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de Amaral M, Carvajalino-Fernández JM, Nicieza AG, Tejedo M. Urea and glucose modulation during freezing exposure in three temperate frogs reveals specific targets in relation to climate. J Therm Biol 2024; 121:103854. [PMID: 38657317 DOI: 10.1016/j.jtherbio.2024.103854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/21/2024] [Accepted: 04/01/2024] [Indexed: 04/26/2024]
Abstract
Amphibian diversity is most prominent in the warm and humid tropical and subtropical regions across the globe. Nonetheless, amphibians also inhabit high-altitude tropical mountains and regions at medium and high latitudes, exposing them to subzero temperatures and requiring behavioural or physiological adaptations to endure freezing events. While freeze tolerance has been predominantly reported in high-latitude zones where species endure prolonged freezing (several weeks or months), less is known about mid-latitudes amphibians exposed to occasional subzero temperatures. In this study, we employed a controlled ecological protocol, subjecting three frog species from the Iberian Peninsula (Rana parvipalmata, Epidalea calamita, and Pelobates cultripes) to a 2-h exposure to temperatures of -2 °C to investigate the accumulation of urea and glucose as physiological mechanisms associated with survival at freezing temperatures. Our results revealed a moderate response in the production of cryoprotectant metabolites under experimental freezing conditions, particularly urea, with notable findings in R. parvipalmata and E. calamita and no response in P. cultripes. However, no significant alterations in glucose concentrations were observed in any of the studied frog species. This relatively weak freezing tolerance response differs from the strong response exhibited by amphibians inhabiting high latitudes and enduring prolonged freezing conditions, suggesting potential reliance on behavioural adaptations to cope with occasional freezing episodes.
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Affiliation(s)
- Marjoriane de Amaral
- Laboratory of Metabolism and Comparative Endocrinology, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; Department of Evolutionary Ecology, Estación Biológica de Doñana, CSIC, Sevilla, Spain
| | | | - Alfredo G Nicieza
- Biodiversity Research Institute (IMIB), University of Oviedo-Principality of Asturias-CSIC, Mieres, Spain; Department of Biology of Organisms and Systems, University of Oviedo, Oviedo, Spain
| | - Miguel Tejedo
- Department of Evolutionary Ecology, Estación Biológica de Doñana, CSIC, Sevilla, Spain.
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2
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Sugiura S, Hayashi M. Defenses of whirligig beetles against native and invasive frogs. PeerJ 2024; 12:e17214. [PMID: 38646489 PMCID: PMC11027905 DOI: 10.7717/peerj.17214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/19/2024] [Indexed: 04/23/2024] Open
Abstract
Many native insects have evolved defenses against native predators. However, their defenses may not protect them from non-native predators due to a limited shared history. The American bullfrog, Aquarana catesbeiana (Anura: Ranidae), which has been intentionally introduced to many countries, is believed to impact native aquatic animals through direct predation. Adults of whirligig beetles (Coleoptera: Gyrinidae), known for swimming and foraging on the water surface of ponds and streams, reportedly possess chemical defenses against aquatic predators, such as fish. Although whirligig beetles potentially encounter both bullfrogs and other frogs in ponds and lakes, the effectiveness of their defenses against frogs has been rarely studied. To assess whether whirligig beetles can defend against native and non-native frogs, we observed the behavioral responses of the native pond frog, Pelophylax nigromaculatus (Anura: Ranidae), and the invasive non-native bullfrog, A. catesbeiana, to native whirligig beetles, Gyrinus japonicus and Dineutus orientalis, in Japan. Adults of whirligig beetles were provided to frogs under laboratory conditions. Forty percent of G. japonicus and D.orientalis were rejected by P. nigromaculatus, while all whirligig beetles were easily consumed by A. catesbeiana. Chemical and other secondary defenses of G. japonicus and D. orientalis were effective for some individuals of P. nigromaculatus but not for any individuals of A. catesbeiana. These results suggest that native whirligig beetles suffer predation by invasive non-native bullfrogs in local ponds and lakes in Japan.
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Affiliation(s)
- Shinji Sugiura
- Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, Japan
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3
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Sorrell CA, Burmeister SS. Orientation by environmental geometry and feature cues in the green and black poison frog (Dendrobates auratus). Anim Cogn 2023; 26:2023-2030. [PMID: 37698756 DOI: 10.1007/s10071-023-01820-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 09/13/2023]
Abstract
The ability to use environmental geometry when orienting in space reflects an animal's ability to use a global, allocentric framework. Therefore, understanding when and how animal's use geometry relative to other types of cues in the environment has interested comparative cognition researchers for decades. Yet, only two amphibians have been tested to date. We trained the poison frog Dendrobates auratus to find goal shelters in a rectangular arena, in the presence and absence of a feature cue, and assessed the relative influence of the two types of cues using probe trials. We chose D. auratus because the species has complex interactions with their physical and social environments, including parental care that requires navigating to and from distant locations. We found that, like many vertebrates, D. auratus are capable of using geometric information to relocate goals. In addition, the frogs preferentially used the more reliable feature cue when the location of the feature conflicted with the geometry of the arena. The frogs were equally successful at using the feature cue when it was proximal or distal to the goal shelter, consistent with prior studies that found that D. auratus can use distal cues in a flexible manner. Our results provide further evidence that amphibians can use environmental geometry during orientation. Future studies that examine when and how amphibians use geometry relative to other types of cues will contribute to a more complete picture of spatial cognition in this important, yet understudied, group.
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Affiliation(s)
- Cody A Sorrell
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Sabrina S Burmeister
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA.
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Douglas AJ, Katzenback BA. The wood frog (Rana sylvatica): An emerging comparative model for anuran immunity and host-ranavirus interactions. Dev Comp Immunol 2023; 147:104733. [PMID: 37550009 DOI: 10.1016/j.dci.2023.104733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 05/06/2023] [Accepted: 05/09/2023] [Indexed: 08/09/2023]
Abstract
The wood frog (Rana sylvatica) is widely distributed across North America and is the only amphibian found north of the Arctic Circle due to its remarkable ability to tolerate whole-body freezing. Recent mass mortalities attributable to Ranavirus spp. (family Iridoviridae) in wild juvenile wood frogs, coupled with the apparent high susceptibility of wood frogs to experimental infection with frog virus 3 (FV3), the type species of the Ranavirus genus, or FV3-like isolates underscore the serious threat ranaviruses poses to wood frog populations. Despite the ecological relevance and unique life history of wood frogs, our understanding of the wood frog immune system and antiviral response to ranaviral infections is in its infancy. Here we aim to (1) synthesize the limited knowledge of wood frog immune defences, (2) review recent progress in establishing the wood frog as a study system for ranavirus infection, and (3) highlight the future use of wood frogs as a model anuran to provide insight into the evolution of anuran immune systems and antiviral responses.
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Affiliation(s)
- Alexander J Douglas
- Department of Biology, University of Waterloo, Waterloo, Ontario, N2L3G1, Canada
| | - Barbara A Katzenback
- Department of Biology, University of Waterloo, Waterloo, Ontario, N2L3G1, Canada.
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Sugiura S, Hayashi M. Bombardiers and assassins: mimetic interactions between unequally defended insects. PeerJ 2023; 11:e15380. [PMID: 37304866 PMCID: PMC10252827 DOI: 10.7717/peerj.15380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 04/18/2023] [Indexed: 06/13/2023] Open
Abstract
In defensive mimicry, resemblance between unequally defended species can be parasitic; this phenomenon has been termed quasi-Batesian mimicry. Few studies have used real co-mimics and their predators to test whether the mimetic interactions were parasitic. Here, we investigated the mimetic interaction between two well-defended insect species, the bombardier beetle Pheropsophus occipitalis jessoensis (Coleoptera: Carabidae) and the assassin bug Sirthenea flavipes (Hemiptera: Reduviidae), using their potential predator, the pond frog Pelophylax nigromaculatus (Anura: Ranidae), which coexists with these insect species in the same habitat in Japan. We observed behavioural responses of this frog species (adults and juveniles) to adult Ph. occipitalis jessoensis and adult S. flavipes under laboratory conditions. Among the frogs, 100% and 75% rejected Ph. occipitalis jessoensis and S. flavipes, respectively, suggesting that, compared with the assassin bug S. flavipes, the bombardier beetle Ph. occipitalis jessoensis is more well-defended against frogs. An assassin bug or a bombardier beetle was provided to a frog that had encountered the other insect species. Frogs with a history of assassin bug encounter demonstrated a lower rate of attack toward bombardier beetles. Similarly, frogs with a history of bombardier beetle encounter demonstrated a lower rate of attack toward assassin bugs. Therefore, both the bombardier beetle Ph. occipitalis jessoensis and the assassin bug S. flavipes benefit from the mimetic interaction.
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Affiliation(s)
- Shinji Sugiura
- Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, Japan
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Terblanche N, Measey J. The conservation value of freshwater habitats for frog communities of lowland fynbos. PeerJ 2023; 11:e15516. [PMID: 37304861 PMCID: PMC10249618 DOI: 10.7717/peerj.15516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 05/15/2023] [Indexed: 06/13/2023] Open
Abstract
Amphibians are more threatened than any other vertebrate class, yet evidence for many threats is missing. The Cape lowland fynbos (endemic scrub biome) is threatened by habitat loss, and natural temporary freshwater habitats are removed in favour of permanent impoundments. In this study, we determine amphibian assemblages across different freshwater habitat types with special attention to the presence of invasive fish. We find that anuran communities differ primarily by habitat type, with permanent water habitats having more widespread taxa, while temporary water bodies have more range restricted taxa. Invasive fish are found to have a significant impact on frogs with toads most tolerant of their presence. Temporary freshwater habitats are a conservation priority in the area, and their amphibian assemblages represent endemic taxa that are intolerant of invasive fish. Conservation of a biodiverse amphibian assemblage in lowland fynbos areas will rely on the creation of temporary freshwater habitats, rather than a northern hemisphere pond based solution.
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Affiliation(s)
- Naas Terblanche
- Riverglade Retirement Village, Parklands, Unaffiliated, Cape Town, South Africa
| | - John Measey
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa
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Shinad K, Chaudhary A, Prasadan PK, Singh HS. Phylogenetic relationships of two species of Haematoloechus (Trematoda: Haematoloechidae) infecting Euphlyctis spp. from the biodiversity hotspot, Western Ghats, India. Parasitol Int 2023; 93:102721. [PMID: 36528328 DOI: 10.1016/j.parint.2022.102721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 12/11/2022] [Accepted: 12/11/2022] [Indexed: 12/15/2022]
Abstract
During a parasitological survey in the biodiversity hotspot, two species of the digenetic trematode, Haematoloechus from the lungs of Indian skipper frog Euphlyctis cyanophlyctis and the Indian green frog, E. hexadactylus inhabiting the biodiversity hotspot, Western Ghats, India, were found and described using morphological and molecular tools. Morphological examinations indicated that the two species are Haematoloechus almorai Pande, 1937 and H. (H.) variegatus capyristes (Klein, 1905; Ingles, 1932) Odening, 1958 as previously described in the original manuscripts but with some morphological differences. The ITS region (ITS1, 5.8S and ITS2) and 28S gene of ribosomal DNA sequences were performed for phylogenetic studies showed that the sequences of these species did not match with any of the previously reported sequences on GenBank database. Phylogenetic analysis placed H. almorai and H. (H.) variegatus capyristes in a well-supported clade under the genus Haematoloechus. This is the first molecular study of present Haematoloechus species from the Western Ghats, India and discussed their phylogenetic position.
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Affiliation(s)
- Keloth Shinad
- Ecological Parasitology and Tropical Biodiversity Laboratory, Department of Zoology, Kannur University, Mananthavady Campus, Wayanad, Kerala 670645, India
| | - Anshu Chaudhary
- Molecular Taxonomy Laboratory, Department of Zoology, Chaudhary Charan Singh University, Meerut, Uttar Pradesh 250004, India
| | - Puthanpurayil Kandambeth Prasadan
- Ecological Parasitology and Tropical Biodiversity Laboratory, Department of Zoology, Kannur University, Mananthavady Campus, Wayanad, Kerala 670645, India.
| | - Hridaya Shanker Singh
- Molecular Taxonomy Laboratory, Department of Zoology, Chaudhary Charan Singh University, Meerut, Uttar Pradesh 250004, India; Maa Shakumbhari University, Saharanpur, Uttar Pradesh 247120, India
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Medina-Ortiz K, Navia F, Mosquera-Gil C, Sánchez A, Sterling G, Fierro L, Castaño S. Identification of the NA +/K +-ATPase α-Isoforms in Six Species of Poison Dart Frogs and their Sensitivity to Cardiotonic Steroids. J Chem Ecol 2023; 49:116-132. [PMID: 36877397 PMCID: PMC10102066 DOI: 10.1007/s10886-023-01404-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 03/07/2023]
Abstract
Cardiotonic steroids (CTS) are a group of compounds known to be toxic due to their ability to inhibit the Na+/K+-ATPase (NKA), which is essential to maintain the balance of ions in animal cells. An evolutionary strategy of molecular adaptation to avoid self-intoxication acquired by CTS defended organisms and their predators is the structural modification of their NKA where specific amino acid substitutions confer resistant phenotypes. Several lineages of poison dart frogs (Dendrobatidae) are well known to sequester a wide variety of lipophilic alkaloids from their arthropod diet, however there is no evidence of CTS-sequestration or dietary exposure. Interestingly this study identified the presence of α-NKA isoforms (α1 and α2) with amino acid substitutions indicative of CTS-resistant phenotypes in skeletal muscle transcriptomes obtained from six species of dendrobatids: Phyllobates aurotaenia, Oophaga anchicayensis, Epipedobates boulengeri, Andinobates bombetes, Andinobates minutus, and Leucostethus brachistriatus, collected in the Valle del Cauca (Colombia). P. aurotaenia, A. minutus, and E. boulengeri presented two variants for α1-NKA, with one of them having these substitutions. In contrast, O. anchicayensis and A. bombetes have only one α1-NKA isoform with an amino acid sequence indicative of CTS susceptibility and an α2-NKA with one substitution that could confer a reduced affinity for CTS. The α1 and α2 isoforms of L. brachistriatus do not contain substitutions imparting CTS resistance. Our findings indicate that poison dart frogs express α-NKA isoforms with different affinities for CTS and the pattern of this expression might be influenced by factors related to evolutionary, physiological, ecological, and geographical burdens.
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Affiliation(s)
- Katherine Medina-Ortiz
- Laboratorio de Herpetología Y Toxinología, Department of Physiological Sciences, Faculty of Health, Universidad del Valle, Cali, Colombia.
| | - Felipe Navia
- Laboratorio de Herpetología Y Toxinología, Department of Physiological Sciences, Faculty of Health, Universidad del Valle, Cali, Colombia
| | - Claudia Mosquera-Gil
- Laboratorio de Herpetología Y Toxinología, Department of Physiological Sciences, Faculty of Health, Universidad del Valle, Cali, Colombia
| | - Adalberto Sánchez
- Laboratorio de Herpetología Y Toxinología, Department of Physiological Sciences, Faculty of Health, Universidad del Valle, Cali, Colombia
| | - Gonzalo Sterling
- Laboratorio de Herpetología Y Toxinología, Department of Physiological Sciences, Faculty of Health, Universidad del Valle, Cali, Colombia
| | - Leonardo Fierro
- Laboratorio de Herpetología Y Toxinología, Department of Physiological Sciences, Faculty of Health, Universidad del Valle, Cali, Colombia
| | - Santiago Castaño
- Laboratorio de Herpetología Y Toxinología, Department of Physiological Sciences, Faculty of Health, Universidad del Valle, Cali, Colombia.
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He QL, Deng K, Wang XP, Chen QH, Wang TL, Wang JC, Cui JG. Heterospecific eavesdropping on disturbance cues of a treefrog. Anim Cogn 2023; 26:515-522. [PMID: 36131103 DOI: 10.1007/s10071-022-01690-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 08/30/2022] [Accepted: 09/04/2022] [Indexed: 11/01/2022]
Abstract
Alarm signals and cues are crucial to animal survival and vary greatly across species. Eavesdropping on heterospecific alarm signals and cues can provide eavesdroppers with information about potential threats. In addition to acoustic alarm signals, evidence has accumulated that chemical alarm cues and disturbance cues can also play a role in alerting conspecifics to potential danger in adult anurans (frogs and toads). However, there is very little known about whether disturbance cues are exploited by heterospecifics. In the present study, we conducted a binary choice experiment and a prey chemical discrimination experiment, respectively, to test the responses of a sympatric anuran species (red webbed treefrogs, Rhacophorus rhodopus) and a sympatric predator species (Chinese green tree vipers, Trimeresurus stejnegeri) to disturbance odors emitted by serrate-legged small treefrogs (Kurixalus odontotarsus). In the binary choice experiment, we found that the presence of disturbance odors did not significantly trigger the avoidance behavior of R. rhodopus. In the prey chemical discrimination experiment, compared with odors from undisturbed K. odontotarsus (control odors) and odorless control, T. stejnegeri showed a significantly higher tongue-flick rate in response to disturbance odors. This result implies that disturbance odor cues of K. odontotarsus can be exploited by eavesdropping predators to detect prey. Our study provides partial evidence for heterospecific eavesdropping on disturbance cues and has an important implication for understanding heterospecific eavesdropping on chemical cues of adult anurans.
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Affiliation(s)
- Qiao-Ling He
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No.9 Section 4, Renmin South Road, Chengdu, 610041, China.,University of Chinese Academy of Science, Beijing, 100049, China
| | - Ke Deng
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No.9 Section 4, Renmin South Road, Chengdu, 610041, China.
| | - Xiao-Ping Wang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No.9 Section 4, Renmin South Road, Chengdu, 610041, China.,University of Chinese Academy of Science, Beijing, 100049, China
| | - Qing-Hua Chen
- Ministry of Ecology and Environment, South China Institute of Environmental Sciences, Guangzhou, 510530, China
| | - Tong-Liang Wang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, 571158, China
| | - Ji-Chao Wang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, 571158, China
| | - Jian-Guo Cui
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No.9 Section 4, Renmin South Road, Chengdu, 610041, China.
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do Amaral-Silva L, Santin JM. A brainstem preparation allowing simultaneous access to respiratory motor output and cellular properties of motoneurons in American bull frogs. J Exp Biol 2022; 225:jeb244079. [PMID: 35574670 PMCID: PMC9250796 DOI: 10.1242/jeb.244079] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 05/06/2022] [Indexed: 10/25/2023]
Abstract
Breathing is generated by a complex neural circuit, and the ability to monitor the activity of multiple network components simultaneously is required to uncover the cellular basis of breathing. In neonatal rodents, a single brainstem slice can be obtained to record respiratory-related motor nerve discharge along with individual rhythm-generating cells or motoneurons because of the close proximity of these neurons in the brainstem. However, most ex vivo preparations in other vertebrates can only capture respiratory motor outflow or electrophysiological properties of putative respiratory neurons in slices without relevant synaptic inputs. Here, we detail a method to horizontally slice away the dorsal portion of the brainstem to expose fluorescently labeled motoneurons for patch-clamp recordings in American bullfrogs. This 'semi-intact' preparation allows tandem recordings of motor output and single motoneurons during respiratory-related synaptic inputs. The rhythmic motor patterns are comparable to those from intact preparations and operate at physiological temperature and [K+]. Thus, this preparation provides the ability to record network and cellular outputs simultaneously and may lead to new mechanistic insights into breathing control across vertebrates.
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Affiliation(s)
- Lara do Amaral-Silva
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC 27403, USA
| | - Joseph M. Santin
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC 27403, USA
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Abstract
Elastic recoil drives some of the fastest and most powerful biological movements. For effective use of elastic recoil, the tuning of muscle and spring force capacity is essential. Although studies of invertebrate organisms that use elastic recoil show evidence of increased force capacity in their energy loading muscle, changes in the fundamental properties of such muscles have yet to be documented in vertebrates. Here, we used three species of frogs (Cuban tree frogs, bullfrogs and cane toads) that differ in jumping power to investigate functional shifts in muscle-spring tuning in systems using latch-mediated spring actuation (LaMSA). We hypothesized that variation in jumping performance would result from increased force capacity in muscles and relatively stiffer elastic structures, resulting in greater energy storage. To test this, we characterized the force-length property of the plantaris longus muscle-tendon unit (MTU), and quantified the maximal amount of energy stored in elastic structures for each species. We found that the plantaris longus MTU of Cuban tree frogs produced higher mass-specific energy and mass-specific forces than the other two species. Moreover, we found that the plantaris longus MTU of Cuban tree frogs had higher pennation angles than the other species, suggesting that muscle architecture was modified to increase force capacity through packing of more muscle fibers. Finally, we found that the elastic structures were relatively stiffer in Cuban tree frogs. These results provide a mechanistic link between the tuned properties of LaMSA components, energy storage capacity and whole-system performance.
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Affiliation(s)
- Elizabeth Mendoza
- Department of Ecology and Evolutionary Biology, 321 Steinhaus Hall, University of California Irvine, Irvine, CA 92617, USA
| | - Emanuel Azizi
- Department of Ecology and Evolutionary Biology, 321 Steinhaus Hall, University of California Irvine, Irvine, CA 92617, USA
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de Amaral M, Von Dentz MC, Ohlweiler R, Hoff MLM, Heiermann D, Colombo P, Kucharski LC. Seasonal variations in the intermediate metabolism in South American tree-frog Boana pulchella. J Comp Physiol B 2021. [PMID: 34799758 DOI: 10.1007/s00360-021-01420-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 09/09/2021] [Accepted: 11/03/2021] [Indexed: 10/19/2022]
Abstract
Seasonal metabolic changes can be observed in many anurans' species. In subtropical environments with environmental temperatures variations, the temperature is a factor that can influence the extent and intensity of activity in many anuran species. Nonetheless, some species of subtropical frogs may remain active throughout the year. Boana pulchella, a subtropical species, seems to be able to survive low temperatures and remain reproductively active even in the coldest months. Therefore, we hypothesized that B. pulchella presents seasonal changes in the energy metabolism to sustain activity during all year. This study evaluated the main energy substrate levels and metabolism of B. pulchella in plasma, liver and muscle of male individuals collected in winter, spring, summer and fall in the state of Rio Grande do Sul, Brazil. Our results showed that B. pulchella has a higher glycolytic oxidation rate in liver (P = 0.0152) and muscle (P = 0.0003) and higher glycogenesis from glucose in muscle (P = 0.0002) in summer, indicating the main energy substrates in this season is glucose. The higher muscle glycogen (P = 0.0008) and lower plasma glucose in fall (P = 0.0134) may indicate an anticipatory regulation for storing to the most thermally demanding cold period: winter. These results indicated seasonal differences in the main energy substrates, and these metabolic changes among seasons can be part of a metabolic adjustment allowing maintenance of reproductive activity all year in Boana pulchella species.
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Smalling KL, Oja EB, Cleveland DM, Davenport JM, Eagles-Smith C, Campbell Grant EH, Kleeman PM, Halstead BJ, Stemp KM, Tornabene BJ, Bunnell ZJ, Hossack BR. Metal accumulation varies with life history, size, and development of larval amphibians. Environ Pollut 2021; 287:117638. [PMID: 34426379 DOI: 10.1016/j.envpol.2021.117638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/15/2021] [Accepted: 06/20/2021] [Indexed: 06/13/2023]
Abstract
Amphibian larvae are commonly used as indicators of aquatic ecosystem health because they are susceptible to contaminants. However, there is limited information on how species characteristics and trophic position influence contaminant loads in larval amphibians. Importantly, there remains a need to understand whether grazers (frogs and toads [anurans]) and predators (salamanders) provide comparable information on contaminant accumulation or if they are each indicative of unique environmental processes and risks. To better understand the role of trophic position in contaminant accumulation, we analyzed composite tissues for 10 metals from larvae of multiple co-occurring anuran and salamander species from 20 wetlands across the United States. We examined how metal concentrations varied with body size (anurans and salamanders) and developmental stage (anurans) and how the digestive tract (gut) influenced observed metal concentrations. Across all wetlands, metal concentrations were greater in anurans than salamanders for all metals tested except mercury (Hg), selenium (Se), and zinc (Zn). Concentrations of individual metals in anurans decreased with increasing weight and developmental stage. In salamanders, metal concentrations were less correlated with weight, indicating diet played a role in contaminant accumulation. Based on batches of similarly sized whole-body larvae compared to larvae with their digestive tracts removed, our results indicated that tissue type strongly affected perceived concentrations, especially for anurans (gut represented an estimated 46-97% of all metals except Se and Zn). This suggests the reliability of results based on whole-body sampling could be biased by metal, larval size, and development. Overall, our data shows that metal concentrations differs between anurans and salamanders, which suggests that metal accumulation is unique to feeding behavior and potentially trophic position. To truly characterize exposure risk in wetlands, species of different life histories, sizes and developmental stages should be included in biomonitoring efforts.
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Affiliation(s)
- Kelly L Smalling
- US Geological Survey, New Jersey Water Science Center, Lawrenceville, NJ, 08648, USA.
| | - Emily B Oja
- US Geological Survey, Northern Rocky Mountain Science Center, Missoula, MT, 59812, USA
| | - Danielle M Cleveland
- US Geological Survey, Columbia Environmental Research Center, Columbia, MO, 65201, USA
| | - Jon M Davenport
- Department of Biology, Appalachian State University, Boone, NC, 28608, USA
| | - Collin Eagles-Smith
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA
| | - Evan H Campbell Grant
- U.S. Geological Survey, Eastern Ecological Science Center, S.O. Conte Anadromous Fish Research Laboratory, Turner Falls, MA, 01376, USA
| | - Patrick M Kleeman
- US Geological Survey, Western Ecological Research Center, Point Reyes Field Station, Point Reyes Station, CA, 94956, USA
| | - Brian J Halstead
- US Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, CA, 95620, USA
| | - Kenzi M Stemp
- Department of Biology, Appalachian State University, Boone, NC, 28608, USA
| | - Brian J Tornabene
- Wildlife Biology Program, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT, 59812, USA
| | - Zachary J Bunnell
- US Geological Survey, New Jersey Water Science Center, Lawrenceville, NJ, 08648, USA
| | - Blake R Hossack
- US Geological Survey, Northern Rocky Mountain Science Center, Missoula, MT, 59812, USA; Wildlife Biology Program, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT, 59812, USA
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14
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Robinson SA, Chlebak RJ, Young SD, Dalton RL, Gavel MJ, Prosser RS, Bartlett AJ, de Solla SR. Clothianidin alters leukocyte profiles and elevates measures of oxidative stress in tadpoles of the amphibian, Rana pipiens. Environ Pollut 2021; 284:117149. [PMID: 33894534 DOI: 10.1016/j.envpol.2021.117149] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/07/2021] [Accepted: 04/11/2021] [Indexed: 06/12/2023]
Abstract
Neonicotinoid pesticide use is widespread and highly debated, as evidenced by recent attention received from the public, academics and pesticide regulatory agencies. However, relatively little is known about the physiological effects of neonicotinoid insecticides on aquatic vertebrates. Amphibians (larval stages in particular) are excellent vertebrate bioindicators in aquatic systems due to their risk of exposure and sensitivity to environmental stressors. Previous work with wood frog (Rana sylvatica) tadpoles exposed to formulated products containing thiamethoxam or clothianidin in outdoor mesocosms found significant shifts in leukocyte profiles, suggesting the tadpoles were physiologically stressed. The main objective of the present study was to characterize this stress response further using complementary measures of stress after exposure to clothianidin on northern leopard frogs (Rana pipiens) during their aquatic larval stages. Laboratory static-renewal exposures were conducted over eight weeks with the technical product clothianidin at 0, 0.23, 1, 10 and 100 μg/L, and diquat dibromide at 532 μg/L was used as a positive control. We assessed tadpole leukocyte profiles and measures of oxidative stress as these sub-lethal alterations could affect amphibian fitness. We found changes in several types of leukocytes at 1 and 10 μg/L, suggesting that these tadpoles exhibited signs of mild physiological stress. Clothianidin also induced an oxidative stress response at 0.23, 1 and 100 μg/L. However, we found no differences in survival, growth, development time or hepatosomatic index in frogs exposed to clothianidin. Our study indicates that tadpoles chronically exposed to clothianidin have increased stress responses, but in the absence of concentration-response relationships and effects on whole-organism endpoints, the implications on the overall health and fitness of these changes are unclear.
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Affiliation(s)
- Stacey A Robinson
- Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Division, Ottawa, Ontario, Canada.
| | - Ryan J Chlebak
- Department of Biology, Carleton University, Ottawa, Ontario, Canada.
| | - Sarah D Young
- Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Division, Ottawa, Ontario, Canada.
| | - Rebecca L Dalton
- Department of Biology, Carleton University, Ottawa, Ontario, Canada; Environment and Climate Change Canada, Ecological Assessment Division, Gatineau, Quebec, Canada.
| | - Melody J Gavel
- Department of Biology, Carleton University, Ottawa, Ontario, Canada.
| | - Ryan S Prosser
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada.
| | - Adrienne J Bartlett
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Burlington, Ontario, Canada.
| | - Shane R de Solla
- Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Division, Burlington, Ontario, Canada.
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15
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Fang K, Dai W, Chen H, Wang J, Gao H, Sha Z, Cao L. The effect of integrated rice-frog ecosystem on rice morphological traits and methane emission from paddy fields. Sci Total Environ 2021; 783:147123. [PMID: 34088155 DOI: 10.1016/j.scitotenv.2021.147123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/09/2021] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
Integrated Rice-frog Ecosystem (IRFE) has the potential to reduce methane (CH4) emission and maintain yields from paddy fields. However, the quantitative relationship between rice morphological traits and CH4 emission remains to be explored. In this study, a 2-year field experiment was conducted to evaluate the effect of IRFE on rice morphological traits and CH4 emission from paddy fields and the ecological mechanisms. This study was conducted to analyze twelve aboveground and eight underground rice morphological traits, rice yields, and CH4 flux and emission from the paddy fields with six frog densities (0, 3750, 7500, 15,000, 30,000, and 60,000 frogs ha-1). The results showed that IRFE reduced CH4 emission by 24.70%-41.75% and 21.68%-51.21% in the 2018 and 2019 rice growth seasons, respectively. Moreover, CH4 emission decreased with the increase of frogs. Frogs also increased the diameter, biomass, and volume of rice roots, thus promoting rice growth. Root biomass, thousand-grain weight, and harvest index were also closely related to the yield. Root porosity and oxygen secretion capacity were negatively correlated with CH4 flux. Frogs increased root porosity and oxygen secretion, thereby reducing CH4 emission. The present study demonstrated that reducing CH4 emission and improving rice yields could be simultaneously achieved by altering rice morphological traits in IRFE.
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Affiliation(s)
- Kaikai Fang
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Wei Dai
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Huiyan Chen
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Jun Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Hui Gao
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Zhimin Sha
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Key Laboratory of Technology and Model for Cyclic Utilization from Agricultural Resources, Ministry of Agriculture and Rural, China.
| | - Linkui Cao
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
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16
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Velázquez-Urrieta Y, Pérez-Ponce de León G. A new species of Gorgoderina (Digenea: Gorgoderidae) from Rana berlandieri in Los Tuxtlas tropical rainforest, Mexico, with the elucidation of its life cycle. Parasitol Int 2021; 83:102352. [PMID: 33872792 DOI: 10.1016/j.parint.2021.102352] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 04/05/2021] [Accepted: 04/14/2021] [Indexed: 01/04/2023]
Abstract
Species in the genus Gorgoderina Looss, 1902 are parasites of the urinary bladder of amphibians and include around 50 species described globally. Molecular data on species of the genus are scarce, as is the information of their life-cycle patterns. During a survey on the genetic characterization of the frog trematodes in the tropical rain forest of Los Tuxtlas, in the Gulf of Mexico slope of Mexico, specimens of two morphotypes of Gorgoderina were sampled from the Rio Grande leopard frog, Rana berlandieri. One of them represented an undescribed species which is described herein as Gorgoderina rosamondae n. sp., whereas the other one was morphologically very similar to an apparently widely distributed North American species, G. attenuata, which has been previously reported in the same geographical area. Specimens of both morphotypes were sequenced for two nuclear and one mitochondrial genes. Phylogenetic trees corroborated the distinction of the new species, and data on the internal transcribed spacer 2 revealed genetic differences between G. attenuata sequenced from frogs in USA and specimens of Gorgoderina sp. from Los Tuxtlas, indicating the possibility that they also represent an undescribed species. COI sequences showed high genetic divergence values between the new species and Gorgoderina sp. from Los Tuxtlas (8.63-9.99%). Additionally, COI sequences of the larval forms (sporocyst, cercariae and metacercariae) sampled in the same locality from their first and second intermediate hosts (Pisidium sp. and Agriogomphus tumens, respectively) showed conspecificity, and the 3 host life-cycle of the new species was elucidated.
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Affiliation(s)
- Yanet Velázquez-Urrieta
- Posgrado en Ciencias Biológicas, Instituto de Biología, Universidad Nacional Autónoma de México, s/n, Ciudad Universitaria, Coyoacán, Ciudad de México, C.P. 04510, Mexico
| | - Gerardo Pérez-Ponce de León
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer circuito exterior s/n, Ciudad Universitaria, Coyoacán, Ciudad de México, C.P. 04510, Mexico.
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Whitfield SM, Alvarado-Barboza G, Abarca JG, Zumbado-Ulate H, Jimenez RR, Kerby J. Ranavirus is widespread in Costa Rica and co-occurs with threatened amphibians. Dis Aquat Organ 2021; 144:89-98. [PMID: 33830072 DOI: 10.3354/dao03576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Amphibians are globally threatened by emerging infectious diseases, and ranaviruses are among the most concerning pathogens to threaten species in the wild. We sampled for ranaviruses in wild amphibians at 8 sites in Costa Rica, spanning broad climatic zones and taxonomic associations. Seven of these sites are inhabited by highly threatened amphibian species that persist at low global population sizes after population declines due to amphibian chytridiomycosis. One of the surveyed sites is occupied by an introduced amphibian species, which is relatively rare in Central America but may be an important pathway for long-distance transport of ranaviruses. We detected ranavirus using quantitative polymerase chain reaction in 16.3% of the 243 individuals and among 5 of our 8 sites, but not at the site with the introduced species. Infection prevalence varied among species and sites, but not with mean annual temperature or mean annual precipitation. Infection intensity did not vary with species, site, temperature, or precipitation. Our results show that ranavirus infection is spatially widespread in Costa Rica, affecting a broad range of host species, and occurs across climatic zones-though we encountered no mortality or morbidity in our sampled species. Ranaviruses are known to cause intermittent mass mortality in amphibian populations, and the threatened species sampled here are likely vulnerable to population impacts from emerging ranaviruses. Therefore, we believe the potential impacts of ranaviruses on amphibian populations in tropical regions have likely been underestimated, and that they should be viewed as a potential major stressor to threatened amphibians in tropical regions.
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18
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Zhang S, Teraoka H, Kaiya H, Kitazawa T. Motilin- and ghrelin-induced contractions in isolated gastrointestinal strips from three species of frogs. Gen Comp Endocrinol 2021; 300:113649. [PMID: 33153968 DOI: 10.1016/j.ygcen.2020.113649] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 10/07/2020] [Accepted: 10/17/2020] [Indexed: 12/26/2022]
Abstract
Ghrelin (GHRL) and motilin (MLN), gut peptides isolated from the mucosa of the stomach and duodenum, respectively, stimulate gastrointestinal (GI) motility in mammals and birds. However, the functions of MLN and GHRL in amphibian GI tracts have not been examined in detail. To clarify the regulation of GI motility by the two peptides, the effects of human MLN and rat GHRL on contractility of isolated GI strips from three species of frogs, the black-spotted pond frog (pond frog; Pelophylax nigromaculata), bullfrog (Lithobates catesbeiana) and Western clawed frog (Xenopus; Xenopus tropicalis), were examined in in vitro experiments. The GI tract of each frog was divided into the stomach, upper intestine, middle intestine and lower intestine. Human MLN caused contractions of the stomach in the pond frog and upper intestine in the bullfrog and Xenopus, but other GI regions were insensitive to human MLN. Erythromycin did not cause contraction of the upper intestine of the bullfrog and Xenopus. Rat GHRL did not cause contraction of the stomach and small intestines in the pond frog and bullfrog, but it caused a concentration-dependent contraction in the stomach and upper intestine of Xenopus, while des-acyl rat GHRL did not cause any contraction of them. In conclusion, human MLN caused the contraction of the stomach or upper intestine in the three species of frogs, but GHRL was effective only in the stomach and upper intestine of Xenopus. On the basis of these data, MLN but not GHRL causes the GI region-dependent contractions in the frogs.
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Affiliation(s)
- Shuangyi Zhang
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Hiroki Teraoka
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Hiroyuki Kaiya
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka 564-8565, Japan
| | - Takio Kitazawa
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan.
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Jungblut LD, Reiss JO, Pozzi AG. Olfactory subsystems in the peripheral olfactory organ of anuran amphibians. Cell Tissue Res 2021; 383:289-99. [PMID: 33247771 DOI: 10.1007/s00441-020-03330-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/27/2020] [Indexed: 10/22/2022]
Abstract
Anuran amphibians (frogs and toads) typically have a complex life cycle, involving aquatic larvae that metamorphose to semi-terrestrial juveniles and adults. However, the anuran olfactory system is best known in Xenopus laevis, an animal with secondarily aquatic adults. The larval olfactory organ contains two distinct sensory epithelia: the olfactory epithelium (OE) and vomeronasal organ (VNO). The adult organ contains three: the OE, the VNO, and a "middle cavity" epithelium (MCE), each in its own chamber. The sensory epithelia of Xenopus larvae have overlapping sensory neuron morphology (ciliated or microvillus) and olfactory receptor gene expression. The MCE of adults closely resembles the OE of larvae, and senses waterborne odorants; the adult OE is distinct and senses airborne odorants. Olfactory subsystems in other (non-pipid) anurans are diverse. Many anuran larvae show a patch of olfactory epithelium exposed in the buccal cavity (bOE), associated with a grazing feeding mode. And other anuran adults do not have a sensory MCE, but many have a distinct patch of epithelium adjacent to the OE, the recessus olfactorius (RO), which senses waterborne odorants. Olfaction plays a wide variety of roles in the life of larval and adult anurans, and some progress has been made in identifying relevant odorants, including pheromones and feeding cues. Increased knowledge of the diversity of olfactory structure, of odorant receptor expression patterns, and of factors that affect the access of odorants to sensory epithelia will enable us to better understand the adaptation of the anuran olfactory system to aquatic and terrestrial environments.
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Ozoliņa Z, Deksne G, Pupins M, Gravele E, Gavarane I, Kirjušina M. Alaria alata mesocercariae prevalence and predilection sites in amphibians in Latvia. Parasitol Res 2020; 120:145-152. [PMID: 33210196 DOI: 10.1007/s00436-020-06951-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 10/28/2020] [Indexed: 10/23/2022]
Abstract
Alaria alata is known as a trematode with a complex life cycle. The trematode Alaria alata infects amphibians as second intermediate hosts. In the present study, we examined 390 amphibians-European water frogs Pelophylax esculentus complex (n = 335), common frogs Rana temporaria (n = 19), moor frogs Rana arvalis (n = 3), and common toads Bufo bufo (n = 30) collected from randomly selected wetland habitats in Latvia. Out of all examined specimens, 80 were tadpoles and 310 were adult amphibians. Mesocercariae of A. alata was detected in 108 specimens from all examined amphibian species, except the common toad, reaching the overall prevalence of 27.7%. Tadpoles were found to be more frequently infected with A. alata, when compared with adults, 58.8% and 22.4%, respectively. The results showed that mesocercariae accumulate in visceral membranes, different internal organs, and muscles in the head area. This is a comprehensive study to identify A. alata mesocercariae predilection sites in amphibians.
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Affiliation(s)
- Zanda Ozoliņa
- Institute of Food Safety Animal Health and Environment "BIOR", Lejupes Street 3, Riga, LV-1076, Latvia.
| | - Gunita Deksne
- Institute of Food Safety Animal Health and Environment "BIOR", Lejupes Street 3, Riga, LV-1076, Latvia.,Faculty of Biology, University of Latvia, Jelgavas Street 1, Riga, LV-1004, Latvia
| | - Mihails Pupins
- Institute of Life Sciences and Technology, Daugavpils University, Parādes Street 1A, Daugavpils, LV-5401, Latvia
| | - Evita Gravele
- Institute of Life Sciences and Technology, Daugavpils University, Parādes Street 1A, Daugavpils, LV-5401, Latvia
| | - Inese Gavarane
- Institute of Life Sciences and Technology, Daugavpils University, Parādes Street 1A, Daugavpils, LV-5401, Latvia
| | - Muza Kirjušina
- Institute of Life Sciences and Technology, Daugavpils University, Parādes Street 1A, Daugavpils, LV-5401, Latvia
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Rivory P, Brown G, Shilton C, Shine R, Šlapeta J. Apparent lack of spill-over of parasites from an invasive anuran: PCR detects Entamoeba in cane toads ( Rhinella marina) but not in sympatric Australian native frogs. Int J Parasitol Parasites Wildl 2020; 12:207-213. [PMID: 32685367 PMCID: PMC7355385 DOI: 10.1016/j.ijppaw.2020.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 06/30/2020] [Accepted: 06/30/2020] [Indexed: 11/12/2022]
Abstract
The recent detection of a novel amoebozoan parasite (Entamoeba sp. CT1) killing invasive cane toads (Rhinella marina) in tropical Australia raises concerns of potential spill-over into native anuran populations. Considering the vulnerability of anuran communities globally, Entamoeba sp. CT1 may pose a serious threat to anuran biodiversity. Through PCR-based detection and molecular identification, we investigated the prevalence of Entamoeba spp. in the faeces and colon tissue of cane toads (Rhinella marina) and eleven native Australian frog species from a single locality in the Northern Territory. No Entamoeba DNA was detected in samples of native frog faeces (N = 57) or colons (N = 17). Entamoeba DNA was detected in 24% of 45 cane toads (95%CI 14.08–38.82). Both E. ranarum and Entamoeba sp. CT1 were present in cane toads. The failure of faecal samples to indicate Entamoeba spp. in infected cane toads may be due to cysts in faeces being shed intermittently, degraded before analysis, or impervious to lysis prior to DNA isolation. Our results suggest that native frogs do not carry the pathogen in an area where 20–30% of cane toads are infected with Entamoeba sp. CT1. We demonstrate the importance of recognising PCR inhibition prior to molecular diagnostics, and the apparent inadequacy of faecal samples for the detection of Entamoeba spp. in anurans. Entamoeba spp. were detected in cane toads, but not in faeces or colons of native frogs. PCR inhibition of anuran faecal samples. Additional purification, the presence of inhibition was reduced.
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Affiliation(s)
- Phoebe Rivory
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, New South Wales, 2006, Australia
| | - Gregory Brown
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, New South Wales, 2109, Australia
| | - Cathy Shilton
- Berrimah Veterinary Laboratory, Northern Territory Government, GPO Box 3000, Darwin, Northern Territory, 0801, Australia
| | - Richard Shine
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, New South Wales, 2109, Australia
| | - Jan Šlapeta
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, New South Wales, 2006, Australia
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Richards CT, Eberhard EA. In vitro virtual reality: an anatomically explicit musculoskeletal simulation powered by in vitro muscle using closed-loop tissue-software interaction. J Exp Biol 2020; 223:jeb210054. [PMID: 32253284 DOI: 10.1242/jeb.210054] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 03/20/2020] [Indexed: 11/20/2022]
Abstract
Muscle force-length dynamics are governed by intrinsic contractile properties, motor stimulation and mechanical load. Although intrinsic properties are well characterised, physiologists lack in vitro instrumentation to account for combined effects of limb inertia, musculoskeletal architecture and contractile dynamics. We introduce in vitro virtual reality (in vitro-VR) which enables in vitro muscle tissue to drive a musculoskeletal jumping simulation. In hardware, muscle force from a frog plantaris was transmitted to a software model where joint torques, inertia and ground reaction forces were computed to advance the simulation at 1 kHz. To close the loop, simulated muscle strain was returned to update in vitro length. We manipulated (1) stimulation timing and (2) the virtual muscle's anatomical origin. This influenced interactions among muscular, inertial, gravitational and contact forces dictating limb kinematics and jump performance. We propose that in vitro-VR can be used to illustrate how neuromuscular control and musculoskeletal anatomy influence muscle dynamics and biomechanical performance.
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23
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Wolmarans NJ, Bervoets L, Meire P, Wepener V. Current Status and Future Prognosis of Malaria Vector Control Pesticide Ecotoxicology and Xenopus sp. Rev Environ Contam Toxicol 2020; 252:131-171. [PMID: 31463624 DOI: 10.1007/398_2019_35] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Anurans from the genus Xenopus have long been used as standard testing organisms and occur naturally in tropical and sub-tropical areas where malaria vector control pesticides are actively used. However, literature on the toxic effects of these pesticides is limited. This review analyses the available data pertaining to both Xenopus and the pesticides used for malaria vector control in order to determine the pesticides that have the greatest potential to influence amphibian health while also identifying gaps in literature that need to be addressed. Amphibian diversity has shown the fastest decline of any group, yet there are still voids in our understanding of how this is happening. The lack of basic toxicity data on amphibians with regard to pesticides is an issue that needs to be addressed in order to improve effectiveness of amphibian conservation strategies. Meta-analyses performed in this review show that, at current usage, with the available acute toxicity literature, the pyrethroid pesticide group could hold the highest potential to cause acute toxicity to Xenopus sp. in relation to the other MVCPs discussed, but the lack of data cripples the efficacy with which meta-analyses can be performed and conclusions made from such analyses. Several studies have shown that DDT accumulates in Xenopus sp. from malaria vector control areas, but accumulation of other MVCPs in frogs is still largely unknown. Through this review we hope to encourage future research into the field of amphibian ecotoxicology and to promote the use of the Xenopus standard model in order to build comprehensive datasets that may be used in amphibian conservation.
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Affiliation(s)
- Nico J Wolmarans
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa.
- Laboratory of Systemic, Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Antwerp, Belgium.
| | - Lieven Bervoets
- Laboratory of Systemic, Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Patrick Meire
- Ecosystem Management Research Group (Ecobe), Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Victor Wepener
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
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Sievers M, Hale R, Parris KM, Melvin SD, Lanctôt CM, Swearer SE. Contaminant-induced behavioural changes in amphibians: A meta-analysis. Sci Total Environ 2019; 693:133570. [PMID: 31369889 DOI: 10.1016/j.scitotenv.2019.07.376] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/20/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Environmental contamination contributes to the threatened status of many amphibian populations. Many contaminants alter behaviour at concentrations commonly experienced in the environment, with negative consequences for individual fitness, populations and communities. A comprehensive, quantitative evaluation of the behavioural sensitivity of amphibians is warranted to better understand the population-level and resultant ecological impacts of contaminants. We conducted a systematic review and meta-analysis evaluating behavioural changes following exposure to contaminants. Most studies were conducted in North America and Europe on larval stages, and 64% of the 116 studies focussed on the effects of insecticides. We found that a suite of contaminants influence a wide range of behaviours in amphibians, with insecticides typically invoking the strongest responses. In particular, insecticides increased rates of abnormal swimming, and reduced escape responses to simulated predator attacks. Our analysis identified five key needs for future research, in particular the need: (1) for researchers to provide more details of experimental protocols and results (2) to develop a strong research base for future quantitative reviews, (3) to broaden the suite of contaminants tested, (4) to better study and thus understand the effects of multiple stressors, and (5) to establish the ecological importance of behavioural alterations. Behavioural endpoints provide useful sub-lethal indicators of how contaminants influence amphibians, and coupled with standard ecotoxicological endpoints, can provide valuable information for population models assessing the broader ecological consequences of environmental contamination.
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Affiliation(s)
- Michael Sievers
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia; School of Ecosystem and Forest Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia; Australian Rivers Institute - Coast & Estuaries, Griffith University, Gold Coast, Queensland 4222, Australia.
| | - Robin Hale
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Kirsten M Parris
- School of Ecosystem and Forest Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Steven D Melvin
- Australian Rivers Institute, Griffith University, Southport, Queensland 4222, Australia
| | - Chantal M Lanctôt
- Australian Rivers Institute, Griffith University, Southport, Queensland 4222, Australia
| | - Stephen E Swearer
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
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25
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Glaberman S, Kiwiet J, Aubee CB. Evaluating the role of fish as surrogates for amphibians in pesticide ecological risk assessment. Chemosphere 2019; 235:952-958. [PMID: 31299708 DOI: 10.1016/j.chemosphere.2019.06.166] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/20/2019] [Accepted: 06/21/2019] [Indexed: 06/10/2023]
Abstract
Ecological risk of chemicals to aquatic-phase amphibians has historically been evaluated by comparing estimated environmental concentrations in surface water to surrogate toxicity data from fish species. Despite their obvious similarities, there are biological disparities among fish and amphibians that could affect their exposure and response to chemicals. Given the alarming decline in amphibians, in which anthropogenic pollutants play at least some role, investigating the risk of chemicals to amphibians is becoming increasingly important. Here, we evaluate relative sensitivity of fish and larval aquatic-phase amphibians to 45 different pesticides using existing data from three standardized toxicity test designs: (1) amphibian metamorphosis assay (AMA) with the African clawed frog (Xenopus laevis); (2) fish short-term reproduction assay (FSTRA) with the fathead minnow (Pimephales promelas); (3) fish early life stage test (ELS) with fathead minnows or rainbow trout (Oncorhynchus mykiss). The advantage of this dataset over previous work is that the underlying studies are consistent in exposure method, study duration, test species, endpoints measured, and number of concentrations tested. We found very strong positive relationships between fish and frog lowest adverse effect concentrations (LOAEC) for survival [Spearman's rank correlation (rs) = 0.88], body weight (rs = 0.86), and length (rs = 0.89) with only one out of 45 chemicals (propiconazole) exhibiting 100-folder greater sensitivity in frogs relative to fish. While our results suggest comparable toxicity for pesticides between fish and aquatic-phase amphibians under these test conditions, further research with a greater diversity of amphibians and exposure scenarios will help determine the relevance of these results across species and life stages.
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Affiliation(s)
- Scott Glaberman
- George Mason University, Department of Environmental Science and Policy, USA; University of South Alabama, Department of Biology, USA.
| | - Jean Kiwiet
- University of South Alabama, Department of Biology, USA
| | - Catherine B Aubee
- U.S. Environmental Protection Agency, Office of Pesticide Programs, USA
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26
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Mokhatla M, Measey J, Smit B. The role of ambient temperature and body mass on body temperature, standard metabolic rate and evaporative water loss in southern African anurans of different habitat specialisation. PeerJ 2019; 7:e7885. [PMID: 31660269 PMCID: PMC6814148 DOI: 10.7717/peerj.7885] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 09/12/2019] [Indexed: 12/12/2022] Open
Abstract
Temperature and water availability are two of the most important variables affecting all aspects of an anuran’s key physiological processes such as body temperature (Tb), evaporative water loss (EWL) and standard metabolic rate (SMR). Since anurans display pronounced sexual dimorphism, evidence suggests that these processes are further influenced by other factors such as vapour pressure deficit (VPD), sex and body mass (Mb). However, a limited number of studies have tested the generality of these results across a wide range of ecologically relevant ambient temperatures (Ta), while taking habitat use into account. Thus, the aim of this study was to investigate the role of Ta on Tb, whole-animal EWL and whole-animal SMR in three wild caught African anuran species with different ecological specialisations: the principally aquatic African clawed frog (Xenopus laevis), stream-breeding common river frog (Amietia delalandii), and the largely terrestrial raucous toad (Sclerophrys capensis). Experiments were conducted at a range of test temperatures (5–35 °C, at 5 °C increments). We found that VPD better predicted rates of EWL than Ta in two of the three species considered. Moreover, we found that Tb, whole-animal EWL and whole-animal SMR increased with increasing Ta, while Tb increased with increasing Mb in A. delalandii and S. capensis but not in X. laevis. Whole-animal SMR increased with increasing Mb in S. capensis only. We did not find any significant effect of VPD, Mb or sex on whole-animal EWL within species. Lastly, Mb did not influence Tb, whole-animal SMR and EWL in the principally aquatic X. laevis. These results suggest that Mb may not have the same effect on key physiological variables, and that the influence of Mb may also depend on the species ecological specialisation. Thus, the generality of Mb as an important factor should be taken in the context of both physiology and species habitat specialisation.
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Affiliation(s)
- Mohlamatsane Mokhatla
- Centre for Invasion Biology, Department of Botany and Zoology, University of Stellenbosch, Stellenbosch, South Africa.,Scientific Services, South African National Parks, Sedgefield, South Africa
| | - John Measey
- Centre for Invasion Biology, Department of Botany and Zoology, University of Stellenbosch, Stellenbosch, South Africa
| | - Ben Smit
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa.,Department Zoology, Nelson Mandela University, Port Elizabeth, South Africa
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27
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Collings AJ, Richards CT. Digital dissection of the pelvis and hindlimb of the red-legged running frog, Phlyctimantis maculatus, using Diffusible Iodine Contrast Enhanced computed microtomography (DICE μCT). PeerJ 2019; 7:e7003. [PMID: 31211012 PMCID: PMC6557250 DOI: 10.7717/peerj.7003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 04/23/2019] [Indexed: 12/26/2022] Open
Abstract
Background The current study applies both traditional and Diffusible Iodine Contrast Enhanced computed microtomography (DICE µCT) techniques to reveal the musculoskeletal anatomy of Phlyctimantis maculatus. DICE µCT has emerged as a powerful tool to visualise intricate musculoskeletal anatomy. By generating 3D digital models, anatomical analyses can be conducted non-destructively, preserving the in situ 3D topography of the system, therefore eliminating some of the drawbacks associated with traditional methods. We aim to describe the musculature of the spine, pelvis, and hindlimb, compare the musculoskeletal anatomy and pelvic morphology of P. maculatus with functionally diverse frogs, and produce 3D digital anatomy reference data. Method An adult frog was stained using an aqueous Lugol’s solution and scanned in a SkyScan1176 in vivo µCT scanner. Scan images were reconstructed, resampled, and digitally segmented to produce a 3D model. A further adult female frog was dissected traditionally for visualisation of tendinous insertions. Results Our work revealed three main findings: (1) P. maculatus has similar gross muscular anatomy to Rana catesbeiana (bullfrog) but is distinct from those species that exhibit ancestral traits (leopelmids) and those that are highly specialised (pipids), (2) P. maculatus’s pelvic anatomy best fits the description of Emerson’s walking/hopping pelvic morphotype IIA, and (3) a split in the semimembranosus and gracilis major muscles is consistent with the reported myology in other anuran species. Discussion While DICE µCT methods were instrumental in characterising the 3D anatomy, traditional dissection was still required to visualise important structures such as the knee aponeurosis, tendinous insertions, and fasciae. Nonetheless, the anatomical data presented here marks the first detailed digital description of an arboreal and terrestrial frog. Further, our digital model presents P. maculatus as a good frog model system and as such has formed a crucial platform for further functional analysis within the anuran pelvis and hindlimb.
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Affiliation(s)
- Amber J Collings
- School of Science Engineering and Design, Teesside University, Middlesbrough, United Kingdom.,Structure and Motion Laboratory, Royal Veterinary College, London, United Kingdom
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28
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Páez-Vacas MI, Oleas NH. Isolation and characterization of 12 microsatellite loci in Epipedobates anthonyi (Amphibia: Anura: Dendrobatidae) for population genetic analysis. Mol Biol Rep 2019; 46:3519-3522. [PMID: 30929161 DOI: 10.1007/s11033-019-04771-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 03/19/2019] [Indexed: 11/26/2022]
Abstract
Tropical anurans are among the most diverse and vulnerable organisms on Earth, yet the evolutionary mechanisms behind their diversity remain relatively unexplored. Epipedobates anthonyi is a poison frog that inhabits southern Ecuador and northern Peru along a broad elevational range (0-1800 m). Throughout its range, this species exhibits variation in phenotypic traits, such as color, advertisement calls, and alkaloid composition. The aim of this study is to isolate and characterize microsatellite loci to investigate patterns of genetic variation within the species. Using a next-generation sequencing approach to screen an enriched genomic library, we report twelve polymorphic microsatellite loci. The number of alleles per locus ranged from 7 to 15 per population. For the two populations tested, mean observed heterozygosity was 0.69 and 0.79, and mean expected heterozigosity was 0.84 and 0.85 respectively. Only locus EAN002 showed significant departure of HWE in both populations. None of the loci showed consistent null alleles in both populations. Also, no evidence of linkage disequilibrium was found across loci. In this paper, we report for the first time 12 microsatellite loci for E. anthonyi. These markers will be used to further elucidate evolutionary mechanisms underlying genetic and phenotypic variation across the species' range.
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Affiliation(s)
- Mónica I Páez-Vacas
- Centro de Investigación de la Biodiversidad y Cambio Climático (BioCamb) e Ingeniería en Biodiversidad y Recursos Genéticos, Facultad de Ciencias de Medio Ambiente, Universidad Tecnológica Indoamérica, Machala y Sabanilla, EC170301, Quito, Ecuador
- Department of Biology, Graduate Degree Program in Ecology, Colorado State University, 1878 Campus Delivery, Fort Collins, CO, 80523, USA
| | - Nora H Oleas
- Centro de Investigación de la Biodiversidad y Cambio Climático (BioCamb) e Ingeniería en Biodiversidad y Recursos Genéticos, Facultad de Ciencias de Medio Ambiente, Universidad Tecnológica Indoamérica, Machala y Sabanilla, EC170301, Quito, Ecuador.
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29
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Castro DP, Rodrigues JFM, Borges-Leite MJ, Lima DC, Borges-Nojosa DM. Anuran diversity indicates that Caatinga relictual Neotropical forests are more related to the Atlantic Forest than to the Amazon. PeerJ 2019; 6:e6208. [PMID: 30647999 PMCID: PMC6330954 DOI: 10.7717/peerj.6208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 12/04/2018] [Indexed: 11/24/2022] Open
Abstract
The relationships among the morphoclimatic domains of South America have been a major biogeographical issue of recent years. Palynological, geological and phytogeographical data suggest that the Amazon Forest and the Atlantic Forest were connected during part of the Tertiary and Quaternary periods. This study uses amphibians as model organisms to investigate whether relict northeastern forests are a transition between the Amazon Forest and the Atlantic Forest. We compiled matrices of species composition for four different phytogeographic formations and "Brejos de Altitude," and analyzed them using clustering methods and Cladistic Analysis of Distributions and Endemism. Our results indicate that the anurofauna of these northeastern forest relicts is most similar in composition to the areas of the Atlantic Forest included in this study, and most dissimilar to the Amazon Forest, which leads us to affirm that events of biotic exchange were more frequent within the Atlantic Forest areas.
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Affiliation(s)
- Deborah P. Castro
- Programa de Pós-Graduação em Ecologia e Recursos Naturais/Departamento de Biologia, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
- Faculdade de Educação de Itapipoca, Universidade Estadual do Ceará, Itapipoca, Ceará, Brazil
| | - João Fabrício M. Rodrigues
- Departamento de Ecologia/Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Maria Juliana Borges-Leite
- Programa de Pós-Graduação em Ecologia e Recursos Naturais/Departamento de Biologia, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
| | - Daniel Cassiano Lima
- Faculdade de Educação de Itapipoca, Universidade Estadual do Ceará, Itapipoca, Ceará, Brazil
| | - Diva Maria Borges-Nojosa
- Programa de Pós-Graduação em Ecologia e Recursos Naturais/Departamento de Biologia, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
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30
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Salla RF, Rizzi-Possignolo GM, Oliveira CR, Lambertini C, Franco-Belussi L, Leite DS, Silva-Zacarin ECM, Abdalla FC, Jenkinson TS, Toledo LF, Jones-Costa M. Novel findings on the impact of chytridiomycosis on the cardiac function of anurans: sensitive vs. tolerant species. PeerJ 2018; 6:e5891. [PMID: 30425891 PMCID: PMC6228586 DOI: 10.7717/peerj.5891] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/29/2018] [Indexed: 12/01/2022] Open
Abstract
Background Understanding of the physiological effects of chytridiomycosis is crucial to worldwide amphibian conservation. Therefore, we analyzed the cardiac function of two anuran species (Xenopus laevis and Physalaemus albonotatus) with different susceptibilities to infection by the causative agent of chytridiomycosis, Batrachochytrium dendrobatidis (hereafter Bd). Methods We analyzed the in situ heart rate (fH - bpm), relative ventricular mass (RVM -%), and Ca2+ handling in heart of Bd infected animals compared to uninfected controls of both study species. Results Bd infection resulted in a 78% decrease in contraction force values in P. albonotatus when compared to the less susceptible X. laevis. This negative effect was even more evident (82%) for the cardiac pumping capacity. The time to reach peak tension was 125% longer in P. albonotatus than in X. laevis, and cardiac relaxation was 57% longer. Discussion These results indicate a delay in the cardiac cycle of P. albonotatus on a beat-to-beat basis, which was corroborated by the bradycardia observed in situ. In summary, Bd-sensitive species present impaired cardiac function, which could be a factor in mortality risk. The more pronounced effects of Bd in P. albonotatus may not only result from electrolyte imbalance, as previously reported, but also could be an effect of toxins produced by Bd. For X. laevis, the ability to promote cardiac adjustments seems to be an important homeostatic feature that allows greater tolerance to chytridiomycosis. This study provides new physiological mechanisms underlying the tolerance or susceptibility of amphibian species to chytridiomycosis, which determine their adaptability to survive in the affected environments.
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Affiliation(s)
- Raquel F Salla
- Department of Biology, Universidade Federal de São Carlos, Sorocaba, SP, Brazil.,Department of Animal Biology, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Gisele M Rizzi-Possignolo
- Department of Biology, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | | | - Carolina Lambertini
- Department of Animal Biology, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | | | - Domingos S Leite
- Department of Genetic, Evolution, Microbiology and Immunology, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | | | - Fábio C Abdalla
- Department of Biology, Universidade Federal de São Carlos, Sorocaba, SP, Brazil
| | - Thomas S Jenkinson
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, United States of America
| | - Luís Felipe Toledo
- Department of Animal Biology, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Monica Jones-Costa
- Department of Biology, Universidade Federal de São Carlos, Sorocaba, SP, Brazil
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31
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van Wilgen NJ, Gillespie MS, Richardson DM, Measey J. A taxonomically and geographically constrained information base limits non-native reptile and amphibian risk assessment: a systematic review. PeerJ 2018; 6:e5850. [PMID: 30425887 PMCID: PMC6230440 DOI: 10.7717/peerj.5850] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 09/27/2018] [Indexed: 11/20/2022] Open
Abstract
For many taxa, new records of non-native introductions globally occur at a near exponential rate. We undertook a systematic review of peer-reviewed publications on non-native herpetofauna, to assess the information base available for assessing risks of future invasions, resulting in 836 relevant papers. The taxonomic and geographic scope of the literature was also compared to a published database of all known invasions globally. We found 1,116 species of herpetofauna, 95% of which were present in fewer than 12 studies. Nearly all literature on the invasion ecology of herpetofauna has appeared since 2000, with a strong focus on frogs (58%), particularly cane toads (Rhinella marina) and their impacts in Australia. While fewer papers have been published on turtles and snakes, proportionately more species from both these groups have been studied than for frogs. Within each herpetofaunal group, there are a handful of well-studied species: R. marina, Lithobates catesbeianus, Xenopus laevis, Trachemys scripta, Boiga irregularis and Anolis sagrei. Most research (416 papers; 50%) has addressed impacts, with far fewer studies on aspects like trade (2%). Besides Australia (213 studies), most countries have little location-specific peer-reviewed literature on non-native herpetofauna (on average 1.1 papers per established species). Other exceptions were Guam, the UK, China, California and France, but even their publication coverage across established species was not even. New methods for assessing and prioritizing invasive species such as the Environmental Impact Classification for Alien Taxa provide useful frameworks for risk assessment, but require robust species-level studies. Global initiatives, similar to the Global Amphibian Assessment, using the species and taxonomic groups identified here, are needed to derive the level of information across broad geographic ranges required to apply these frameworks. Expansive studies on model species can be used to indicate productive research foci for understudied taxa.
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Affiliation(s)
- Nicola J van Wilgen
- Cape Research Centre, South African National Parks, Steenberg, Western Cape, South Africa.,Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland, South Africa
| | - Micaela S Gillespie
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland, South Africa
| | - David M Richardson
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland, South Africa
| | - John Measey
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland, South Africa
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32
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Richards CT, Porro LB. A novel kinematics analysis method using quaternion interpolation-a case study in frog jumping. J Theor Biol 2018; 454:410-24. [PMID: 29913132 DOI: 10.1016/j.jtbi.2018.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 05/18/2018] [Accepted: 06/06/2018] [Indexed: 11/24/2022]
Abstract
Spherical Linear Interpolation (SLERP) has long been used in computer animation to interpolate movements between two 3D orientations. We developed a forward kinematics (FK) approach using quaternions and SLERP to predict how frogs modulate jump kinematics between start posture and takeoff. Frog limb kinematics have been studied during various activities, yet the causal link between differences in joint kinematics and locomotor variation remains unknown. We varied 1) takeoff angle from 8 to 60°; 2) turn angle from 0 to 18°; and 3) initial body pitch from 0 to 70°. Simulations were similar to experimentally observed frog kinematics. Findings suggest a fundamental mechanism whereby limb elevation is modulated by thigh and shank adduction. Forward thrust is produced by thigh and proximal foot retraction with little contribution from the shank except to induce asymmetries for turning. Kinematic shifts causing turns were subtle, marked only by slight counter-rotation of the left versus right shank as well as a 10% timing offset in proximal foot adduction. Additionally, inclining initial body tilt influenced the centre of mass trajectory to determine direction of travel at takeoff. Most importantly, our theory suggests firstly that the convergence of leg segment rotation axes toward a common orientation is crucial both for limb extension and for coordinating jump direction; and, secondly, the challenge of simulating 3D kinematics is simplified using SLERP because frog limbs approximately follow linear paths in unit quaternion space. Our methodology can be applied more broadly to study living and fossil frog taxa as well as to inspire new control algorithms for robotic limbs.
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33
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Prokić MD, Borković-Mitić SS, Krizmanić II, Mutić JJ, Gavrić JP, Despotović SG, Gavrilović BR, Radovanović TB, Pavlović SZ, Saičić ZS. Oxidative stress parameters in two Pelophylax esculentus complex frogs during pre- and post-hibernation: Arousal vs heavy metals. Comp Biochem Physiol C Toxicol Pharmacol 2017; 202:19-25. [PMID: 28757213 DOI: 10.1016/j.cbpc.2017.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/21/2017] [Accepted: 07/25/2017] [Indexed: 11/29/2022]
Abstract
In spring, frogs from temperate regions are faced with arousal-induced oxidative stress and exposure to various xenobiotics from the environment. The question is whether pollutants can significantly modify the antioxidative defense system (AOS) response of hibernators during recovery from hibernation. If this assumption is true, we would then expect different patterns of seasonal variations in the AOS between individuals exposed to different levels of pollution. To examine this assumption, we determined the relationship between seasonal variations of accumulated metals and AOS parameters in the skin and muscle of two frog species from the Pelophylax esculentus complex (P. ridibundus and P. esculentus) inhabiting two localities (the Danube-Tisza-Danube canal and the Ponjavica River) with different levels of pollution during pre- and post-hibernation periods, respectively autumn and spring. Our results showed that even though there were differences in the concentrations of accumulated metals and AOS parameters between localities and species, the frogs displayed almost the same patterns of AOS variations during seasons, with a higher AOS response observed in spring. The parameters SH groups, GSH, GR and SOD had been contributed most rather than others. Our findings indicate that oxidative stress during the post-hibernation period was mainly caused by the organisms' recovery from hibernation, as the result of natural selection acting on the AOS, and that the accumulated metals did not significantly modify the AOS response. The present study provides new insight into the biological and physiological cellular responses of frogs to arousal stress.
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Affiliation(s)
- Marko D Prokić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
| | - Slavica S Borković-Mitić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Imre I Krizmanić
- Faculty of Biology, Institute of Zoology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia
| | - Jelena J Mutić
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Jelena P Gavrić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Svetlana G Despotović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Branka R Gavrilović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Tijana B Radovanović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Slađan Z Pavlović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Zorica S Saičić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
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34
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Kanagavel A, Parvathy S, Nirmal N, Divakar N, Raghavan R. Do frogs really eat cardamom? Understanding the myth of crop damage by amphibians in the Western Ghats, India. Ambio 2017; 46:695-705. [PMID: 28233252 PMCID: PMC5595740 DOI: 10.1007/s13280-017-0908-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/01/2017] [Accepted: 02/04/2017] [Indexed: 06/06/2023]
Abstract
In the Western Ghats of India, amphibians are culled at cardamom plantations since they are perceived to consume cardamom. To better understand the relationship between amphibians and cardamom, a study was undertaken at these plantations, which harbor numerous threatened and range-restricted amphibians. We undertook questionnaire surveys with 298 respondents at 148 plantations across southern India. Time-activity budget and diet analysis surveys were undertaken to determine whether amphibians really consumed cardamom. The conception that amphibians eat cardamom was found to be widespread especially among small-sized plantations, leading to negative perceptions and a lack of interest in amphibian conservation. The plantation community perceives a substantial economic loss due to amphibians, even though this is non-existent as revealed by our field surveys. These perceptions would lead to a continued intolerance of amphibian presence in plantations. A suitable outreach initiative re-affirming facts and spreading awareness on the positive role of amphibians would need to be conducted to negate this age-old myth.
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Affiliation(s)
- Arun Kanagavel
- Conservation Research Group, St. Albert’s College, Cochin, Kerala 682018 India
| | - Sethu Parvathy
- Conservation Research Group, St. Albert’s College, Cochin, Kerala 682018 India
| | - Nithula Nirmal
- Conservation Research Group, St. Albert’s College, Cochin, Kerala 682018 India
| | - Nithin Divakar
- Conservation Research Group, St. Albert’s College, Cochin, Kerala 682018 India
| | - Rajeev Raghavan
- Department of Fisheries Resource Management, Kerala University of Fisheries and Ocean Studies (KUFOS), Cochin, 682506 India
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Abstract
Background Ongoing conversion, disturbance and fragmentation of tropical forests stress this ecosystem and cause the decline or disappearance of many species. Particular traits have been identified which indicate an increasing extinction risk of a species, but traits facilitating survival in altered habitats have mostly been neglected. Here we search for traits that make a species tolerant to disturbances, thus independent of pristine forests. We identify the fauna that have an increasing effect on the ecosystem and its functioning in our human-dominated landscapes. Methods We use a unique set of published data on the occurrences of 243 frog species in pristine and altered forests throughout the tropics. We established a forest dependency index with four levels, based on these occurrence data and applied Random Forest classification and binomial Generalized Linear Models to test whether species life history traits, ecological traits or range size influence the likelihood of a species to persist in disturbed habitats. Results Our results revealed that indirect developing species exhibiting a large range size and wide elevational distribution, being independent of streams, and inhabiting the leaf litter, cope best with modifications of their natural habitats. Conclusion The traits identified in our study will likely persist in altered tropical forest systems and are comparable to those generally recognized for a low species extinction risk. Hence our findings will help to predict future frog communities in our human-dominated world. Electronic supplementary material The online version of this article (doi:10.1186/s12898-017-0135-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mareike Hirschfeld
- Department Diversity Dynamics, Museum für Naturkunde Berlin-Leibniz Institute for Evolutionary and Biodiversity Science, Invalidenstraße 43, 10115, Berlin, Germany.
| | - Mark-Oliver Rödel
- Department Diversity Dynamics, Museum für Naturkunde Berlin-Leibniz Institute for Evolutionary and Biodiversity Science, Invalidenstraße 43, 10115, Berlin, Germany
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36
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Abstract
The near infrared reflection peak in some frogs has been speculated to be either for enhancing crypticity, or to help them with thermoregulation. The theoretical background for the thermoregulatory processes has been established before, but little consideration has been given to the contribution from the frogs' reflection spectra differences. In this investigation, the reflection spectra from a range of different species of frogs were taken and combined with precise surface area measurements of frogs and an approximation to the mass transfer coefficient of agar frog models. These were then used to simulate the temperature and water evaporation in anurans with and without the near infrared reflective peak. We have shown that the presence of the near infrared reflection peak can contribute significantly to the temperature and evaporative water loss of a frog. The significance of the steady-state temperature differences between frogs with and without the near infrared reflection peak is discussed in a realistic and an extreme scenario. Temperature differences of up to 3.2°C were found, and the rehydration period was increased by up to 16.7%, although this does not reduce the number of rehydration events between dawn and dusk. Summary: We show that the presence of a reflection peak in the NIR in some frogs can contribute to a temperature difference of up to 3.2°C, which extends the period they can go without rehydration by over an hour (22.7%).
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Affiliation(s)
- Francisco Herrerías-Azcué
- Photon Science Institute, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK
| | - Chris Blount
- Photon Science Institute, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK
| | - Mark Dickinson
- Photon Science Institute, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK
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Costa S, Lopes I, Proença DN, Ribeiro R, Morais PV. Diversity of cutaneous microbiome of Pelophylax perezi populations inhabiting different environments. Sci Total Environ 2016; 572:995-1004. [PMID: 27522290 DOI: 10.1016/j.scitotenv.2016.07.230] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 07/29/2016] [Accepted: 07/31/2016] [Indexed: 05/21/2023]
Abstract
Potential synergetic interaction between chemicals, climate change and the emergence of opportunistic diseases is of utmost concern within the amphibian decline scenario. Understand the structure and dynamic of this microbiome and how environmental stressors act on this community is a priority. The present study aimed to: i) characterize the skin microbiome of Pelophylax perezi frog by looking for variations between populations in reference and under stress conditions (one metal contaminated and another with salinity fluctuations) and ii) evaluate the tolerance of skin-isolated bacteria to chemical contamination. Skin swabs were collected from frog populations inhabiting three reference sites (LB, VA and AM), one metal-rich contaminated (TP) and one brackish lentic aquatic system (SL). The frogs' skin microbiome was characterized by culture independent method (DGGE) and by cultivation methods. DGGE showed a characteristic profile in frogs from TP population. Results of recovered communities revealed low morphotype diversity and density (Colony Forming Units per frog) on individuals from TP population, comparatively to the other sampled populations. Isolated bacteria identified based on 16S rRNA gene sequence belong mainly to the classes Actinobacteria and Alphaproteobacteria. Ecotoxicological assays with acid-metal contaminated effluent (ETP) showed that the percentage of tolerant strains was higher in frogs from TP population than in SL and LB populations. In conclusion, results suggest that: a) environmental specific characteristics, as the presence of chemical contaminants, influence the composition of amphibian microbiome, comparing with sites without such contaminants; b) there are differences in microbiome composition between populations; and c) bacteria historically exposed to effluent may evolve tolerance to this kind of contamination.
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Affiliation(s)
- Sara Costa
- Department of Biology and CESAM, Campus of Santiago, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Isabel Lopes
- Department of Biology and CESAM, Campus of Santiago, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Diogo Neves Proença
- Department of Biology and CESAM, Campus of Santiago, University of Aveiro, 3810-193 Aveiro, Portugal; Department of Life Sciences and CEMUC, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Rui Ribeiro
- Department of Life Sciences and CEMUC, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Paula V Morais
- Department of Life Sciences and CEMUC, University of Coimbra, 3004-517 Coimbra, Portugal.
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Prokić MD, Borković-Mitić SS, Krizmanić II, Mutić JJ, Trifković JĐ, Gavrić JP, Despotović SG, Gavrilović BR, Radovanović TB, Pavlović SZ, Saičić ZS. Bioaccumulation and effects of metals on oxidative stress and neurotoxicity parameters in the frogs from the Pelophylax esculentus complex. Ecotoxicology 2016; 25:1531-1542. [PMID: 27629268 DOI: 10.1007/s10646-016-1707-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/08/2016] [Indexed: 06/06/2023]
Abstract
Metals are involved in the formation of reactive oxygen species and can induce oxidative stress. The aim of this study was to assess the effects of several metals on oxidative stress in the skin and muscle of the Pelophylax esculentus "complex" frogs (parental species Pelophylax ridibundus, Pelophylax lessonae, and their hybrid Pelophylax esculentus) that inhabit the wetland Obedska Bara in Serbia, and the potential use of these species as bioindicator organisms in biomonitoring studies. The biomarkers of oxidative stress (SOD, CAT, GSH-Px, GR, GST activities and GSH, SH concentrations) and cholinesterase activity were investigated. The concentrations of nine metals (Fe, Cu, Zn, As, Cd, Cr, Hg, Ni, and Pb) were measured in the water and tissues. Correlations were established between metals and biomarkers in the tissues. The results of metal accumulation distinguished the skin of P. lessonae and muscle of P. ridibundus from other P. esculentus complex species. The oxidative stress biomarkers observed in P. ridibundus and P. esculentus had greater similarity than in P. lessonae. The P. lessonae displayed the highest number of correlations between biomarkers and metals. The results of tissue responses revealed that skin was more susceptible to metal-induced oxidative stress, with only exception of As. In the light of these findings, we can suggest the use of P. esculentus complex species as a biomonitoring species in studies of metal accumulation and metal-induced oxidative stress, but with special emphasis on P. lessonae.
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Affiliation(s)
- Marko D Prokić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia.
| | - Slavica S Borković-Mitić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia
| | - Imre I Krizmanić
- Faculty of Biology, Institute of Zoology, University of Belgrade, Studentski trg 16, Belgrade, 11000, Serbia
| | - Jelena J Mutić
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, 11158, Serbia
| | - Jelena Đ Trifković
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, 11158, Serbia
| | - Jelena P Gavrić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia
| | - Svetlana G Despotović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia
| | - Branka R Gavrilović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia
| | - Tijana B Radovanović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia
| | - Slađan Z Pavlović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia
| | - Zorica S Saičić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia
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39
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Mathieu-Denoncourt J, Martyniuk CJ, Loughery JR, Yargeau V, de Solla SR, Langlois VS. Lethal and sublethal effects of phthalate diesters in Silurana tropicalis larvae. Environ Toxicol Chem 2016; 35:2511-2522. [PMID: 26924002 DOI: 10.1002/etc.3413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/24/2015] [Accepted: 02/24/2016] [Indexed: 06/05/2023]
Abstract
Phthalates are compounds used in polymers to increase their flexibility and are now ubiquitous in the environment as a result of widespread use. Because few studies have focused on the adverse effects of these chemicals in aquatic species, the present study aimed to determine the effects of phthalate diesters in amphibians. Western clawed frog (Silurana tropicalis) tadpoles were acutely exposed to water spiked with monomethyl phthalate (MMP; 1.3-1595.5 mg/L), dimethyl phthalate (DMP; 0.03-924.0 mg/L), or dicyclohexyl phthalate (DCHP; 0.3-99.3 mg/L). Because few studies have addressed the toxicity of these specific phthalates in most organisms, the present study used higher concentrations of these chemicals to determine their toxicity pathways in amphibians and at the same time investigate a suite of genes known to be altered by the well-studied phthalates. Both DMP and DCHP increased larval mortality (9.1-924.0 mg/L DMP and 4.1-99.3 mg/L DCHP), increased frequency of malformations in tadpoles (0.1-34.1 mg/L DMP and 4.1-19.0 mg/L DCHP), and up-regulated cellular stress-related messenger-RNA (mRNA) levels (4.1 mg/L DCHP). To characterize the molecular toxicity pathway of these phthalates in tadpoles, transcriptome analysis was conducted using a custom microarray. Parametric analysis of gene set enrichment revealed important changes in the expression of genes related to drug metabolism and transport, liver metabolism, xenobiotic clearance, and xenobiotic metabolism after DMP and DCHP treatments, although these responses were less pronounced with MMP (the metabolite of DMP). The present study is one of the few studies that demonstrated complementarity between gene expression analysis and organismal effects. Environ Toxicol Chem 2016;35:2511-2522. © 2016 SETAC.
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Affiliation(s)
- Justine Mathieu-Denoncourt
- Chemistry and Chemical Engineering Department, Royal Military College of Canada, Kingston, Ontario, Canada
| | - Christopher J Martyniuk
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, UF Genetics Institute, University of Florida, Gainesville, Florida, USA
- Department of Biology, University of New Brunswick and Canadian Rivers Institute, New Brunswick, Canada
| | - Jennifer R Loughery
- Department of Biology, University of New Brunswick and Canadian Rivers Institute, New Brunswick, Canada
| | - Viviane Yargeau
- Department of Chemical Engineering, McGill University, Quebec, Canada
| | - Shane R de Solla
- Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | - Valerie S Langlois
- Chemistry and Chemical Engineering Department, Royal Military College of Canada, Kingston, Ontario, Canada.
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40
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Bissegger S, Langlois VS. Androgens modulate gene expression and specific DNA methylation pattern of steroid 5α-reductases in the frog Silurana tropicalis. Gen Comp Endocrinol 2016; 234:123-32. [PMID: 26987288 DOI: 10.1016/j.ygcen.2016.03.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/12/2016] [Indexed: 12/15/2022]
Abstract
In vertebrates, androgens are essential in many biological functions, including reproduction, immune system, metabolism, cardiovascular function, and the central nervous system. The most potent androgen 5α-dihydrotestosterone (5α-DHT), which is actively involved in sexual differentiation and development, is converted from testosterone (T) by the steroid 5α-reductases type 1, 2, and 3 (Srd5α1, Srd5α2, and Srd5α3). Alternatively, steroid 5β-reductase (Srd5β) converts T to 5β-dihydrotestosterone (5β-DHT), a metabolite believed to be involved in steroid clearance. Recent studies suggested that Srd5 isoforms are targets for endocrine disruption. Thus, understanding the regulation of Srd5 is important to expand our knowledge on how exogenous compounds can interfere with these enzymes. In this study, we exposed frog brain, liver, and gonads ex vivo to T, 5α-DHT, and 5β-DHT in order to investigate the regulation of srd5 in response to androgens as a simulation of endocrine disrupting chemicals with androgenic properties. Androgens did not modulate srd5α2, suggesting that this isoform is not regulated by T and 5α-DHT in frogs. However, the DNA methylation of srd5α2 increased following 5α-DHT treatment suggesting that androgens can modulate epigenetic mechanisms in amphibians. In contrast, the DNA methylation of srd5α1 and srd5α3 remained stable after androgen exposure, but the mRNA levels of srd5α1 and srd5α3 were modulated by T, 5α-DHT, and 5β-DHT in a sex- and tissue-specific manner. While T positively regulates srd5α1 and srd5α3 in testes, T negatively regulates srd5α3 in ovaries. Moreover, exposure to T also increased the mRNA level of srd5β in the male brain suggesting a mechanism to protect the brain from androgen action by elimination of T into 5β-DHT. Thus, exogenous compounds with androgenic properties potentially interact with srd5 transcription and DNA methylation pattern, which could adversely affect biological functions of vertebrates during development and reproduction.
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Affiliation(s)
- Sonja Bissegger
- Chemistry and Chemical Engineering Department, Royal Military College of Canada, Kingston, ON, Canada
| | - Valerie S Langlois
- Chemistry and Chemical Engineering Department, Royal Military College of Canada, Kingston, ON, Canada.
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41
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Gibson LA, Koch I, Reimer KJ, Cullen WR, Langlois VS. Life cycle exposure of the frog Silurana tropicalis to arsenate: Steroid- and thyroid hormone-related genes are differently altered throughout development. Gen Comp Endocrinol 2016; 234:133-41. [PMID: 26393310 DOI: 10.1016/j.ygcen.2015.09.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 08/28/2015] [Accepted: 09/11/2015] [Indexed: 10/23/2022]
Abstract
Arsenic contaminates water surface and groundwater worldwide. Several studies have suggested that arsenic acts as an endocrine disruptor in mammalian and non-mammalian species, although its chronic effect during development remains largely unknown. To address this question, life cycle exposures to 0, 0.3 and 0.8ppm of arsenate (pentavalent arsenic; As(V)) were performed in the Western clawed frog (Silurana tropicalis) from the gastrulae stage (developmental stage Nieuwkoop-Faber; NF12) until metamorphosis (NF66). Tissue samples were collected at the beginning of feeding (NF46; whole body), sexual development (NF56; liver), and at metamorphosis completion (NF66; liver and gonadal mesonephros complex). Real-time RT-PCR analysis quantified decreases in mRNA levels of genes related to estrogen- (estrogen receptor alpha and aromatase), androgen- (androgen receptor and steroid 5-alpha-reductase type 2), and cholesterol metabolism- (steroidogenic acute regulatory protein) at stage NF46. Similarly, arsenate decreased steroid 5-alpha-reductase type 2 expression in stage NF56 livers, but transcript increases were observed for both estrogen receptor alpha and steroidogenic acute regulatory protein at this stage. Given the changes observed in the expression of genes essential for proper sexual development, gonadal histological analysis was carried out in stage NF66 animals. Arsenate treatments did not alter sex ratio or produce testicular oocytes. On the other hand, arsenate interfered with thyroid hormone-related transcripts at NF66. Specifically, thyroid hormone receptor beta and deiodinase type 2 mRNA levels were significantly reduced after arsenate treatment in the gonadal mesonephros complex. This reduction in thyroid hormone-related gene expression, however, was not accompanied by any morphological changes measured. In summary, environmentally relevant concentrations of As(V) altered steroidogenesis-, sex steroid signaling- and thyroid hormone-related gene expression, although transcriptional changes varied among tissues and developmental stages.
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Affiliation(s)
- Laura A Gibson
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Canada
| | - Iris Koch
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Canada
| | - Kenneth J Reimer
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Canada
| | | | - Valerie S Langlois
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Canada.
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42
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Jansson E, Mattsson A, Goldstone J, Berg C. Sex-dependent expression of anti-Müllerian hormone (amh) and amh receptor 2 during sex organ differentiation and characterization of the Müllerian duct development in Xenopus tropicalis. Gen Comp Endocrinol 2016; 229:132-44. [PMID: 26987287 DOI: 10.1016/j.ygcen.2016.03.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 01/12/2016] [Accepted: 03/11/2016] [Indexed: 12/31/2022]
Abstract
Amphibian gonadal differentiation involves the action of sex steroids. Recent research indicates that the anti-Müllerian hormone (AMH) is involved in testicular development in some lower vertebrate species. For amphibians there is a lack of data on ontogenetic expression of the AMH receptor AMHR2/amhr2 and of progesterone receptors (PGRS/pgrs). Here we expand the knowledge on amphibian sex differentiation by characterizing ontogenetic mRNA levels of amh, amhr2, intracellular and membrane pgrs (ipgr and mpgr beta) and cytochrome P450 19a1 (cyp19a1) (ovarian marker) in the urogenital complex of the model species Xenopus (Silurana) tropicalis. Furthermore, we characterized the ontogenetic development of the Müllerian ducts (precursors of the female reproductive tract) histologically. The developmental period investigated spanned from beginning of gonadal differentiation, Nieuwkoop and Faber (NF) stage 51, to 4weeks post-metamorphosis. The Müllerian ducts were first observed at NF 64 in both sexes. Male-enhanced amh mRNA levels from NF 53/54 to 6days post-metamorphosis and female-enhanced cyp19a1 levels from NF 53 to 4weeks post-metamorphosis were noted. The sexually dimorphic mRNA level profile was more distinct for amh than for cyp19a1. The pgrs mRNA levels increased over the studied period and showed no sex differences. At later developmental stages, the amhr2 mRNA level was increased in putative females compared with males. Our findings suggest that AMH has a role in gonadal differentiation in X. tropicalis. We propose relative gonadal amh mRNA level as a testicular marker during early gonadal development in amphibians.
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Affiliation(s)
- Erika Jansson
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Uppsala, Sweden.
| | - Anna Mattsson
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Uppsala, Sweden.
| | - Jared Goldstone
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States.
| | - Cecilia Berg
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Uppsala, Sweden.
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Sakai M, Gomi T, Negishi JN, Iwamoto A, Okada K. Different cesium-137 transfers to forest and stream ecosystems. Environ Pollut 2016; 209:46-52. [PMID: 26629645 DOI: 10.1016/j.envpol.2015.11.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 11/14/2015] [Accepted: 11/16/2015] [Indexed: 06/05/2023]
Abstract
Understanding the mechanisms of (137)Cs movement across different ecosystems is crucial for projecting the environmental impact and management of nuclear contamination events. Here, we report differential movement of (137)Cs in adjacent forest and stream ecosystems. The food webs of the forest and stream ecosystems in our study were similar, in that they were both dominated by detrital-based food webs and the basal energy source was terrestrial litter. However, the concentration of (137)Cs in stream litter was significantly lower than in forest litter, the result of (137)Cs leaching from litter in stream water. The difference in (137)Cs concentrations between the two types of litter was reflected in the (137)Cs concentrations in the animal community. While the importance of (137)Cs fallout and the associated transfer to food webs has been well studied, research has been primarily limited to cases in a single ecosystem. Our results indicate that there are differences in the flow of (137)Cs through terrestrial and aquatic ecosystems, and that (137)Cs concentrations are reduced in both basal food resources and higher trophic animals in aquatic systems, where primary production is subsidized by a neighboring terrestrial ecosystem.
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Affiliation(s)
- Masaru Sakai
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
| | - Takashi Gomi
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
| | - Junjiro N Negishi
- Faculty of Environmental Earth Science, Hokkaido University, N10, W5, Kita-ku, Sapporo, Hokkaido 060-0860, Japan.
| | - Aimu Iwamoto
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
| | - Kengo Okada
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
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Prokić M, Borković-Mitić S, Krizmanić I, Gavrić J, Despotović S, Gavrilović B, Radovanović T, Pavlović S, Saičić Z. Comparative study of oxidative stress parameters and acetylcholinesterase activity in the liver of Pelophylax esculentus complex frogs. Saudi J Biol Sci 2017; 24:51-8. [PMID: 28053571 DOI: 10.1016/j.sjbs.2015.09.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 08/13/2015] [Accepted: 09/01/2015] [Indexed: 11/23/2022] Open
Abstract
Comparative activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), the phase II biotransformation enzyme glutathione-S-transferase (GST), the concentrations of total glutathione (GSH), sulfhydryl groups (–SH) and the activity of the neurotoxicity biomarker acetylcholinesterase (AChE) were investigated in the livers of species belonging to the Pelophylax esculentus “complex” (parental species Pelophylax ridibundus, Pelophylax lessonae, and their hybrid Pelophylax kl. esculentus) from the wetland, Obedska bara in Serbia. The condition factor (CF) and hepato somatic index (HSI) were also calculated. All three species were caught at same locality and were exposed to the same environmental conditions. Liver SOD activity was lower in P. ridibundus than in P. kl. esculentus and P. lessonae; higher activities of CAT, GR and GST were observed in P. kl. esculentus frogs as compared to their parental species. The activity of GSH-Px was significantly lower in P. kl. esculentus. The activity of AChE was increased in P. lessonae as compared to P. kl. esculentus and P. ridibundus. Similar concentrations of GSH and —SH groups were observed in all investigated species. P. kl. esculentus had a higher CF, while the HSI was lower when compared to the parental species. Our findings suggest that the parental species (P. ridibundus and P. lessonae) possess more similar antioxidative responses to environmental conditions than the hybrid species P. kl. esculentus. The obtained results improve our understanding of the biology and physiology of these three closely related species.
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45
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Martyniuk CJ, Bissegger S, Langlois VS. Reprint of "Current perspectives on the androgen 5 alpha-dihydrotestosterone (DHT) and 5 alpha-reductases in teleost fishes and amphibians". Gen Comp Endocrinol 2014; 203:10-20. [PMID: 24954687 DOI: 10.1016/j.ygcen.2014.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The androgen 5 alpha-dihydrotestosterone (DHT) is a steroidogenic metabolite that has received little attention in non-mammalian species. DHT is produced by the reduction of the double-bond of testosterone by a group of enzymes called 5 alpha-reductases of which there can be multiple isoforms (i.e., srd5a1, srd5a2, and srd5a3). Data from amphibians suggest that the expression of the srd5a genes occurs in early development, and continues until adulthood; however insufficient data exist in fish species, where DHT is thought to be relatively biologically inactive. Here, we demonstrate that fathead minnow (FHM; Pimephales promelas) developing embryos and adults express srd5a enzyme isoforms. During FHM embryogenesis, both srd5a1 and srd5a3 mRNA levels were significantly correlated in expression levels while srd5a2 showed a more unique pattern of expression. In adult FHMs, males had significantly higher levels of srd5a2 in the liver and gonad compared to females. In the male and female liver, transcript levels for srd5a2 were more abundant compared to srd5a1 and srd5a3, suggesting a prominent role for srd5a2 in this tissue. Interestingly, the ovary expressed higher mRNA levels of srd5a3 than the testis. Thus, data suggest that srd5a isoforms can show sexually dimorphic expression patterns in fish. We also conducted a literature review of the biological effects observed in embryonic and adult fish and amphibians after treatments with DHT and DHT-related compounds. Treatments with DHT in teleost fishes and amphibians have resulted in unexpected biological responses that are characteristic of both androgens and anti-androgens. For example, in fish DHT can induce vitellogenin in vitro from male and female hepatocytes and can increase 17β-estradiol production from the teleost ovary. We propose, that to generate further understanding of the roles of DHT in non-mammals, studies are needed that (1) address how DHT is synthesized within tissues of fish and amphibians; (2) examine the full range of biological responses to endogenous DHT, and its interactions with other signaling pathways; and (3) investigate how DHT production varies with reproductive stage. Lastly, we suggest that the Srd5a enzymes can be targets of endocrine disruptors in fish and frogs, which may result in disruptions in the estrogen:androgen balance in aquatic organisms.
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Affiliation(s)
| | - Sonja Bissegger
- Chemistry and Chemical Engineering Department, Royal Military College of Canada, Kingston, ON K7K 7B4, Canada.
| | - Valérie S Langlois
- Chemistry and Chemical Engineering Department, Royal Military College of Canada, Kingston, ON K7K 7B4, Canada.
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46
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Bissegger S, Martyniuk CJ, Langlois VS. Transcriptomic profiling in Silurana tropicalis testes exposed to finasteride. Gen Comp Endocrinol 2014; 203:137-45. [PMID: 24530632 DOI: 10.1016/j.ygcen.2014.01.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 01/24/2014] [Accepted: 01/28/2014] [Indexed: 01/14/2023]
Abstract
Investigations of endocrine disrupting chemicals found in aquatic ecosystems with estrogenic and androgenic modes of action have increased over the past two decades due to a surge of evidence of adverse effects in wildlife. Chemicals that disrupt androgen signalling and steroidogenesis can result in an imbalanced conversion of testosterone (T) into 17β-estradiol (E2) and other androgens such as 5α-dihydrotestosterone (5α-DHT). Therefore, a better understanding of how chemicals perturb these pathways is warranted. In this study, the brain, liver, and testes of Silurana tropicalis were exposed ex vivo to the human drug finasteride, a potent steroid 5α-reductase inhibitor and a model compound to study the inhibition of the conversion of T into 5α-DHT. These experiments were conducted (1) to determine organ specific changes in sex steroid production after treatment, and (2) to elucidate the transcriptomic response to finasteride in testicular tissue. Enzyme-linked immunosorbent assays were used to measure hormone levels in media following finasteride incubation for 6 h. Finasteride significantly increased T levels in the media of liver and testis tissue, but did not induce any changes in E2 and 5α-DHT production. Gene expression analysis was performed in frog testes and data revealed that finasteride treatment significantly altered 1,434 gene probes. Gene networks associated with male reproduction such as meiosis, hormone biosynthesis, sperm entry, gonadotropin releasing hormone were affected by finasteride exposure as well as other pathways such as oxysterol synthesis, apoptosis, and epigenetic regulation. For example, this study suggests that the mode of action by which finasteride induces cellular damage in testicular tissue as reported by others, is via oxidative stress in testes. This data also suggests that 5-reductase inhibition disrupts the expression of genes related to reproduction. It is proposed that androgen-disrupting chemicals may mediate their action via 5-reductases and that the effects of environmental pollutants are not limited to the androgen receptor signalling.
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Affiliation(s)
- Sonja Bissegger
- Chemistry and Chemical Engineering Department, Royal Military College of Canada, Kingston, ON, Canada.
| | - Christopher J Martyniuk
- Department of Biology and the Canadian River Institute, University of New Brunswick, NB, Canada.
| | - Valérie S Langlois
- Chemistry and Chemical Engineering Department, Royal Military College of Canada, Kingston, ON, Canada.
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Maddock ST, Day JJ, Nussbaum RA, Wilkinson M, Gower DJ. Evolutionary origins and genetic variation of the Seychelles treefrog, Tachycnemis seychellensis (Duméril and Bibron, 1841) (Amphibia: Anura: Hyperoliidae). Mol Phylogenet Evol 2014; 75:194-201. [PMID: 24555995 PMCID: PMC4101239 DOI: 10.1016/j.ympev.2014.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 02/06/2014] [Accepted: 02/08/2014] [Indexed: 11/30/2022]
Abstract
The hyperoliid frog Tachycnemis seychellensis, the only species of its genus, is endemic to the four largest granitic islands of the Seychelles archipelago and is reliant on freshwater bodies for reproduction. Its presence in the Seychelles is thought to be the product of a transoceanic dispersal, diverging from the genus Heterixalus, its closest living relative (currently endemic to Madagascar), between approximately 10-35Ma. A previous study documented substantial intraspecific morphological variation among island populations and also among populations within the largest island (Mahé). To assess intraspecific genetic variation and to infer the closest living relative(s) of T. seychellensis, DNA sequence data were generated for three mitochondrial and four nuclear markers. These data support a sister-group relationship between T. seychellensis and Heterixalus, with the divergence between the two occurring between approximately 11-19Ma based on cytb p-distances. Low levels of genetic variation were found among major mitochondrial haplotype clades of T. seychellensis (maximum 0.7% p-distance concatenated mtDNA), and samples from each of the islands (except La Digue) comprised multiple mitochondrial haplotype clades. Two nuclear genes (rag1 and tyr) showed no variation, and the other two (rho and pomc) lacked any notable geographic structuring, counter to patterns observed within presumably more vagile Seychelles taxa such as lizards. The low levels of genetic variation and phylogeographic structure support an interpretation that there is a single but morphologically highly variable species of Seychelles treefrog. The contrasting genetic and morphological intraspecific variation may be attributable to relatively recent admixture during low sea-level stands, ecophenotypic plasticity, local adaptation to different environmental conditions, and/or current and previously small population sizes. Low genetic phylogeographic structure but substantial morphological variation is unusual within anurans.
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Affiliation(s)
- Simon T Maddock
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK; Department of Life Sciences, The Natural History Museum, London SW7 5BD, UK.
| | - Julia J Day
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Ronald A Nussbaum
- Museum of Zoology and Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109-1079, USA
| | - Mark Wilkinson
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK; Department of Life Sciences, The Natural History Museum, London SW7 5BD, UK
| | - David J Gower
- Department of Life Sciences, The Natural History Museum, London SW7 5BD, UK
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48
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Katzenback BA, Holden HA, Falardeau J, Childers C, Hadj-Moussa H, Avis TJ, Storey KB. Regulation of the Rana sylvatica brevinin-1SY antimicrobial peptide during development and in dorsal and ventral skin in response to freezing, anoxia and dehydration. ACTA ACUST UNITED AC 2014; 217:1392-401. [PMID: 24436376 DOI: 10.1242/jeb.092288] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Brevinin-1SY is the only described antimicrobial peptide (AMP) of Rana sylvatica. As AMPs are important innate immune molecules that inhibit microbes, this study examined brevinin-1SY regulation during development and in adult frogs in response to environmental stress. The brevinin-1SY nucleotide sequence was identified and used for protein modeling. Brevinin-1SY was predicted to be an amphipathic, hydrophobic, alpha helical peptide that inserts into a lipid bilayer. Brevinin-1SY transcripts were detected in tadpoles and were significantly increased during the later stages of development. Effects of environmental stress (24 h anoxia, 40% dehydration or 24 h frozen) on the mRNA levels of brevinin-1SY in the dorsal and ventral skin were examined. The brevinin-1SY mRNA levels were increased in dorsal and ventral skin of dehydrated frogs, and in ventral skin of anoxic frogs, compared with controls (non-stressed). Brevinin-1SY protein levels in peptide extracts of dorsal skin showed a similar, but not significant, trend to that of brevinin-1SY mRNA levels. Antimicrobial activity of skin extracts from control and stressed animals were assessed for Escherichia coli, Bacillus subtilis, Saccharomyces cerevisiae, Botrytis cinerea, Rhizopus stolonifer and Pythium sulcatum using disk diffusion assays. Peptide extracts of dorsal skin from anoxic, frozen and dehydrated animals showed significantly higher inhibition of E. coli and P. sulcatum than from control animals. In ventral skin peptide extracts, significant growth inhibition was observed in frozen animals for E. coli and P. sulcatum, and in anoxic animals for B. cinerea, compared with controls. Environmental regulation of brevinin-1SY may have important implications for defense against pathogens.
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Martyniuk CJ, Bissegger S, Langlois VS. Current perspectives on the androgen 5 alpha-dihydrotestosterone (DHT) and 5 alpha-reductases in teleost fishes and amphibians. Gen Comp Endocrinol 2013; 194:264-74. [PMID: 24095809 DOI: 10.1016/j.ygcen.2013.09.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 09/23/2013] [Accepted: 09/26/2013] [Indexed: 11/29/2022]
Abstract
The androgen 5 alpha-dihydrotestosterone (DHT) is a steroidogenic metabolite that has received little attention in non-mammalian species. DHT is produced by the reduction of the double-bond of testosterone by a group of enzymes called 5 alpha-reductases of which there can be multiple isoforms (i.e., srd5a1, srd5a2, and srd5a3). Data from amphibians suggest that the expression of the srd5a genes occurs in early development, and continues until adulthood; however insufficient data exist in fish species, where DHT is thought to be relatively biologically inactive. Here, we demonstrate that fathead minnow (FHM; Pimephales promelas) developing embryos and adults express srd5a enzyme isoforms. During FHM embryogenesis, both srd5a1 and srd5a3 mRNA levels were significantly correlated in expression levels while srd5a2 showed a more unique pattern of expression. In adult FHMs, males had significantly higher levels of srd5a2 in the liver and gonad compared to females. In the male and female liver, transcript levels for srd5a2 were more abundant compared to srd5a1 and srd5a3, suggesting a prominent role for srd5a2 in this tissue. Interestingly, the ovary expressed higher mRNA levels of srd5a3 than the testis. Thus, data suggest that srd5a isoforms can show sexually dimorphic expression patterns in fish. We also conducted a literature review of the biological effects observed in embryonic and adult fish and amphibians after treatments with DHT and DHT-related compounds. Treatments with DHT in teleost fishes and amphibians have resulted in unexpected biological responses that are characteristic of both androgens and anti-androgens. For example, in fish DHT can induce vitellogenin in vitro from male and female hepatocytes and can increase 17β-estradiol production from the teleost ovary. We propose, that to generate further understanding of the roles of DHT in non-mammals, studies are needed that (1) address how DHT is synthesized within tissues of fish and amphibians; (2) examine the full range of biological responses to endogenous DHT, and its interactions with other signaling pathways; and (3) investigate how DHT production varies with reproductive stage. Lastly, we suggest that the Srd5a enzymes can be targets of endocrine disruptors in fish and frogs, which may result in disruptions in the estrogen:androgen balance in aquatic organisms.
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50
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Jaafar I, Chai TC, Sah SAM, Akil MAMM. Checklist and Simple Identification Key for Frogs and Toads from District IV of The MADA Scheme, Kedah, Malaysia. Trop Life Sci Res 2009; 20:49-57. [PMID: 24575178 PMCID: PMC3819053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
A survey was conducted to catalogue the diversity of anurans in District IV of the Muda Agriculture Development Authority Scheme (MADA) in Kedah Darul Aman, Malaysia, from July 1996 to January 1997. Eight species of anurans from three families were present in the study area. Of these, the Common Grass Frog (Fejevarya limnocharis) was the most abundant, followed by Mangrove Frog (Fejevarya cancrivora), Long-legged Frog (Hylarana macrodactyla), and Common Toad (Duttaphrynus melanostictus). Puddle Frog (Occidozyga lima), Taiwanese Giant Frog (Hoplobatrachus rugulosus), and Banded Bullfrog (Kaluola pulchra) were rare during the sampling period, and only one Paddy Frog (Hylarana erythraea) was captured. A simple identification key for the anurans of this area is included for use by scientists and laymen alike.
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Affiliation(s)
- Ibrahim Jaafar
- School of Distance Education, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia
| | - Teoh Chia Chai
- School of Distance Education, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia
| | - Shahrul Anuar Mohd Sah
- School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia
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