Shedao pit-vipers(Gloydius shedaoensis) on Snake Island in the Liaoning Province,China,are among the most imperiled species in China.The isolated and unique populations are crucial in the recovery of this endangered s...Shedao pit-vipers(Gloydius shedaoensis) on Snake Island in the Liaoning Province,China,are among the most imperiled species in China.The isolated and unique populations are crucial in the recovery of this endangered species by providing a way for conservation and management.Research based on the ecological simulation tools can evaluate alternative mitigation strategies in terms of their benefits to the populations,which are vital for informed decision-making.In this paper,using the program VORTEX 9.42,we developed a population viability analysis(PVA) for the Shedao pit-viper to:(1) address the extinction likelihood of the population;(2) simulate population dynamics under various environment events,and(3) evaluate the efficacy of current protection and management strategies.Overall,we found the population to be susceptible to the factors of catastrophic events,mortality and environment capacity.The population is recovering slowly at present on account of improvement of habitat and greater food availability.Under the current conditions,the probability of extinction in 100 years is approximately zero.These data coincide with the evidence that the wild population may be arriving at K.Our results strengthen the view that protection and management can create a pronounced effect on populations of this endangered species.展开更多
OBJECTIVE To investigate the thrombolytic and antiplatelet effects of a novel plasminogen activator from the venom of Gloydius brevicaudus viper(GBV-PA)in vitro and in vivo.METHODS Thrombolytic experiments were perfor...OBJECTIVE To investigate the thrombolytic and antiplatelet effects of a novel plasminogen activator from the venom of Gloydius brevicaudus viper(GBV-PA)in vitro and in vivo.METHODS Thrombolytic experiments were performed in rabbit models of ear vein thrombosis and carotid artery thrombosis,and in dog model of acute cerebral infarction.Inhibition of thrombus formation was evaluated in rat inferior vena cava thrombosis model and ferric chloride-induced arterial thrombosis.In vitro,we assayed the antithrombotic effect of GBV-PA on rabbit blood clots,euglobulin lysis time(ELT)of rabbit plasma,and on ADP-induced platelet aggregation.RESULTS GBV-PA intravenous administ ration significantly reduced vascular recanalization times of rabbit ear veins thrombosis and thrombus weight of rabbit carotid artery thrombosis.The arterial recanalization rates were dose-and time-dependently improved after administration of GBV-PA in canine acute cerebral infarction model.Thrombus length and weight was significantly reduced by GBV-PA both in rat inferior vena cava and ferric chloride-induced arterial thrombosis models.Thrombus formation of blood of rabbits they were administrated with GBV-PA was also inhibited.GBV-PA radically reduced plasma ELT of rabbit′s blood clots.ADP-induced platelet aggregation was inhibited by GBV-PA in a dose-dependent manner with a half-maximal inhibitory concentration of 19.9μg·mL-1.CONCLUSION This study demonstrates that GBV-PA is a thrombolytic and antiplatelet agent.It has significant antithrombotic effects on various in vitro and in vivo experimental models of thrombosis.The mechanisms that underline its antithrombotic effects were related to GBV-PA′s capabilities of increasing fibrinolytic activities and inhibition of platelet aggregation.展开更多
Group living has increasingly been emphasized due to its potential consequence on inbreeding, nevertheless, the relationship between group living and inbreeding risk is largely unknown. The endangered snake species, S...Group living has increasingly been emphasized due to its potential consequence on inbreeding, nevertheless, the relationship between group living and inbreeding risk is largely unknown. The endangered snake species, Shedao pit viper(Gloydius shedaoensis) inhabiting mostly on Shedao Island(meaning "snake island" in Chinese), provides an excellent model system for research on group living and inbreeding risk. Small island area, high population density and extreme seasonal foraging opportunity prompt many individuals to live on the same tree, which likely increase the potential mating among relatives. To confirm this probability, we used genotypes from 13 microsatellites DNA markers and examined the genetic relationships between pair of individuals lived on the same tree. The results showed that snakes on the same tree did not show closer relationships compared with individuals from different trees. The group constructions based on scenarios of parental-offspring, full-sibling, half-sibling as well as cousin were not consistent with tree-based group living. In addition, we did not find significant correlation between pair of individual genetic distance and geographic distance going beyond trees, suggesting group living on trees might not elevate inbreeding risk.展开更多
Island species and their ecosystems play an important role in global biodiversity preservation,and many vulnerable island species are conservation priorities.Although insular habitat likely facilitates the species div...Island species and their ecosystems play an important role in global biodiversity preservation,and many vulnerable island species are conservation priorities.Although insular habitat likely facilitates the species diversification process,it may also aggravate the fragility of these species with high risk of inbreeding.The Shedao pit-viper Gloydius shedaoensis is an island endemic species with an extremely high population density,which has been categorized as vulnerable in the IUCN(International Union for the Conservation of Nature and Natural Resources)Red List.We collected 13,148 SNP(Single Nucleotide Polymorphism)from across its genome and examined its genetic diversity and demographic history.The Shedao pit-viper has a low genetic diversity but shows no sign of inbreeding.Furthermore,population genetic structure analysis,including the neighbor-joining tree,principal coordinate analysis,clustering,and spatial autocorrelation,revealed a general lack of spatial structure.Only the isolation by distance residues suggested a weak patchiness.Overall,the population is nearly panmictic and gene flow is evenly distributed across the island.A large number of individuals,small size of the island,and the lack of population structure likely all contribute to the lack of inbreeding in this species.We also detected signs of male-biased dispersal,which likely is another inbreeding avoidance strategy.Historical demographic analysis suggested that the historical population size and distribution of the species are much larger than their current ones.The multiple transgressive–regressive events since the Late Pleistocene are likely the main cause of the population size changes.Taken together,our results provide a basic scientific foundation for the conservation of this interesting and important species.展开更多
基金funded by the Dalian City Environment Protection Bureau
文摘Shedao pit-vipers(Gloydius shedaoensis) on Snake Island in the Liaoning Province,China,are among the most imperiled species in China.The isolated and unique populations are crucial in the recovery of this endangered species by providing a way for conservation and management.Research based on the ecological simulation tools can evaluate alternative mitigation strategies in terms of their benefits to the populations,which are vital for informed decision-making.In this paper,using the program VORTEX 9.42,we developed a population viability analysis(PVA) for the Shedao pit-viper to:(1) address the extinction likelihood of the population;(2) simulate population dynamics under various environment events,and(3) evaluate the efficacy of current protection and management strategies.Overall,we found the population to be susceptible to the factors of catastrophic events,mortality and environment capacity.The population is recovering slowly at present on account of improvement of habitat and greater food availability.Under the current conditions,the probability of extinction in 100 years is approximately zero.These data coincide with the evidence that the wild population may be arriving at K.Our results strengthen the view that protection and management can create a pronounced effect on populations of this endangered species.
基金The project supported by the Natural Science Foundation of Fujian Province(2007J0008and C0720002)the Training Program of Fujian Excellent Talents in University
文摘OBJECTIVE To investigate the thrombolytic and antiplatelet effects of a novel plasminogen activator from the venom of Gloydius brevicaudus viper(GBV-PA)in vitro and in vivo.METHODS Thrombolytic experiments were performed in rabbit models of ear vein thrombosis and carotid artery thrombosis,and in dog model of acute cerebral infarction.Inhibition of thrombus formation was evaluated in rat inferior vena cava thrombosis model and ferric chloride-induced arterial thrombosis.In vitro,we assayed the antithrombotic effect of GBV-PA on rabbit blood clots,euglobulin lysis time(ELT)of rabbit plasma,and on ADP-induced platelet aggregation.RESULTS GBV-PA intravenous administ ration significantly reduced vascular recanalization times of rabbit ear veins thrombosis and thrombus weight of rabbit carotid artery thrombosis.The arterial recanalization rates were dose-and time-dependently improved after administration of GBV-PA in canine acute cerebral infarction model.Thrombus length and weight was significantly reduced by GBV-PA both in rat inferior vena cava and ferric chloride-induced arterial thrombosis models.Thrombus formation of blood of rabbits they were administrated with GBV-PA was also inhibited.GBV-PA radically reduced plasma ELT of rabbit′s blood clots.ADP-induced platelet aggregation was inhibited by GBV-PA in a dose-dependent manner with a half-maximal inhibitory concentration of 19.9μg·mL-1.CONCLUSION This study demonstrates that GBV-PA is a thrombolytic and antiplatelet agent.It has significant antithrombotic effects on various in vitro and in vivo experimental models of thrombosis.The mechanisms that underline its antithrombotic effects were related to GBV-PA′s capabilities of increasing fibrinolytic activities and inhibition of platelet aggregation.
基金supported by grants from Liaoning Snake Island Laotie Mountain National Nature Reserve (grant number: Y8Y3041)Biodiversity Survey and Assessment Project of the Ministry of Ecology a nd Environment (gra nt number: 2019HJ2096001006)。
文摘Group living has increasingly been emphasized due to its potential consequence on inbreeding, nevertheless, the relationship between group living and inbreeding risk is largely unknown. The endangered snake species, Shedao pit viper(Gloydius shedaoensis) inhabiting mostly on Shedao Island(meaning "snake island" in Chinese), provides an excellent model system for research on group living and inbreeding risk. Small island area, high population density and extreme seasonal foraging opportunity prompt many individuals to live on the same tree, which likely increase the potential mating among relatives. To confirm this probability, we used genotypes from 13 microsatellites DNA markers and examined the genetic relationships between pair of individuals lived on the same tree. The results showed that snakes on the same tree did not show closer relationships compared with individuals from different trees. The group constructions based on scenarios of parental-offspring, full-sibling, half-sibling as well as cousin were not consistent with tree-based group living. In addition, we did not find significant correlation between pair of individual genetic distance and geographic distance going beyond trees, suggesting group living on trees might not elevate inbreeding risk.
基金Key Laboratory of Southwest China Wildlife Resources Conservation(Ministry of Education),China West Normal University(XNYB18-02)Nature Conservation of Snake Island and Laotieshan Mountain,Dalian,China(Y8Y3041).
文摘Island species and their ecosystems play an important role in global biodiversity preservation,and many vulnerable island species are conservation priorities.Although insular habitat likely facilitates the species diversification process,it may also aggravate the fragility of these species with high risk of inbreeding.The Shedao pit-viper Gloydius shedaoensis is an island endemic species with an extremely high population density,which has been categorized as vulnerable in the IUCN(International Union for the Conservation of Nature and Natural Resources)Red List.We collected 13,148 SNP(Single Nucleotide Polymorphism)from across its genome and examined its genetic diversity and demographic history.The Shedao pit-viper has a low genetic diversity but shows no sign of inbreeding.Furthermore,population genetic structure analysis,including the neighbor-joining tree,principal coordinate analysis,clustering,and spatial autocorrelation,revealed a general lack of spatial structure.Only the isolation by distance residues suggested a weak patchiness.Overall,the population is nearly panmictic and gene flow is evenly distributed across the island.A large number of individuals,small size of the island,and the lack of population structure likely all contribute to the lack of inbreeding in this species.We also detected signs of male-biased dispersal,which likely is another inbreeding avoidance strategy.Historical demographic analysis suggested that the historical population size and distribution of the species are much larger than their current ones.The multiple transgressive–regressive events since the Late Pleistocene are likely the main cause of the population size changes.Taken together,our results provide a basic scientific foundation for the conservation of this interesting and important species.
