1
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Salla RF, Costa MJ, Abdalla FC, Oliveira CR, Tsukada E, Boeing GANS, Prado J, Carvalho T, Ribeiro LP, Rebouças R, Toledo LF. Estrogen contamination increases vulnerability of amphibians to the deadly chytrid fungus. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170337. [PMID: 38301782 DOI: 10.1016/j.scitotenv.2024.170337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/31/2023] [Accepted: 01/19/2024] [Indexed: 02/03/2024]
Abstract
Aquatic contaminants and infectious diseases are among the major drivers of global amphibian declines. However, the interaction of these factors is poorly explored and could better explain the amphibian crisis. We exposed males and females of the Brazilian Cururu Toad, Rhinella icterica, to an environmentally relevant concentration of the estrogen 17-alpha-ethinylestradiol (an emerging contaminant) and to the chytrid infection (Batrachochytrium dendrobatidis), in their combined and isolated forms, and the ecotoxicity was determined by multiple biomarkers: cutaneous, hematological, cardiac, hepatic, and gonadal analysis. Our results showed that Cururu toads had many physiological alterations in response to the chytrid infection, including the appearance of cutaneous Langerhans's cells, increased blood leukocytes, increased heart contraction force and tachycardia, increased hepatic melanomacrophage cells, which in turn led to gonadal atrophy. The estrogen, in turn, increased the susceptibility of the toads to the chytrid infection (higher Bd loads) and maximized the deleterious effects of the pathogen: reducing leukocytes, decreasing the contraction force, and causing greater tachycardia, increasing hepatic melanomacrophage cells, and leading to greater gonadal atrophy, which were more extreme in females. The exposure to estrogen also revealed important toxicodynamic pathways of this toxicant, as shown by the immunosuppression of exposed animals, and the induction of the first stages of feminization in males, which corroborates that the synthetic estrogen acts as an endocrine disruptor. Such an intricate relationship is unprecedented and reinforces the importance of studying the serious consequences that multiple environmental stressors can cause to aquatic populations.
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Affiliation(s)
- Raquel F Salla
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil; Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil.
| | - Monica Jones Costa
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil; Laboratório de Fisiologia da Conservação (LaFisC), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Fabio Camargo Abdalla
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil; Laboratório de Biologia Estrutural e Funcional (LaBEF), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Cristiane R Oliveira
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Elisabete Tsukada
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Guilherme Andrade Neto Schmitz Boeing
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil; Laboratório de Biologia Estrutural e Funcional (LaBEF), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Joelma Prado
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil
| | - Tamilie Carvalho
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Luisa P Ribeiro
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil
| | - Raoni Rebouças
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil
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2
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Berger L, Skerratt LF, Kosch TA, Brannelly LA, Webb RJ, Waddle AW. Advances in Managing Chytridiomycosis for Australian Frogs: Gradarius Firmus Victoria. Annu Rev Anim Biosci 2024; 12:113-133. [PMID: 38358840 DOI: 10.1146/annurev-animal-021122-100823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Extensive knowledge gains from research worldwide over the 25 years since the discovery of chytridiomycosis can be used for improved management. Strategies that have saved populations in the short term and/or enabled recovery include captive breeding, translocation into disease refugia, translocation from resistant populations, disease-free exclosures, and preservation of disease refuges with connectivity to previous habitat, while antifungal treatments have reduced mortality rates in the wild. Increasing host resistance is the goal of many strategies under development, including vaccination and targeted genetic interventions. Pathogen-directed strategies may be more challenging but would have broad applicability. While the search for the silver bullet solution continues, we should value targeted local interventions that stop extinction and buy time for evolution of resistance or development of novel solutions. As for most invasive species and infectious diseases, we need to accept that ongoing management is necessary. For species continuing to decline, proactive deployment and assessment of promising interventions are more valid than a hands-off, do-no-harm approach that will likely allow further extinctions.
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Affiliation(s)
- Lee Berger
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Tiffany A Kosch
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Laura A Brannelly
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Rebecca J Webb
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Anthony W Waddle
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
- Applied Biosciences, Macquarie University, Sydney, New South Wales, Australia;
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3
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Palacios-Marquez JJ, Guevara-Fiore P. Parasitism in viviparous vertebrates: an overview. Parasitol Res 2023; 123:53. [PMID: 38100003 DOI: 10.1007/s00436-023-08083-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 12/01/2023] [Indexed: 12/18/2023]
Abstract
The reproductive mode of viviparity has independently evolved in various animal taxa. It refers to the condition in which the embryos or young develop inside the female's body during gestation, providing advantages such as protection, nutrition, and improved survival chances. However, parasites and diseases can be an evolutionary force that limit the host's resources, leading to physiological, morphological, and behavioral changes that impose additional costs on both the pregnant female and her offspring. This review integrates the primary literature published between 1980 and 2021 on the parasitism of viviparous hosts. We describe aspects such as reproductive investment in females, offspring sex ratios, lactation investment in mammals, alterations in birth intervals, current reproductive investment, variations between environments, immune system activity in response to immunological challenges, and other factors that can influence the interaction between viviparous females and parasites. Maintaining pregnancy incurs costs in managing the mother's resources and regulating the immune system's responses to the offspring, while simultaneously maintaining an adequate defense against parasites and pathogens. Parasites can significantly influence this reproductive mode: parasitized females adjust their investment in survival and reproduction based on their life history, environmental factors, and the diversity of encountered parasites.
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Affiliation(s)
- Juan J Palacios-Marquez
- Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, Blvd. Valsequillo y Av. San Claudio, Edificio Bio-1, Ciudad Universitaria, Col. Jardines de San Manuel, 72580, Puebla, CP, Mexico
| | - Palestina Guevara-Fiore
- Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, Blvd. Valsequillo y Av. San Claudio, Edificio Bio-1, Ciudad Universitaria, Col. Jardines de San Manuel, 72580, Puebla, CP, Mexico.
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4
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Lyth S, Betancourt AJ, Price TAR, Verspoor RL. The suppression of a selfish genetic element increases a male's mating success in a fly. Ecol Evol 2023; 13:e10719. [PMID: 37964789 PMCID: PMC10641306 DOI: 10.1002/ece3.10719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/20/2023] [Accepted: 10/27/2023] [Indexed: 11/16/2023] Open
Abstract
X chromosome meiotic drive (XCMD) kills Y-bearing sperm during spermatogenesis, leading to the biased transmission of the selfish X chromosome. Despite this strong transmission, some natural XCMD systems remain at low and stable frequencies, rather than rapidly spreading through populations. The reason may be that male carriers can have reduced fitness, as they lose half of their sperm, only produce daughters, and may carry deleterious alleles associated with XCMD. Thus, females may benefit from avoiding mating with male carriers, yielding a further reduction in fitness. Genetic suppressors of XCMD, which block the killing of Y sperm and restore fair Mendelian inheritance, are also common and could prevent the spread of XCMD. However, whether suppressed males are as fit as a wild-type male remains an open question, as the effect that genetic suppressors may have on a male's mating success is rarely considered. Here, we investigate the mating ability of XCMD males and suppressed XCMD males in comparison to wild-type males in the fruit fly Drosophila subobscura, where drive remains at a stable frequency of 20% in wild populations where it occurs. We use both competitive and non-competitive mating trials to evaluate male mating success in this system. We found no evidence that unsuppressed XCMD males were discriminated against. Remarkably, however, their suppressed XCMD counterparts had a higher male mating success compared to wild-type controls. Unsuppressed XCMD males suffered 12% lower offspring production in comparison to wild-type males. This cost appears too weak to counter the transmission advantage of XCMD, and thus the factors preventing the spread of XCMD remain unclear.
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Affiliation(s)
- Sophie Lyth
- Institute of InfectionVeterinary and Ecological Sciences, University of LiverpoolLiverpoolUK
| | - Andrea J. Betancourt
- Institute of InfectionVeterinary and Ecological Sciences, University of LiverpoolLiverpoolUK
| | - Tom A. R. Price
- Institute of InfectionVeterinary and Ecological Sciences, University of LiverpoolLiverpoolUK
| | - Rudi L. Verspoor
- Institute of InfectionVeterinary and Ecological Sciences, University of LiverpoolLiverpoolUK
- Institute of SystemsMolecular, and Integrative Biology, University of LiverpoolLiverpoolUK
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5
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Lampo M, Señaris C, González K, Ballestas O. Smaller size of harlequin toads from populations long exposed to the fungal disease chytridiomycosis. Biotropica 2023. [DOI: 10.1111/btp.13220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Affiliation(s)
- Margarita Lampo
- Fundación para el Desarrollo de las Ciencias Físicas, Matemáticas y Naturales Avenida Universidad Palacio de las Academias, Piso 3 Caracas Venezuela
- Centro de Ecología Instituto Venezolano de Investigaciones Científicas Km 11 de la Panamericana Caracas Venezuela
| | - Celsa Señaris
- Estación Biológica de Doñana (EBD‐CSIC) Avda. Américo Vespucio, 26 41092 Sevilla Spain
| | - Katiuska González
- Centro de Ecología Instituto Venezolano de Investigaciones Científicas Km 11 de la Panamericana Caracas Venezuela
| | - Onil Ballestas
- Centro de Ecología Instituto Venezolano de Investigaciones Científicas Km 11 de la Panamericana Caracas Venezuela
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6
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Su R, Zhang S, Zhang X, Wang S, Zhang W. Neglected skin-associated microbial communities: a unique immune defense strategy of Bufo raddei under environmental heavy metal pollution. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:22330-22342. [PMID: 36284045 DOI: 10.1007/s11356-022-23803-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
Amphibians defend against pathogens using skin microbial communities, in addition to innate and adaptive immunity. Despite skin microbial communities play a key role in the immune function of amphibians, few studies have focused on the changes in its composition and function. In the present study, we identified the variation in adaptive immunity, as well as the corresponding changes in skin microbiome of Bufo raddei living in a heavy metal polluted area. The adaptive immunity of B. raddei in heavy metal polluted area was significantly lower than that in relatively unpolluted area. Further, different skin bacterial communities were found in the two areas. In the heavy metal polluted area, Actinobacteria and Microbacterium were the dominant bacteria in the skin microbiome of B. raddei, which showed broad-spectrum antibacterial activity. Besides, the antibiotic synthesis was also increased in metabolic pathways. The present study suggested that the adaptive immunity of B. raddei was weakened under long-term heavy metal stress. However, the toads increased the abundance of bacteriostatic bacteria by regulating the composition of skin microbiome, which released a large number of bacteriostatic metabolites and enhanced the host resistance to external pathogens in turn.
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Affiliation(s)
- Rui Su
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Sheng Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xueying Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Shengnan Wang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Wenya Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
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7
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Wu NC. Pathogen load predicts host functional disruption: A meta‐analysis of an amphibian fungal panzootic. Funct Ecol 2023. [DOI: 10.1111/1365-2435.14245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Nicholas C. Wu
- Hawkesbury Institute for the Environment Western Sydney University Richmond New South Wales Australia
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8
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Brannelly LA, Sharma P, Wallace DK. Captive breeding in the endangered alpine tree frog, Litoria verreauxii alpina. PeerJ 2023; 11:e15179. [PMID: 37101793 PMCID: PMC10124539 DOI: 10.7717/peerj.15179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 03/14/2023] [Indexed: 04/28/2023] Open
Abstract
Amphibians are experiencing dramatic worldwide declines and many species are reliant on captive breeding programs to ensure continued survival. However, captive breeding in amphibians is not always successful because many species, especially ones in decline, have particular and specific breeding needs. The endangered alpine tree frog, Litoria verreauxii alpina, has never been bred in captivity before. Due to its dramatic declines across the Australian Alps caused by the global pandemic chytridiomycosis, the species is a potential candidate for captive assurance colonies, which rely on captive breeding. For this study we tested hormone induction using two hormones that have had some success in other amphibian species, to no avail. We then tried outdoor breeding mesocosms during the winter/spring at temperatures similar to their natural breeding season, which was successful. Sixty-five percent of the egg masses laid successfully hatched tadpoles. Females laid more than one clutch over the experiment indicating either a shorter than annual ovulation cycle, or that females are capable of partial ovulation during breeding events. Outdoor breeding mesocosms are a possibility outside the native climate of a species, provided that temperatures overlap with their natural environment. Here, we highlight that troubleshooting is essential before embarking on a captive breeding program of a species that has not been bred before. Hormonal induction of breeding is not always successful; therefore, outdoor mesocosms might be required to achieve healthy tadpoles.
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Affiliation(s)
- Laura A. Brannelly
- Melbourne Veterinary School, University of Melbourne, Werribee, Victoria, Australia
| | - Preeti Sharma
- Melbourne Veterinary School, University of Melbourne, Werribee, Victoria, Australia
- School of Environment and Science, Griffith University, Southport, Queensland, Australia
| | - Danielle K. Wallace
- Melbourne Veterinary School, University of Melbourne, Werribee, Victoria, Australia
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9
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Zhang W, Sun H, Su R, Wang S. Fat rather than health - Ecotoxic responses of Bufo raddei to environmental heavy metal stress during the non-breeding season. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 244:114040. [PMID: 36055043 DOI: 10.1016/j.ecoenv.2022.114040] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/25/2022] [Accepted: 08/28/2022] [Indexed: 06/15/2023]
Abstract
The non-breeding season is a critical period for iteroparous animals to repair damage and store energy, which is crucial for future survival and reproductive success. However, it is unknown how animals allocate energy efficiently among reproduction, self-maintenance, and repair of oxidative damage caused by breeding during the non-breeding period, particularly under pollution. In the present study, the self-maintenance response and reproductive strategy of Bufo raddei to long-term environmental heavy metal stress was explored during the non-breeding season. Heavy metal enrichment level, organ coefficients, nutritional status, gonadal developmental level, oxidation level, and the immune status of B. raddei during the non-breeding season were tested, energy allocation preferences and energy consumption costs were analyzed. The results revealed significant heavy metal accumulation through biomagnification in the organs of B. raddei from the polluted area. Under long-term environmental heavy metal pollution, the energy investment by B. raddei for growth and energy storage was higher than that for health-maintenance during the early life cycle stage. The energy inputted for immune and antioxidant functions was significantly lower, and the energy inputted for self-maintenance during the early life stage was significantly higher than that during the late stage. B. raddei from a heavy metal polluted area spent more energy consumption cost on immunity and oxidative stress, but suffered higher oxidative stress and lower immune status. Moreover, the reproductive input of individuals in a heavy metal polluted area was generally low during the non-breeding season, and the energy input for reproduction limited the energy input for self-maintenance in females.
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Affiliation(s)
- Wenya Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
| | - Hao Sun
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Rui Su
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Shengnan Wang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
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10
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Corbel Q, Carazo P. Perception of dead conspecifics increases reproductive investment in fruit flies. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Quentin Corbel
- Ethology, Ecology and Evolution group; Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia Valencia Spain
| | - Pau Carazo
- Ethology, Ecology and Evolution group; Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia Valencia Spain
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11
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Gulyas L, Powell JR. Cold shock induces a terminal investment reproductive response in C. elegans. Sci Rep 2022; 12:1338. [PMID: 35079060 PMCID: PMC8789813 DOI: 10.1038/s41598-022-05340-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 12/08/2021] [Indexed: 12/04/2022] Open
Abstract
Challenges from environmental stressors have a profound impact on many life-history traits of an organism, including reproductive strategy. Examples across multiple taxa have demonstrated that maternal reproductive investment resulting from stress can improve offspring survival; a form of matricidal provisioning when death appears imminent is known as terminal investment. Here we report a reproductive response in the nematode Caenorhabditis elegans upon exposure to acute cold shock at 2 °C, whereby vitellogenic lipid movement from the soma to the germline appears to be massively upregulated at the expense of parental survival. This response is dependent on functional TAX-2; TAX-4 cGMP-gated channels that are part of canonical thermosensory mechanisms in worms and can be prevented in the presence of activated SKN-1/Nrf2, the master stress regulator. Increased maternal provisioning promotes improved embryonic cold shock survival, which is notably suppressed in animals with impaired vitellogenesis. These findings suggest that cold shock in C. elegans triggers terminal investment to promote progeny fitness at the expense of parental survival and may serve as a tractable model for future studies of stress-induced progeny plasticity.
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Affiliation(s)
- Leah Gulyas
- Department of Biology, Gettysburg College, Gettysburg, PA, 17325, USA.,Plant and Microbial Biology Department, University of California Berkeley, Berkeley, CA, 94702, USA
| | - Jennifer R Powell
- Department of Biology, Gettysburg College, Gettysburg, PA, 17325, USA.
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12
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Comizzoli P, Power ML, Bornbusch SL, Muletz-Wolz CR. Interactions between reproductive biology and microbiomes in wild animal species. Anim Microbiome 2021; 3:87. [PMID: 34949226 PMCID: PMC8697499 DOI: 10.1186/s42523-021-00156-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 12/18/2021] [Indexed: 12/24/2022] Open
Abstract
Many parts of the animal body harbor microbial communities, known as animal-associated microbiomes, that affect the regulation of physiological functions. Studies in human and animal models have demonstrated that the reproductive biology and such microbiomes also interact. However, this concept is poorly studied in wild animal species and little is known about the implications to fertility, parental/offspring health, and survival in natural habitats. The objective of this review is to (1) specify the interactions between animals' reproductive biology, including reproductive signaling, pregnancy, and offspring development, and their microbiomes, with an emphasis on wild species and (2) identify important research gaps as well as areas for further studies. While microbiomes present in the reproductive tract play the most direct role, other bodily microbiomes may also contribute to facilitating reproduction. In fish, amphibians, reptiles, birds, and mammals, endogenous processes related to the host physiology and behavior (visual and olfactory reproductive signals, copulation) can both influence and be influenced by the structure and function of microbial communities. In addition, exposures to maternal microbiomes in mammals (through vagina, skin, and milk) shape the offspring microbiomes, which, in turn, affects health later in life. Importantly, for all wild animal species, host-associated microbiomes are also influenced by environmental variations. There is still limited literature on wild animals compared to the large body of research on model species and humans. However, the few studies in wild species clearly highlight the necessity of increased research in rare and endangered animals to optimize conservation efforts in situ and ex situ. Thus, the link between microbiomes and reproduction is an emerging and critical component in wild animal conservation.
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Affiliation(s)
- Pierre Comizzoli
- Smithsonian Conservation Biology Institute, National Zoological Park, Veterinary Hospital MRC5502, PO Box 37012, Washington, DC 20013 USA
| | - Michael L. Power
- Smithsonian Conservation Biology Institute, National Zoological Park, Veterinary Hospital MRC5502, PO Box 37012, Washington, DC 20013 USA
| | - Sally L. Bornbusch
- Smithsonian Conservation Biology Institute, National Zoological Park, Veterinary Hospital MRC5502, PO Box 37012, Washington, DC 20013 USA
| | - Carly R. Muletz-Wolz
- Smithsonian Conservation Biology Institute, National Zoological Park, Veterinary Hospital MRC5502, PO Box 37012, Washington, DC 20013 USA
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13
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Earls KN, Porter MS, Rinehart JP, Greenlee KJ. Thermal history of alfalfa leafcutting bees affects nesting and diapause incidence. J Exp Biol 2021; 224:272604. [PMID: 34694400 DOI: 10.1242/jeb.243242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/20/2021] [Indexed: 11/20/2022]
Abstract
Variable spring temperatures may expose developing insects to sublethal conditions, resulting in long-term consequences. The alfalfa leafcutting bee, Megachile rotundata, overwinters as a prepupa inside a brood cell, resuming development in spring. During these immobile stages of development, bees must tolerate unfavorable temperatures. In this study, we tested how exposure to low temperature stress during development affects subsequent reproduction and characteristics of the F1 generation. Developing male and female M. rotundata were exposed to either constant (6°C) or fluctuating (1 h day-1 at 20°C) low temperature stress for 1 week, during the pupal stage, to mimic a spring cold snap. Treated adults were marked and released into field cages, and reproductive output was compared with that of untreated control bees. Exposure to low temperatures during the pupal stage had mixed effects on reproduction and offspring characteristics. Females treated with fluctuating low temperatures were more likely to nest compared with control bees or those exposed to constant low temperature stress. Sublethal effects may have contributed to low nesting rates of bees exposed to constant low temperatures. Females from that group that were able to nest had fewer, larger offspring with high viability, suggesting a trade-off. Interestingly, offspring of bees exposed to fluctuating low temperatures were more likely to enter diapause, indicating that thermal history of parents, even during development, is an important factor in diapause determination.
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Affiliation(s)
- Kayla N Earls
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA
| | - Monique S Porter
- Department of Biochemistry and Molecular Biology, Penn State University, State College, PA 16801, USA
| | - Joseph P Rinehart
- Edward T. Schafer Agricultural Research Center, U.S. Department of Agriculture/Agricultural Research Station, Fargo, ND 58102, USA
| | - Kendra J Greenlee
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA
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14
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Valenzuela-Sánchez A, Azat C, Cunningham AA, Delgado S, Bacigalupe LD, Beltrand J, Serrano JM, Sentenac H, Haddow N, Toledo V, Schmidt BR, Cayuela H. Interpopulation differences in male reproductive effort drive the population dynamics of a host exposed to an emerging fungal pathogen. J Anim Ecol 2021; 91:308-319. [PMID: 34704260 DOI: 10.1111/1365-2656.13603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 10/04/2021] [Indexed: 11/28/2022]
Abstract
Compensatory recruitment is a key demographic mechanism that has allowed the coexistence of populations of susceptible amphibians with Batrachochytrium dendrobatidis (Bd), a fungus causing one of the most devastating emerging infectious disease ever recorded among vertebrates. However, the underlying processes (e.g. density-dependent increase in survival at early life stages, change in reproductive traits) as well as the level of interpopulation variation in this response are poorly known. We explore potential mechanisms of compensatory recruitment in response to Bd infection by taking advantage of an amphibian system where male reproductive traits are easy to quantify in free-living populations. The Southern Darwin's frog Rhinoderma darwinii is a vocal sac-brooding species that exhibits a high susceptibility to lethal Bd infection. Using a 7-year capture-recapture study at four populations with contrasting Bd infection status (one high prevalence, one low prevalence and two Bd-free populations), we evaluated whether Bd-positive populations exhibited a higher adult recruitment and a higher male reproductive effort than Bd-negative populations. We also estimated population growth rates to explore whether recruitment compensated for the negative impacts of Bd on the survival of adults. In addition, we evaluated a potential demographic signal of compensatory recruitment (i.e. positive relationship between the proportion of juveniles and Bd prevalence) in response to Bd infection using raw count data from 13 R. darwinii populations. The high Bd prevalence population exhibited the highest male reproductive effort and the highest recruitment among the four monitored populations. This led to a growing population during the study period despite high mortality of adult hosts. In contrast, males from the population with low Bd prevalence had a low reproductive effort and this population, which had the lowest adult recruitment, was declining during the study period despite adults having a higher survival in comparison to the high Bd prevalence population. We also found a demographic signal of compensatory recruitment in response to Bd infection in our broader analysis of 13 R. darwinii populations. Our study underlines the importance of interpopulation variation in life-history strategies on the fate of host populations after infectious disease emergence. Our results also suggest that an increase in reproductive effort can be one of the processes underlying compensatory recruitment in populations of Bd-susceptible amphibians.
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Affiliation(s)
- Andrés Valenzuela-Sánchez
- ONG Ranita de Darwin, Valdivia, Chile.,Instituto de Conservación, Biodiversidad y Territorio, Facultad de Ciencias Forestales y Recursos Naturales, Universidad Austral de Chile, Valdivia, Chile.,Sustainability Research Centre & PhD in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Santiago, Chile
| | - Claudio Azat
- Sustainability Research Centre & PhD in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Santiago, Chile
| | | | | | - Leonardo D Bacigalupe
- Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | | | - José M Serrano
- ONG Ranita de Darwin, Valdivia, Chile.,Museo de Zoología 'Alfonso L. Herrera', Departamento Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Hugo Sentenac
- Institute of Zoology, Zoological Society of London, London, UK.,Royal Veterinary College, University of London, London, UK
| | - Natashja Haddow
- Sustainability Research Centre & PhD in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Santiago, Chile.,Institute of Zoology, Zoological Society of London, London, UK.,Royal Veterinary College, University of London, London, UK
| | | | - Benedikt R Schmidt
- Info fauna karch, Neuchâtel, Switzerland.,Institut für Evolutionsbiologie und Umweltwissenschaften, Universität Zürich, Zürich, Switzerland
| | - Hugo Cayuela
- Department of Ecology and Evolution, Biophore, University of Lausanne, Lausanne, Switzerland
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15
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Brannelly LA, Webb RJ, Jiang Z, Berger L, Skerratt LF, Grogan LF. Declining amphibians might be evolving increased reproductive effort in the face of devastating disease. Evolution 2021; 75:2555-2567. [PMID: 34383313 DOI: 10.1111/evo.14327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/08/2021] [Accepted: 07/20/2021] [Indexed: 12/12/2022]
Abstract
The devastating infectious disease chytridiomycosis has caused declines of amphibians across the globe, yet some populations are persisting and even recovering. One understudied effect of wildlife disease is changes in reproductive effort. Here, we aimed to understand if the disease has plastic effects on reproduction and if reproductive effort could evolve with disease endemism. We compared the effects of experimental pathogen exposure (trait plasticity) and population-level disease history (evolution in trait baseline) on reproductive effort using gametogenesis as a proxy in the declining and endangered frog Litoria verreauxii alpina. We found that unexposed males from disease-endemic populations had higher reproductive effort, which is consistent with an evolutionary response to chytridiomycosis. We also found evidence of trait plasticity, where males and females were affected differently by infection: pathogen exposed males had higher reproductive effort (larger testes), whereas females had reduced reproductive effort (smaller and fewer developed eggs) regardless of the population of origin. Infectious diseases can cause plastic changes in the reproductive effort at an individual level, and population-level disease exposure can result in changes to baseline reproductive effort; therefore, individual- and population-level effects of disease should be considered when designing management and conservation programs for threatened and declining species.
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Affiliation(s)
- Laura A Brannelly
- One Health Research Group, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia
| | - Rebecca J Webb
- One Health Research Group, School of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
| | - Zhixuan Jiang
- One Health Research Group, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia
| | - Lee Berger
- One Health Research Group, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia
| | - Lee F Skerratt
- One Health Research Group, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia
| | - Laura F Grogan
- Environmental Futures Research Institute, Griffith University, Southport, Queensland, Australia.,Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
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16
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Lopes PC, French SS, Woodhams DC, Binning SA. Sickness behaviors across vertebrate taxa: proximate and ultimate mechanisms. J Exp Biol 2021; 224:260576. [PMID: 33942101 DOI: 10.1242/jeb.225847] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
There is nothing like a pandemic to get the world thinking about how infectious diseases affect individual behavior. In this respect, sick animals can behave in ways that are dramatically different from healthy animals: altered social interactions and changes to patterns of eating and drinking are all hallmarks of sickness. As a result, behavioral changes associated with inflammatory responses (i.e. sickness behaviors) have important implications for disease spread by affecting contacts with others and with common resources, including water and/or sleeping sites. In this Review, we summarize the behavioral modifications, including changes to thermoregulatory behaviors, known to occur in vertebrates during infection, with an emphasis on non-mammalian taxa, which have historically received less attention. We then outline and discuss our current understanding of the changes in physiology associated with the production of these behaviors and highlight areas where more research is needed, including an exploration of individual and sex differences in the acute phase response and a greater understanding of the ecophysiological implications of sickness behaviors for disease at the population level.
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Affiliation(s)
- Patricia C Lopes
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
| | - Susannah S French
- Department of Biology and The Ecology Center, Utah State University, Logan, UT 84322, USA
| | - Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Sandra A Binning
- Département de Sciences Biologiques, Université de Montréal, Montréal, QC, Canada, H3C 3J7
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17
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Kelleher SR, Scheele BC, Silla AJ, Keogh JS, Hunter DA, Endler JA, Byrne PG. Disease influences male advertisement and mating outcomes in a critically endangered amphibian. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.01.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Delaney DM, Hoekstra LA, Janzen FJ. Age Predicts Risky Investment Better Than Residual Reproductive Value. Am Nat 2021; 197:461-472. [PMID: 33755533 DOI: 10.1086/713174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractLife-history theory predicts that investment in reproduction should increase as future reproductive potential (i.e., residual reproductive value [RRV]) decreases. Researchers have thus intuitively used age as a proxy for RRV and assume that RRV decreases with age when interpreting age-specific investment. Yet age is an imperfect proxy for RRV and may even be a poor correlate in some systems. We used a 31-year study of the nesting ecology of painted turtles (Chrysemys picta) to assess how age and RRV compare in explaining variation in a risky investment behavior. We predicted that RRV would be a better predictor of risky investment than age because RRV accounts for variation in future reproductive potential across life. We found that RRV was high in early life, slowly decreased until midlife, and then steadily decreased to terminal reproduction. However, age predicted risky behavior better than RRV. This finding suggests that stronger correlates of age (e.g., size) may be more responsible for this behavior in turtles. This study highlights that researchers should not assume that age-specific investment is driven by RRV and that future work should quantify RRV to more directly test this key element of life-history theory.
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19
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Spence AR, French SS, Hopkins GR, Durso AM, Hudson SB, Smith GD, Neuman‐Lee LA. Long‐term monitoring of two snake species reveals immune–endocrine interactions and the importance of ecological context. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2021; 333:744-755. [DOI: 10.1002/jez.2442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/18/2020] [Accepted: 12/10/2020] [Indexed: 11/06/2022]
Affiliation(s)
- Austin R. Spence
- Department of Ecology and Evolutionary Biology University of Connecticut Storrs Connecticut USA
| | - Susannah S. French
- Department of Biology, Ecology Center Utah State University Logan Utah USA
| | | | - Andrew M. Durso
- Department of Biological Sciences Florida Gulf Coast University Fort Myers Florida USA
| | - Spencer B. Hudson
- Department of Biology, Ecology Center Utah State University Logan Utah USA
| | - Geoffrey D. Smith
- Department of Biological Sciences Dixie State University St. George Utah USA
| | - Lorin A. Neuman‐Lee
- Department of Biological Sciences Arkansas State University Jonesboro Arkansas USA
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20
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Brannelly LA, McCallum HI, Grogan LF, Briggs CJ, Ribas MP, Hollanders M, Sasso T, Familiar López M, Newell DA, Kilpatrick AM. Mechanisms underlying host persistence following amphibian disease emergence determine appropriate management strategies. Ecol Lett 2020; 24:130-148. [PMID: 33067922 DOI: 10.1111/ele.13621] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/18/2020] [Accepted: 09/08/2020] [Indexed: 12/19/2022]
Abstract
Emerging infectious diseases have caused many species declines, changes in communities and even extinctions. There are also many species that persist following devastating declines due to disease. The broad mechanisms that enable host persistence following declines include evolution of resistance or tolerance, changes in immunity and behaviour, compensatory recruitment, pathogen attenuation, environmental refugia, density-dependent transmission and changes in community composition. Here we examine the case of chytridiomycosis, the most important wildlife disease of the past century. We review the full breadth of mechanisms allowing host persistence, and synthesise research on host, pathogen, environmental and community factors driving persistence following chytridiomycosis-related declines and overview the current evidence and the information required to support each mechanism. We found that for most species the mechanisms facilitating persistence have not been identified. We illustrate how the mechanisms that drive long-term host population dynamics determine the most effective conservation management strategies. Therefore, understanding mechanisms of host persistence is important because many species continue to be threatened by disease, some of which will require intervention. The conceptual framework we describe is broadly applicable to other novel disease systems.
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Affiliation(s)
- Laura A Brannelly
- Veterinary BioSciences, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic, 3030, Australia
| | - Hamish I McCallum
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Nathan, Qld., 4111, Australia
| | - Laura F Grogan
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Nathan, Qld., 4111, Australia.,Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Cheryl J Briggs
- Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Maria P Ribas
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia.,Wildlife Conservation Medicine Research Group, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain
| | - Matthijs Hollanders
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Thais Sasso
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Nathan, Qld., 4111, Australia
| | - Mariel Familiar López
- School of Environment and Sciences, Griffith University, Gold Coast, Qld., 4215, Australia
| | - David A Newell
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Auston M Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
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21
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Bell SC, Heard GW, Berger L, Skerratt LF. Connectivity over a disease risk gradient enables recovery of rainforest frogs. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02152. [PMID: 32343856 DOI: 10.1002/eap.2152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 02/14/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Chytridiomycosis has been a key driver of global frog declines and extinctions, particularly for high-altitude populations across Australia and the Americas. While recent evidence shows some species are recovering, the extent of such recoveries and the mechanisms underpinning them remain poorly resolved. We surveyed the historical latitudinal and elevational range of four Australian rainforest frogs that disappeared from upland sites between 1989 and 1994 to establish their contemporary distribution and elevational limits, and investigate factors affecting population recovery. Five rainforest streams were surveyed from mountain-base to summit (30 sites in total), with swabs collected from the target species (Litoria dayi, L. nannotis, L. rheocola, and L. serrata) to determine their infection status, and data loggers deployed to measure microclimatic variation across the elevational gradient. Infection probability increased with elevation and canopy cover as it was tightly and inversely correlated with stream-side air temperature. Occupancy patterns suggest varying responses to this disease threat gradient. Two species, L. rheocola and L. serrata, were found over their full historical elevational range (≥1,000 m above sea level [asl]), while L. dayi was not detected above 400 m (formerly known up to 900 m asl) and L. nannotis was not detected above 800 m (formerly known up to 1,200 m asl). Site occupancy probability was negatively related to predicted infection prevalence for L. dayi, L. nannotis, and L. rheocola, but not L. serrata, which appears to now tolerate high fungal burdens. This study highlights the importance of environmental refuges and connectivity across disease risk gradients for the persistence and natural recovery of frogs susceptible to chytridiomycosis. Likewise, in documenting both interspecific variation in recovery rates and intraspecific differences between sites, this study suggests interactions between disease threats and host selection exist that could be manipulated. For example, translocations may be warranted where connectivity is poor or the increase in disease risk is too steep to allow recolonization, combined with assisted selection or use of founders from populations that have already undergone natural selection.
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Affiliation(s)
- Sara C Bell
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, 4811, Australia
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Geoffrey W Heard
- Institute of Land, Water and Society, Charles Sturt University, Albury, New South Wales, 2640, Australia
- Victorian Department of Environment, Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria, 3084, Australia
| | - Lee Berger
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
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22
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Iglesias‐Carrasco M, Fox RJ, Vega‐Trejo R, Jennions MD, Head ML. An experimental test for body size‐dependent effects of male harassment and an elevated copulation rate on female lifetime fecundity and offspring performance. J Evol Biol 2019; 32:1262-1273. [DOI: 10.1111/jeb.13526] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/13/2019] [Accepted: 08/19/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Maider Iglesias‐Carrasco
- Division of Ecology and Evolution Research School of Biology Australian National University Canberra ACT Australia
| | - Rebecca J. Fox
- Division of Ecology and Evolution Research School of Biology Australian National University Canberra ACT Australia
| | - Regina Vega‐Trejo
- Division of Ecology and Evolution Research School of Biology Australian National University Canberra ACT Australia
- Department of Zoology/Ethology Stockholm University Stockholm Sweden
| | - Michael D. Jennions
- Division of Ecology and Evolution Research School of Biology Australian National University Canberra ACT Australia
| | - Megan L. Head
- Division of Ecology and Evolution Research School of Biology Australian National University Canberra ACT Australia
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23
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Monnens M, Frost EJ, Clark M, Sewell MA, Vanhove MPM, Artois T. Description and ecophysiology of a new species of Syndesmis Silliman, 1881 (Rhabdocoela: Umagillidae) from the sea urchin Evechinus chloroticus (Valenciennes, 1846) Mortensen, 1943 in New Zealand. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2019; 10:71-82. [PMID: 31372337 PMCID: PMC6658996 DOI: 10.1016/j.ijppaw.2019.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 11/27/2022]
Abstract
A new rhabdocoel of the genus Syndesmis Silliman, 1881 (Umagillidae) is described from the intestine of the New Zealand sea urchin Evechinus chloroticus (Valenciennes, 1846) Mortensen, 1943a. This new species, Syndesmis kurakaikina n. sp., is morphologically distinct and can easily be recognised by its very long (±1 mm) stylet and its bright-red colour. In addition to providing a formal description, we present some observations on reproduction and life history of this new species. Fecundity is comparable to that of other umagillids and the rate of egg production and development increases with temperature. Hatching in this species is induced by intestinal fluids of its host. Relevant to global warming, we assessed the effect of temperature on survival, fecundity, and development. The tests indicate that Syndesmis kurakaikina n. sp. is tolerant of a wide range of temperatures (11-25 °C) and that its temperature optimum lies between 18.0 and 21.5 °C. Egg viability is, however, significantly compromised at the higher end of this temperature range, with expelled egg capsules often being deformed and showing increasingly lower rates of hatching. Given this, a rise in global temperature might increase the risk of Syndesmis kurakaikina n. sp. infecting new hosts and would possibly facilitate the spread of these endosymbionts.
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Affiliation(s)
- Marlies Monnens
- Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Agoralaan Gebouw D, B-3590, Diepenbeek, Belgium
| | - Emily J Frost
- School of Biological Sciences, University of Auckland, Private Bag, 92019, Auckland, New Zealand
| | - Miriam Clark
- School of Biological Sciences, University of Auckland, Private Bag, 92019, Auckland, New Zealand
| | - Mary A Sewell
- School of Biological Sciences, University of Auckland, Private Bag, 92019, Auckland, New Zealand
| | - Maarten P M Vanhove
- Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Agoralaan Gebouw D, B-3590, Diepenbeek, Belgium.,Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37, Brno, Czech Republic.,Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven, Charles Debériotstraat 32, B-3000, Leuven, Belgium.,Zoology Unit, Finnish Museum of Natural History, University of Helsinki, P.O.Box 17, FI-00014, Helsinki, Finland
| | - Tom Artois
- Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Agoralaan Gebouw D, B-3590, Diepenbeek, Belgium
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24
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Gulyas L, Powell JR. Predicting the Future: Parental Progeny Investment in Response to Environmental Stress Cues. Front Cell Dev Biol 2019; 7:115. [PMID: 31275936 PMCID: PMC6593227 DOI: 10.3389/fcell.2019.00115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/05/2019] [Indexed: 01/13/2023] Open
Abstract
Environmental stressors can severely limit the ability of an organism to reproduce as lifespan is decreased and resources are shifted away from reproduction to survival. Although this is often detrimental to the organism's reproductive fitness, certain other reproductive stress responses may mitigate this effect by increasing the likelihood of progeny survival in the F1 and subsequent generations. Here we review three means by which these progeny may be conferred a competitive edge as a result of stress encountered in the parental generation: heritable epigenetic modifications to nucleotides and histones, simple maternal investments of cytosolic components, and the partially overlapping phenomenon of terminal investment, which can entail extreme parental investment strategies in either cytosolic components or gamete production. We examine instances of these categories and their ability to subsequently impact offspring fitness and reproduction. Ultimately, without impacting nucleotide sequence, these more labile alterations may shape development, evolution, ecology and even human health, necessitating further understanding and research into the specific mechanisms by which environmental stressors are sensed and elicit a corresponding response in the parental germline.
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Affiliation(s)
- Leah Gulyas
- Department of Biology, Gettysburg College, Gettysburg, PA, United States
| | - Jennifer R Powell
- Department of Biology, Gettysburg College, Gettysburg, PA, United States
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25
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Śliwińska EB, Martyka R, Martyka M, Cichoń M, Tryjanowski P. A biotrophic fungal infection of the great burnet Sanguisorba officinalis indirectly affects caterpillar performance of the endangered scarce large blue butterfly Phengaris teleius. INSECT SCIENCE 2019; 26:555-568. [PMID: 29115041 DOI: 10.1111/1744-7917.12556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/18/2017] [Accepted: 10/25/2017] [Indexed: 06/07/2023]
Abstract
Interactions between ecological communities of herbivores and microbes are commonly mediated by a shared plant. A tripartite interaction between a pathogenic fungus-host plant-herbivorous insect is an example of such mutual influences. In such a system a fungal pathogen commonly has a negative influence on the morphology and biochemistry of the host plant, with consequences for insect herbivore performance. Here we studied whether the biotrophic fungus Podosphaera ferruginea, attacking the great burnet Sanguisorba officinalis, affects caterpillar performance of the endangered scarce large blue butterfly Phengaris teleius. Our results showed that the pathogenic fungus affected the number and size of inflorescences produced by food-plants and, more importantly, had indirect, plant-mediated effects on the abundance, body mass and immune response of caterpillars. Specifically, we found the relationship between caterpillar abundance and variability in inflorescence size on a plant to be positive among healthy food-plants, and negative among infected food-plants. Caterpillars that fed on healthy food-plants were smaller than those that fed on infected food-plants in one studied season, while there was no such difference in the other season. We observed the relationship between caterpillar immune response and the proportion of infected great burnets within a habitat patch to be positive when caterpillars fed on healthy food-plants, and negative when caterpillars fed on infected food-plants. Our results suggest that this biotrophic fungal infection of the great burnet may impose a significant indirect influence on P. teleius caterpillar performance with potential consequences for the population dynamics and structure of this endangered butterfly.
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Affiliation(s)
- Ewa B Śliwińska
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
| | - Rafał Martyka
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
| | - Mirosław Martyka
- Institute of Mathematical and Natural Science, State Higher Vocational School in Tarnów, Tarnów, Poland
| | - Mariusz Cichoń
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
| | - Piotr Tryjanowski
- Institute of Zoology, Poznań University of Life Sciences, Poznań, Poland
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26
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Barradas I, Vázquez V. Backward Bifurcation as a Desirable Phenomenon: Increased Fecundity Through Infection. Bull Math Biol 2019; 81:2029-2050. [PMID: 30941647 DOI: 10.1007/s11538-019-00604-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/26/2019] [Indexed: 10/27/2022]
Abstract
Backward or subcritical bifurcation is usually considered an undesirable phenomenon in epidemiology since control measures require a reduction in R0 not below one but below a much smaller value. However, there are contexts for which a backward or subcritical bifurcation is not a bad thing; it can even be desirable. Such is the case for any characteristic that can be passed to the next generation (genetically fixed or not) and that increases the effective reproductive rate of the host or the total number of individuals. In the present work, we study an epidemiological model consisting of two classes, susceptible and "infected" individuals; the model considers a characteristic that is passed from "infected" to "susceptible" by direct "contact," for instance increased fecundity. We analyze conditions for the appearance of a backward or subcritical bifurcation. We discuss the advantage for the population under infection, since the total number of individuals increases at equilibrium. If one takes that as a proxy for increased fitness, it would increase the species' ecological success. One key element in the model is the fact that "susceptible" individuals have "susceptible" descendants, but "infected" individuals can have "infected" descendants as well as "susceptible" ones. A somehow rare addition for epidemiological models, the fact that "infected" individuals reproduce more rapidly than the susceptible ones, leads to unexpected consequences. Facilitating the "inoculation" increases the total population size, i.e., the backward or subcritical bifurcation appears, with desirable consequences for the population. We show that an increase in the number of susceptible newborns is the main reason for the appearance of a backward or subcritical bifurcation, which induces a bigger population size. We analyze the effect of different combinations of susceptible/infected birth rates. This kind of phenomenon has been observed for bacterial infections in several insects-bacteria and nematodes-bacteria interactions; in particular, it has been intensely studied in interactions of wasps and flies with the genus Wolbachia. It has also been shown in amphibians.
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Affiliation(s)
- Ignacio Barradas
- Centro de Investigación en Matemáticas, Apartado Postal 402, 36000, Guanajuato, Guanajuato, Mexico.
| | - Virgilio Vázquez
- Instituto de Física y Matemáticas, Universidad Tecnológica de la Mixteca, 69000, Huajuapan de León, Oaxaca, Mexico
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27
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Campbell L, Bower DS, Clulow S, Stockwell M, Clulow J, Mahony M. Interaction between temperature and sublethal infection with the amphibian chytrid fungus impacts a susceptible frog species. Sci Rep 2019; 9:83. [PMID: 30643160 PMCID: PMC6331562 DOI: 10.1038/s41598-018-35874-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 11/07/2018] [Indexed: 11/09/2022] Open
Abstract
The amphibian chytrid fungus Batrachochytrium dendrobatidis is an emerging infectious pathogen present on every continent except Antarctica. It causes the disease chytridiomycosis in a subset of species but does not always result in disease or death for every host. Ambient temperature influences both amphibian metabolism and chytrid pathogenicity, however the interactive effects on host physiology is not well understood. We investigated the sublethal effect of B. dendrobatidis infection on a susceptible host, Litoria aurea to test (1) whether the infection load, metabolic activity, body fat and gonad size differed in L. aurea at either 24 °C or 12 °C ambient temperatures and (2) whether previous Bd infection caused long-term changes to body fat and gonad size. Litoria aurea in 12 °C treatments had higher infection loads of B. dendrobatidis and lower survivorship. Metabolic rate was higher and fat mass was lower in infected individuals and in animals in 24 °C treatments. Male L. aurea previously infected with B. dendrobatidis had smaller testes 5 months-post clearance of infection, an effect likely to translate to fitness costs in wild populations. These experiments demonstrate a physiological cost to sublethal B. dendrobatidis infection, which suggests a reduction in host fitness mediated by temperature in the host's environment regardless of whether infection leads to mortality.
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Affiliation(s)
- Lachlan Campbell
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, Newcastle, 2300, NSW, Australia.
| | - Deborah S Bower
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, Newcastle, 2300, NSW, Australia.,James Cook University, Townsville, 4811, Qld, Australia
| | - Simon Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, Newcastle, 2300, NSW, Australia.,Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Michelle Stockwell
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, Newcastle, 2300, NSW, Australia
| | - John Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, Newcastle, 2300, NSW, Australia
| | - Michael Mahony
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, Newcastle, 2300, NSW, Australia
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Bower DS, Brannelly LA, McDonald CA, Webb RJ, Greenspan SE, Vickers M, Gardner MG, Greenlees MJ. A review of the role of parasites in the ecology of reptiles and amphibians. AUSTRAL ECOL 2018. [DOI: 10.1111/aec.12695] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Deborah S. Bower
- College of Science and Engineering; James Cook University; Townsville Queensland 4811 Australia
- School of Environmental and Rural Science; University of New England; Armidale New South Wales Australia
| | - Laura A. Brannelly
- Department of Biological Sciences; University of Pittsburgh; Pittsburgh Pennsylvania USA
| | - Cait A. McDonald
- Department of Ecology and Evolutionary Biology; Cornell University; Ithaca New York USA
| | - Rebecca J. Webb
- College of Public Health, Medical and Veterinary Sciences; James Cook University; Townsville Queensland Australia
| | - Sasha E. Greenspan
- Department of Biological Sciences; University of Alabama; Tuscaloosa Alabama USA
| | - Mathew Vickers
- College of Science and Engineering; James Cook University; Townsville Queensland 4811 Australia
| | - Michael G. Gardner
- College of Science and Engineering; Flinders University; Adelaide South Australia Australia
- Evolutionary Biology Unit; South Australian Museum; Adelaide South Australia Australia
| | - Matthew J. Greenlees
- School of Life and Environmental Sciences; University of Sydney; Sydney New South Wales Australia
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Guo R, Zhang W, Yang Y, Ding J, Yang W, Zhang Y. Variation of fitness and reproductive strategy in male Bufo raddei under environmental heavy metal pollution. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 164:253-260. [PMID: 30121500 DOI: 10.1016/j.ecoenv.2018.08.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/08/2018] [Accepted: 08/10/2018] [Indexed: 06/08/2023]
Abstract
Environmental pollution is known to adversely affect amphibian reproduction and survival, however, the knowledge of environmental heavy metal pollution on fitness of male amphibian is largely unknown. The present study aimed to explore the variation in fitness of male Bufo raddei, a widespread anuran in northwest China, subjected to long-term heavy metal stress in Baiyin (BY) city. BY is heavily polluted by heavy metals mainly copper, zinc, lead and cadmium; meanwhile, Liujiaxia (LJX), a relatively unpolluted area, was chosen as control. Differences in advertisement call, larynx size, breeding glands size, as well as forearm force during courtship and amplexus in male B. raddei between the two populations were analyzed. The results revealed a competitive advantage in advertisement call in BY population, together with larger breeding glands size and forearm force, which demonstrated a relatively higher fitness. Using skeletochronological analysis, we found that more than 40% of males from BY began to breed at 2 years old, which was only 6.93% for males from LJX. Correspondingly, the average age for all males participate in breeding was younger from BY than from LJX. Not surprisingly, males from BY showed a relatively lower body condition. All these results illustrated males from BY invested more in reproduction to increase fitness at the cost of health and survival. This reproductive trade-off might ultimately influence stability of B. raddei population because of the environmental heavy metal pollution.
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Affiliation(s)
- Rui Guo
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Wenya Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China.
| | - Ying Yang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Jian Ding
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Wenzhi Yang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Yingmei Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China.
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30
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Brannelly LA, Martin G, Llewelyn J, Skerratt LF, Berger L. Age- and size-dependent resistance to chytridiomycosis in the invasive cane toad Rhinella marina. DISEASES OF AQUATIC ORGANISMS 2018; 131:107-120. [PMID: 30460917 DOI: 10.3354/dao03278] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In Australia, the cane toad Rhinella marina and chytrid fungus Batrachochytrium dendrobatidis (Bd) are examples of invasive species that have had dramatic impacts on native fauna. However, little is known about the interaction between Bd and cane toads. We aimed to explore the interaction of these 2 species in 3 parts. First, we collated data from the literature on Bd infection in wild cane toads. Second, we tested the susceptibility of recently metamorphosed cane toads to Bd infection. Finally, we modelled the distribution of the 2 species in Australia to identify where they overlap and, therefore, might interact. Through our data collation, we found that adult cane toads are infrequently infected and do not carry high infection burdens; however, our infection experiment showed that metamorphs are highly susceptible to infection and disease, but resistance appears to increase with increasing toad size. Niche modelling revealed overlapping distributions and the potential for cane toads to be affected by chytridiomycosis in the wild. While Bd can cause mortality in small juveniles in the laboratory, warm microhabitats used by wild toads likely prevent infection, and furthermore, high mortality of juveniles is unlikely to affect the adult populations because they are highly fecund. However, to demonstrate the impact of Bd on wild cane toad populations, targeted field studies are required to assess (1) the overall impact of chytridiomycosis on recruitment especially in cooler areas more favourable for Bd and (2) whether cane toad juveniles can amplify Bd exposure of native amphibian species in these areas.
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Affiliation(s)
- Laura A Brannelly
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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31
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Pigeault R, Cozzarolo CS, Choquet R, Strehler M, Jenkins T, Delhaye J, Bovet L, Wassef J, Glaizot O, Christe P. Haemosporidian infection and co-infection affect host survival and reproduction in wild populations of great tits. Int J Parasitol 2018; 48:1079-1087. [PMID: 30391229 DOI: 10.1016/j.ijpara.2018.06.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/06/2018] [Accepted: 06/19/2018] [Indexed: 12/20/2022]
Abstract
Theoretical studies predict that parasitic infection may impact host longevity and ultimately modify the trade-off between reproduction and survival. Indeed, a host may adjust its energy allocation in current reproduction to balance the negative effects of parasitism on its survival prospects. However, very few empirical studies tested this prediction. Avian haemosporidian parasites provide an excellent opportunity to assess the influence of parasitic infection on both host survival and reproduction. They are represented by three main genera (Plasmodium, Haemoproteus and Leucocytozoon) and are highly prevalent in many bird populations. Here we provide the first known long-term field study (12 years) to explore the effects of haemosporidian parasite infection and co-infection on fitness in two populations of great tits (Parus major), using a multistate modeling framework. We found that while co-infection decreased survival probability, both infection and co-infection increased reproductive success. This study provides evidence that co-infections can be more virulent than single infections. It also provides support for the life-history theory which predicts that reproductive effort can be adjusted to balance one's fitness when survival prospects are challenged.
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Affiliation(s)
- R Pigeault
- Département d'Ecologie & Evolution, Lausanne, Switzerland.
| | - C-S Cozzarolo
- Département d'Ecologie & Evolution, Lausanne, Switzerland
| | - R Choquet
- Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175, Montpellier, France
| | - M Strehler
- Département d'Ecologie & Evolution, Lausanne, Switzerland
| | - T Jenkins
- Département d'Ecologie & Evolution, Lausanne, Switzerland; Musée cantonal de zoologie, Lausanne, Switzerland
| | - J Delhaye
- Département d'Ecologie & Evolution, Lausanne, Switzerland; Evolution et Diversité Biologique, Université Toulouse 3, France
| | - L Bovet
- Département d'Ecologie & Evolution, Lausanne, Switzerland
| | - J Wassef
- Département d'Ecologie & Evolution, Lausanne, Switzerland
| | - O Glaizot
- Musée cantonal de zoologie, Lausanne, Switzerland
| | - P Christe
- Département d'Ecologie & Evolution, Lausanne, Switzerland
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32
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Zhang W, Guo R, Ai S, Yang Y, Ding J, Zhang Y. Long-term heavy metal pollution varied female reproduction investment in free-living anura, Bufo raddei. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 159:136-142. [PMID: 29734069 DOI: 10.1016/j.ecoenv.2018.05.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/28/2018] [Accepted: 05/01/2018] [Indexed: 06/08/2023]
Abstract
Environment contamination is known to affect the growth, reproduction, and even mortality of anuran species, and hence modulate their life history traits. Although knowledge of the ability of amphibians to cope with harsh environments has gained ongoing research, the reproductive strategy of free-living amphibians subjected to long-term heavy metal pollution is largely unknown. This study aimed to explore the variation in the life history traits, including age structure, maturation age, reproductive investment, and reproduction trade-off, in female Bufo raddei, a widespread anuran in Baiyin (BY) in northwest of China, subjected to sublethal heavy metal pollution. B. raddei collected from Liujiaxia (LJX), a relatively unpolluted area, were used as control. Skeletochronological analysis revealed variation in the average breeding age of females: more than 70% of females from BY began to breed 1 year before the toads collected from LJX. Females from BY tended to prioritize reproduction over survival and invested more in their first reproductive event. Further, females in BY with a high fluctuating asymmetry index showed a relatively lower reproductive investment. For trade-off in offspring number and size, BY population optimize larger clutch sizes with smaller egg size compared with population in LJX. Changes in female reproductive investment caused by heavy metal pollution might ultimately alter the structural stability of amphibian population.
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Affiliation(s)
- Wenya Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China.
| | - Rui Guo
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Shiwei Ai
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Ying Yang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Jian Ding
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Yingmei Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, PR China
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33
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Effects of Emerging Infectious Diseases on Amphibians: A Review of Experimental Studies. DIVERSITY-BASEL 2018. [DOI: 10.3390/d10030081] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Numerous factors are contributing to the loss of biodiversity. These include complex effects of multiple abiotic and biotic stressors that may drive population losses. These losses are especially illustrated by amphibians, whose populations are declining worldwide. The causes of amphibian population declines are multifaceted and context-dependent. One major factor affecting amphibian populations is emerging infectious disease. Several pathogens and their associated diseases are especially significant contributors to amphibian population declines. These include the fungi Batrachochytrium dendrobatidis and B. salamandrivorans, and ranaviruses. In this review, we assess the effects of these three pathogens on amphibian hosts as found through experimental studies. Such studies offer valuable insights to the causal factors underpinning broad patterns reported through observational studies. We summarize key findings from experimental studies in the laboratory, in mesocosms, and from the field. We also summarize experiments that explore the interactive effects of these pathogens with other contributors of amphibian population declines. Though well-designed experimental studies are critical for understanding the impacts of disease, inconsistencies in experimental methodologies limit our ability to form comparisons and conclusions. Studies of the three pathogens we focus on show that host susceptibility varies with such factors as species, host age, life history stage, population and biotic (e.g., presence of competitors, predators) and abiotic conditions (e.g., temperature, presence of contaminants), as well as the strain and dose of the pathogen, to which hosts are exposed. Our findings suggest the importance of implementing standard protocols and reporting for experimental studies of amphibian disease.
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34
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Brannelly LA, Roberts AA, Skerratt LF, Berger L. Using Terminal Transferase-mediated dUTP Nick End-labelling (TUNEL) and Caspase 3/7 Assays to Measure Epidermal Cell Death in Frogs with Chytridiomycosis. J Vis Exp 2018. [PMID: 29863673 DOI: 10.3791/57345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Amphibians are experiencing a great loss in biodiversity globally and one of the major causes is the infectious disease chytridiomycosis. This disease is caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), which infects and disrupts frog epidermis; however, pathological changes have not been explicitly characterized. Apoptosis (programmed cell death) can be used by pathogens to damage host tissue, but can also be a host mechanism of disease resistance for pathogen removal. In this study, we quantify epidermal cell death of infected and uninfected animals using two different assays: terminal transferase-mediated dUTP nick end-labelling (TUNEL), and caspase 3/7. Using ventral, dorsal, and thigh skin tissue in the TUNEL assay, we observe cell death in the epidermal cells in situ of clinically infected animals and compare cell death with uninfected animals using fluorescent microscopy. In order to determine how apoptosis levels in the epidermis change over the course of infection we remove toe-tip samples fortnightly over an 8-week period, and use a caspase 3/7 assay with extracted proteins to quantify activity within the samples. We then correlate caspase 3/7 activity with infection load. The TUNEL assay is useful for localization of cell death in situ, but is expensive and time intensive per sample. The caspase 3/7 assay is efficient for large sample sizes and time course experiments. However, because frog toe tip biopsies are small there is limited extract available for sample standardization via protein quantification methods, such as the Bradford assay. Therefore, we suggest estimating skin surface area through photographic analysis of toe biopsies to avoid consuming extracts during sample standardization.
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Affiliation(s)
- Laura A Brannelly
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University; Department of Biological Sciences, University of Pittsburgh;
| | - Alexandra A Roberts
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University
| | - Lee F Skerratt
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University
| | - Lee Berger
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University
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35
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Duffield KR, Hampton KJ, Houslay TM, Hunt J, Rapkin J, Sakaluk SK, Sadd BM. Age‐dependent variation in the terminal investment threshold in male crickets. Evolution 2018; 72:578-589. [DOI: 10.1111/evo.13443] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/26/2018] [Accepted: 01/29/2018] [Indexed: 01/17/2023]
Affiliation(s)
- Kristin R. Duffield
- Behavior, Ecology, Evolution and Systematics Section, School of Biological Sciences Illinois State University Normal Illinois 61761
| | - Kylie J. Hampton
- Behavior, Ecology, Evolution and Systematics Section, School of Biological Sciences Illinois State University Normal Illinois 61761
| | - Thomas M. Houslay
- Center for Ecology and Conservation, College of Life and Environmental Sciences University of Exeter Penryn TR10 9FE United Kingdom
| | - John Hunt
- Center for Ecology and Conservation, College of Life and Environmental Sciences University of Exeter Penryn TR10 9FE United Kingdom
- School of Science and Health and Hawkesbury Institute for the Environment, Western Sydney University Penrith NSW 2751 Australia
| | - James Rapkin
- Center for Ecology and Conservation, College of Life and Environmental Sciences University of Exeter Penryn TR10 9FE United Kingdom
| | - Scott K. Sakaluk
- Behavior, Ecology, Evolution and Systematics Section, School of Biological Sciences Illinois State University Normal Illinois 61761
| | - Ben M. Sadd
- Behavior, Ecology, Evolution and Systematics Section, School of Biological Sciences Illinois State University Normal Illinois 61761
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Abstract
Although reproductive strategies can be influenced by a variety of intrinsic and extrinsic factors, life history theory provides a rigorous framework for explaining variation in reproductive effort. The terminal investment hypothesis proposes that a decreased expectation of future reproduction (as might arise from a mortality threat) should precipitate increased investment in current reproduction. Terminal investment has been widely studied, and a variety of intrinsic and extrinsic cues that elicit such a response have been identified across an array of taxa. Although terminal investment is often treated as a static strategy, the level at which a cue of decreased future reproduction is sufficient to trigger increased current reproductive effort (i.e., the terminal investment threshold) may depend on context, including the internal state of the organism or its current external environment, independent of the cue that triggers a shift in reproductive investment. Here, we review empirical studies that address the terminal investment hypothesis, exploring both the intrinsic and extrinsic factors that mediate its expression. Based on these studies, we propose a novel framework within which to view the strategy of terminal investment, incorporating factors that influence an individual's residual reproductive value beyond a terminal investment trigger - the dynamic terminal investment threshold.
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37
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Giehr J, Grasse AV, Cremer S, Heinze J, Schrempf A. Ant queens increase their reproductive efforts after pathogen infection. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170547. [PMID: 28791176 PMCID: PMC5541571 DOI: 10.1098/rsos.170547] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 06/01/2017] [Indexed: 05/31/2023]
Abstract
Infections with potentially lethal pathogens may negatively affect an individual's lifespan and decrease its reproductive value. The terminal investment hypothesis predicts that individuals faced with a reduced survival should invest more into reproduction instead of maintenance and growth. Several studies suggest that individuals are indeed able to estimate their body condition and to increase their reproductive effort with approaching death, while other studies gave ambiguous results. We investigate whether queens of a perennial social insect (ant) are able to boost their reproduction following infection with an obligate killing pathogen. Social insect queens are special with regard to reproduction and aging, as they outlive conspecific non-reproductive workers. Moreover, in the ant Cardiocondyla obscurior, fecundity increases with queen age. However, it remained unclear whether this reflects negative reproductive senescence or terminal investment in response to approaching death. Here, we test whether queens of C. obscurior react to infection with the entomopathogenic fungus Metarhizium brunneum by an increased egg-laying rate. We show that a fungal infection triggers a reinforced investment in reproduction in queens. This adjustment of the reproductive rate by ant queens is consistent with predictions of the terminal investment hypothesis and is reported for the first time in a social insect.
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Affiliation(s)
- Julia Giehr
- Zoology/Evolutionary Biology, University of Regensburg, 93053 Regensburg, Germany
| | - Anna V. Grasse
- IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Sylvia Cremer
- IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Jürgen Heinze
- Zoology/Evolutionary Biology, University of Regensburg, 93053 Regensburg, Germany
| | - Alexandra Schrempf
- Zoology/Evolutionary Biology, University of Regensburg, 93053 Regensburg, Germany
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Abstract
Reproduction of amphibians includes ovulation, spermiation, fertilization, oviposition, larval stage and development, and metamorphosis. A problem at any stage could lead to reproductive failure. To stimulate reproduction, environmental conditions must be arranged to simulate changes in natural habits. Reproductive life history is well documented in amphibians; a thorough knowledge of this subject will aid the practitioner in diagnosis and treatment. Technologies for artificial reproduction are developing rapidly, and some protocols may be transferable to privately kept or endangered species. Reproductive tract disorders are rarely described; no bacterial or viral diseases are known that specifically target the amphibian reproductive system.
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39
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Brannelly LA, Roberts AA, Skerratt LF, Berger L. Epidermal cell death in frogs with chytridiomycosis. PeerJ 2017; 5:e2925. [PMID: 28168107 PMCID: PMC5291105 DOI: 10.7717/peerj.2925] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 12/19/2016] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Amphibians are declining at an alarming rate, and one of the major causes of decline is the infectious disease chytridiomycosis. Parasitic fungal sporangia occur within epidermal cells causing epidermal disruption, but these changes have not been well characterised. Apoptosis (planned cell death) can be a damaging response to the host but may alternatively be a mechanism of pathogen removal for some intracellular infections. METHODS In this study we experimentally infected two endangered amphibian species Pseudophryne corroboree and Litoria verreauxii alpina with the causal agent of chytridiomycosis. We quantified cell death in the epidermis through two assays: terminal transferase-mediated dUTP nick end-labelling (TUNEL) and caspase 3/7. RESULTS Cell death was positively associated with infection load and morbidity of clinically infected animals. In infected amphibians, TUNEL positive cells were concentrated in epidermal layers, correlating to the localisation of infection within the skin. Caspase activity was stable and low in early infection, where pathogen loads were light but increasing. In animals that recovered from infection, caspase activity gradually returned to normal as the infection cleared. Whereas, in amphibians that did not recover, caspase activity increased dramatically when infection loads peaked. DISCUSSION Increased cell death may be a pathology of the fungal parasite, likely contributing to loss of skin homeostatic functions, but it is also possible that apoptosis suppression may be used initially by the pathogen to help establish infection. Further research should explore the specific mechanisms of cell death and more specifically apoptosis regulation during fungal infection.
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Affiliation(s)
- Laura A Brannelly
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University , Townsville , QLD , Australia
| | - Alexandra A Roberts
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University , Townsville , QLD , Australia
| | - Lee F Skerratt
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia; Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Lee Berger
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia; Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, Victoria, Australia
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40
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Kosch TA, Eimes JA, Didinger C, Brannelly LA, Waldman B, Berger L, Skerratt LF. Characterization of MHC class IA in the endangered southern corroboree frog. Immunogenetics 2016; 69:165-174. [DOI: 10.1007/s00251-016-0965-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/29/2016] [Indexed: 01/12/2023]
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41
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Brannelly LA, Webb RJ, Skerratt LF, Berger L. Effects of chytridiomycosis on hematopoietic tissue in the spleen, kidney and bone marrow in three diverse amphibian species. Pathog Dis 2016; 74:ftw069. [DOI: 10.1093/femspd/ftw069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2016] [Indexed: 01/12/2023] Open
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