 23℃, FiO2 14.5%), and hot normobaric hypoxic (HH; 35℃, FiO2 14.5%) environments. Relative humidity was set to 50% in all trials. The vastus lateralis muscle oxygenation was evaluated during exercise using near-infrared spectroscopy. The oxygen uptake (VO2) and arterial oxygen saturation (SpO2) were also monitored. There was no significant difference in peak or mean power output among the three conditions. The reduction in tissue saturation index was significantly greater in the HH (-17.0 ± 2.7%) than in the HYP (-10.4 ± 2.8%) condition during the second sprint (p < 0.05). The average VO2 and SpO2 were significantly lower in the HYP (VO2 = 980 ± 52 mL/min, SpO2 = 82.9 ± 0.8%) and HH (VO2 = 965 ± 42 mL/min, SpO2 = 83.2 ± 1.2%) than in the NOR (VO2 = 1149 ± 40 mL/min, SpO2 = 90.6 ± 1.4%; p < 0.05) condition. In conclusion, muscle oxygen saturation was reduced to a greater extent in the HH than in the HYP condition during the second bout of three 15-s maximal cycling sprints, despite the equivalent hypoxic stress between HH and HYP.
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Affiliation(s)
- Keiichi Yamaguchi
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Tomohiro Imai
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Haruka Yatsutani
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Shiga, Japan
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Santana CM, Gauger P, Vetger A, Magstadt D, Kim DS, Shrestha D, Charavaryamath C, Rumbeiha WK. Ambient hydrogen sulfide exposure increases the severity of influenza A virus infection in swine. Arch Environ Occup Health 2021; 76:526-538. [PMID: 33750267 DOI: 10.1080/19338244.2021.1896986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Hydrogen sulfide (H2S) is common in concentrated pig feed operations from the decomposition of manure. Ambient H2S is a respiratory tract irritant and an environmental stressor for caretakers and pigs. Influenza A virus (IAV), a zoonotic pathogen, has caused prior pandemics. The effects of H2S or IAV alone on the respiratory system have been investigated, but their interaction has not. We hypothesized that exposure to environmentally-relevant H2S concentrations increases the pathogenicity of IAV infection in swine. Thirty-five, three-week old pigs of mixed sex were exposed to breathing air or H2S via inhalation 6 hours daily for 12 days. After 7 days, pigs were inoculated with H3N2 IAV (or a placebo). Results showed that ambient H2S increased the severity of respiratory distress and lung pathology. H2S also suppressed IL-IL-1β, IL-6 and IL-8 cytokine response in BALF and increased viral loads and nasal shedding.
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Affiliation(s)
- Cristina M Santana
- Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Phillip Gauger
- Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Amber Vetger
- Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Drew Magstadt
- Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Dong-Suk Kim
- Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Denusha Shrestha
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | | | - Wilson K Rumbeiha
- Department of Molecular Biosciences, University of California, Davis, CA, USA
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Forte E, Siletsky SA, Borisov VB. In Escherichia coli Ammonia Inhibits Cytochrome bo3 But Activates Cytochrome bd-I. Antioxidants (Basel) 2020; 10:E13. [PMID: 33375541 DOI: 10.3390/antiox10010013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/18/2020] [Accepted: 12/21/2020] [Indexed: 12/14/2022] Open
Abstract
Interaction of two redox enzymes of Escherichia coli, cytochrome bo3 and cytochrome bd-I, with ammonium sulfate/ammonia at pH 7.0 and 8.3 was studied using high-resolution respirometry and absorption spectroscopy. At pH 7.0, the oxygen reductase activity of none of the enzymes is affected by the ligand. At pH 8.3, cytochrome bo3 is inhibited by the ligand, with 40% maximum inhibition at 100 mM (NH4)2SO4. In contrast, the activity of cytochrome bd-I at pH 8.3 increases with increasing the ligand concentration, the largest increase (140%) is observed at 100 mM (NH4)2SO4. In both cases, the effector molecule is apparently not NH4+ but NH3. The ligand induces changes in absorption spectra of both oxidized cytochromes at pH 8.3. The magnitude of these changes increases as ammonia concentration is increased, yielding apparent dissociation constants Kdapp of 24.3 ± 2.7 mM (NH4)2SO4 (4.9 ± 0.5 mM NH3) for the Soret region in cytochrome bo3, and 35.9 ± 7.1 and 24.6 ± 12.4 mM (NH4)2SO4 (7.2 ± 1.4 and 4.9 ± 2.5 mM NH3) for the Soret and visible regions, respectively, in cytochrome bd-I. Consistently, addition of (NH4)2SO4 to cells of the E. coli mutant containing cytochrome bd-I as the only terminal oxidase at pH 8.3 accelerates the O2 consumption rate, the highest one (140%) being at 27 mM (NH4)2SO4. We discuss possible molecular mechanisms and physiological significance of modulation of the enzymatic activities by ammonia present at high concentration in the intestines, a niche occupied by E. coli.
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Abstract
Low-oxygen areas are expanding in the oceans as a result of climate change. Work carried out during the past two decades suggests that, in addition to impairing basic physiological functions, hypoxia can also affect fish behaviour. Given that many fish species are known to school, and that schooling is advantageous for their survival, the effect of hypoxia on schooling behaviour may have important ecological consequences. Here, we review the effects of hypoxia on school structure and dynamics, together with the mechanisms that cause an increase in school volume and that ultimately lead to school disruption. Furthermore, the effect of hypoxia generates a number of trade-offs in terms of schooling positions and school structure. Field observations have found that large schools of fish can exacerbate hypoxic conditions, with potential consequences for school structure and size. Therefore, previous models that predict the maximum size attainable by fish schools in relation to oxygen levels are also reviewed. Finally, we suggest that studies on the effect of hypoxia on schooling need to be integrated with those on temperature and ocean acidifications within a framework aimed at increasing our ability to predict the effect of multiple stressors of climate change on fish behaviour.This article is part of the themed issue 'Physiological determinants of social behaviour in animals'.
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Affiliation(s)
- Paolo Domenici
- IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Torregrande 09170, Oristano, Italy
| | - John F Steffensen
- Marine Biological Section, University of Copenhagen, Københavns Universitet, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - Stefano Marras
- IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Torregrande 09170, Oristano, Italy
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Zhang B, Kula A, Mack KML, Zhai L, Ryce AL, Ni WM, DeAngelis DL, Van Dyken JD. Carrying capacity in a heterogeneous environment with habitat connectivity. Ecol Lett 2017; 20:1118-1128. [PMID: 28712141 DOI: 10.1111/ele.12807] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [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: 02/07/2017] [Revised: 03/25/2017] [Accepted: 06/03/2017] [Indexed: 11/28/2022]
Abstract
A large body of theory predicts that populations diffusing in heterogeneous environments reach higher total size than if non-diffusing, and, paradoxically, higher size than in a corresponding homogeneous environment. However, this theory and its assumptions have not been rigorously tested. Here, we extended previous theory to include exploitable resources, proving qualitatively novel results, which we tested experimentally using spatially diffusing laboratory populations of yeast. Consistent with previous theory, we predicted and experimentally observed that spatial diffusion increased total equilibrium population abundance in heterogeneous environments, with the effect size depending on the relationship between r and K. Refuting previous theory, however, we discovered that homogeneously distributed resources support higher total carrying capacity than heterogeneously distributed resources, even with species diffusion. Our results provide rigorous experimental tests of new and old theory, demonstrating how the traditional notion of carrying capacity is ambiguous for populations diffusing in spatially heterogeneous environments.
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Affiliation(s)
- Bo Zhang
- Department of Biology, University of Miami, Coral Gables, FL, USA
| | - Alex Kula
- Department of Biology, University of Miami, Coral Gables, FL, USA
| | - Keenan M L Mack
- Department of Biology, Illinois College, Jacksonville, IL, USA
| | - Lu Zhai
- Department of Biology, University of Miami, Coral Gables, FL, USA.,Department of Mathematics, University of Miami, Coral Gables, FL, USA
| | - Arrix L Ryce
- Department of Biology, University of Miami, Coral Gables, FL, USA
| | - Wei-Ming Ni
- School of Mathematics, University of Minnesota, Minneapolis, MN, USA.,Center for Partial Differential Equations, East China Normal University, Putuo Qu, Shanghai Shi, China
| | - Donald L DeAngelis
- Wetland and Aquatic Research Center, U.S. Geological Survey, Gainesville, FL, USA
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Di Cosmo A, Polese G. Neuroendocrine-Immune Systems Response to Environmental Stressors in the Cephalopod Octopus vulgaris. Front Physiol 2016; 7:434. [PMID: 27733834 PMCID: PMC5039199 DOI: 10.3389/fphys.2016.00434] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/13/2016] [Indexed: 12/11/2022] Open
Abstract
Under a continuous changing environment, animals are challenged with stresses and stimuli which demanding adaptation at behavioral and physiological levels. The adaptation strategies are finely regulated by animal nervous, endocrine, and immune systems. Although it's been established by now the usage of integrative approach to the study the endocrine and nervous systems (neuroendocrine), yet our understanding of how they cooperate with the immune system remains far from complete. The possible role that immune system plays as a component of the network has only been recognized recently. Octopus vulgaris is an important member of cephalopods and is considered as a model species, with considerable information about the neuroendocrine and immune systems. In the current review, we anticipate to shed light on the complexity and cross talk among the three systems and how they cooperate in setting physiological response to stresses-stimuli in O. vulgaris as a target species and primary example.
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Affiliation(s)
- Anna Di Cosmo
- Department of Biology, University of Napoli Federico II Napoli, Italy
| | - Gianluca Polese
- Department of Biology, University of Napoli Federico II Napoli, Italy
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Ahnelt H, Schade FM, Wegner M. Ocean acidification leads to deformations of caudal vein angio-architecture in juvenile threespine stickleback, Gasterosteus aculeatus Linnaeus. J Fish Dis 2016; 39:1001-1005. [PMID: 27378184 DOI: 10.1111/jfd.12417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 08/09/2015] [Accepted: 08/11/2015] [Indexed: 06/06/2023]
Affiliation(s)
- H Ahnelt
- Department of Theoretical Biology, University of Vienna, Vienna, Austria
| | - F M Schade
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, List, Germany
| | - M Wegner
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, List, Germany
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Zozaya-Valdés E, Roth-Schulze AJ, Thomas T. Effects of Temperature Stress and Aquarium Conditions on the Red Macroalga Delisea pulchra and its Associated Microbial Community. Front Microbiol 2016; 7:161. [PMID: 26925036 PMCID: PMC4757742 DOI: 10.3389/fmicb.2016.00161] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 02/01/2016] [Indexed: 01/08/2023] Open
Abstract
In recent years, there has been an increase in the rate and severity of diseases affecting habitat-forming marine organisms, such as corals, sponges, and macroalgae. Delisea pulchra is a temperate red macroalga that suffers from a bleaching disease that is more frequent during summer, when seawater temperatures are elevated and the alga's chemical defense is weakened. A bacterial cause for the disease is implied by previous studies showing that some isolated strains can cause bleaching in vitro and that host-associated microbial communities are distinct between diseased and healthy individuals. However, nothing is known about the successional events in the microbial community that occur during the development of the disease. To study this aspect in the future, we aimed here to develop an experimental setup to study the bleaching disease in a controllable aquarium environment. Application of a temperature stress (up to 27°C) did not cause a clear and consistent pattern of bleaching, suggesting that temperature alone might not be the only or main factor to cause the disease. The results also showed that the aquarium conditions alone are sufficient to produce bleaching symptoms. Microbial community analysis based on 16S rRNA gene fingerprinting and sequencing showed significant changes after 15 days in the aquarium, indicating that the native microbial associates of D. pulchra are not stably maintained. Microbial taxa that were enriched in the aquarium-held D. pulchra thalli, however, did not match on a taxonomic level those that have been found to be enriched in natural bleaching events. Together our observations indicate that environmental factors, other than the ones investigated here, might drive the bleaching disease in D. pulchra and that the aquarium conditions have substantial impact on the alga-associated microbiome.
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Affiliation(s)
| | | | - Torsten Thomas
- Centre for Marine Bio-Innovation and School of Biotechnology and Biomolecular Sciences, The University of New South Wales, SydneyNSW, Australia
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Abstract
Context: Noise acts as an environmental stressor as has been demonstrated by an increased brain acetyl cholinesterase activity as well as elevated plasma corticosterone and adrenocorticotropic hormone levels. Noise can lead to neurodegenerative changes in the brain and in the ear. Aim: This study was undertaken to investigate the effect of chronic noise on growth and development during the sensitive period of embryonic life. Materials and Methods: In this study, we analyzed the body weight, brain weight and brain size following prenatal chronic noise exposure. Fertilized eggs of domestic chicks were exposed to chronic excessive acoustic stimulation with frequency of the sound ranging from 30 to 3000 Hz with a peak at 2700 Hz was given at 110 dB sound pressure level from embryonic day (E) 10 until hatching. Results: An appreciable decrease in body weight, brain weight and brain size was evident in the experimental group exposed to noise. A generalized decrease in the neuronal nuclear size and increase in the density of neurons was also observed. Conclusion: These observations could be an indicator of growth and developmental retardation following exposure to noise.
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Affiliation(s)
- Alpana Goel Kesar
- Department of Anatomy, PDM Dental College, Bahadurgarh, Haryana, India
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Tene Fossog B, Antonio-Nkondjio C, Kengne P, Njiokou F, Besansky NJ, Costantini C. Physiological correlates of ecological divergence along an urbanization gradient: differential tolerance to ammonia among molecular forms of the malaria mosquito Anopheles gambiae. BMC Ecol 2013; 13:1. [PMID: 23294940 PMCID: PMC3548750 DOI: 10.1186/1472-6785-13-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 12/27/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Limitations in the ability of organisms to tolerate environmental stressors affect their fundamental ecological niche and constrain their distribution to specific habitats. Evolution of tolerance, therefore, can engender ecological niche dynamics. Forest populations of the afro-tropical malaria mosquito Anopheles gambiae have been shown to adapt to historically unsuitable larval habitats polluted with decaying organic matter that are found in densely populated urban agglomerates of Cameroon. This process has resulted in niche expansion from rural to urban environments that is associated with cryptic speciation and ecological divergence of two evolutionarily significant units within this taxon, the molecular forms M and S, among which reproductive isolation is significant but still incomplete. Habitat segregation between the two forms results in a mosaic distribution of clinally parapatric patches, with the M form predominating in the centre of urban agglomerates and the S form in the surrounding rural localities. We hypothesized that development of tolerance to nitrogenous pollutants derived from the decomposition of organic matter, among which ammonia is the most toxic to aquatic organisms, may affect this pattern of distribution and process of niche expansion by the M form. RESULTS Acute toxicity bioassays indicated that populations of the two molecular forms occurring at the extremes of an urbanization gradient in Yaounde, the capital of Cameroon, differed in their response to ammonia. The regression lines best describing the dose-mortality profile differed in the scale of the explanatory variable (ammonia concentration log-transformed for the S form and linear for the M form), and in slope (steeper for the S form and shallower for the M form). These features reflected differences in the frequency distribution of individual tolerance thresholds in the two populations as assessed by probit analysis, with the M form exhibiting a greater mean and variance compared to the S form. CONCLUSIONS In agreement with expectations based on the pattern of habitat partitioning and exposure to ammonia in larval habitats in Yaounde, the M form showed greater tolerance to ammonia compared to the S form. This trait may be part of the physiological machinery allowing forest populations of the M form to colonize polluted larval habitats, which is at the heart of its niche expansion in densely populated human settlements in Cameroon.
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Affiliation(s)
- Billy Tene Fossog
- Institut de Recherche pour le Développement (IRD), Unité Mixte de Recherche MIVEGEC (UM1, UM2, CNRS 5290, IRD 224), Montpellier, France
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde I, Yaounde, Cameroon
| | - Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaounde, Cameroon
| | - Pierre Kengne
- Institut de Recherche pour le Développement (IRD), Unité Mixte de Recherche MIVEGEC (UM1, UM2, CNRS 5290, IRD 224), Montpellier, France
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaounde, Cameroon
| | - Flobert Njiokou
- Faculty of Sciences, University of Yaounde I, Yaounde, Cameroon
| | - Nora J Besansky
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Carlo Costantini
- Institut de Recherche pour le Développement (IRD), Unité Mixte de Recherche MIVEGEC (UM1, UM2, CNRS 5290, IRD 224), Montpellier, France
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaounde, Cameroon
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