The Iberian hare(Lepus granatensis)is an endemic species distributed in Spain and Portugal.Myxomatosis outbreaks affecting this species were detected in 2018 in Central and Southern Spain,spreading afterward.Aiming to...The Iberian hare(Lepus granatensis)is an endemic species distributed in Spain and Portugal.Myxomatosis outbreaks affecting this species were detected in 2018 in Central and Southern Spain,spreading afterward.Aiming to evaluate factors affecting the status of hare population after the arrival of myxomatosis,we conducted 108 nocturnal hare counts in Central Spain during two study periods(winter/spring and summer/autumn)in 54 different hunting grounds,covering 1071 km and observing 884 individuals.The mean density in winter/spring was 7.66 hares/100 ha,(range 6.14-9.54/100 ha),while in summer/autumn,it was 3.4 hares/100 ha(range 2.6-4.4/100 ha).Densities of hares were not affected by the dominant habitat and the presence/absence of myxomatosis outbreaks.Hares were more abundant at hunting grounds at a higher altitude and in those conducting targeted management,while detection of myxomatosis was related to lower altitude and higher levels of game management.A MaxEnt model used to generate a risk map for myxomatosis occurrence showed that the temperature annual range was the most important predictor,which suggests that environmental factors affecting myxomatosis vectors(mosquitoes,fleas,and ticks)could play a key role in disease transmission.As myxomatosis in hares is becoming endemic,hare densities may be improved by game management and the monitoring and surveillance of this emerging disease.These surveillance programs could be the basis of effective collaborations between hunters,researchers,and environmental managers.展开更多
In this study, we report that we successfully cloned and sequenced a chitinase gene from the ovotestis of Kuroda’s sea hare Aplysia kurodai. By using reverse transcription-polymerase chain reaction (RT-PCR) and a sys...In this study, we report that we successfully cloned and sequenced a chitinase gene from the ovotestis of Kuroda’s sea hare Aplysia kurodai. By using reverse transcription-polymerase chain reaction (RT-PCR) and a system for the 5’ and 3’ rapid amplification of cDNA ends, we obtained a 1352 bp chitinase gene (AkChi) from the ovotestis of A. kurodai. AkChi contains a 1263 bp open reading frame that encodes 421 amino acids. The domain structure predicted from the deduced amino acid sequence was an N-terminal signal peptide and a catalytic domain of glycoside hydrolase (GH) family 18 chitinase. A comparative analysis of the deduced amino acid sequences of AkChi with those of the acidic mammalian chitinase of the California sea hare Aplysia californica revealed the highest homology at 83%. The purified chitinase from the ovotestis was digested by trypsin, and 119 residues of digested peptides were consistent with the deduced amino acid sequence of AkChi. We used RT-PCR to evaluate the expression of AkChi in various tissues of A. kurodai, and we observed that AkChi was expressed only in the ovotestis. A phylogenetic tree analysis, performed using the amino acid sequences of AkChi and known GH family 18 chitinases, showed that AkChi was separated from the molluscan chitinases with a chitin binding domain. To our knowledge, this is the first study demonstrating the cDNA cloning of an ovotestis chitinase from a sea hare.展开更多
We applied <em>n</em>-variable conserving nonlinear differential equations (<em>n</em>-CNDEs) to the population data of the 10-year cycles of Canadian lynx (1821-2016) and the snowshoe hare (18...We applied <em>n</em>-variable conserving nonlinear differential equations (<em>n</em>-CNDEs) to the population data of the 10-year cycles of Canadian lynx (1821-2016) and the snowshoe hare (1845-1921). Modeling external effects as perturbations to population dynamics, recovering and restorations from disintegrations (or extinctions), stability and survival strategies are discussed in terms of the conservation law inherent to dynamical interactions among species. The 2-variable conserving nonlinear interaction (2CNIs) is extended to 3, 4, ... <em>n</em>-variable conserving nonlinear interactions (<em>n</em>-CNIs) of species by adjusting minimum unknown parameters. The population cycle of species is a manifestation of conservation laws existing in complicated ecosystems, which is suggested from the CNDE analysis as <em>a standard rhythm</em> of interactions. The ecosystem is a consequence of the long history of nonlinear interactions and evolutions among life-beings and the natural environment, and the population dynamics of an ecosystem are observed as approximate CNIs. Physical analyses of the conserving quantity in nonlinear interactions would help us understand why and how they have developed. The standard rhythm found in nonlinear interactions should be considered as a manifestation of the survival strategy and the survival of the fittest to the balance of biological systems. The CNDEs and nonlinear differential equations with time-dependent coefficients would help find useful physical information on the survival of the fittest and symbiosis in an ecosystem.展开更多
Objective:To investigate clinicopathological,bacteriological and pathological aspects of an experimental infection with Yersinia pseudotuberculosis(Y.pseudotuberculosis)in hares in order to verify the efficacy of sero...Objective:To investigate clinicopathological,bacteriological and pathological aspects of an experimental infection with Yersinia pseudotuberculosis(Y.pseudotuberculosis)in hares in order to verify the efficacy of serology for the in vivo diagnosis.Moreover,the pathogenicity of two Y.pseudotuberculosis strains was investigated in order to detect potential differences.Methods:Twelve European brown hares(Lepus europaeus,Pallas)were experimentally infected per os and via conjunctival mucosae with Y.pseudotuberculosis:six subjects were infected with a strain isolated from a naturally infected hare(YpH)and six subjects with a strain isolated from a naturally infected rabbit(YpR).Two hares were used as negative controls.All animals were subjected to clinical,bacteriological and serological examinations during 9 weeks following the infection and,at the end of the control period,subjects still alive were euthanized and submitted to a complete post mortem examination.Results:All faecal samples collected during the control period were positive for bacteriological examinations and to a PCR for the inv gene of Y.pseudotuberculosis,while only one Yp H-infected hare showed a positive haemocultures.From the 2nd to the 9th week post infection(pi),serological analysis revealed specific antibodies with titers ranging from 1:10 to 1:160 in all YpH-infected and two YpR-infected subjects.All the Yp H-infected and two Yp R-infected hares scored positive for Y.pseudotuberculosis by means of bacteriological investigations.Grossly,suppurative multifocal lesions were detected in liver,spleen,kidney and sub-mandibular lymph nodes in both YpH-and YpR-infected hares and confirmed with histopathology.Pulmonary lesions were observed only in Yp H-infected subjects.Immunohistochemistry confirmed the presence of bacterial antigen in all infected animals.Conclusion:Results of this study revealed that YpH strain is more pathogenic for hares than the YpR strain;moreover the serological test performed in this study could be used for the diagnosis of p展开更多
Optimal escape theory predicts that animals would balance the costs and benefits of flight. One cost of not fleeing is the ongoing cost of vigilance for upcoming environmental threats. Our results show that FID increa...Optimal escape theory predicts that animals would balance the costs and benefits of flight. One cost of not fleeing is the ongoing cost of vigilance for upcoming environmental threats. Our results show that FID increases for vigilant hares with predator starting distance, due to the costs acquired by continuing to scan for ecological dangers. The presence of conspecifics within proximity distance for social hare was reduced FID due to collective vigilance, while a solitary animal had greater FID, due to less cooperative defense for predator detection. In both seasons, detection and flight initiation distance of the focal hare increased in open habitat due to a higher probability of detection for upcoming danger, while dense cover provided concealment but reduced the probability of detecting an incoming threat, reducing FID. Moreover, proximity to roads and the nearest refuge significantly influenced anti-predator risk by compensation energy to cope with approaching stimuli. In a landscape with heavy human hunting in retaliation to plantations damage has modified the natural behavior of the hare in the Shigar valley. The findings are discussed in the context of hare FID by humans and the suggestions for management and mitigation of human-wildlife conflict are also considered.展开更多
基金We are grateful to all hunters and game managers who kindly participated in the study and helped in field work.Special thanks are given to the Hunters’and Coursing Federation of Castilla-La Mancha.We thank anonymous reviewers for their comments.This study was funded by Junta de Castilla-La Mancha and core funds from Fundación Artemisan.We are indebted to L.G.L.for her support,S.P.V.for compiling data of lagomorph hunting in Castilla-La Mancha,and the Laboratorio Central de Veterinaria de Algete for providing the outbreaks’information.
文摘The Iberian hare(Lepus granatensis)is an endemic species distributed in Spain and Portugal.Myxomatosis outbreaks affecting this species were detected in 2018 in Central and Southern Spain,spreading afterward.Aiming to evaluate factors affecting the status of hare population after the arrival of myxomatosis,we conducted 108 nocturnal hare counts in Central Spain during two study periods(winter/spring and summer/autumn)in 54 different hunting grounds,covering 1071 km and observing 884 individuals.The mean density in winter/spring was 7.66 hares/100 ha,(range 6.14-9.54/100 ha),while in summer/autumn,it was 3.4 hares/100 ha(range 2.6-4.4/100 ha).Densities of hares were not affected by the dominant habitat and the presence/absence of myxomatosis outbreaks.Hares were more abundant at hunting grounds at a higher altitude and in those conducting targeted management,while detection of myxomatosis was related to lower altitude and higher levels of game management.A MaxEnt model used to generate a risk map for myxomatosis occurrence showed that the temperature annual range was the most important predictor,which suggests that environmental factors affecting myxomatosis vectors(mosquitoes,fleas,and ticks)could play a key role in disease transmission.As myxomatosis in hares is becoming endemic,hare densities may be improved by game management and the monitoring and surveillance of this emerging disease.These surveillance programs could be the basis of effective collaborations between hunters,researchers,and environmental managers.
文摘In this study, we report that we successfully cloned and sequenced a chitinase gene from the ovotestis of Kuroda’s sea hare Aplysia kurodai. By using reverse transcription-polymerase chain reaction (RT-PCR) and a system for the 5’ and 3’ rapid amplification of cDNA ends, we obtained a 1352 bp chitinase gene (AkChi) from the ovotestis of A. kurodai. AkChi contains a 1263 bp open reading frame that encodes 421 amino acids. The domain structure predicted from the deduced amino acid sequence was an N-terminal signal peptide and a catalytic domain of glycoside hydrolase (GH) family 18 chitinase. A comparative analysis of the deduced amino acid sequences of AkChi with those of the acidic mammalian chitinase of the California sea hare Aplysia californica revealed the highest homology at 83%. The purified chitinase from the ovotestis was digested by trypsin, and 119 residues of digested peptides were consistent with the deduced amino acid sequence of AkChi. We used RT-PCR to evaluate the expression of AkChi in various tissues of A. kurodai, and we observed that AkChi was expressed only in the ovotestis. A phylogenetic tree analysis, performed using the amino acid sequences of AkChi and known GH family 18 chitinases, showed that AkChi was separated from the molluscan chitinases with a chitin binding domain. To our knowledge, this is the first study demonstrating the cDNA cloning of an ovotestis chitinase from a sea hare.
文摘We applied <em>n</em>-variable conserving nonlinear differential equations (<em>n</em>-CNDEs) to the population data of the 10-year cycles of Canadian lynx (1821-2016) and the snowshoe hare (1845-1921). Modeling external effects as perturbations to population dynamics, recovering and restorations from disintegrations (or extinctions), stability and survival strategies are discussed in terms of the conservation law inherent to dynamical interactions among species. The 2-variable conserving nonlinear interaction (2CNIs) is extended to 3, 4, ... <em>n</em>-variable conserving nonlinear interactions (<em>n</em>-CNIs) of species by adjusting minimum unknown parameters. The population cycle of species is a manifestation of conservation laws existing in complicated ecosystems, which is suggested from the CNDE analysis as <em>a standard rhythm</em> of interactions. The ecosystem is a consequence of the long history of nonlinear interactions and evolutions among life-beings and the natural environment, and the population dynamics of an ecosystem are observed as approximate CNIs. Physical analyses of the conserving quantity in nonlinear interactions would help us understand why and how they have developed. The standard rhythm found in nonlinear interactions should be considered as a manifestation of the survival strategy and the survival of the fittest to the balance of biological systems. The CNDEs and nonlinear differential equations with time-dependent coefficients would help find useful physical information on the survival of the fittest and symbiosis in an ecosystem.
文摘Objective:To investigate clinicopathological,bacteriological and pathological aspects of an experimental infection with Yersinia pseudotuberculosis(Y.pseudotuberculosis)in hares in order to verify the efficacy of serology for the in vivo diagnosis.Moreover,the pathogenicity of two Y.pseudotuberculosis strains was investigated in order to detect potential differences.Methods:Twelve European brown hares(Lepus europaeus,Pallas)were experimentally infected per os and via conjunctival mucosae with Y.pseudotuberculosis:six subjects were infected with a strain isolated from a naturally infected hare(YpH)and six subjects with a strain isolated from a naturally infected rabbit(YpR).Two hares were used as negative controls.All animals were subjected to clinical,bacteriological and serological examinations during 9 weeks following the infection and,at the end of the control period,subjects still alive were euthanized and submitted to a complete post mortem examination.Results:All faecal samples collected during the control period were positive for bacteriological examinations and to a PCR for the inv gene of Y.pseudotuberculosis,while only one Yp H-infected hare showed a positive haemocultures.From the 2nd to the 9th week post infection(pi),serological analysis revealed specific antibodies with titers ranging from 1:10 to 1:160 in all YpH-infected and two YpR-infected subjects.All the Yp H-infected and two Yp R-infected hares scored positive for Y.pseudotuberculosis by means of bacteriological investigations.Grossly,suppurative multifocal lesions were detected in liver,spleen,kidney and sub-mandibular lymph nodes in both YpH-and YpR-infected hares and confirmed with histopathology.Pulmonary lesions were observed only in Yp H-infected subjects.Immunohistochemistry confirmed the presence of bacterial antigen in all infected animals.Conclusion:Results of this study revealed that YpH strain is more pathogenic for hares than the YpR strain;moreover the serological test performed in this study could be used for the diagnosis of p
文摘Optimal escape theory predicts that animals would balance the costs and benefits of flight. One cost of not fleeing is the ongoing cost of vigilance for upcoming environmental threats. Our results show that FID increases for vigilant hares with predator starting distance, due to the costs acquired by continuing to scan for ecological dangers. The presence of conspecifics within proximity distance for social hare was reduced FID due to collective vigilance, while a solitary animal had greater FID, due to less cooperative defense for predator detection. In both seasons, detection and flight initiation distance of the focal hare increased in open habitat due to a higher probability of detection for upcoming danger, while dense cover provided concealment but reduced the probability of detecting an incoming threat, reducing FID. Moreover, proximity to roads and the nearest refuge significantly influenced anti-predator risk by compensation energy to cope with approaching stimuli. In a landscape with heavy human hunting in retaliation to plantations damage has modified the natural behavior of the hare in the Shigar valley. The findings are discussed in the context of hare FID by humans and the suggestions for management and mitigation of human-wildlife conflict are also considered.
