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Inigo Martinezsolano - One of the best experts on this subject based on the ideXlab platform.
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morphological and molecular data to describe a hybrid population of the common toad Bufo Bufo and the spined toad Bufo spinosus in western france
Contributions to Zoology, 2017Co-Authors: Tania Trujillo, Jorge Gutierrezrodriguez, Jan W. Arntzen, Inigo MartinezsolanoAbstract:The use of hyper-variable markers across species is often hindered by low cross-species amplification success, a reduced level of polymorphism or a high frequency of null alleles. However, optimizing sets of reliable and informative markers that can be consistently amplified and scored across taxa is key to address questions about patterns of genetic diversity and structure, hybridization and speciation. Here we present 14 newly developed microsatellite markers in the Spined toad (Bufo spinosus), assess their polymorphism in two Iberian populations and test for cross-species amplification in the closely related Common toad (Bufo Bufo). We then use the 12 loci co-amplifying in both species to the study of a morphologically intermediate population (Moyaux) from the contact zone in northwest France as well as reference populations of the two species from both sides of the contact zone. Individuals from Moyaux had mtDNA haplotypes of the two species and were identified as hybrids in analyses with software NewHybrids. These results provide solid evidence for ongoing hybridization between B. Bufo and B. spinosus, with no apparent restrictions to gene flow.
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concordant morphological and molecular clines in a contact zone of the common and spined toad Bufo Bufo and b spinosus in the northwest of france
Frontiers in Zoology, 2016Co-Authors: Jan W. Arntzen, Tania Trujillo, Jorge Gutierrezrodriguez, Onno Schaap, Roland Butot, Klaas Vrieling, Inigo MartinezsolanoAbstract:Hybrid zones are regions where individuals of two species meet and produce hybrid progeny, and are often regarded as natural laboratories to understand the process of species formation. Two microevolutionary processes can take place in hybrid zones, with opposing effects on population differentiation. Hybridization tends to produce genetic homogenization, reducing species differences, whereas the presence of mechanisms of reproductive isolation result in barriers to gene flow, maintaining or increasing differences between taxa. Here we study a contact zone between two hybridizing toad species, Bufo Bufo and B. spinosus, through a combination of molecular (12 polymorphic microsatellites, four nuclear and two mitochondrial SNP markers) and morphological data in a transect in the northwest of France. The results show largely concordant clines across markers, defining a narrow hybrid zone of ca. 30 km wide. Most hybrids in the centre of the contact zone are classified as F2 or backcrossed individuals, with no individuals assigned to the F1 hybrid class. We discuss the implications of these results for our understanding of the evolutionary history of these species. We anticipate that the toad contact zone here described will become an important asset in the study of hybrid zone dynamics and evolutionary biology because of its easy access and the abundance of the species involved.
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how complex is the Bufo Bufo species group
Various articles, 2013Co-Authors: J W Arntzen, Ernesto Recuero, Daniele Canestrelli, Inigo MartinezsolanoAbstract:Species delineation remains one of the most challenging tasks in the study of biodiversity, mostly owing to the application of different species concepts, which results in contrasting taxonomic arrangements. This has important practical consequences, since species are basic units in fields like ecology and conservation biology. We here review molecular genetic evidence relevant to the systematics of toads in the Bufo Bufo species group (Anura, Bufonidae). Two studies recently published in this journal (Recuero et al., MPE 62: 71–86 and Garci´a-Porta et al., MPE 63: 113–130) addressed this issue but reached opposing conclusions on the taxonomy of the group (four versus two species). In particular, allozyme data in the latter paper were interpreted as evidence for hybridization across species (between B. Bufo–B. spinosus and B. Bufo–B. verrucosissimus). We tested claims for hybridization through re-analysis of allozyme data for individuals instead of populations, to be able to distinguish between sympatry with and without admixture, and found no evidence of hybridization across taxa. We propose alternative explanations for the observed patterns that Garci´a-Porta et al. (2012) failed to consider. In the absence of unequivocal evidence for hybridization and introgression, we reject the proposal to downgrade Bufo spinosus and Bufo verrucosissimus to the subspecies level.
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patterns of gene flow and source sink dynamics in high altitude populations of the common toad Bufo Bufo anura Bufonidae
Biological Journal of The Linnean Society, 2008Co-Authors: Inigo Martinezsolano, Elena G GonzalezAbstract:Understanding patterns of genetic structure is fundamental for developing successful management programmes for deme-structured organisms, such as amphibians. We used five microsatellite loci and DNA sequences of the mitochondrial control region to assess the relative influences of landscape (geographic distance, altitude and rivers as corridors for dispersal) and historical factors on patterns of gene flow in populations of the toad Bufo Bufo in Central Spain. We sampled 175 individuals from eight populations distributed along two major river drainages and used maximum-likelihood and Bayesian approaches to infer patterns of gene flow and population structure. The mitochondrial DNA data show closely-related haplotypes distributed across the Iberian Peninsula with no geographic structuring, suggesting recent differentiation of haplotypes and extensive gene flow between populations. On the other hand, microsatellites provide finer resolution, showing that high altitude populations (> 2000 m) exchange lower numbers of migrants with other populations. The results of Bayesian estimates for recent migration rates in high altitude populations suggest source-sink dynamics between ponds that are consistent with independent data from monitoring over the past 20 years. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95, 824–839.
Ivana Novak - One of the best experts on this subject based on the ideXlab platform.
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Ion transport mechanisms in the mesonephric collecting duct system of the toad Bufo Bufo: microelectrode recordings from isolated and perfused tubules
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2004Co-Authors: Nadja Møbjerg, Erik Larsen, Ivana NovakAbstract:It is not clear how and whether terrestrial amphibians handle NaCl transport in the distal nephron. Therefore, we studied ion transport in isolated perfused collecting tubules and ducts from toad, Bufo Bufo, by means of microelectrodes. No qualitative difference in basolateral cell membrane potential (Vbl) was observed between tubules and ducts in response to ion substitutions, inhibitor and agonist applications. Cl- substitution experiments indicated a small Cl- conductance in the basolateral membrane. The apical membrane did not have a significant Cl- conductance. Luminal [Na+] steps and amiloride application showed a small apical Na+ conductance. Arginine vasotocin depolarized Vbl. The small apical Na+ conductance indicates that the collecting duct system contributes little to NaCl reabsorption when compared to aquatic amphibians. In contrast, Vbl rapidly depolarized upon lowering of [Na+] in the bath, demonstrating the presence of a Na+-coupled anion transporter. [HCO3-] steps revealed that this transporter is not a Na+-HCO3- cotransporter. Together, our results indicate that a major task of the collecting duct system in B. Bufo is not conductive NaCl transport but rather K+ secretion, as shown by our previous studies. Moreover, our results indicate the presence of a novel basolateral Na+-coupled anion transporter, the identity of which remains to be elucidated.
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k transport in the mesonephric collecting duct system of the toad Bufo Bufo microelectrode recordings from isolated and perfused tubules
The Journal of Experimental Biology, 2002Co-Authors: Nadja Møbjerg, Erik Larsen, Ivana NovakAbstract:SUMMARY We studied the mechanisms of K+ transport in cells from isolated and perfused collecting tubules and ducts from the mesonephric kidney of the toad Bufo Bufo. Cells were impaled with microelectrodes across the basal cell membrane. The basolateral membrane potential (Vbl) depolarized upon change of bath [K+] from 3 to 20 mmol l-1 demonstrating a large K+ conductance in this membrane. In collecting tubules and collecting ducts a Vbl of -66±2 mV and -74±4 mV depolarized by 30±2 mV and 36±3 mV, respectively (N=23; 15). The K+ channel inhibitor Ba2+ (1 mmol l-1) inhibited the basolateral K+ conductance and depolarized a Vbl of -64±4 mV by 30±6 mV (N=8). Luminal K+ steps (3 to 20 mmol l-1) demonstrated a K+ conductance in the apical cell membrane. In collecting tubules and collecting ducts a Vbl of -70±3 mV and -73±3 mV depolarized by 11±3 mV and 16±3 mV, respectively (N=11; 11). This conductance could also be inhibited by Ba2+, which depolarized a Vbl of -71±5 mV by 9±3 mV (N=5). The pump inhibitor ouabain (1 mmol l-1) depolarized Vbl, but addition of furosemide to bath solution did not affect Vbl. The [K+] in urine varied from 1.3 to 22.8 mmol l-1. In conclusion, we propose that the collecting duct system of B. Bufo secretes K+ into the urine via luminal K+ channels.
Attila Hettyey - One of the best experts on this subject based on the ideXlab platform.
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Relationships Between Chemical Defenses of Common Toad (Bufo Bufo) Tadpoles and Bacterial Community Structure of their Natural Aquatic Habitat
Journal of Chemical Ecology, 2020Co-Authors: János Ujszegi, Balázs Vajna, Ágnes M. Móricz, Dániel Krüzselyi, Kristóf Korponai, Gergely Krett, Attila HettyeyAbstract:Many organisms synthesize secondary metabolites against natural enemies. However, to which environmental factors the production of these metabolites is adjusted to is poorly investigated in animals, especially so in vertebrates. Bufadienolides are steroidal compounds that are present in a wide range of plants and animals and, if present in large quantities, can provide protection against natural enemies, such as pathogens. In a correlative study involving 16 natural populations we investigated how variation in bufadienolide content of larval common toads ( Bufo Bufo ) is associated with the bacterial community structure of their aquatic environment. We also evaluated pond size, macrovegetation cover, and the abundance of predators, conspecifics and other larval amphibians. We measured toxin content of tadpoles using HPLC-MS and determined the number of bufadienolide compounds (NBC) and the total quantity of bufadienolides (TBQ). AICc-based model selection revealed strong relationships of NBC and TBQ with bacterial community structure of the aquatic habitat as well as with the presence of conspecific tadpoles. The observed relationships may have arisen due to adaptation to local bacterial communities, phenotypic plasticity, differential biotransformation of toxin compounds by different bacterial communities, or a combination of these processes. Bacterial groups that contribute to among-population variation in toxin content remain to be pinpointed, but our study suggesting that toxin production may be influenced by the bacterial community of the environment represents an important step towards understanding the ecological and evolutionary processes leading to microbiota-mediated variation in skin toxin profiles of aquatic vertebrates.
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Data for Chemical defence of toad tadpoles under risk by four predator species
2019Co-Authors: Bálint Üveges, Ágnes M. Móricz, Dániel Krüzselyi, Herbert Hoi, Veronika Bókony, Márk Szederkényi, Katharina Mahr, Attila HettyeyAbstract:Data file for "Chemical defence of toad tadpoles under risk by four predator species" (Ecology and Evolution, doi: 10.1002/ece3.5202). The data contains two worksheets, one dataset for the analysis of bufadienolide toxins of common toad (Bufo Bufo) and one dataset for the predation trials.
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age dependent changes in sensitivity to a pesticide in tadpoles of the common toad Bufo Bufo
Aquatic Toxicology, 2017Co-Authors: Zsanett Miko, János Ujszegi, Attila HettyeyAbstract:The worldwide en masse application of pesticides and the frequently reported malign effects on several non-target organisms underpin the importance of ecotoxicological research on these anthropogenic pollutants. Previous studies showed that sensitivity to herbicides can vary widely depending on additional stress factors, on the species and even on the population investigated. However, there is little information about how sensitivity changes during ontogeny, and how the duration of exposure is linked to the magnitude of malign effects, even though this knowledge would be important for the interpretation of toxicity test results and for formulating recommendations regarding the timing of pesticide application. We exposed tadpoles of the common toad (Bufo Bufo) to three concentrations (0, 2 and 4mg a.e./L) of a glyphosate-based herbicide during the 1st, 2nd, 3rd, 4th, or 5th period of larval development or during the entire experiment, and measured survival, time until metamorphosis and body mass at metamorphosis to estimate fitness-consequences. Younger tadpoles were more sensitive to the herbicide in all measured traits than older ones, and this age-dependence was especially pronounced at the high herbicide concentration. Furthermore, tadpoles exposed to the herbicide during the entire experiment developed slower than tadpoles exposed only early on, but we did not observe a similar effect either on body mass or survival. The observed age-dependence of sensitivity to herbicides draws attention to the fact that results of toxicity tests obtained for one age-class are not necessarily generalizable across ontogeny. Also, the age of test animals has to be considered when planning ecotoxicological studies and interpreting their results. Finally, taking into account the temporal breeding habits of local amphibians when planning pesticide application would be highly favourable: if tadpoles would not get exposed to the herbicide during their most sensitive early development, they would sustain less anthropogenic damage from our efforts of controlling weeds.
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allocation in reproduction is not tailored to the probable number of matings in common toad Bufo Bufo males
Behavioral Ecology and Sociobiology, 2012Co-Authors: Attila Hettyey, Balazs Vagi, Janos Torok, Herbert HoiAbstract:The theory of life history evolution assumes trade-offs between competing fitness traits such as reproduction, somatic growth, and maintenance. One prediction of this theory is that if large individuals have a higher reproductive success, small/young individuals should invest less in reproduction and allocate more resources in growth than large/old individuals. We tested this prediction using the common toad (Bufo Bufo), a species where mating success of males is positively related to their body size. We measured testes mass, soma mass, and sperm stock size in males of varying sizes that were either (1) re-hibernated at the start of the breeding season, (2) kept without females throughout the breeding season, or (3) repeatedly provided with gravid females. In the latter group, we also estimated fertilization success and readiness to re-mate. Contrary to our predictions, the relationship between testes mass and soma mass was isometric, sperm stock size relative to testes mass was unrelated to male size, fertilization success was not higher in matings with larger males, and smaller males were not less likely to engage in repeated matings than larger males. These results consistently suggest that smaller males did not invest less in reproduction to be able to allocate more in growth than larger males. Causes for this unexpected result may include relatively low year-to-year survival, unpredictable between-year variation in the strength of sexual selection and low return rates of lowered reproductive investment.
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changes in sperm stores ejaculate size fertilization success and sexual motivation over repeated matings in the common toad Bufo Bufo anura Bufonidae
Biological Journal of The Linnean Society, 2009Co-Authors: Attila Hettyey, Balazs Vagi, Gergely Hevizi, Janos TorokAbstract:Fertilization is of central importance in the determination of reproductive success for both males and females. In species where males have the chance to mate repeatedly within a short period of time, sperm stocks may become depleted and males may have to carefully economize on their sperm reserves. Also, intensive intrasexual competition for females and repeated matings may lead to exhaustion on the behavioural level. To determine whether the reproductive potential of males is limited and if such a limitation is due to behavioural exhaustion or sperm depletion, we experimentally investigated changes in sperm stores, sperm expenditure, fertilization success, and sexual motivation over three repeated matings in the common toad, Bufo Bufo, where the breeding season is short and sequential polygyny occurs. At the end of the breeding season, the number of sperm stored in the testes of males mated repeatedly was close to 50% lower than in testes of unmated males. Ejaculate size, which was estimated by applying a novel method allowing direct quantification, decreased by 88% from first to third matings. We also observed a drop in fertilization success from the first two to third matings by 65%, which was largest in males that had started the reproductive season in bad body condition. Some of these males also showed a decreased interest in females in the third mating round. Our results suggest that sperm depletion and loss of sexual motivation may together set a limit to the reproductive potential of common toad males. The present study draws attention to a limitation in reproductive potential, which may occur more often than currently anticipated and has the potential to strongly influence several aspects of reproductive behaviour. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 361–371. ADDITIONAL KEYWORDS: ejaculate collection – exhaustion – natural history – reproduction – sexual conflict – sperm depletion.
Nadja Møbjerg - One of the best experts on this subject based on the ideXlab platform.
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Ion transport mechanisms in the mesonephric collecting duct system of the toad Bufo Bufo: microelectrode recordings from isolated and perfused tubules
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2004Co-Authors: Nadja Møbjerg, Erik Larsen, Ivana NovakAbstract:It is not clear how and whether terrestrial amphibians handle NaCl transport in the distal nephron. Therefore, we studied ion transport in isolated perfused collecting tubules and ducts from toad, Bufo Bufo, by means of microelectrodes. No qualitative difference in basolateral cell membrane potential (Vbl) was observed between tubules and ducts in response to ion substitutions, inhibitor and agonist applications. Cl- substitution experiments indicated a small Cl- conductance in the basolateral membrane. The apical membrane did not have a significant Cl- conductance. Luminal [Na+] steps and amiloride application showed a small apical Na+ conductance. Arginine vasotocin depolarized Vbl. The small apical Na+ conductance indicates that the collecting duct system contributes little to NaCl reabsorption when compared to aquatic amphibians. In contrast, Vbl rapidly depolarized upon lowering of [Na+] in the bath, demonstrating the presence of a Na+-coupled anion transporter. [HCO3-] steps revealed that this transporter is not a Na+-HCO3- cotransporter. Together, our results indicate that a major task of the collecting duct system in B. Bufo is not conductive NaCl transport but rather K+ secretion, as shown by our previous studies. Moreover, our results indicate the presence of a novel basolateral Na+-coupled anion transporter, the identity of which remains to be elucidated.
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k transport in the mesonephric collecting duct system of the toad Bufo Bufo microelectrode recordings from isolated and perfused tubules
The Journal of Experimental Biology, 2002Co-Authors: Nadja Møbjerg, Erik Larsen, Ivana NovakAbstract:SUMMARY We studied the mechanisms of K+ transport in cells from isolated and perfused collecting tubules and ducts from the mesonephric kidney of the toad Bufo Bufo. Cells were impaled with microelectrodes across the basal cell membrane. The basolateral membrane potential (Vbl) depolarized upon change of bath [K+] from 3 to 20 mmol l-1 demonstrating a large K+ conductance in this membrane. In collecting tubules and collecting ducts a Vbl of -66±2 mV and -74±4 mV depolarized by 30±2 mV and 36±3 mV, respectively (N=23; 15). The K+ channel inhibitor Ba2+ (1 mmol l-1) inhibited the basolateral K+ conductance and depolarized a Vbl of -64±4 mV by 30±6 mV (N=8). Luminal K+ steps (3 to 20 mmol l-1) demonstrated a K+ conductance in the apical cell membrane. In collecting tubules and collecting ducts a Vbl of -70±3 mV and -73±3 mV depolarized by 11±3 mV and 16±3 mV, respectively (N=11; 11). This conductance could also be inhibited by Ba2+, which depolarized a Vbl of -71±5 mV by 9±3 mV (N=5). The pump inhibitor ouabain (1 mmol l-1) depolarized Vbl, but addition of furosemide to bath solution did not affect Vbl. The [K+] in urine varied from 1.3 to 22.8 mmol l-1. In conclusion, we propose that the collecting duct system of B. Bufo secretes K+ into the urine via luminal K+ channels.
Ren-wang Jiang - One of the best experts on this subject based on the ideXlab platform.
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Bufospirostenin a and Bufogargarizin c steroids with rearranged skeletons from the toad Bufo Bufo gargarizans
Journal of Natural Products, 2017Co-Authors: Hai-yan Tian, Lei Wang, Xiao-qi Zhang, Lijun Ruan, Qingfei Zheng, Nanhao Chen, Ren-wang JiangAbstract:Bufospirostenin A (1) and Bufogargarizin C (2), two novel steroids with rearranged A/B rings, were isolated from the toad Bufo Bufo gargarizans. Compound 1 represents the first spirostanol found in animals. Compound 2 is an unusual bufadienolide with a cycloheptatriene B ring. Their structures were elucidated by spectroscopic analysis, single crystal X-ray diffraction analysis, and computational calculations.
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structures and inhibitory activity against breast cancer cells of new bufadienolides from the eggs of toad Bufo Bufo gargarizans
RSC Advances, 2016Co-Authors: Pengwei Zhang, Hai-yan Tian, Dong-mei Zhang, Lei Wang, Qiulin Nie, Shiwen Zhou, Ren-wang JiangAbstract:Two new 19-norbufadienolides (1 and 2), one new 14,15-epoxy bufadienolide (3), and eight rare bufadienolide–fatty acid conjugates (4–11), together with four known ones (12–15) were isolated from the eggs of toad Bufo Bufo gargarizans. Their chemical structures were elucidated by extensive spectroscopic methods in combination with X-ray diffraction analyses. Furthermore, we tested the inhibitory effect of these compounds against breast cancer cell lines MCF-7 and MDA-MB-231. Most of them showed strong cytotoxicity with IC50 values less than 0.1 μM. The further mechanistic study showed that they could induce apoptosis and cycle arrest in the G2/M phase in MCF-7 cells.
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C23 Steroids from the Venom of Bufo Bufo gargarizans
2016Co-Authors: Hai-yan Tian, Jun-shan Liu, Dong-mei Zhang, Lei Wang, Shi-lin Luo, Ying Wang, Xiao-qi Zhang, Ren-wang JiangAbstract:Five new C23 steroids (1–5) together with five known bufadienolides (6–10) were isolated from the venom of Bufo Bufo gargarizans (ChanSu in Chinese). The structures of the new steroids were elucidated by extensive spectroscopic methods in combination with X-ray diffraction analysis. Among these C23 steroids, only compound 3 showed cytotoxicities against HepG2 and A549 cancer cells, with respective IC50 values of 26.8 ± 8.3 and 45.6 ± 2.5 μM. In contrast, the bufadienolides (7–10) displayed potent inhibitory activities against these cancer cells, with respective IC50 values in the ranges 0.5–5.5 and 0.6–6.5 μM, but relatively less cytotoxicity on normal mouse spleen cells. In addition, the Na+/K+-ATPase inhibitory activities of 2, 5, and 7 revealed that the lactone moiety of a bufadienolide was important for the inhibitory activity
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Bufadienolides with cytotoxic activity from the skins of Bufo Bufo gargarizans.
Fitoterapia, 2015Co-Authors: Hai-yan Tian, Yu-he Lei, Dong-mei Zhang, Lei Wang, Ren-wang JiangAbstract:Abstract Twelve new bufadienolides (1–12), along with fourteen known analogues (13–26) were isolated from the skins of Bufo Bufo gargarizans Cantor. Their chemical structures were elucidated on the basis of NMR, HRESIMS and X-ray diffraction analysis. Compound 1 was an unusual bufadienolide with 3,19-epoxy moiety and A/B trans ring junction. Compounds 2–4 were rare bufadienolides possessing 10-H or 10-carboxyl units. All the isolated compounds were tested for their cytotoxic effects on HepG2, A549 and HeLa cells. Six new compounds (2, 3, 5, 6, 10 and 12) displayed significant anti-proliferative activities with IC50 values ranging from 0.049 to 1.856 μM. Arenobufagin (24) exhibited the most potent cytotoxic activity with IC50 value 0.011 μM. In addition, the present data provided more insight into the structure–activity relationships of bufadienolides.
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new cytotoxic c 3 dehydrated bufadienolides from the venom of Bufo Bufo gargarizans
Chinese Chemical Letters, 2014Co-Authors: Hai-yan Tian, Jun-shan Liu, Ren-wang Jiang, Dong-mei Zhang, Xiao-qi Zhang, Pengwei Zhang, Wencai YeAbstract:Abstract Three new C-3 dehydrated bufadienolides were isolated from the venom of Bufo Bufo gargarizans . Their structures were elucidated as 5 β ,12 β -12,14-dihydroxy-11-oxobufa-3,20,22-trienolide ( 1 ), 5 β ,12 β -12,14-dihydroxy-11-oxobufa-2,20,22-trienolide ( 2 ), and 5 β ,12 α -12,14-dihydroxy-11-oxobufa-2,20,22-trienolide ( 3 ) on the basis of extensive spectroscopic analysis, especially 1D NMR and 2D NMR data. In addition, all three compounds were tested for their cytotoxic activities against A549 and HepG2 cancer cell lines. Compounds 2 and 3 showed significant cytotoxicities with IC 50 values less than 10 μmol/L on both cancer cells.
