Currently nine families of tailed amphibians, including 682 species, are recognised in the world. Five of these families, including some 166 species, occur in the Old World (Europe, Asia, and Northern Africa). The f...Currently nine families of tailed amphibians, including 682 species, are recognised in the world. Five of these families, including some 166 species, occur in the Old World (Europe, Asia, and Northern Africa). The family of hynobiid salamanders (hynobiidae) is endemic to this region, whereas the other families also are represented in the New World (America). Salamanders of the Old Worm is a comprehensive monograph authored by Max Sparreboom. With this book, which aims to be an up- date of Robert Thorn's book of 1969, the author presents updated information on salamander species diversity in this region. The book is bound to become a classic in its field: it contains descriptions of all five families and 166 salamander species, a taxonomical diagnosis, distribution maps, and a wealth of information on habitat preferences, behaviour, threats, conservation, etc. Every species chapter is followed by a comment by the author and references to technical literature. For many species the biological information comes from the author himself, who made observations of behaviour in aquariums and in the field. This knowledge is supplemented with information from the scientific literature, which is synthesized in a systematic way. What will especially appeal to the reader is the great number of beautiful pictures in the text, showing details of morphological characters, habitat and bebaviour in the different life history stages. These features add to the value of the book, both in scientific and artistic aspects.展开更多
Salamanders are unique among tetrapods in their ability to regenerate the limbs throughout life.Like other poikilothermic amphibians,salamanders also show a remarkable capacity to survive long periods of starvation.Wh...Salamanders are unique among tetrapods in their ability to regenerate the limbs throughout life.Like other poikilothermic amphibians,salamanders also show a remarkable capacity to survive long periods of starvation.Whether the physiological reserves necessary for tissue regeneration are preserved or sacrificed in starved salamanders is unknown.In the current study,we maintained Iberian ribbed newts(Pleurodeles waltl)under extreme physiological stress to assess the extent of regeneration and identify the molecular and cellular changes that may occur under such conditions.After 19 months of complete food deprivation,the animals exhibited extensive morphological and physiological adaptations but remained behaviorally active and vigilant.Autophagy was elevated in different tissues and the transformed gut microbiota indicated remodeling of the intestinal tract related to autophagy.Upon limb amputation in animals starved for 21 months,regeneration proceeded with progenitor cell proliferation and migration,leading to limb blastema formation.However,limb outgrowth and patterning were substantially attenuated.Blockage of autophagy inhibited cell proliferation and blastema formation in starved animals,but not in fed animals.Hence,tissue autophagy and the regenerative response were tightly coupled only when animals were under stress.Our results demonstrate that under adverse conditions,salamanders can exploit alternative strategies to secure blastema formation for limb regeneration.展开更多
Previous work found that different Japanese lineages of salamanders had quite different levels of species and genetic diversity. Lineages vary from having one to several species and the extent of genetic variation amo...Previous work found that different Japanese lineages of salamanders had quite different levels of species and genetic diversity. Lineages vary from having one to several species and the extent of genetic variation among lineages differs substantially. Most speciose,genus Hynobius contains 18 species and several potential cryptic species. We explore genetic diversity in this genus by combining comprehensive sampling and mitochondrial DNA sequences. Based on this and previous analyses of salamanders,relative times of divergence are employed to evaluate the relationship between age and diversity among the four major lineages whose distributions broadly overlap on the islands. For Hynobius,our analyses are congruent with the previously reported high level of cryptic diversity in morphology and allozymes,particularly in species composed of non-sister matrilines. Both species and genetic diversity correlate with the relative ages of the lineages. This correlation indicates that the variation in levels of diversity can be explained,to a considerable extent,by the hypothesis that older insular lineages have accumulated greater diversity. In addition to the Korean Peninsula,H. leechii might have survived in another Pleistocene glacial refugium north of the peninsula and this refugium provided a source of colonization after the last glacial maximum.展开更多
Andrias davidianus(Chinese giant salamander,CGS)is the largest and oldest extant amphibian species in the world and is a source of prospective functional food in China.However,the progress of functional peptides minin...Andrias davidianus(Chinese giant salamander,CGS)is the largest and oldest extant amphibian species in the world and is a source of prospective functional food in China.However,the progress of functional peptides mining was slow due to lack of reference genome and protein sequence data.In this study,we illustrated full-length transcriptome sequencing to interpret the proteome of CGS meat and obtain 10703 coding DNA sequences.By functional annotation and amino acid composition analysis,we have discovered various genes related to signal transduction,and 16 genes related to longevity.We have also found vast variety of functional peptides through protein coding sequence(CDS)analysis by comparing the data obtained with the functional peptide database.Val-Pro-Ile predicted by the CDS analysis was released from the CGS meat through enzymatic hydrolysis,suggesting that our approach is reliable.This study suggested that transcriptomic analysis can be used as a reference to guide polypeptide mining in CGS meat,thereby providing a powerful mining strategy for the bioresources with unknown genomic and proteomic sequences.展开更多
The Mediterranean region possesses a rich diversity of salamanders,which also exhibit a high degree of ecological diversification.It is assumed that the presence of salamanders is dependent on the level of vegetation ...The Mediterranean region possesses a rich diversity of salamanders,which also exhibit a high degree of ecological diversification.It is assumed that the presence of salamanders is dependent on the level of vegetation cover in terrestrial habitats,but the strength of this association is likely to vary among species.In this study,we investigated the patterns of habitat utilization for Mediterranean salamanders based on 589 records of 33 species.We tested the hypothesis that the association between salamander presence and vegetation density varies among genera or reproductive modes(i.e.terrestrial vs aquatic).The results show that vegetation cover has similar influences on terrestrial and aquatic groups but important differences are identified for lotic and lentic aquatic species.Our findings also indicate that the aquatic lotic,terrestrial,and small-body species deviate significantly from that expected from the background range of variation.展开更多
Cynops orientalis(C.orientalis)has a pronounced ability to regenerate its spinal cord after injury.Thus,exploring the molecular mechanism of this process could provide new approaches for promoting mammalian spinal cor...Cynops orientalis(C.orientalis)has a pronounced ability to regenerate its spinal cord after injury.Thus,exploring the molecular mechanism of this process could provide new approaches for promoting mammalian spinal cord regeneration.In this study,we established a model of spinal cord thoracic transection injury in C.orientalis,which is an endemic species in China.We performed RNA sequencing of the contused axolotl spinal cord at two early time points after spinal cord injury–during the very acute stage(4 days)and the subacute stage(7 days)–and identified differentially expressed genes;additionally,we performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses,at each time point.Transcriptome sequencing showed that 13,059 genes were differentially expressed during C.orientalis spinal cord regeneration compared with uninjured animals,among which 4273 were continuously downregulated and 1564 were continuously up-regulated.Down-regulated genes were most enriched in the Gene Ontology term“multicellular organismal process”and in the ribosome pathway at 10 days following spinal cord injury.We found that multiple genes associated with energy metabolism were down-regulated and multiple genes associated with the lysosome were up-regulated after spinal cord injury,indicating the importance of low metabolic activity during wound healing.Immune response-associated pathways were activated during the early acute phase(4 days),while the expression of extracellular matrix proteins such as glycosaminoglycan and collagen,as well as tight junction proteins,was lower at 10 days post-spinal cord injury than 4 days post-spinal cord injury.However,compared with 4 days post-injury,at 10 days post-injury neuroactive ligand-receptor interactions were no longer down-regulated,up-regulated differentially expressed genes were enriched in pathways associated with cancer and the cell cycle,and SHH,VIM,and Sox2 were prominently up-regulated.Immunofluorescence staining showed that glial fibrillary acidic protein was up-regulated in axolotl ependymoglial cells after injury,similar to what is observed in mammalian astrocytes after spinal cord injury,even though axolotls do not form a glial scar during regeneration.We suggest that low intracellular energy production could slow the rapid amplification of ependymoglial cells,thereby inhibiting reactive gliosis,at early stages after spinal cord injury.Extracellular matrix degradation slows cellular responses,represses the expression of neurogenic genes,and reactivates a transcriptional program similar to that of embryonic neuroepithelial cells.These ependymoglial cells act as neural stem cells:they migrate and proliferate to repair the lesion and then differentiate to replace lost glial cells and neurons.This provides the regenerative microenvironment that allows axon growth after injury.展开更多
Chinese giant salamander(Andrias davidianus)is salamander germplasm resource that only distributed in China.It is the material basis of the evolution principle research,genetic research and artificial breeding.Since t...Chinese giant salamander(Andrias davidianus)is salamander germplasm resource that only distributed in China.It is the material basis of the evolution principle research,genetic research and artificial breeding.Since the 1990s,overharvesting,water pollution and habitat changes have seriously destroyed the germplasm resources of A.davidianus,their population density has decreased since then.Strengthening the protection and rational utilization of A.davidianus germplasm resources are key factors in impacting the healthy,stable and sustainable development of A.davidianus industry.Under the above background,we discussed the current problems with the protection for A.davidianus germplasm resources,put forward suggestions for the conservation of A.davidianus germplasm resources.It is expected to provide a reference to effective protection for A.davidianus germplasm resources,and provide a scientific foundation for further studies,so as to promote the high-quality development of related industry.展开更多
This study analyzes storm-triggered landslides in the US Appalachians, in the current geological setting. Concave valleys that favor the convergence of surface runoff are the primary locales for landslides. If the slo...This study analyzes storm-triggered landslides in the US Appalachians, in the current geological setting. Concave valleys that favor the convergence of surface runoff are the primary locales for landslides. If the slopes are weathered to the same degree and have the same vegetation coverage, slope orientation (azimuthal) is not critical for slope stability. However, it is found that for the region south of the Black Mountains (North Carolina), north-facing slopes are more prone to slide, because, for the regions not limited by water availability (annual precipitation), the northern slopes usually are grass slopes. For the slopes of the Blue Ridge Mountains, south facing slopes are more prone to slide. Gravity measurements over the past decade reveal that geological conditions, the chute system and underground cracks over the region are stable. Future changes in storm-triggered landslide frequency are primarily controlled by changes in extreme precipitation. Thus, a series of ensemble climate model experiments is carried out to investigate possible changes in future extreme precipitation events, using a weather model forced by atmospheric perturbations from ensemble climate models. Over 50 locations are identified as prone to future landslides. Many of these locales are natural habitats to the Appalachian salamanders. In a future warmer climate, more severe extreme precipitation events are projected because of increased atmospheric water vapor and more frequent passages of tropical cyclone remnants. There is also a likely shift of tropical cyclone tracks and associated extreme precipitations, and the cluster center of Appalachians’s scarps is expected to move westward, with ecological consequences for the endemic salamanders.展开更多
This study analyzes storm-triggered landslides in the US Appalachians, in the current geological setting. Concave valleys that favor the convergence of surface runoff are the primary locales for landslides. If the slo...This study analyzes storm-triggered landslides in the US Appalachians, in the current geological setting. Concave valleys that favor the convergence of surface runoff are the primary locales for landslides. If the slopes are weathered to the same degree and have the same vegetation coverage, slope orientation (azimuthal) is not critical for slope stability. However, it is found that for the region south of the Black Mountains (North Carolina), north-facing slopes are more prone to slide, because, for the regions not limited by water availability (annual precipitation), the northern slopes usually are grass slopes. For the slopes of the Blue Ridge Mountains, south facing slopes are more prone to slide. Gravity measurements over the past decade reveal that geological conditions, the chute system and underground cracks over the region are stable. Future changes in storm-triggered landslide frequency are primarily controlled by changes in extreme precipitation. Thus, a series of ensemble climate model experiments is carried out to investigate possible changes in future extreme precipitation events, using a weather model forced by atmospheric perturbations from ensemble climate models. Over 50 locations are identified as prone to future landslides. Many of these locales are natural habitats to the Appalachian salamanders. In a future warmer climate, more severe extreme precipitation events are projected because of increased atmospheric water vapor and more frequent passages of tropical cyclone remnants. There is also a likely shift of tropical cyclone tracks and associated extreme precipitations, and the cluster center of Appalachians’s scarps is expected to move westward, with ecological consequences for the endemic salamanders.展开更多
Andrias davidianus,i.e.Chinese giant salamander(CGS),is one of the largest and oldest amphibians existing in the world and is also one of the valuable biological resources of China.Wild CGS has been threatened with ex...Andrias davidianus,i.e.Chinese giant salamander(CGS),is one of the largest and oldest amphibians existing in the world and is also one of the valuable biological resources of China.Wild CGS has been threatened with extinction in the past decades due to over capturing,deterioration of natural environment,the slow breeding and growth of the wild species in nature.However,in the past twenty years,with the breakthrough and progress of artificial breeding technology by artificial insemination,the number of artificially cultivated CGS has increased rapidly.Artificially cultivated CGS can either be released to the CGS living environment to increase the population in nature or legally applied in food and medicinal industry as a feedstock due to the unique nutritional and medicinal values of CGS as recorded historically.In this review,the nutritional components,bioactive components and medicinal activities of the artificially cultivated CGS will be summarized.The mucus,skin,meat and bone of CGS contain many different bioactive substances thereby having various medicinal activities including anti-aging,anti-fatigue,anti-tumor,therapy of burn and anti-infection and other physiological functions.This paper will further discuss the potential applications of the artificially cultivated CGS in healthcare industry and prospects of future technological development.展开更多
Biodiversity is declining globally by an unprecedented extinction rate.This is especially true for amphibians,accounting for 24.3%of all threatened vertebrates.As the largest extant amphibian species in the world,wild...Biodiversity is declining globally by an unprecedented extinction rate.This is especially true for amphibians,accounting for 24.3%of all threatened vertebrates.As the largest extant amphibian species in the world,wild populations of the Chinese giant salamander(Genus Andrias)(CGS)have decreased dramatically because of overexploitation and habitat degradation.Translocation has become an important strategy for restoring threatened wild populations worldwide.However,disordered tra nsloca tion usually has negative effects on the native populations.We provide an overview of CGS translocation and show that disordered translocation can increase local population extinction.Nearly four times the estimated number of wild individuals have been released across China.There a re three types of translocation used for CGS,namely,reinforcement,reintroduction and ecological replacement,the last of which accounts for over one-third of translocations.Our genetic screening revealed that most released individuals were not from local populations,with one to four lineages detected in every release site(n=6).This disordered translocation can potentially reduce the genetic integrity of original populations.Hence,we suggest suspending current CGS translocation activities immediately,until more robust measures can be developed and implemented to improve the current translocation program,especially with respect to lineage identifica tion a nd the identifica tion of appropriate release sites.展开更多
Morganella morganii strain 602-1 was isolated from a sick Chinese giant salamander (Andrias davidianus). The strain 602-1 was identified through its physiological and biochemical properties and 16S rDNA gene amplifi...Morganella morganii strain 602-1 was isolated from a sick Chinese giant salamander (Andrias davidianus). The strain 602-1 was identified through its physiological and biochemical properties and 16S rDNA gene amplification and analyses. Pathogenicity was proven by experimental animal infection, and histopathological examination. The results showed that the amplified 16S rDNA sequence of strain 602-1 was 1455 bp, and showed 99% identity with M. morganii. In the host infection experiment, the mortality of Chinese giant salamanders was about 70%. Pathological changes occurred in the spleen, heart, liver, kidney and intestine. This study will help the prevention, understanding and cure for M. morganii infections in amphibians.展开更多
Loop-mediated isothermal ampliifcation (LAMP) is a novel nucleic acid diagnostic method that can amplify rapidly a target template under isothermal conditions. In this study, a LAMP assay for rapid detection of Chin...Loop-mediated isothermal ampliifcation (LAMP) is a novel nucleic acid diagnostic method that can amplify rapidly a target template under isothermal conditions. In this study, a LAMP assay for rapid detection of Chinese giant salamander ranavirus(CGSRV) was developed from culture isolates and clinical samples. The LAMP assay was developed by designing one set of four speciifc primers, targeting the major capsid protein (MCP) gene of CGSRV. Reaction time and temperature were optimal for 40 min at 62°C. The developed LAMP assay is speciifc and highly sensitive for CGSRV detection, the detection limit could reach about 5 copies of cloned viral genomic fragments. The sensitivity of the LAMP assay was about 1000 and 10-fold higher than that of both conventional and nested PCR, respectively. The LAMP ampliifcation produces a typical ladder-like pattern of products on an agarose gel that can be visually inspected after addition of ethidium bromide. The LAMP assay was evaluated further with clinical samples, and the results indicated the suitability and simplicity of the test as a rapid diagnostic tool for the detection of CGSRV.展开更多
As a group of intestinal hormones and neurotransmitters, cholecystokinins(CCKs) regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally...As a group of intestinal hormones and neurotransmitters, cholecystokinins(CCKs) regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally contain a DYMGWMDFG sequence at the C-terminus. Many CCKs have been reported in mammals. However, only a few have been reported in amphibians, such as Hyla nigrovittata, Xenopus laevis, and Rana catesbeiana, with none reported in urodele amphibians like newts and salamanders. Here, a CCK called CCK-TV was identified and characterized from the skin of the salamander Tylototriton verrucosus. This CCK contained an amino acid sequence of DYMGWMDF-NH2 as seen in other CCKs. A c DNA encoding the CCK precursor containing 129 amino acid residues was cloned from the c DNA library of T. verrucosus skin. The CCK-TV had the potential to induce the contraction of smooth muscle strips isolated from porcine gallbladder, eliciting contraction at a concentration of 5.0x10-11 mol/L and inducing maximal contraction at a concentration of 2.0x10-6 mol/L. The EC50 was 13.6 nmol/L. To the best of our knowledge, this is the first report to identify the presence of a CCK in an urodele amphibian.展开更多
Internasal bones have generally been recorded in teleostean and tetrapod fossils, being absent in most extant vertebrates. Presently, there has been one case of the internasal bone discovered in a living salamander, P...Internasal bones have generally been recorded in teleostean and tetrapod fossils, being absent in most extant vertebrates. Presently, there has been one case of the internasal bone discovered in a living salamander, Pseudohynobius puxiongensis (Caudata: Hynobiidae). The second case discovered in living salamanders is reported in this article, which is present in one of five specimens ofHynobius maoershanensis, a species endemic to China. This case is again regarded as individual variation. Thus, the presence of an "internasal bone" may represent intraspecific variation and is thus a misleading taxonomic character.展开更多
The morphological characteristics of the dorsal skin of trunk in two species of hynobiid salamanders, Batrachuperus pinchonii and Hynobius chinensis were examined by light microscopy. The basic structures of the skin ...The morphological characteristics of the dorsal skin of trunk in two species of hynobiid salamanders, Batrachuperus pinchonii and Hynobius chinensis were examined by light microscopy. The basic structures of the skin in the two species are similar and consist of two layers: epidermis and dermis. The epidermis consists of stratum corneum, stratum intermedium and stratum germinativum, while the dermis is composed of a stratum spongiosum and stratum compactum. However, some species-specific variation has been identified (e.g., the distribution of capillary vessels and gland cells, and the thickness of skin). H. chinensis is a terrestrial species and only lives in water during breeding period, but B. pinchonii is aquatic and remains aquatic throughout its lifetime. The differences in the distribution of capillary vessels and gland cells are related to their different habitats, and show a morphological adaptation.展开更多
The Chinese giant salamander(Andrias davidianus) is the largest living amphibian in the world. Aeromonas hydrophila strain L602 was isolated from A. davidianus. The 16S rDNA gene of this isolate was amplified using PC...The Chinese giant salamander(Andrias davidianus) is the largest living amphibian in the world. Aeromonas hydrophila strain L602 was isolated from A. davidianus. The 16S rDNA gene of this isolate was amplified using PCR,and the phylogenetic tree was constructed by the neighbor-joining method. Four virulence genes(aerA,aha1,hly and alt) of A. hydrophila were amplified by PCR and drug resistances were tested using Kirby-Bauer disk diffusion method. The results showed that the length of this 16S rDNA sequence was 1453 bp,which showed 99% homology with A. hydrophila. The GenBank accession number was JX155398. Phylogenetic analysis indicated it grouped together with A. hydrophila. Four virulence genes were all detected,indicating that strain L602 was highly virulent. This stain was resistant to four antibiotics(vibramycin,furazolidone,ampicillin and erythromycin),while it was insensitive to streptomycin. Furthermore,this strain was susceptible to six antibiotics(sulfafurazole,ciprofloxacin,penbritin,norfloxacin,florfenicol and enrofloxacin). This study will help to validate the classification and virulence of pathogenic bacteria in amphibians.展开更多
In order to facilitate herpetological research for herpetologists in and outside of China,we will report all the type specimens of Amphibia and Reptilia deposited in the Herpetological Museum of the Chengdu Institute ...In order to facilitate herpetological research for herpetologists in and outside of China,we will report all the type specimens of Amphibia and Reptilia deposited in the Herpetological Museum of the Chengdu Institute of Biology(CIB),Chinese Academy of Sciences(CAS) in series. This report focuses on the type specimens of the family Hynobiidae of Urodela in Amphibia,which comprises seven species. Each entry provides the genus name,species name,information of the original description,the catalog number of holotype,sex,type locality,information of allotype(if any) and paratype,number and distribution of deposited specimens,and comments where they are appropriate.展开更多
Numerous amphibian species occupy microhabitats with buffered thermal and moisture conditions,typically under forest canopies.Here,we assessed whether the insular endemic Salamandra corsica also uses this type of habi...Numerous amphibian species occupy microhabitats with buffered thermal and moisture conditions,typically under forest canopies.Here,we assessed whether the insular endemic Salamandra corsica also uses this type of habitat,which could have important implications for its conservation.We used data loggers to record the air temperature and air humidity at 4 h intervals over a period of 2 years,at 13 stations with a confirmed presence of S.corsica.These data were compared with those recorded at Corsican weather stations and those generated by a climate model(WorldClim 2).The weather station data showed significant deviations from the probe data,by an average of-1.26℃(minimum temperature),+2.61℃(maximum temperature),and-0.04%(relative humidity).Similarly,the WorldClim 2 data showed significant deviations from the probe data,by an average of-2.49°C(minimum temperature)and+1.69℃(maximum temperature).These discrepancies refl ect the use of densely vegetated and topographically complex habitats by S.corsica,which reduce temperature fluctuations.Overall,our results highlight the importance of natural vegetal cover in the conservation of populations of this endemic salamander.展开更多
文摘Currently nine families of tailed amphibians, including 682 species, are recognised in the world. Five of these families, including some 166 species, occur in the Old World (Europe, Asia, and Northern Africa). The family of hynobiid salamanders (hynobiidae) is endemic to this region, whereas the other families also are represented in the New World (America). Salamanders of the Old Worm is a comprehensive monograph authored by Max Sparreboom. With this book, which aims to be an up- date of Robert Thorn's book of 1969, the author presents updated information on salamander species diversity in this region. The book is bound to become a classic in its field: it contains descriptions of all five families and 166 salamander species, a taxonomical diagnosis, distribution maps, and a wealth of information on habitat preferences, behaviour, threats, conservation, etc. Every species chapter is followed by a comment by the author and references to technical literature. For many species the biological information comes from the author himself, who made observations of behaviour in aquariums and in the field. This knowledge is supplemented with information from the scientific literature, which is synthesized in a systematic way. What will especially appeal to the reader is the great number of beautiful pictures in the text, showing details of morphological characters, habitat and bebaviour in the different life history stages. These features add to the value of the book, both in scientific and artistic aspects.
基金This study was supported by the National Natural Science Foundation of China(31771617)and HZAU-AGIS Cooperation Fund(SZYJY2021009)。
文摘Salamanders are unique among tetrapods in their ability to regenerate the limbs throughout life.Like other poikilothermic amphibians,salamanders also show a remarkable capacity to survive long periods of starvation.Whether the physiological reserves necessary for tissue regeneration are preserved or sacrificed in starved salamanders is unknown.In the current study,we maintained Iberian ribbed newts(Pleurodeles waltl)under extreme physiological stress to assess the extent of regeneration and identify the molecular and cellular changes that may occur under such conditions.After 19 months of complete food deprivation,the animals exhibited extensive morphological and physiological adaptations but remained behaviorally active and vigilant.Autophagy was elevated in different tissues and the transformed gut microbiota indicated remodeling of the intestinal tract related to autophagy.Upon limb amputation in animals starved for 21 months,regeneration proceeded with progenitor cell proliferation and migration,leading to limb blastema formation.However,limb outgrowth and patterning were substantially attenuated.Blockage of autophagy inhibited cell proliferation and blastema formation in starved animals,but not in fed animals.Hence,tissue autophagy and the regenerative response were tightly coupled only when animals were under stress.Our results demonstrate that under adverse conditions,salamanders can exploit alternative strategies to secure blastema formation for limb regeneration.
基金supported by the Chinese Academy of Sciences (09C3011100, KSCX2- YW-Z-0906, KSCX2-EW-J-22)the National Natural Science Foundation of China (NSFC-30870287, NSFC-30900134)the Natural Sciences and Engineering Research Council (Canada) Discovery Grant 3148
文摘Previous work found that different Japanese lineages of salamanders had quite different levels of species and genetic diversity. Lineages vary from having one to several species and the extent of genetic variation among lineages differs substantially. Most speciose,genus Hynobius contains 18 species and several potential cryptic species. We explore genetic diversity in this genus by combining comprehensive sampling and mitochondrial DNA sequences. Based on this and previous analyses of salamanders,relative times of divergence are employed to evaluate the relationship between age and diversity among the four major lineages whose distributions broadly overlap on the islands. For Hynobius,our analyses are congruent with the previously reported high level of cryptic diversity in morphology and allozymes,particularly in species composed of non-sister matrilines. Both species and genetic diversity correlate with the relative ages of the lineages. This correlation indicates that the variation in levels of diversity can be explained,to a considerable extent,by the hypothesis that older insular lineages have accumulated greater diversity. In addition to the Korean Peninsula,H. leechii might have survived in another Pleistocene glacial refugium north of the peninsula and this refugium provided a source of colonization after the last glacial maximum.
基金funded by Shenzhen Science and Technology Innovation Commission(KCXFZ20201221173207022)。
文摘Andrias davidianus(Chinese giant salamander,CGS)is the largest and oldest extant amphibian species in the world and is a source of prospective functional food in China.However,the progress of functional peptides mining was slow due to lack of reference genome and protein sequence data.In this study,we illustrated full-length transcriptome sequencing to interpret the proteome of CGS meat and obtain 10703 coding DNA sequences.By functional annotation and amino acid composition analysis,we have discovered various genes related to signal transduction,and 16 genes related to longevity.We have also found vast variety of functional peptides through protein coding sequence(CDS)analysis by comparing the data obtained with the functional peptide database.Val-Pro-Ile predicted by the CDS analysis was released from the CGS meat through enzymatic hydrolysis,suggesting that our approach is reliable.This study suggested that transcriptomic analysis can be used as a reference to guide polypeptide mining in CGS meat,thereby providing a powerful mining strategy for the bioresources with unknown genomic and proteomic sequences.
文摘The Mediterranean region possesses a rich diversity of salamanders,which also exhibit a high degree of ecological diversification.It is assumed that the presence of salamanders is dependent on the level of vegetation cover in terrestrial habitats,but the strength of this association is likely to vary among species.In this study,we investigated the patterns of habitat utilization for Mediterranean salamanders based on 589 records of 33 species.We tested the hypothesis that the association between salamander presence and vegetation density varies among genera or reproductive modes(i.e.terrestrial vs aquatic).The results show that vegetation cover has similar influences on terrestrial and aquatic groups but important differences are identified for lotic and lentic aquatic species.Our findings also indicate that the aquatic lotic,terrestrial,and small-body species deviate significantly from that expected from the background range of variation.
基金the National Natural Science Foundation of China,Nos.32270516,31970413the Natural Science Foundation of Anhui Province,No.1908085MC83(to JL)a Start-up grant from Nanjing Agricultural University,No.804090。
文摘Cynops orientalis(C.orientalis)has a pronounced ability to regenerate its spinal cord after injury.Thus,exploring the molecular mechanism of this process could provide new approaches for promoting mammalian spinal cord regeneration.In this study,we established a model of spinal cord thoracic transection injury in C.orientalis,which is an endemic species in China.We performed RNA sequencing of the contused axolotl spinal cord at two early time points after spinal cord injury–during the very acute stage(4 days)and the subacute stage(7 days)–and identified differentially expressed genes;additionally,we performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses,at each time point.Transcriptome sequencing showed that 13,059 genes were differentially expressed during C.orientalis spinal cord regeneration compared with uninjured animals,among which 4273 were continuously downregulated and 1564 were continuously up-regulated.Down-regulated genes were most enriched in the Gene Ontology term“multicellular organismal process”and in the ribosome pathway at 10 days following spinal cord injury.We found that multiple genes associated with energy metabolism were down-regulated and multiple genes associated with the lysosome were up-regulated after spinal cord injury,indicating the importance of low metabolic activity during wound healing.Immune response-associated pathways were activated during the early acute phase(4 days),while the expression of extracellular matrix proteins such as glycosaminoglycan and collagen,as well as tight junction proteins,was lower at 10 days post-spinal cord injury than 4 days post-spinal cord injury.However,compared with 4 days post-injury,at 10 days post-injury neuroactive ligand-receptor interactions were no longer down-regulated,up-regulated differentially expressed genes were enriched in pathways associated with cancer and the cell cycle,and SHH,VIM,and Sox2 were prominently up-regulated.Immunofluorescence staining showed that glial fibrillary acidic protein was up-regulated in axolotl ependymoglial cells after injury,similar to what is observed in mammalian astrocytes after spinal cord injury,even though axolotls do not form a glial scar during regeneration.We suggest that low intracellular energy production could slow the rapid amplification of ependymoglial cells,thereby inhibiting reactive gliosis,at early stages after spinal cord injury.Extracellular matrix degradation slows cellular responses,represses the expression of neurogenic genes,and reactivates a transcriptional program similar to that of embryonic neuroepithelial cells.These ependymoglial cells act as neural stem cells:they migrate and proliferate to repair the lesion and then differentiate to replace lost glial cells and neurons.This provides the regenerative microenvironment that allows axon growth after injury.
基金Supported by the Project of Henan Province for Tackling Key Problems in Science and Technology(212102110386)the National Spark Program Project(2011ga750009).
文摘Chinese giant salamander(Andrias davidianus)is salamander germplasm resource that only distributed in China.It is the material basis of the evolution principle research,genetic research and artificial breeding.Since the 1990s,overharvesting,water pollution and habitat changes have seriously destroyed the germplasm resources of A.davidianus,their population density has decreased since then.Strengthening the protection and rational utilization of A.davidianus germplasm resources are key factors in impacting the healthy,stable and sustainable development of A.davidianus industry.Under the above background,we discussed the current problems with the protection for A.davidianus germplasm resources,put forward suggestions for the conservation of A.davidianus germplasm resources.It is expected to provide a reference to effective protection for A.davidianus germplasm resources,and provide a scientific foundation for further studies,so as to promote the high-quality development of related industry.
文摘This study analyzes storm-triggered landslides in the US Appalachians, in the current geological setting. Concave valleys that favor the convergence of surface runoff are the primary locales for landslides. If the slopes are weathered to the same degree and have the same vegetation coverage, slope orientation (azimuthal) is not critical for slope stability. However, it is found that for the region south of the Black Mountains (North Carolina), north-facing slopes are more prone to slide, because, for the regions not limited by water availability (annual precipitation), the northern slopes usually are grass slopes. For the slopes of the Blue Ridge Mountains, south facing slopes are more prone to slide. Gravity measurements over the past decade reveal that geological conditions, the chute system and underground cracks over the region are stable. Future changes in storm-triggered landslide frequency are primarily controlled by changes in extreme precipitation. Thus, a series of ensemble climate model experiments is carried out to investigate possible changes in future extreme precipitation events, using a weather model forced by atmospheric perturbations from ensemble climate models. Over 50 locations are identified as prone to future landslides. Many of these locales are natural habitats to the Appalachian salamanders. In a future warmer climate, more severe extreme precipitation events are projected because of increased atmospheric water vapor and more frequent passages of tropical cyclone remnants. There is also a likely shift of tropical cyclone tracks and associated extreme precipitations, and the cluster center of Appalachians’s scarps is expected to move westward, with ecological consequences for the endemic salamanders.
文摘This study analyzes storm-triggered landslides in the US Appalachians, in the current geological setting. Concave valleys that favor the convergence of surface runoff are the primary locales for landslides. If the slopes are weathered to the same degree and have the same vegetation coverage, slope orientation (azimuthal) is not critical for slope stability. However, it is found that for the region south of the Black Mountains (North Carolina), north-facing slopes are more prone to slide, because, for the regions not limited by water availability (annual precipitation), the northern slopes usually are grass slopes. For the slopes of the Blue Ridge Mountains, south facing slopes are more prone to slide. Gravity measurements over the past decade reveal that geological conditions, the chute system and underground cracks over the region are stable. Future changes in storm-triggered landslide frequency are primarily controlled by changes in extreme precipitation. Thus, a series of ensemble climate model experiments is carried out to investigate possible changes in future extreme precipitation events, using a weather model forced by atmospheric perturbations from ensemble climate models. Over 50 locations are identified as prone to future landslides. Many of these locales are natural habitats to the Appalachian salamanders. In a future warmer climate, more severe extreme precipitation events are projected because of increased atmospheric water vapor and more frequent passages of tropical cyclone remnants. There is also a likely shift of tropical cyclone tracks and associated extreme precipitations, and the cluster center of Appalachians’s scarps is expected to move westward, with ecological consequences for the endemic salamanders.
基金The authors would like to thank the National Key R&D Plan of China for providing support(NO:2016YFD0400203-4).
文摘Andrias davidianus,i.e.Chinese giant salamander(CGS),is one of the largest and oldest amphibians existing in the world and is also one of the valuable biological resources of China.Wild CGS has been threatened with extinction in the past decades due to over capturing,deterioration of natural environment,the slow breeding and growth of the wild species in nature.However,in the past twenty years,with the breakthrough and progress of artificial breeding technology by artificial insemination,the number of artificially cultivated CGS has increased rapidly.Artificially cultivated CGS can either be released to the CGS living environment to increase the population in nature or legally applied in food and medicinal industry as a feedstock due to the unique nutritional and medicinal values of CGS as recorded historically.In this review,the nutritional components,bioactive components and medicinal activities of the artificially cultivated CGS will be summarized.The mucus,skin,meat and bone of CGS contain many different bioactive substances thereby having various medicinal activities including anti-aging,anti-fatigue,anti-tumor,therapy of burn and anti-infection and other physiological functions.This paper will further discuss the potential applications of the artificially cultivated CGS in healthcare industry and prospects of future technological development.
基金supported by the National Key Programme of Research and Development,Ministry of Science and Technology(2016YFC0503200)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23080101)+3 种基金the Biodiversity Survey and Assessment Project of the Ministry of Ecology and Environment,China(2019HJ2096001006)the Open Project of CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization&Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province(KXYSWS2006)the Construction of Basic Conditions Platform of Sichuan Science and Technology Department(2019JDPT0020)China Biodiversity Observa tion Networks(Sino BON)。
文摘Biodiversity is declining globally by an unprecedented extinction rate.This is especially true for amphibians,accounting for 24.3%of all threatened vertebrates.As the largest extant amphibian species in the world,wild populations of the Chinese giant salamander(Genus Andrias)(CGS)have decreased dramatically because of overexploitation and habitat degradation.Translocation has become an important strategy for restoring threatened wild populations worldwide.However,disordered tra nsloca tion usually has negative effects on the native populations.We provide an overview of CGS translocation and show that disordered translocation can increase local population extinction.Nearly four times the estimated number of wild individuals have been released across China.There a re three types of translocation used for CGS,namely,reinforcement,reintroduction and ecological replacement,the last of which accounts for over one-third of translocations.Our genetic screening revealed that most released individuals were not from local populations,with one to four lineages detected in every release site(n=6).This disordered translocation can potentially reduce the genetic integrity of original populations.Hence,we suggest suspending current CGS translocation activities immediately,until more robust measures can be developed and implemented to improve the current translocation program,especially with respect to lineage identifica tion a nd the identifica tion of appropriate release sites.
基金supported by the research grants from Science and Technology Department of Sichuan (2013FZ0014)Construction Project of Postgraduate Academic Degree in Southwest University for Nationalities (2013XWD–S071007)
文摘Morganella morganii strain 602-1 was isolated from a sick Chinese giant salamander (Andrias davidianus). The strain 602-1 was identified through its physiological and biochemical properties and 16S rDNA gene amplification and analyses. Pathogenicity was proven by experimental animal infection, and histopathological examination. The results showed that the amplified 16S rDNA sequence of strain 602-1 was 1455 bp, and showed 99% identity with M. morganii. In the host infection experiment, the mortality of Chinese giant salamanders was about 70%. Pathological changes occurred in the spleen, heart, liver, kidney and intestine. This study will help the prevention, understanding and cure for M. morganii infections in amphibians.
基金supported by the Sichuan Technology Support Planning (No. 2014 NZ0027)
文摘Loop-mediated isothermal ampliifcation (LAMP) is a novel nucleic acid diagnostic method that can amplify rapidly a target template under isothermal conditions. In this study, a LAMP assay for rapid detection of Chinese giant salamander ranavirus(CGSRV) was developed from culture isolates and clinical samples. The LAMP assay was developed by designing one set of four speciifc primers, targeting the major capsid protein (MCP) gene of CGSRV. Reaction time and temperature were optimal for 40 min at 62°C. The developed LAMP assay is speciifc and highly sensitive for CGSRV detection, the detection limit could reach about 5 copies of cloned viral genomic fragments. The sensitivity of the LAMP assay was about 1000 and 10-fold higher than that of both conventional and nested PCR, respectively. The LAMP ampliifcation produces a typical ladder-like pattern of products on an agarose gel that can be visually inspected after addition of ethidium bromide. The LAMP assay was evaluated further with clinical samples, and the results indicated the suitability and simplicity of the test as a rapid diagnostic tool for the detection of CGSRV.
基金supported by the National Basic Research Program of China(973 Program)(2013CB911300)National Natural Science Foundation of China(U1132601)the Chinese Academy of Sciences(SAJC201308)
文摘As a group of intestinal hormones and neurotransmitters, cholecystokinins(CCKs) regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally contain a DYMGWMDFG sequence at the C-terminus. Many CCKs have been reported in mammals. However, only a few have been reported in amphibians, such as Hyla nigrovittata, Xenopus laevis, and Rana catesbeiana, with none reported in urodele amphibians like newts and salamanders. Here, a CCK called CCK-TV was identified and characterized from the skin of the salamander Tylototriton verrucosus. This CCK contained an amino acid sequence of DYMGWMDF-NH2 as seen in other CCKs. A c DNA encoding the CCK precursor containing 129 amino acid residues was cloned from the c DNA library of T. verrucosus skin. The CCK-TV had the potential to induce the contraction of smooth muscle strips isolated from porcine gallbladder, eliciting contraction at a concentration of 5.0x10-11 mol/L and inducing maximal contraction at a concentration of 2.0x10-6 mol/L. The EC50 was 13.6 nmol/L. To the best of our knowledge, this is the first report to identify the presence of a CCK in an urodele amphibian.
基金supported by the grants of the National Natural Science Foundation of China(NSFC)(30870287)the Chinese Academy of Sciences(KSCX2-EW-J-22)to Xiaomao ZENGthe grants of NSFC(30900138)and Henan University of Science and Technology Foundation(09001367)to Jianli XIONG
文摘Internasal bones have generally been recorded in teleostean and tetrapod fossils, being absent in most extant vertebrates. Presently, there has been one case of the internasal bone discovered in a living salamander, Pseudohynobius puxiongensis (Caudata: Hynobiidae). The second case discovered in living salamanders is reported in this article, which is present in one of five specimens ofHynobius maoershanensis, a species endemic to China. This case is again regarded as individual variation. Thus, the presence of an "internasal bone" may represent intraspecific variation and is thus a misleading taxonomic character.
基金supported by the grants of the National Natural Science Foundation of China(30900138)the Henan University of Science and Technology Foundation(09001367)the Science and Technology Program of Henan Province(122102110035)to Jianli XIONG
文摘The morphological characteristics of the dorsal skin of trunk in two species of hynobiid salamanders, Batrachuperus pinchonii and Hynobius chinensis were examined by light microscopy. The basic structures of the skin in the two species are similar and consist of two layers: epidermis and dermis. The epidermis consists of stratum corneum, stratum intermedium and stratum germinativum, while the dermis is composed of a stratum spongiosum and stratum compactum. However, some species-specific variation has been identified (e.g., the distribution of capillary vessels and gland cells, and the thickness of skin). H. chinensis is a terrestrial species and only lives in water during breeding period, but B. pinchonii is aquatic and remains aquatic throughout its lifetime. The differences in the distribution of capillary vessels and gland cells are related to their different habitats, and show a morphological adaptation.
基金supported by the Research Grant from the Science and Technology Department of Sichuan, China (2011JY0095)the Construction Project of Southwest University for Nationalities (2011XWD-S071007)
文摘The Chinese giant salamander(Andrias davidianus) is the largest living amphibian in the world. Aeromonas hydrophila strain L602 was isolated from A. davidianus. The 16S rDNA gene of this isolate was amplified using PCR,and the phylogenetic tree was constructed by the neighbor-joining method. Four virulence genes(aerA,aha1,hly and alt) of A. hydrophila were amplified by PCR and drug resistances were tested using Kirby-Bauer disk diffusion method. The results showed that the length of this 16S rDNA sequence was 1453 bp,which showed 99% homology with A. hydrophila. The GenBank accession number was JX155398. Phylogenetic analysis indicated it grouped together with A. hydrophila. Four virulence genes were all detected,indicating that strain L602 was highly virulent. This stain was resistant to four antibiotics(vibramycin,furazolidone,ampicillin and erythromycin),while it was insensitive to streptomycin. Furthermore,this strain was susceptible to six antibiotics(sulfafurazole,ciprofloxacin,penbritin,norfloxacin,florfenicol and enrofloxacin). This study will help to validate the classification and virulence of pathogenic bacteria in amphibians.
基金supported by the grant of the National Natural Science Foundation of China (NSFC) (30870287) to Xiaomao ZENGthe grants of NSFC (30900138)Henan University of Science and Technology Foundation (09001367) to Jianli XIONG
文摘In order to facilitate herpetological research for herpetologists in and outside of China,we will report all the type specimens of Amphibia and Reptilia deposited in the Herpetological Museum of the Chengdu Institute of Biology(CIB),Chinese Academy of Sciences(CAS) in series. This report focuses on the type specimens of the family Hynobiidae of Urodela in Amphibia,which comprises seven species. Each entry provides the genus name,species name,information of the original description,the catalog number of holotype,sex,type locality,information of allotype(if any) and paratype,number and distribution of deposited specimens,and comments where they are appropriate.
文摘Numerous amphibian species occupy microhabitats with buffered thermal and moisture conditions,typically under forest canopies.Here,we assessed whether the insular endemic Salamandra corsica also uses this type of habitat,which could have important implications for its conservation.We used data loggers to record the air temperature and air humidity at 4 h intervals over a period of 2 years,at 13 stations with a confirmed presence of S.corsica.These data were compared with those recorded at Corsican weather stations and those generated by a climate model(WorldClim 2).The weather station data showed significant deviations from the probe data,by an average of-1.26℃(minimum temperature),+2.61℃(maximum temperature),and-0.04%(relative humidity).Similarly,the WorldClim 2 data showed significant deviations from the probe data,by an average of-2.49°C(minimum temperature)and+1.69℃(maximum temperature).These discrepancies refl ect the use of densely vegetated and topographically complex habitats by S.corsica,which reduce temperature fluctuations.Overall,our results highlight the importance of natural vegetal cover in the conservation of populations of this endemic salamander.