A genetic study was carried out on spadefoot toads (Pelobates syriacus) from habitats of various locations and altitudes in northern Israel. Cytochrome b and 12S were amplified by PCR for the analysis of genetic varia...A genetic study was carried out on spadefoot toads (Pelobates syriacus) from habitats of various locations and altitudes in northern Israel. Cytochrome b and 12S were amplified by PCR for the analysis of genetic variation based on five DNA polymorphisms and for RAPD PCR. The nucleotide sequences of the mitochondrial DNA fragments were determined from a 460 bp clone of cytochrome b and a 380 bp clone of 12S (GenBank accession numbers, FJ595199-FJ59-5203). No genetic variation was found among the populations with regard to 12S. According to the analysis of five sequences using Arlequin software, there was a high gene identity among the populations (98.7%-99.6%). Both populations, Elrom Pond breeding site, at the highest altitude and Fara Pond, at the lowest, had the lowest identities as compared to other populations. The DNA variation among P. syri-acus populations from various breeding sites, according to band sharing (BS), when using the OP-4 primer, was 0.92-1.00. Similarity was low between the population of Elrom Pond and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS), as well as between the population of Fara Pond at the lowest altitude, and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS). Similar results were obtained when comparing the results obtained using primer OPA-3. The lowest similarity was found between populations of the highest altitude (Elrom Pond) and lowest altitude (Fara Pond), relative to the other ponds (Kash Pond, Raihania Pond and Sasa Pond) with a BS of 0.93.展开更多
Toads and lizards have been a part of our ecosystems for millions of years and they are good indicators of environmental health. Toads and lizards can be infected by different types of parasites; blood parasites are o...Toads and lizards have been a part of our ecosystems for millions of years and they are good indicators of environmental health. Toads and lizards can be infected by different types of parasites; blood parasites are one of the most important parasites. The present study was conducted to survey and identify different blood parasites in Mabuya sp. lizard and Buforegularis toad in two locations in Khartoum state. Fifteen samples of Mabuya sp and fifteen samples of Buforegularis were collected. All Toads and lizards were dissected and tissue from spleen and liver were examined. The microscopic diagnosis detected Sauroleishmania and Haemogregarina spp parasites in both Mabuya and B. regularis while Microfilariae spp was detected in Mabuya sp. Trypanosoma spp was detected in only one specimen of B. regularis. The results also indicated Sauroleishmania parasites and Haemogregarina spp parasites in the sampled toads and lizards in the two locations. The study of blood parasites and their effects in diversity and health of toads and lizards is necessary to determine the impacts of infections in these animals and the use of the results as indicator of hemoparasites in the environmental as well as the food chain.展开更多
Roadkill has become a pivotal issue in the global decline of amphibian populations.Conventional research methods have typically relied on the examination of dried carcasses found long after wildlife-vehicle collisions...Roadkill has become a pivotal issue in the global decline of amphibian populations.Conventional research methods have typically relied on the examination of dried carcasses found long after wildlife-vehicle collisions, which influnce the accuracy of the taxonomic classification and assessment of roadkill rates. To overcome these limitations, we conducted a nocturnal survey on National Road G108in the Qinling Mountains immediately following a night rainstorm in July 2016. We employed molecular techniques to distinguish species that are morphologically identical but share overlapping habitats. Our investigation revealed that within five hours, 92 amphibians from five different species were documented across three 2-km road transects. Among these, 31 individuals were identified as roadkill,resulting in an overall rate of 33%, or roughly five fatalities per kilometer. Significantly, the mountain stream frogs Nanorana quadranus and N. taihangnica comprised 40.2% and 30.4% of the total individuals observed, with mortality rates of 35.1% and 25.0%,respectively. We found no significant variation in mortality rates between different age groups or genders for either species. Our research suggests that conducting surveys at night, immediately following summer rainstorms, is an efficient strategy for evaluating the impacts of roadkill. The post-rain foraging behaviors and the dispersal of juveniles are key factors contributing to road crossings outside of the breeding season. Consequently, this study recommends that traffic authorities in mountainous areas take measures to reduce vehicle traffic following summer rainstorms in order to minimize the threat to amphibian lives.展开更多
Wetlands are unique ecological environments capable of harboring high biodiversity.However,urbanization can degrade,eliminate,or transformthese habitats.Although amphibians utilize habitats created by humans in urban ...Wetlands are unique ecological environments capable of harboring high biodiversity.However,urbanization can degrade,eliminate,or transformthese habitats.Although amphibians utilize habitats created by humans in urban landscapes,few studies have investigated the infuence of thehabitat quality on the life history of anurans.We assessed life history traits such as snout-vent length(SVL),body condition,and reproductiveinvestment in the South American common toad Rhinella arenarum,to determine whether urbanization is harmful or benefcial to this species.We sampled wetlands with different levels of urbanization in Río Cuarto city,Córdoba,Argentina.We recorded males with lower SVL in mediumurbanized wetlands and those with the highest SVL in both low and high urbanization categories,similar to what was found for body conditionswith males with low body conditions inhabiting wetlands with a medium degree of urbanization.In females,lower SVL was recorded in mediumurbanization and highest SVL in high and low urbanization.It is observed that females recorded in highly urbanized wetlands have a very lowbody condition.The reproductive investment parameters were not signifcantly different,but we observed an association between a greaternumber of eggs and clutch size with wetlands of low urbanization.These results show a variability of responses of R.arenarum to urbanization,which could be due to phenotypic plasticity in its life history parameters,allowing it to inhabit urban areas.Continuous monitoring of the speciesin these wetlands is needed to determine if these biological responses are temporary or persistent.展开更多
THE nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus para-bigeminalis, are all visual centres. They receive their tectal input ipsilaterally and project backipsilaterally in teleosts an...THE nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus para-bigeminalis, are all visual centres. They receive their tectal input ipsilaterally and project backipsilaterally in teleosts and birds, or bilaterally in amphibians and reptiles, as well as in mam-mals. It is well known that NI receives its visual excitation through the ipsilateral optic tec-tum (OT). NI mainly exerts inhibition on the ipsilateral OT in frogs.A recent study展开更多
It has been established that the nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus parabigeminalis, receive input from the ipsilateral tectum and project back ipsilaterally in teleosts a...It has been established that the nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus parabigeminalis, receive input from the ipsilateral tectum and project back ipsilaterally in teleosts and birds, or bilaterally in amphibians, reptiles and mammals.The nucleus receives visual excitation from the ipsilateral tectum. while it mainly exerts inhibition on cells recorded from the ipsilateral tectum. A recent study by Wang and coworkers shows that the nucleus isthmi pars magnoceUularis (Imc) and展开更多
Hibernation is one of the fundamental strategies in response to cold environmental temperatures.During hibernation,the endocrine and circadian systems ensure minimal expenditure of energy for survival.The circadian rh...Hibernation is one of the fundamental strategies in response to cold environmental temperatures.During hibernation,the endocrine and circadian systems ensure minimal expenditure of energy for survival.The circadian rhythms of key hormones,melatonin(MT),corticosterone(CORT),triiodothyronine(T3),and thyroxine(T4),and the underlying molecular regulatory mechanisms of hibernation have been well determined in mammals but not in ectotherms.Here,a terrestrial hibernating species,Asiatic toad(Bufo gargarizans),was employed to investigate the plasma CORT,MT,T3,and T4;and the retina,brain,and liver mRNA expression of the core clock genes,including circadian locomotor output cycles kaput(Clock),brain and muscle ARNT-like 1(Bmal1),cryptochrome(Cry)1 and 2,and period(Per)1 and 2,at 7-time points over a 24-h period under acute cold(1 day at 4℃),and hibernation(45 days at 4℃).Our results showed that the circadian rhythms of the core clock genes were rather unaffected by acute cold exposure in the retina,unlike the brain and liver.In contrast,during hibernation,the liver clock genes displayed significant circadian oscillations,while those in the retina and brain stopped ticking.Furthermore,plasma CORT expressed circadian oscillations in both groups,and T3 in acute cold exposure group,whereas T4 and MT did not.Our results reveal that the plasma CORT and the liver sustain rhythmicity when the brain was not,indicating that the liver clock along with the adrenal clock synergistically maintains the metabolic requirements to ensure basic survival in hibernating Asiatic toads.展开更多
The distribution of exposure to Hg in amphibians remains unknown on most continents.The Ussuri broadleaf and mixed forests ecoregion is a region of high biodiversity, the nine species of amphibia living on its territo...The distribution of exposure to Hg in amphibians remains unknown on most continents.The Ussuri broadleaf and mixed forests ecoregion is a region of high biodiversity, the nine species of amphibia living on its territory are prey for over 25 threatened and rare vertebrate species. To understand the potential risks to wildlife, we measured the total mercury(THg) content in the Siberian wood frog(Rana amurensis) and the Sakhalin toad(Bufo sachalinensis) from the same locality. In total THg level was measured in 134 samples of liver, kidneys,and muscles via atomic absorption. Mean THg concentrations mg/kg dry weight(DW) were 0.055± 0.018 in muscles, 0.126 ± 0.040 in kidneys, and 0.140 ± 0.062 in liver in the immature Siberian wood frogs. In the adults of Siberian wood frogs, the mean THg concentrations were 0.035 ± 0.005 in muscles,0.081 ± 0.006 in kidneys and 0.030 ± 0.005 in liver.Statistically significant differences in THg content between the two age groups were obtained only for the liver(p = 0.008). The mean THg of the Sakhalin toad was 0.058 ± 0.007 in muscles, 0.085 ± 0.009 in kidneys, and 0.137 ± 0.019 in liver. THg content in immature Siberian wood frogs and Sakhalin toads showed no statistically significant differences. THg correlations between tissues and organs were found.The THg content in amphibians was found to be comparable with the THg content of producers in terrestrial ecosystems and lower compared to species from other classes of terrestrial vertebrates. There is an assumption that other species of tailless amphibians of the genera Rana and Bufo may contain similar levels of total mercury in anthropogenically unpolluted or slightly polluted boreal landscapes of the Russia. For those boreal ecosystems that are already subject to pollution, our results may be used to justify specific actions when restoring ecosystem services, structures, and functions efficiently and effectively.展开更多
In this work, we described a new species of the Asian horned toad, Boulenophrys gaolanensis sp. nov., based on the type series collected from Gaolan Island, Jinwan District, Zhuhai City, Guangdong Province, China. Thi...In this work, we described a new species of the Asian horned toad, Boulenophrys gaolanensis sp. nov., based on the type series collected from Gaolan Island, Jinwan District, Zhuhai City, Guangdong Province, China. This new species is distinguished from all other congeners by a combination of morphological characters and the notable phylogenetic divergence. This discovery of new species in the understudied southwestern Pearl River Delta brings the total number of recognized Boulenophrys species to 68, with 63 found in China,and also highlights the need for further herpetological research and conservation on the understudied and ecologically vulnerable islands.展开更多
Bufadienolides,naturally occurring steroids primarily found in toads,have garnered attention for their pharmacological properties and ecological significance.In this study,we isolated and identified 21 bufadienolides ...Bufadienolides,naturally occurring steroids primarily found in toads,have garnered attention for their pharmacological properties and ecological significance.In this study,we isolated and identified 21 bufadienolides from the gallbladders of Bufo gargarizans,comprising four new compounds and 17 known ones.Notably,the predominance of 15 bufadienolides with a 3α-OH configuration in toad bile differs significantly from the 3β-OH bufadienolides found in venom secreted by toad glands.Moreover,our investigation into the biotransformation of 3β-OH and 3α-OH bufadienolides in the liver and kidney tissues of toads revealed an irreversible conversion from 3β-OH to 3α-OH bufadienolides,suggesting a crucial role in toad self-detoxification.These findings provide valuable insights into the structural diversity of bufadienolides and advance our understanding of their medical and ecological significance.展开更多
A microelectrode array（MEA） is presented, which is composed of 60 independent electrodes with 59 working ones and one reference one, and they are divided into 30 pairs. Except for the reference electrode, each pair ...A microelectrode array（MEA） is presented, which is composed of 60 independent electrodes with 59 working ones and one reference one, and they are divided into 30 pairs. Except for the reference electrode, each pair consists of one stimulating electrode and one recording electrode. Supported by the peripheral circuits, four electrode states to study the bioelectrical signal of biological tissue or slice cultured in-vitro on the surface of the electrodes can be realized through each pair of electrodes. The four electrode states are stimulation, recording, stimulation and recording simultaneously, and isolation. The state of each pair of working electrodes can be arbitrarily controlled according to actual needs. The MEAs are fabricated in printed circuit board （PCB） technology. The total area of the PCB-based MEA is 49 mm × 49 mm. The impedance measurement of MEA is carried out in 0.9% sodium chloride solution at room temperature by means of 2-point measurements with an Agilent LCR meter, and the test signal for the impedance measurement is sinusoidal （AC voltage 50 mV, sweeping frequency 20 Hz to 10 kHz）. The electrode impedance is between 200 and 3 kΩ while the frequency is between 500 and 1 000 Hz. The electrode impedance magnitude is inversely proportional to the frequency. Experiments of toad sciatic nerve in-vitro stimulation and recording and signal regeneration between isolated toad sciatic nerves are carried out on the PCB-based MEA. The results show that the MEA can be used for bioelectrical signal stimulation, recording, stimulation and recording simultaneously, and isolation of biological tissues or slices in-vitro.展开更多
Predators induce plastic responses in multiple prey taxa, ranging from morphological to behavioral or physiological changes. In amphibians, tadpoles activate plastic responses to reduce predation risk by reducing thei...Predators induce plastic responses in multiple prey taxa, ranging from morphological to behavioral or physiological changes. In amphibians, tadpoles activate plastic responses to reduce predation risk by reducing their activity rate and altering their morphology, specifically tail depth and pigmentation. Furthermore, there is now evidence that tadpoles＇ defenses are modi- fied when predators combine with other stressful factors such as pollutants or competitors, but our knowledge on the physiologi- cal responses underlying these responses is still scarce. Here we study physiological responses in Pelobates cultripes tadpoles exposed to a natural predator （larvae of the aquatic beetle Dytiscus circumflexus）, non-lethal concentrations of herbicide （gly- phosate, 0.5 mg/L and 1.0 mg/L） or both factors combined. We measured corticosterone levels, standard metabolic rate, oxidative damage （TBARS） and activity of antioxidant enzymes, and immune response （via leukocyte count）. Tadpoles reduced their corti- costerone concentration by ca. 24% in the presence of predator cues, whereas corticosterone did not change in the presence of glyphosate. Two enzymes involved in antioxidant response also decreased in the presence of predators （14.7% and 13.2% respec- tively） but not to glyphosate. Herbicide, however, increased the number of neutrophils and reduced that of lymphocytes, and had an interaction effect with predator presence. Standard metabolic rate did not vary across treatments in our experiment. Thus we show a marked physiological response to the presence of predators but little evidence for interaction between predators and low levels of herbicide. Multiple assessment of the physiological state of animals is important to understand the basis and conse- quences ofphenotypic plasticity展开更多
Three new C-3 dehydrated bufadienolides were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated as 5β,12β-12,14-dihydroxy-11-oxobufa-3,20,22-trienolide （1）, 5β,12β- 12,14-dihydrox...Three new C-3 dehydrated bufadienolides were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated as 5β,12β-12,14-dihydroxy-11-oxobufa-3,20,22-trienolide （1）, 5β,12β- 12,14-dihydroxy-11 -oxobufa-2,20,22-trienolide （2）, and 5β,12β-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 IC50 values less than 10 μmol/L on both cancer cells.展开更多
We studied the effects of nasal thermosensible gels containing Chinese medicine Xingbi on Bufo gargarizans maxillary mucosal cilia movement and the ciliotoxicity in rats nasal mucosa. The saline water was used as a bl...We studied the effects of nasal thermosensible gels containing Chinese medicine Xingbi on Bufo gargarizans maxillary mucosal cilia movement and the ciliotoxicity in rats nasal mucosa. The saline water was used as a blank control, and 1% hydrochloric acid of methamphetamine Massachusetts was used as the negative control. Compared with normal saline control, the relative percentage of the lasting time of ciliary movement treated with Chinese medicine Xingbi was 94.1%. There was no remarkable pathological change in the tissue slice of nasal mucosa, and no stimulation on nasal mucous membrane was observed. So these data suggest that nasal thermosensible gel of Chinese medicine Xingbi is of high safety. It has no damage to the mucosa of toads and rats and can be used for intranasal administration.展开更多
文摘A genetic study was carried out on spadefoot toads (Pelobates syriacus) from habitats of various locations and altitudes in northern Israel. Cytochrome b and 12S were amplified by PCR for the analysis of genetic variation based on five DNA polymorphisms and for RAPD PCR. The nucleotide sequences of the mitochondrial DNA fragments were determined from a 460 bp clone of cytochrome b and a 380 bp clone of 12S (GenBank accession numbers, FJ595199-FJ59-5203). No genetic variation was found among the populations with regard to 12S. According to the analysis of five sequences using Arlequin software, there was a high gene identity among the populations (98.7%-99.6%). Both populations, Elrom Pond breeding site, at the highest altitude and Fara Pond, at the lowest, had the lowest identities as compared to other populations. The DNA variation among P. syri-acus populations from various breeding sites, according to band sharing (BS), when using the OP-4 primer, was 0.92-1.00. Similarity was low between the population of Elrom Pond and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS), as well as between the population of Fara Pond at the lowest altitude, and the populations of Kash Pond, Raihania Pond and Sasa Pond (0.92 BS). Similar results were obtained when comparing the results obtained using primer OPA-3. The lowest similarity was found between populations of the highest altitude (Elrom Pond) and lowest altitude (Fara Pond), relative to the other ponds (Kash Pond, Raihania Pond and Sasa Pond) with a BS of 0.93.
文摘Toads and lizards have been a part of our ecosystems for millions of years and they are good indicators of environmental health. Toads and lizards can be infected by different types of parasites; blood parasites are one of the most important parasites. The present study was conducted to survey and identify different blood parasites in Mabuya sp. lizard and Buforegularis toad in two locations in Khartoum state. Fifteen samples of Mabuya sp and fifteen samples of Buforegularis were collected. All Toads and lizards were dissected and tissue from spleen and liver were examined. The microscopic diagnosis detected Sauroleishmania and Haemogregarina spp parasites in both Mabuya and B. regularis while Microfilariae spp was detected in Mabuya sp. Trypanosoma spp was detected in only one specimen of B. regularis. The results also indicated Sauroleishmania parasites and Haemogregarina spp parasites in the sampled toads and lizards in the two locations. The study of blood parasites and their effects in diversity and health of toads and lizards is necessary to determine the impacts of infections in these animals and the use of the results as indicator of hemoparasites in the environmental as well as the food chain.
基金supported by the National Natural Science Foundation of China (32170435)。
文摘Roadkill has become a pivotal issue in the global decline of amphibian populations.Conventional research methods have typically relied on the examination of dried carcasses found long after wildlife-vehicle collisions, which influnce the accuracy of the taxonomic classification and assessment of roadkill rates. To overcome these limitations, we conducted a nocturnal survey on National Road G108in the Qinling Mountains immediately following a night rainstorm in July 2016. We employed molecular techniques to distinguish species that are morphologically identical but share overlapping habitats. Our investigation revealed that within five hours, 92 amphibians from five different species were documented across three 2-km road transects. Among these, 31 individuals were identified as roadkill,resulting in an overall rate of 33%, or roughly five fatalities per kilometer. Significantly, the mountain stream frogs Nanorana quadranus and N. taihangnica comprised 40.2% and 30.4% of the total individuals observed, with mortality rates of 35.1% and 25.0%,respectively. We found no significant variation in mortality rates between different age groups or genders for either species. Our research suggests that conducting surveys at night, immediately following summer rainstorms, is an efficient strategy for evaluating the impacts of roadkill. The post-rain foraging behaviors and the dispersal of juveniles are key factors contributing to road crossings outside of the breeding season. Consequently, this study recommends that traffic authorities in mountainous areas take measures to reduce vehicle traffic following summer rainstorms in order to minimize the threat to amphibian lives.
基金Financial support was provided by Secretaría de Cienciay Técnica-Universidad Nacional de Río Cuarto(SECyTUNRC,Grant PPI 18/C416)Fondo para la Investigación Científca y Tecnológica(FONCyT,Grant PICT BIDPICT 0981-20182530-2019).
文摘Wetlands are unique ecological environments capable of harboring high biodiversity.However,urbanization can degrade,eliminate,or transformthese habitats.Although amphibians utilize habitats created by humans in urban landscapes,few studies have investigated the infuence of thehabitat quality on the life history of anurans.We assessed life history traits such as snout-vent length(SVL),body condition,and reproductiveinvestment in the South American common toad Rhinella arenarum,to determine whether urbanization is harmful or benefcial to this species.We sampled wetlands with different levels of urbanization in Río Cuarto city,Córdoba,Argentina.We recorded males with lower SVL in mediumurbanized wetlands and those with the highest SVL in both low and high urbanization categories,similar to what was found for body conditionswith males with low body conditions inhabiting wetlands with a medium degree of urbanization.In females,lower SVL was recorded in mediumurbanization and highest SVL in high and low urbanization.It is observed that females recorded in highly urbanized wetlands have a very lowbody condition.The reproductive investment parameters were not signifcantly different,but we observed an association between a greaternumber of eggs and clutch size with wetlands of low urbanization.These results show a variability of responses of R.arenarum to urbanization,which could be due to phenotypic plasticity in its life history parameters,allowing it to inhabit urban areas.Continuous monitoring of the speciesin these wetlands is needed to determine if these biological responses are temporary or persistent.
文摘THE nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus para-bigeminalis, are all visual centres. They receive their tectal input ipsilaterally and project backipsilaterally in teleosts and birds, or bilaterally in amphibians and reptiles, as well as in mam-mals. It is well known that NI receives its visual excitation through the ipsilateral optic tec-tum (OT). NI mainly exerts inhibition on the ipsilateral OT in frogs.A recent study
基金Project supported by the National Natural Science Foundation of China
文摘It has been established that the nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus parabigeminalis, receive input from the ipsilateral tectum and project back ipsilaterally in teleosts and birds, or bilaterally in amphibians, reptiles and mammals.The nucleus receives visual excitation from the ipsilateral tectum. while it mainly exerts inhibition on cells recorded from the ipsilateral tectum. A recent study by Wang and coworkers shows that the nucleus isthmi pars magnoceUularis (Imc) and
基金This work was supported by the National Natural Science Foundation of China(NSFC,31270457,30800129 to Z.X.),NSFC(31971413)the Natural Science Foundation of Hebei Province(NSFHB,C2020205038 to D.L).
文摘Hibernation is one of the fundamental strategies in response to cold environmental temperatures.During hibernation,the endocrine and circadian systems ensure minimal expenditure of energy for survival.The circadian rhythms of key hormones,melatonin(MT),corticosterone(CORT),triiodothyronine(T3),and thyroxine(T4),and the underlying molecular regulatory mechanisms of hibernation have been well determined in mammals but not in ectotherms.Here,a terrestrial hibernating species,Asiatic toad(Bufo gargarizans),was employed to investigate the plasma CORT,MT,T3,and T4;and the retina,brain,and liver mRNA expression of the core clock genes,including circadian locomotor output cycles kaput(Clock),brain and muscle ARNT-like 1(Bmal1),cryptochrome(Cry)1 and 2,and period(Per)1 and 2,at 7-time points over a 24-h period under acute cold(1 day at 4℃),and hibernation(45 days at 4℃).Our results showed that the circadian rhythms of the core clock genes were rather unaffected by acute cold exposure in the retina,unlike the brain and liver.In contrast,during hibernation,the liver clock genes displayed significant circadian oscillations,while those in the retina and brain stopped ticking.Furthermore,plasma CORT expressed circadian oscillations in both groups,and T3 in acute cold exposure group,whereas T4 and MT did not.Our results reveal that the plasma CORT and the liver sustain rhythmicity when the brain was not,indicating that the liver clock along with the adrenal clock synergistically maintains the metabolic requirements to ensure basic survival in hibernating Asiatic toads.
基金partially carried out within the state assignment of Ministry of Science and Higher Education of the Russian Federation (124012200182-1)。
文摘The distribution of exposure to Hg in amphibians remains unknown on most continents.The Ussuri broadleaf and mixed forests ecoregion is a region of high biodiversity, the nine species of amphibia living on its territory are prey for over 25 threatened and rare vertebrate species. To understand the potential risks to wildlife, we measured the total mercury(THg) content in the Siberian wood frog(Rana amurensis) and the Sakhalin toad(Bufo sachalinensis) from the same locality. In total THg level was measured in 134 samples of liver, kidneys,and muscles via atomic absorption. Mean THg concentrations mg/kg dry weight(DW) were 0.055± 0.018 in muscles, 0.126 ± 0.040 in kidneys, and 0.140 ± 0.062 in liver in the immature Siberian wood frogs. In the adults of Siberian wood frogs, the mean THg concentrations were 0.035 ± 0.005 in muscles,0.081 ± 0.006 in kidneys and 0.030 ± 0.005 in liver.Statistically significant differences in THg content between the two age groups were obtained only for the liver(p = 0.008). The mean THg of the Sakhalin toad was 0.058 ± 0.007 in muscles, 0.085 ± 0.009 in kidneys, and 0.137 ± 0.019 in liver. THg content in immature Siberian wood frogs and Sakhalin toads showed no statistically significant differences. THg correlations between tissues and organs were found.The THg content in amphibians was found to be comparable with the THg content of producers in terrestrial ecosystems and lower compared to species from other classes of terrestrial vertebrates. There is an assumption that other species of tailless amphibians of the genera Rana and Bufo may contain similar levels of total mercury in anthropogenically unpolluted or slightly polluted boreal landscapes of the Russia. For those boreal ecosystems that are already subject to pollution, our results may be used to justify specific actions when restoring ecosystem services, structures, and functions efficiently and effectively.
基金supported by DFGP Project of Fauna of Guangdong-202115Research and Monitoring Service Project of Hengqin National Wetland Park, Urban Planning and Construction Bureau of Guangdong-Macao In-Depth Cooperation Zone in Hengqin。
文摘In this work, we described a new species of the Asian horned toad, Boulenophrys gaolanensis sp. nov., based on the type series collected from Gaolan Island, Jinwan District, Zhuhai City, Guangdong Province, China. This new species is distinguished from all other congeners by a combination of morphological characters and the notable phylogenetic divergence. This discovery of new species in the understudied southwestern Pearl River Delta brings the total number of recognized Boulenophrys species to 68, with 63 found in China,and also highlights the need for further herpetological research and conservation on the understudied and ecologically vulnerable islands.
基金supported by Guangxi Natural Science Foundation Program(Grant Number 2021GXNSFBA220068)National Natural Science Foundation of China(Grant Number 81872760 and 82204975)+1 种基金Natural Science Foundation of Guangdong province(Grant Number 2021A1515011251)Guangdong scientific scheme(Grant Number 2021A0505030032).
文摘Bufadienolides,naturally occurring steroids primarily found in toads,have garnered attention for their pharmacological properties and ecological significance.In this study,we isolated and identified 21 bufadienolides from the gallbladders of Bufo gargarizans,comprising four new compounds and 17 known ones.Notably,the predominance of 15 bufadienolides with a 3α-OH configuration in toad bile differs significantly from the 3β-OH bufadienolides found in venom secreted by toad glands.Moreover,our investigation into the biotransformation of 3β-OH and 3α-OH bufadienolides in the liver and kidney tissues of toads revealed an irreversible conversion from 3β-OH to 3α-OH bufadienolides,suggesting a crucial role in toad self-detoxification.These findings provide valuable insights into the structural diversity of bufadienolides and advance our understanding of their medical and ecological significance.
基金The National Natural Science Foundation of China(No. 61076118, 90307013, 90707005)the Natural Science Foundation of Jiangsu Province (No. BK2008032)Special Foundation and Open Foundation of the State Key Laboratory of Bioelectronics of Southeast University
文摘A microelectrode array（MEA） is presented, which is composed of 60 independent electrodes with 59 working ones and one reference one, and they are divided into 30 pairs. Except for the reference electrode, each pair consists of one stimulating electrode and one recording electrode. Supported by the peripheral circuits, four electrode states to study the bioelectrical signal of biological tissue or slice cultured in-vitro on the surface of the electrodes can be realized through each pair of electrodes. The four electrode states are stimulation, recording, stimulation and recording simultaneously, and isolation. The state of each pair of working electrodes can be arbitrarily controlled according to actual needs. The MEAs are fabricated in printed circuit board （PCB） technology. The total area of the PCB-based MEA is 49 mm × 49 mm. The impedance measurement of MEA is carried out in 0.9% sodium chloride solution at room temperature by means of 2-point measurements with an Agilent LCR meter, and the test signal for the impedance measurement is sinusoidal （AC voltage 50 mV, sweeping frequency 20 Hz to 10 kHz）. The electrode impedance is between 200 and 3 kΩ while the frequency is between 500 and 1 000 Hz. The electrode impedance magnitude is inversely proportional to the frequency. Experiments of toad sciatic nerve in-vitro stimulation and recording and signal regeneration between isolated toad sciatic nerves are carried out on the PCB-based MEA. The results show that the MEA can be used for bioelectrical signal stimulation, recording, stimulation and recording simultaneously, and isolation of biological tissues or slices in-vitro.
文摘Predators induce plastic responses in multiple prey taxa, ranging from morphological to behavioral or physiological changes. In amphibians, tadpoles activate plastic responses to reduce predation risk by reducing their activity rate and altering their morphology, specifically tail depth and pigmentation. Furthermore, there is now evidence that tadpoles＇ defenses are modi- fied when predators combine with other stressful factors such as pollutants or competitors, but our knowledge on the physiologi- cal responses underlying these responses is still scarce. Here we study physiological responses in Pelobates cultripes tadpoles exposed to a natural predator （larvae of the aquatic beetle Dytiscus circumflexus）, non-lethal concentrations of herbicide （gly- phosate, 0.5 mg/L and 1.0 mg/L） or both factors combined. We measured corticosterone levels, standard metabolic rate, oxidative damage （TBARS） and activity of antioxidant enzymes, and immune response （via leukocyte count）. Tadpoles reduced their corti- costerone concentration by ca. 24% in the presence of predator cues, whereas corticosterone did not change in the presence of glyphosate. Two enzymes involved in antioxidant response also decreased in the presence of predators （14.7% and 13.2% respec- tively） but not to glyphosate. Herbicide, however, increased the number of neutrophils and reduced that of lymphocytes, and had an interaction effect with predator presence. Standard metabolic rate did not vary across treatments in our experiment. Thus we show a marked physiological response to the presence of predators but little evidence for interaction between predators and low levels of herbicide. Multiple assessment of the physiological state of animals is important to understand the basis and conse- quences ofphenotypic plasticity
基金supported by National Natural Science Foundation of China(No.81102518)Postdoctoral Granted Financial Support(No.20110490915)the Guangdong High Level Talent Scheme(R.W.J.)
文摘Three new C-3 dehydrated bufadienolides were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated as 5β,12β-12,14-dihydroxy-11-oxobufa-3,20,22-trienolide （1）, 5β,12β- 12,14-dihydroxy-11 -oxobufa-2,20,22-trienolide （2）, and 5β,12β-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 IC50 values less than 10 μmol/L on both cancer cells.
基金National Natural Science Foundation of China (Grant No.81073117)the construction ofcollege service routines in fujian province key project(Grant No.2008FG-06)
文摘We studied the effects of nasal thermosensible gels containing Chinese medicine Xingbi on Bufo gargarizans maxillary mucosal cilia movement and the ciliotoxicity in rats nasal mucosa. The saline water was used as a blank control, and 1% hydrochloric acid of methamphetamine Massachusetts was used as the negative control. Compared with normal saline control, the relative percentage of the lasting time of ciliary movement treated with Chinese medicine Xingbi was 94.1%. There was no remarkable pathological change in the tissue slice of nasal mucosa, and no stimulation on nasal mucous membrane was observed. So these data suggest that nasal thermosensible gel of Chinese medicine Xingbi is of high safety. It has no damage to the mucosa of toads and rats and can be used for intranasal administration.
