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1.
Dis Aquat Organ ; 137(2): 89-99, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31854327

RESUMO

Pathogenic water molds have a significant impact on many species, especially amphibians. The genus Saprolegnia is a pathogenic oomycete restricted to aquatic and moist habitats, and its presence is strongly linked to the abundance of amphibians and fishes. We investigated the influence of Saprolegnia presence on egg mortality and egg occurrence under varying environmental conditions in the Asiatic toad Bufo gargarizans at 27 breeding sites in the Republic of Korea. We then assessed the impact of Saprolegnia on the presence of B. gargarizans at the 27 sites surveyed weekly during the B. gargarizans breeding season for 3 consecutive years. We used molecular tools to identify the water molds as belonging to an undescribed S. ferax strain. We demonstrated that the presence of S. ferax was positively associated with higher water conductivity and ponds. In addition, while S. ferax prevalence was associated with a reduction in B. gargarizans breeding activity and breeding success, we could not determine its impact on the subsequent breeding seasons. Our study highlights the potential negative effects of Saprolegnia on amphibian reproduction, although additional research is necessary to determine the relationship between Saprolegnia, its hosts and the impacts of habitat loss on amphibians.


Assuntos
Bufonidae , Saprolegnia , Animais , Fungos , República da Coreia
2.
BMC Evol Biol ; 19(1): 208, 2019 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-31706264

RESUMO

BACKGROUND: Two previous studies on interspecific body size variation of anurans found that the key drivers of variation are the species' lifestyles and the environments that they live in. To examine whether those findings apply at the intraspecific level, we conducted a study of the Asian common toad (Duttaphrynus melanostictus), a terrestrial anuran distributed in tropical regions. The body size of toads from 15 locations, covering the majority of their geographic range, and local environmental data were summarized from published literature. We used a model selection process based on an information-theoretic approach to examine the relationship between toad body size and those environmental parameters. RESULTS: We found a positive correlation between the body size of the Asian common toad and the water deficit gradient, but no linkage between body size and temperature-related parameters. Furthermore, there was a positive correlation between the seasonality of precipitation and body size of females from different sampled populations. CONCLUSIONS: As a terrestrial anuran, the Asian common toad should experience greater pressure from environmental fluctuations than aquatic species. It is mainly distributed in tropical regions where temperatures are generally warm and stable, but water availability fluctuates. Therefore, while thermal gradients are not strong enough to generate selection pressure on body size, the moisture gradient is strong enough to select for larger size in both males and females in dryer regions. Larger body size supports more efficient water conservation, a pattern in accordance with the prediction that lifestyles of different species and their local habitats determine the relationship between body size and environment. In addition, larger females occur in regions with greater seasonality in precipitation, which may happen because larger females can afford greater reproductive output in a limited reproductive season.


Assuntos
Tamanho Corporal , Bufonidae/fisiologia , Animais , Ásia , Ecossistema , Feminino , Masculino , Reprodução , Estações do Ano , Temperatura Ambiente , Tempo (Meteorologia)
3.
Biol Lett ; 15(11): 20190689, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31718512

RESUMO

Shifts between habitats during reproduction can induce costs that are independent of the reproductive effort and that often apply to both sexes. Such shifts can also illustrate physiological costs complementary to those involving energetic currencies. In this study, we investigated osmotic consequences of reproduction in a context where reproduction induces a shift from terrestrial habitats to freshwater environments. During reproduction, toads migrate to breeding ponds where males remain for several weeks, while females leave shortly after egg-laying. We assessed plasma osmolality of male spined toads during the whole reproductive period (approx. 30 days) in conjunction with markers of individual condition. We found that osmolality decreases during the protracted period of immersion in freshwater during reproduction, presumably through water influx as indicated by body mass changes. Hormonal markers of metabolism and sexual activity were positively correlated with osmolality. Recent research has highlighted hydric 'costs' of reproduction when access to water is limited. Our study adds to this growing field of investigation, yet with an opposite perspective, where water availability linked to reproduction provokes hyperhydration rather than dehydration.


Assuntos
Bufonidae , Reprodução , Animais , Cruzamento , Ecossistema , Feminino , Masculino , Água
4.
Zootaxa ; 4577(2): zootaxa.4577.2.5, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-31715724

RESUMO

Here we describe a new species of the toad genus Amazophrynella (Bufonidae) from the south margin of the Amazon River in Santarém, state of Pará, Brazilian Amazonia. The new species can be diagnosed by (1) medium body size for the genus: adult females 19.5-20.4 mm SVL, adult males 13.0-14.5 mm SVL; (2) snout acuminate in lateral view; (3) Finger I larger and robust; (4) Finger I nearly equal in size than Finger II; (5) palmar tubercle rounded, covering » of hand; (6) pigmented callus in Finger I in males; in life: (7) brown stain on throat and chest; (8) black dots on venter. Males emit two distinct advertisement calls: the call type 1 consists of a relatively long note (mean 0.248 s) with a mean dominant frequency of 3526 Hz. The call type 2 is arranged in bouts of 6 to 22 notes with mean dominant frequency of 3450 Hz and much shorter note durations (mean 0.034 s). In this study we also redescribe the advertisement call of A. minuta, which also emits a second call type.


Assuntos
Anuros , Bufonidae , Animais , Tamanho Corporal , Brasil , Feminino , Masculino , Rios , Vocalização Animal
5.
Zootaxa ; 4679(2): zootaxa.4679.2.9, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31715964

RESUMO

Using a combination of morphological and molecular data we recognize three new species of Puppet Toad, Sigalegalephrynus Smart, Sarker, Arifin, Harvey, Sidik, Hamidy, Kurniawan Smith, a recently described genus endemic to the highland forests of Sumatra, Indonesia. Phylogenetic analysis of mitochondrial DNA sequences recovered a monophyletic relationship among all Puppet Toads, with two distinct evolutionary clades, a northern and a southern. The northern clade includes Sigalegalephrynus gayoluesensis sp. nov., and S. burnitelongensis sp. nov., and the southern clade includes S. harveyi sp. nov., S. mandailinguensis, and S. minangkabauensis. With the discovery of these three new species, Sigalegalephrynus contains more endemic species than any other genus of toad in Indonesia. We used maximum entropy, implemented in MaxEnt, to identify suitable habitats and occurrence probability of additional undescribed new species from the island. The most important predictors of Sigalegalephrynus distribution were elevation (64.5%) and land cover (7.11%). Based on the probability of presence, it is likely that there are many more species of the genus awaiting discovery in Sumatra. Our analysis, based on IUCN Red List of Threatened Species category and criteria, shows that all of the five species of Sigalegalephrynus are in great risk of extinction and should be placed into the Endangered (EN) category of IUCN Red List.


Assuntos
Anuros , Bufonidae , Animais , Espécies em Perigo de Extinção , Indonésia , Filogenia
6.
Zootaxa ; 4656(3): zootaxa.4656.3.11, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31716818

RESUMO

A new species of Ansonia is described from the Shan Plateau of Myanmar based on an integrative taxonomic analysis that differentiates it from all other congeners. Molecular phylogenetic analyses based on the mitochondrial genes 12S and 16S rRNA and tRNA-val recover A. kyaiktiyoensis sp. nov. as the sister species to A. inthanon from Thailand but differs from it and other congeners by at least a 5.0% sequence divergence. It is further differentiated by the following combination of morphological characters: (1) maximum SVL 24 mm in males and females; (2) first finger shorter than second; (3) absence of interorbital and tarsal ridges; (4) presence of light-coloured interscapular spot; (5) presence of yellow rictal tubercle; (6) absence of wide, light-coloured patch below eye; (7) presence of large, discrete, bright-yellow submandibular spots along the underside of lower jaw; (8) iris yellow-gold; (9) presence of markings on the snout consisting of streaks below the eye to the lip, and on the canthus rostralis to the nostril; (10) dorsum grey-brown with orange-beige spots, a dark-brown X-shaped marking on the back surrounding the interscapular spot, and dark-coloured markings on rump; (11) fore- and hind limbs with orange-beige cross-bars; and (12) venter light-gray with yellow spotting, especially near flanks and underside of hind limbs. Ansonia kyaiktiyoensis sp. nov. is the westernmost known record for the genus and the only species west of the Salween Basin. Its discovery echoes the increasing number of herpetological discoveries being made in upland regions fringing the Ayeyarwady and Salween Basins.


Assuntos
Anuros , Bufonidae , Animais , Feminino , Masculino , Mianmar , Filogenia , RNA Ribossômico 16S , Tailândia
7.
Zootaxa ; 4648(1): zootaxa.4648.1.2, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31716958

RESUMO

Dendrophryniscus brevipollicatus Jiménez de la Espada is a Neotropical bufonid endemic to a small range of the Brazilian Coastal Atlantic Forest, with reduced body size for the family and bromeligenous habit. We reviewed the taxonomic status of populations of D. brevipollicatus from states of Rio de Janeiro and São Paulo, including some continental islands, based on external morphology. We tested our morphological species by a DNA-barcoding approach with sequences of 16S RNA ribosomal gene fragment. DNA-barcoding analysis included other recognized Dendrophryniscus species and was concordant with morphological species diagnosed in our review. Intraspecific genetic distances ranged from 0 to 2.72 % (± 0.91 %). Interspecific distances ranged from 3.35 % (± 0.90 %) to 20.15 (± 2.23 %). Optimal threshold values ranged from 2.8 % to 3.0 % and barcode gap analysis showed that for all individuals the furthest intraspecific distances was always lower than the closest non-conspecific individual. Seven distinct species were recognized. A neotype for D. brevipollicatus was designated and described; the type locality was determined for the Açude da Solidão (22º57'S, 43º17'W, Datum WGS 84; 410 m altitude), Parque Nacional da Tijuca, Municipality of Rio de Janeiro, State of Rio de Janeiro, Brazil. Two species were revalidated: D. imitator (Miranda-Ribeiro), with designation of a lectotype and descriptions of the lectotype and of a topotype from the restricted type locality, Alto da Serra (23o46'S, 46o19'W, Datum WGS 84, 800 m altitude), Municipality of Paranapiacaba, State of São Paulo, Brazil; and D. lauroi (Miranda-Ribeiro), with descriptions of the lectotype and of a topotype from the type locality, Municipality of Angra dos Reis (22o54'S, 44o20'W, Datum WGS 84; 25 m altitude), State of Rio de Janeiro, Brazil. Four new species were described: D. davori sp. nov., from Baixo Caledônia (22º21'S, 42º35'W, Datum WGS 84; 1600 m altitude), Municipality of Nova Friburgo, State of Rio de Janeiro, Brazil; D. haddadi sp. nov., from Parque Estadual da Serra do Mar, Núcleo Santa Virgínia (23o21'S, 45o08'W, Datum WGS 84; 970 m altitude), Municipality of São Luís do Paraitinga, State of São Paulo, Brazil; D. izecksohni sp. nov., from Campo de Fruticultura da Bocaina (currently Núcleo Senador Vergueiro), Municipality of São José do Barreiro (22º38'S, 44º34'W, Datum WGS 84, 540 m altitude), State of São Paulo, Brazil; and D. jureia sp. nov., from Estação Ecológica da Juréia-Itatins-Núcleo Rio Verde (24º22'S, 47º04'W, Datum WGS 84; 32 m altitude), Municipality of Iguape, State of São Paulo, Brazil. Geographical distributions of all species are provided.


Assuntos
Bufonidae , Animais , Brasil , Florestas
8.
Dis Aquat Organ ; 135(3): 241-250, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31535619

RESUMO

Within communities, pathogens and parasites have the potential to indirectly influence predator-prey interactions. For instance, prey that exhibit pathology or altered traits (e.g. behavioral shifts) following infection could be more prone to predation, which is known as parasite-induced vulnerability to predation (PIVP). PIVP has been frequently documented for pathogens with trophic transmission, because predators are often critical in the pathogen's life cycle. However, for pathogens without trophic transmission, PIVP can lead to a healthy herds effect, thereby reducing transmission in the system. In this study, we explored whether the pathogen ranavirus (family Iridoviridae) enhances vulnerability of 4 species of larval amphibians (spring peepers Pseudacris crucifer, gray treefrogs Hyla versicolor, American toads Anaxyrus americanus, and northern leopard frogs Lithobates pipiens) to 2 common tadpole predators (larval green darners Anax junius [hereinafter Anax] and adult water bugs Belostoma flumineum [hereinafter Belostoma]). For each anuran species, we conducted short-term microcosm experiments to assess predation rates on individuals that were or were not exposed to virus. For 3 of the 4 species, we found that exposure to ranavirus decreased survival rates with Anax between 2- and 9-fold. However, we did not see the same trend with Belostoma, which indicates that predator identity is important in this interaction. More specifically, the higher efficiency of Anax in capturing and consuming prey, relative to Belostoma, may allow Anax to capitalize on trait changes induced by virus exposure and enhance the PIVP effect. Our results indicate that trait-mediated indirect effects could play a role in creating healthy herds in amphibian communities.


Assuntos
Anuros/parasitologia , Animais , Bufonidae , Larva , Comportamento Predatório
9.
Environ Pollut ; 254(Pt B): 113052, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31465901

RESUMO

In our study, Bufo gargarizans (B. gargarizans) larvae were exposed to control, 0.5, 5, 10 and 50 mg/L of NaF from Gs 26 to 42. At Gs 42, we evaluated the changes of liver histology and the mRNA levels of target genes in liver. In addition, we also examined the composition and content of fatty acids. Histological analysis revealed that fluoride caused liver injury, such as the increase of number of melanomacrophage centres, atrophy of nucleus, dilation of bile canaliculus, and decrease of quantity, degradation and deposition of lipid droplets. The results of RT-qPCR indicated that exposure to 5, 10 and 50 mg/L of NaF significantly decreased the transcript levels of genes related to fatty acid synthesis (FASN, FAE, MECR, KAR and TECR) in liver. Besides, mRNA expression of genes involved in fatty acid ß-oxidation (ECHS1, HADHA, SCP2, CPT2, ACAA1 and ACAA2) and oxidative stress (SOD, GPx, MICU1 and HSP90) was significantly downregulated in 0.5, 5, 10 and 50 mg/L of NaF treatment groups. Also, in the relative expression of genes associated with synthesis and secretion of bile acid, BSEP significantly increased at 0.5, 5 and 50 mg/L of NaF while HSD3B7 significantly reduced in 0.5, 5, 10 and 50 mg/L of NaF. Finally, the fatty acid extraction and GC-MS analysis showed that the content of saturated fatty acids (SFAs) was decreased and the content of polyunsaturated fatty acids (PUFAs) was increased in all fluoride treatment groups. Taken together, the present results indicated that fluoride-induced the histological alterations of liver might be linked to the disorder of lipid metabolism, oxidative damage.


Assuntos
Bufonidae/fisiologia , Fluoretos/toxicidade , Animais , Ácidos e Sais Biliares/metabolismo , Fluoretos/metabolismo , Larva/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , RNA Mensageiro/metabolismo
10.
Physiol Biochem Zool ; 92(5): 473-480, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31390287

RESUMO

We studied the role of plasma glucose concentration on individuals of Rhinella spinulosa in response to annual temperature variation and freezing temperatures. Measurements and collection of toads were made every 2 mo for a period of 1 yr. To determine whether toads were exposed to low temperatures in their habitat, we proceeded with the study of operating temperatures (T e). The measures of operating temperature were determined by using plaster models placed in the field, simulating the situation where toads are outside or inside shelters, for which it was determined that individuals in the winter season would have been exposed to temperatures below 0°C. Glucose levels measured in field specimens showed an annual variation, but laboratory specimens exposed to freezing temperatures had higher plasma glucose levels than field toads. Furthermore, the crystallization temperature for the species has been recorded at -1.6°C. The increase in glucose concentration indicates its possible use as a cryoprotectant before freezing events in this species of frogs and also in the coldest months at temperatures below 0°C.


Assuntos
Bufonidae/fisiologia , Temperatura Baixa , Crioprotetores/metabolismo , Glucose/metabolismo , Adaptação Fisiológica , Animais , Temperatura Corporal , Congelamento
11.
Chemosphere ; 235: 227-238, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31260863

RESUMO

Nitrate is known to disrupt the thyroid hormone, which is essential for the metamorphosis of amphibians. However, few studies are focused on the effects of nitrate on the maternal thyroid hormone in early amphibian embryos. We aimed to determine the impact of nitrate on maternal thyroid hormone signaling pathway in Bufo gargarizans embryos. B. gargarizans embryos were exposed to different concentrations of nitrate-nitrogen (NO3-N) for 7 days. High concentration of NO3-N (50, 100, and 200 mg/L) could induce embryonic malformation and influence the development of embryos. In addition, maternal T4 and components of the thyroid hormone (TH) signaling pathway were detected by ELISA and RNA-seq, respectively. The expression levels of mRNA related to thyroid hormone and oxidative stress were affected in the early developing embryos in all NO3-N treatment groups. However, the T4 levels and the spatial expression patterns of type II iodothyronine deiodinase (D2), type III iodothyronine deiodinase (D3), thyroid hormone receptor α (TRα), and thyroid hormone receptor ß (TRß) mRNA were not changed by nitrate. In conclusion, the results of our study highlight the crucial role of the maternal thyroid hormone signaling pathway in normal embryonic development, and the adverse effects of nitrate on the expression levels of mRNA related to thyroid hormone signaling pathway and oxidative stress in B. gargarizans embryos.


Assuntos
Bufonidae/crescimento & desenvolvimento , Embrião não Mamífero/citologia , Desenvolvimento Embrionário/efeitos dos fármacos , Metamorfose Biológica/efeitos dos fármacos , Nitratos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Hormônios Tireóideos/metabolismo , Animais , Bufonidae/embriologia , Embrião não Mamífero/efeitos dos fármacos , Iodeto Peroxidase/metabolismo , Estresse Oxidativo/efeitos dos fármacos
12.
J Chromatogr A ; 1603: 179-189, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31255247

RESUMO

Comprehensive analysis and identification of chemical components are very important to evaluate the efficacy and safety of traditional Chinese medicine (TCM). Meanwhile, the discovery of new natural compounds is of great significance for drug exploitation and development. Although two-dimensional liquid chromatography (2D LC) systems expand the peak capacity and improve selectivity and resolution, interpreting the post-processing data is tedious and time-consuming. In this study, an off-line two-dimensional liquid chromatography/ultra-high performance supercritical fluid chromatography tandem quadrupole time-of-flight mass spectrometry (2D LC/UHPSFC-Q-TOF/MS) system was established for systematic chromatographic separation and identification of bufadienolides. Subsequently, the Global Natural Product Social Molecular Networking (GNPS) was applied for dereplication of chemical components of adjacent fractions with high efficiency and accuracy. The key parameters which affected separation and detection with respect to chromatographic conditions and mass spectrometry conditions were optimized. The extract of Venenum Bufonis was fractionated into forty fractions by first-dimensional reversed phase high-performance liquid chromatography (HPLC), which were further analyzed by the second-dimensional UHPSFC-Q-TOF/MS in positive ion mode. The data of forty fractions was imported into GNPS and processed automatically within about five hours. Furthermore, the chemical components with similar featured fragments were classified into the same cluster, which was helpful for components identification. A total of 229 bufadienolides were characterized and two subclasses of compounds (bufogenins conjugated with carboxylic acid and N-heterocyclic bufogenins) were found in Venenum Bufonis for the first time. In addition, UHPSFC exhibited powerful separation ability of isomers in Venenum Bufonis. In this analysis, two new compounds were isolated and fully characterized by NMR verifying the feasibility of this combined analytical strategy. This integrated strategy can improve the efficiency in the detection of new compounds and offer greater observation of isomers from medicinal herbs and other natural sources.


Assuntos
Bufanolídeos/isolamento & purificação , Animais , Produtos Biológicos/análise , Bufanolídeos/química , Bufonidae , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Espectroscopia de Ressonância Magnética , Espectrometria de Massas em Tandem
13.
J Ethnopharmacol ; 242: 112049, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31265888

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Rhinella schneideri and Rhinella marina are toad venoms distributed in different parts of the world, including Brazil, Columbia and amazon. Venoms extracted from different species have many clinical applications such as antimicrobial cardiotonics and treatment of cancer. Aim of the study; In this study, we aim to investigate the effect of venoms extracted from R. schneideri and R. marina on cancer cells and verify possible mechanism of action. MATERIAL AND METHOD: Cytotoxicity analyses was performed using the resazurin reduction assay, where different concentrations of venoms were tested against sensitive CCRF-CEM and P-gp overexpressing ADR/CEM5000 leukemia cells. Programmed cell death was investigated using the flow cytometric annexin V/propidium iodide apoptosis assay. Furthermore, we analyzed flow cytometric cell cycle analyses of CCRF-CEM cells. Effect on tubulin formation was tested using molecular docking and fluorescence microscopy of U2OS-GFP-α-tubulin osteosarcoma cells treated for 24 h with venoms. RESULTS: Cytotoxicity assays revealed a strong activity towards wild-type CCRF-CEM cells (IC50 values of 0.202 ±â€¯0.005 µg/ml and 0.18 ±â€¯0.007 µg/ml for R. schneideri and R. marina, respectively) and multidrug-resistant CEM/ADR5000 cells (IC50 0.403 ±â€¯0.084 µg/ml and 0.32 ±â€¯0.077 µg/ml for R. schneideri and R. marina, respectively). The venoms induced apoptosis as major mechanism of cell death. The venoms induced strong G2/M cell arrest in CCRF-CEM cells. We suggested tubulin as a major target for the venoms. In silico molecular docking of the major constituents of the venoms, i.e. bufalin, marinobufagin, telocinbufagin, hellebrigenin, showed strong binding affinities to tubulin. This result was verified in vitro. The venoms dysregulated microtubule arrangement of U2OS cells expressing GFP-labeled tubulin. Toxicity predictions by QSAR methodology highlighted the toxic features of bufadienolides. CONCLUSION: Our study demonstrated the importance of toad venoms as source of cytotoxic compounds that may serve as lead compounds for the development of novel anticancer drugs.


Assuntos
Venenos de Anfíbios/farmacologia , Antimitóticos/farmacologia , Bufonidae , Venenos de Anfíbios/toxicidade , Animais , Antimitóticos/toxicidade , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Dose Letal Mediana , Simulação de Acoplamento Molecular , Tubulina (Proteína)/metabolismo
14.
Vet Pathol ; 56(5): 789-793, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31221032

RESUMO

Chlamydia pneumoniae is a ubiquitous pathogen causing disease in humans, mammals, birds, reptiles, and amphibians. Since 2012, C. pneumoniae infection has caused neurologic disease and mortality in a breeding colony of endangered Houston toads (Anaxyrus houstonensis) at the Houston Zoo. The purpose of this report is to present the histopathologic and ultrastructural characteristics of C. pneumoniae infection in Houston toads. Fourteen cases were evaluated by histopathology and 1 case was evaluated by electron microscopy. The major histopathologic finding was necrotizing and histiocytic polioencephalomyelitis and ganglionitis. Bacteria formed intracytoplasmic inclusions within neurons but frequently extended into the surrounding tissue from necrotic cells. Ultrastructural evaluation showed the bacteria formed reticulate and elementary bodies characteristic of Chlamydia spp.


Assuntos
Bufonidae/microbiologia , Infecções por Chlamydophila/veterinária , Chlamydophila pneumoniae , Encefalomielite/veterinária , Animais , Animais de Zoológico , Infecções por Chlamydophila/microbiologia , Encefalomielite/microbiologia
15.
Environ Monit Assess ; 191(7): 454, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31222463

RESUMO

It is well-known that the metamorphosis process in amphibians is dependent on thyroid hormones. Laboratory studies have shown that several environmental contaminants can affect the function of thyroid hormones leading to alterations in the amphibian metamorphosis. The basic idea of the present study was to elucidate if the amphibian metamorphosis might be a useful tool as biomarker for effect-based environmental monitoring, examining wild tadpoles for potential thyroid hormone disruption. A laboratory test was performed to identify the responses from exposure to 6-propylthiouracil (PTU), which has a well-known mechanism on the thyroid system, on Swedish tadpoles from the Rana genus. This was followed by an environmental monitoring study where tadpoles of Rana arvalis, R. temporaria, and Bufo bufo were sampled from various sites in Sweden. Morphological data such as body weight, histopathological measurements of the thyroid glands, and environmental parameters were recorded. The results revealed that Rana tadpoles respond similar as other amphibians to PTU exposure, with interrupted development and increased size relative to the developmental stage. Data on some wild tadpoles showed similar features as the PTU exposed, such as high body weight, thus suggesting potential thyroid disrupting effects. However, histological evaluation of thyroid glands and pesticide analyses of the water revealed no clear evidence of chemical interactions. To a minor degree, the changes in body weight may be explained by natural circumstances such as pH, forest cover, and temperature. The present study cannot fully explain whether the high body weights recorded in some tadpoles have natural or chemical explanations. However, the study reveals that it is clearly achievable to catch tadpoles in suitable stages for the use in this type of biomonitoring and that the use of these biomarkers for assessment of thyroid disruption seems to be highly relevant.


Assuntos
Antitireóideos/toxicidade , Bufonidae/embriologia , Monitoramento Ambiental/métodos , Larva/crescimento & desenvolvimento , Praguicidas/toxicidade , Propiltiouracila/toxicidade , Ranidae/embriologia , Glândula Tireoide/patologia , Animais , Metamorfose Biológica , Suécia , Glândula Tireoide/efeitos dos fármacos , Hormônios Tireóideos/metabolismo
16.
Exp Appl Acarol ; 78(1): 133-147, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31093859

RESUMO

A new tick species of the genus Ornithodoros (Acari: Argasidae) was described from larvae collected on the toad Rhinella arenarum in a locality from Argentina belonging to the Monte Biogeographic Province. Ornithodoros montensis n. sp. was described based on morphological traits and sequences of the mitochondrial 16S rRNA gene. The diagnostic characters for this species are a combination of idiosoma oval, dorsal plate pyriform with posterior margin slightly concave, dorsal surface with 17 pairs of setae (7 anterolateral, 4 to 5 central and 5 to 6 posterolateral), ventral surface with 6 pairs of setae and 1 pair on anal valves, three pairs of sternal setae, postcoxal setae absent, and hypostome pointed apically with dental formula 3/3 in the anterior half and 2/2 posteriorly almost to base. Phylogenetic analysis of 16S rDNA sequences and a principal component analysis based on morphometric characters provided additional support to the description of O. montensis as an independent lineage within the genus Ornithodoros. Larvae of O. montensis are phylogenetically closely related to O. puertoricensis, O. rioplatensis, O. talaje s.s., O. guaporensis, O. hasei and O. atacamensis, all of them belonging to the "O. talaje group".


Assuntos
Bufonidae/parasitologia , Interações Hospedeiro-Parasita , Ornithodoros/classificação , Animais , Argentina , Larva/anatomia & histologia , Larva/classificação , Larva/genética , Ornithodoros/anatomia & histologia , Ornithodoros/genética , Ornithodoros/crescimento & desenvolvimento , RNA Ribossômico 16S/análise
17.
Zhonghua Yi Shi Za Zhi ; 49(2): 67-71, 2019 Mar 28.
Artigo em Chinês | MEDLINE | ID: mdl-31137153

RESUMO

The poem "white rabbits pounding herbs and toads pilling" was recorded in Han Yuefu(Folk) poetry, and the corresponding images were also appeared on the pictorial stones of the Han Dynasty. Some scholars held the opinion that the herbs the white rabbits pounded was "toad pills" , and the "pill" was made of toad venom or the other components of toads.By analyzing literature, the images and unearthed objects, this paper concludes that the meaning of "white rabbits pounding herbs and toads pilling" is that white rabbits and toads work together to make the elixir pills.The word "pill" in the poem is a verb rather than a noun.Toads, like white rabbits, are the agent of actions. They are not the raw materials for elixir pills.


Assuntos
Asteraceae , Bufonidae , Animais , Medicina Tradicional Chinesa , Coelhos
18.
Ecotoxicol Environ Saf ; 180: 449-456, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31121551

RESUMO

Cadmium (Cd) is highly hazardous to both terrestrial and aquatic life and it also has multiple negative impacts on amphibian tadpoles and frogs. However, its effects on gut health of amphibian tadpoles are still poorly understood. We used Chinese toad (Bufo gargarizans) tadpoles to examine the effects of chronic cadmium exposure on gut histology and intestinal microbiota by using regular histology analysis and high-throughput sequencing techniques. Tadpoles were exposed to cadmium concentrations at 0, 5, 100 and 200 µg L-1 from Gosner stage 26 to 38. Our results showed 100 and 200 µg L-1 cadmium exposure caused severe gut histopathological alterations while 5 µg L-1 cadmium exposure induced subtle intestine damage. Moreover, species diversity, taxonomic composition and community structure of gut microbiota were influenced by cadmium exposure. Species diversity and richness decreased gradually with the increase of cadmium concentration. Microbial communities of tadpoles in 100 and 200 µg L-1 cadmium exposure groups were remarkably different from those in control group. Furthermore, the relative abundances of prevalent phyla such as Proteobacteria, Bacteroidetes and Firmicutes and dominant genera such as Klebsiella and Aeromonas were also affected by cadmium exposure. We concluded that cadmium could be harmful to tadpole health by inducing intestinal damages and gut microbiota changes.


Assuntos
Bufonidae/crescimento & desenvolvimento , Cádmio/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Intestinos/microbiologia , Larva/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Bufonidae/microbiologia , Relação Dose-Resposta a Droga , Intestinos/crescimento & desenvolvimento , Intestinos/patologia , Larva/crescimento & desenvolvimento , Larva/microbiologia , Testes de Toxicidade Crônica
19.
Ecotoxicol Environ Saf ; 177: 32-38, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30959310

RESUMO

Morphological abnormalities in amphibians may be attributed to contaminants, ultraviolet radiation and trematode parasites, or a synergistic effect between them. In the present study, morphological abnormalities in Rhinella arenarum adults from natural and artificial fluoride-rich environments were identified and evaluated. Three sites were sampled in central Argentina: Los Vallecitos stream (LF-LV), Los Cerros Negros stream (MF-CN), and Decantation ponds (HF-DP), with low (0.33 mg/L), middle (2.03 mg/L) and high (14.0 mg/L) fluoride levels respectively; the latter site is associated with a fluoride mine. Abnormal individuals were photographed and then standard radiographs were taken. Abnormality frequencies and relative percentage of abnormal individuals were calculated for each site. In addition, skeletochronology was used to estimate toad's age. Five abnormality types were identified: syndactyly, ectrodactyly, polydactyly, microphthalmia and ectromelia. Percentages of abnormal individuals per site were: LF-LV = 4%, MF-CN = 21.2% and HF-DP = 6.4%. The MF-CN and HF-DP populations had morphological abnormality frequencies that exceeded the reference value (5%) reported in the literature. The average age did not differ between sites. The results of this study indicate that there is an association between frequency of morphological abnormalities and high fluoride levels.


Assuntos
Bufonidae/anormalidades , Poluentes Ambientais/toxicidade , Fluoretos/toxicidade , Raios Ultravioleta , Animais , Argentina , Bufonidae/parasitologia , Feminino , Tanques , Rios/química
20.
Ecotoxicol Environ Saf ; 178: 137-145, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31002968

RESUMO

Poly- and perfluoroalkyl substances (PFAS) are ubiquitous contaminants that can bioaccumulate in aquatic taxa. Amphibians are particularly vulnerable to contaminants and sensitive to endocrine disruptors during their aquatic larval stage. However, few studies have explored PFAS uptake rates in amphibians, which is critical for designing ecotoxicology studies and assessing the potential for bioaccumulation. Uptake rates of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were measured for larval northern leopard frogs (Rana pipiens), American toads (Anaxyrus americanus), and eastern tiger salamanders (Ambystoma tigrinum) during a 240-h exposure to 10 and 1000 µg/L concentrations. We measured body burden and calculated bioconcentration factor (BCF) every 48 h during the experiments. For all species and exposures, body burdens often reached steady state within 48-96 h of exposure. Steady-state body burdens for PFOA and PFOS ranged from 3819 to 16,481 ng/g dry weight (BCF = 0.46-2.5) and 6955-489,958 ng/g dry weight (47-259 BCFs), respectively. Therefore, PFAS steady state occurs rapidly in the larval amphibians we studied and particularly for PFOS. This result reflects a high potential for PFAS trophic transfer because amphibians are often low in trophic position and are important prey for many aquatic and terrestrial species.


Assuntos
Ácidos Alcanossulfônicos/metabolismo , Bufonidae/metabolismo , Caprilatos/metabolismo , Fluorcarbonetos/metabolismo , Larva/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Carga Corporal (Radioterapia) , Ecotoxicologia , Cadeia Alimentar
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