The outbreak of Yantze vole ( Microtus fortis) population in Dongting Lake region is closely related to the evolvement of lake beaches,because the deposition of lake sediments results in the expansion of lake beaches,...The outbreak of Yantze vole ( Microtus fortis) population in Dongting Lake region is closely related to the evolvement of lake beaches,because the deposition of lake sediments results in the expansion of lake beaches,which provides the possibility of the increase of the vole's population. Reclaiming farmland from lake via building cofferdams,eliminating snails by building cofferdams for eradicating schistosomiasis,and over-hunting predators in the region cause the voles becoming a pest after the 1970s. In recent years,the Three Gorges Project and the conversion from farmland into lake have had deep impacts on the environment in the lake region. The dispatching of the down flow rate by the project has induced the expansion of the low and medium level beaches in the lake region,while converting farmland into lake directly has induced the expansion of the lake beaches,both of which have expanded the potential habitats of the vole's population. Therefore,more attention should be paid to the quantitative variation trend of the vole's population in the future.展开更多
Although the Three Gorges Project(TGP)may have affected the population structure and distribution of plant and animal communities,few studies have analyzed the effect of this project on small mammal communities.Theref...Although the Three Gorges Project(TGP)may have affected the population structure and distribution of plant and animal communities,few studies have analyzed the effect of this project on small mammal communities.Therefore,the present paper compares the small mammal communities inhabiting the beaches of Dongting Lake using field investigations spanning a 20-year period,both before and after the TGP was implemented.Snap traps were used throughout the census.The results indicate that the TGP caused major changes to the structure of the small mammal community at a lake downstream of the dam.First,species abundance on the beaches increased after the project commenced.The striped field mouse(Apodemus agrarius)and the Norway rat(Rattus norvegicus),which rarely inhabited the beach before the TGP,became abundant(with marked population growth)once water was impounded by the Three Gorges Reservoir.Second,dominant species concentration indices exhibited a stepwise decline,indicating that the community structure changed from a single dominant species to a more diverse species mix after TGP implementation.Third,the regulation of water discharge release by the TGP might have caused an increase in the species diversity of the animal community on the beaches.A significant difference in diversity indices was obtained before and after the TGP operation.Similarity indices also indicate a gradual increase in species numbers.Hence,a long-term project should be established to monitor the population fluctuations of the Yangtze vole(Microtus fortis),the striped field mouse and the Norway rat to safeguard against population outbreaks(similar to the Yangtze vole outbreak in 2007),which could cause crop damage to adjacent farmland,in addition to documenting the succession process of the small mammal community inhabiting the beaches of Dongting Lake.展开更多
In terms of taxonomic status,common carp(Cyprinus carpio,Cyprininae)and crucian carp(Carassius auratus,Cyprininae)are different species;however,in this study,a newborn homodiploid crucian carp-like fish(2n=100)(2nNCRC...In terms of taxonomic status,common carp(Cyprinus carpio,Cyprininae)and crucian carp(Carassius auratus,Cyprininae)are different species;however,in this study,a newborn homodiploid crucian carp-like fish(2n=100)(2nNCRC)lineage(F1–F3)was established from the interspecific hybridization of female common carp(2n=100)×male blunt snout bream(Megalobrama amblycephala,Cultrinae,2n=48).The phenotypes and genotypes of 2 n NCRC differed from those of its parents but were closely related to those of the existing diploid crucian carp.We further sequenced the whole mitochondrial(mt)genomes of the 2n NCRC lineage from F1 to F3.The paternal mt DNA fragments were stably embedded in the mt-genomes of F1–F3 generations of 2n NCRC to form chimeric DNA fragments.Along with this chimeric process,numerous base sites of F1–F3 generations of 2 n NCRC underwent mutations.Most of these mutation sites were consistent with the existing diploid crucian carp.Moreover,the mt DNA organization and nucleotide composition of 2n NCRC were more similar to those of the existing diploid crucian carp than those of the parents.The inheritable chimeric DNA fragments and mutant loci in the mt-genomes of different generations of 2nNCRC provided important evidence of the mt DNA change process in the newborn lineage derived from hybridization of different species.Our findings demonstrated for the first time that the paternal mt DNA were transmitted into the mt-genomes of homodiploid lineage,which provided new insights into the existence of paternal mt DNA in the mt DNA inheritance.展开更多
To understand genetic variation and population dispersal in the Yangtze vole Microtusfortis calamorum distributed in the Dongting Lake region, 144 individuals were collected from six habitat patches. The mitochondrial...To understand genetic variation and population dispersal in the Yangtze vole Microtusfortis calamorum distributed in the Dongting Lake region, 144 individuals were collected from six habitat patches. The mitochondrial DNA control region was sequenced and 17 haplotypes were observed. Of the six investigated populations, haplotype and nucleotide diversities of those from larger patches were higher than those from smaller patches. Nonparametric correlation analysis showed that patch size had a positive correlation with haplotype diversity （r = 0.943, P 〈 0.01）. A neighbour-joining tree of the 17 haplotypes showed no geo- graphic genetic structure among the six populations. Analysis of isolation by distance showed that genetic differentiation among the six populations was not positively related to geographic distance. Analysis of mismatch distribution indicated that the voles had passed through a population expansion. The pattern of haplotype distribution in the Changsha population suggests that the population was established by a founder effect展开更多
Fertility control agents for the management of rodent populations are developing and maturing.Investigating the impacts on non-target species of consumption of these agents is essential.The present study assessed the ...Fertility control agents for the management of rodent populations are developing and maturing.Investigating the impacts on non-target species of consumption of these agents is essential.The present study assessed the non-target toxicity effects of quinestrol,a synthetic estrogen-based antifertility agent for managing rodent populations.Various quinestrol doses administered to male and female(n=60 each)chickens through single oral gavage were 0(A),10(B),50(C),and 150(D)mg/kg body weight.Chickens were assessed for effect on body weight,weight of vital and reproductive organs,reproductive hormones,histology of reproductive organs and egg laying rates after 15,30,and 135 days of treatment.Quinestrol did not induce mortality in chickens and its effects were time and dose dependent.The 90%egg-laying rates were delayed by 30,60 for groups B and C compared with the control group,and group D did not reach the 90%egg-laying rate by 135 days.Reproductive organs in males and females returned to normal levels within 30 and 135 days,respectively.With the exception of the FSH concentration in group D,reproductive hormones of both sexes were similar to controls by 30 days.No other significant effects were found.The present research demonstrated the safety of quinestrol on non-target species and facilitates recommendations for the general administration of quinestrol for rodent pest management.展开更多
Rodent pests severely damage agricultural crops.Outbreak risk models of rodent pests often do not include sufficient information regarding geographic variation.Habitat plays an important role in rodent-pest outbreak r...Rodent pests severely damage agricultural crops.Outbreak risk models of rodent pests often do not include sufficient information regarding geographic variation.Habitat plays an important role in rodent-pest outbreak risk,and more information about the relationship between habitat and crop protection is urgently needed.The goal of the present study was to provide an outbreak risk map for the Dongting Lake region and to understand the relationship between rodent-pest outbreak variation and habitat distribution.The main rodent pests in the Dongting Lake region are Yangtze voles(Microtus fortis).These pests cause massive damage in outbreak years,most notably in 2007.Habitat evaluation and ecological details were obtained by analyzing the correlation between habitat suitability and outbreak risk,as indicated by population density and historical events.For the source-sink population,96.18%of Yangtze vole disaster regions were covered by a 10-km buffer zone of suitable habitat in 2007.Historical outbreak frequency and peak population density were significantly correlated with the proportion of land covered by suitable habitat(r=0.68,P=0.04 and r=0.76,P=0.03,respectively).The Yangtze vole population tends to migrate approximately 10 km in outbreak years.Here,we propose a practical method for habitat evaluation that can be used to create integrated pest management plans for rodent pests when combined with basic information on the biology,ecology and behavior of the target species.展开更多
基金Supported by the National Natural Science Foundation(30870402,31170396)Key Knowledge Innovation Project of Chinese Academy of Sciences(KSCX-EW-N-05)
文摘The outbreak of Yantze vole ( Microtus fortis) population in Dongting Lake region is closely related to the evolvement of lake beaches,because the deposition of lake sediments results in the expansion of lake beaches,which provides the possibility of the increase of the vole's population. Reclaiming farmland from lake via building cofferdams,eliminating snails by building cofferdams for eradicating schistosomiasis,and over-hunting predators in the region cause the voles becoming a pest after the 1970s. In recent years,the Three Gorges Project and the conversion from farmland into lake have had deep impacts on the environment in the lake region. The dispatching of the down flow rate by the project has induced the expansion of the low and medium level beaches in the lake region,while converting farmland into lake directly has induced the expansion of the lake beaches,both of which have expanded the potential habitats of the vole's population. Therefore,more attention should be paid to the quantitative variation trend of the vole's population in the future.
基金The National Natural Science Foundation of China(30870402,31170396,51009129)Hunan Natural Science Foundation(14JJ2136)the Chinese Academy of Sciences(KSCX-EW-N-05)provided financial support for this study.
文摘Although the Three Gorges Project(TGP)may have affected the population structure and distribution of plant and animal communities,few studies have analyzed the effect of this project on small mammal communities.Therefore,the present paper compares the small mammal communities inhabiting the beaches of Dongting Lake using field investigations spanning a 20-year period,both before and after the TGP was implemented.Snap traps were used throughout the census.The results indicate that the TGP caused major changes to the structure of the small mammal community at a lake downstream of the dam.First,species abundance on the beaches increased after the project commenced.The striped field mouse(Apodemus agrarius)and the Norway rat(Rattus norvegicus),which rarely inhabited the beach before the TGP,became abundant(with marked population growth)once water was impounded by the Three Gorges Reservoir.Second,dominant species concentration indices exhibited a stepwise decline,indicating that the community structure changed from a single dominant species to a more diverse species mix after TGP implementation.Third,the regulation of water discharge release by the TGP might have caused an increase in the species diversity of the animal community on the beaches.A significant difference in diversity indices was obtained before and after the TGP operation.Similarity indices also indicate a gradual increase in species numbers.Hence,a long-term project should be established to monitor the population fluctuations of the Yangtze vole(Microtus fortis),the striped field mouse and the Norway rat to safeguard against population outbreaks(similar to the Yangtze vole outbreak in 2007),which could cause crop damage to adjacent farmland,in addition to documenting the succession process of the small mammal community inhabiting the beaches of Dongting Lake.
基金supported by the National Natural Science Foundation of China(31802287,31730098,31430088)the China Postdoctoral Science Foundation(2018M632969)+3 种基金the earmarked fund for China Agriculture Research System(CARS-45)the Key Research and Development Program of Hunan Province(2018NK2072)Hunan Provincial Natural Science and Technology Major Project(2017NK1031)the Cooperative Innovation Center of Engineering and New Products for Developmental Biology of Hunan Province(20134486)
文摘In terms of taxonomic status,common carp(Cyprinus carpio,Cyprininae)and crucian carp(Carassius auratus,Cyprininae)are different species;however,in this study,a newborn homodiploid crucian carp-like fish(2n=100)(2nNCRC)lineage(F1–F3)was established from the interspecific hybridization of female common carp(2n=100)×male blunt snout bream(Megalobrama amblycephala,Cultrinae,2n=48).The phenotypes and genotypes of 2 n NCRC differed from those of its parents but were closely related to those of the existing diploid crucian carp.We further sequenced the whole mitochondrial(mt)genomes of the 2n NCRC lineage from F1 to F3.The paternal mt DNA fragments were stably embedded in the mt-genomes of F1–F3 generations of 2n NCRC to form chimeric DNA fragments.Along with this chimeric process,numerous base sites of F1–F3 generations of 2 n NCRC underwent mutations.Most of these mutation sites were consistent with the existing diploid crucian carp.Moreover,the mt DNA organization and nucleotide composition of 2n NCRC were more similar to those of the existing diploid crucian carp than those of the parents.The inheritable chimeric DNA fragments and mutant loci in the mt-genomes of different generations of 2nNCRC provided important evidence of the mt DNA change process in the newborn lineage derived from hybridization of different species.Our findings demonstrated for the first time that the paternal mt DNA were transmitted into the mt-genomes of homodiploid lineage,which provided new insights into the existence of paternal mt DNA in the mt DNA inheritance.
文摘To understand genetic variation and population dispersal in the Yangtze vole Microtusfortis calamorum distributed in the Dongting Lake region, 144 individuals were collected from six habitat patches. The mitochondrial DNA control region was sequenced and 17 haplotypes were observed. Of the six investigated populations, haplotype and nucleotide diversities of those from larger patches were higher than those from smaller patches. Nonparametric correlation analysis showed that patch size had a positive correlation with haplotype diversity （r = 0.943, P 〈 0.01）. A neighbour-joining tree of the 17 haplotypes showed no geo- graphic genetic structure among the six populations. Analysis of isolation by distance showed that genetic differentiation among the six populations was not positively related to geographic distance. Analysis of mismatch distribution indicated that the voles had passed through a population expansion. The pattern of haplotype distribution in the Changsha population suggests that the population was established by a founder effect
基金supported by the International Partnership Program of the Chinese Academy of Sciences(152111KYSB20160089)the Science and Technology Service Network Initiative(KFJ-STS-ZDTP-2021-002)+2 种基金the Science and Technology Service Network Initiative(KFJ-STS-ZDTP-094)the Key Research and Development Project of Hunan Province(2020NK2040)the National Natural Science Foundation of China(U20A20118).
文摘Fertility control agents for the management of rodent populations are developing and maturing.Investigating the impacts on non-target species of consumption of these agents is essential.The present study assessed the non-target toxicity effects of quinestrol,a synthetic estrogen-based antifertility agent for managing rodent populations.Various quinestrol doses administered to male and female(n=60 each)chickens through single oral gavage were 0(A),10(B),50(C),and 150(D)mg/kg body weight.Chickens were assessed for effect on body weight,weight of vital and reproductive organs,reproductive hormones,histology of reproductive organs and egg laying rates after 15,30,and 135 days of treatment.Quinestrol did not induce mortality in chickens and its effects were time and dose dependent.The 90%egg-laying rates were delayed by 30,60 for groups B and C compared with the control group,and group D did not reach the 90%egg-laying rate by 135 days.Reproductive organs in males and females returned to normal levels within 30 and 135 days,respectively.With the exception of the FSH concentration in group D,reproductive hormones of both sexes were similar to controls by 30 days.No other significant effects were found.The present research demonstrated the safety of quinestrol on non-target species and facilitates recommendations for the general administration of quinestrol for rodent pest management.
基金The authors thank Yalan Liu and Yuhuan Ren for providing 2007 Yangtze vole disaster region data.The research was supported by the Knowledge Innovation Program of The Chinese Academy Sciences(KSCXEW-N-05)the Exclusive Research Fund for the Public Good Granted by Ministry of Environment Protection of PRC(2010467022).
文摘Rodent pests severely damage agricultural crops.Outbreak risk models of rodent pests often do not include sufficient information regarding geographic variation.Habitat plays an important role in rodent-pest outbreak risk,and more information about the relationship between habitat and crop protection is urgently needed.The goal of the present study was to provide an outbreak risk map for the Dongting Lake region and to understand the relationship between rodent-pest outbreak variation and habitat distribution.The main rodent pests in the Dongting Lake region are Yangtze voles(Microtus fortis).These pests cause massive damage in outbreak years,most notably in 2007.Habitat evaluation and ecological details were obtained by analyzing the correlation between habitat suitability and outbreak risk,as indicated by population density and historical events.For the source-sink population,96.18%of Yangtze vole disaster regions were covered by a 10-km buffer zone of suitable habitat in 2007.Historical outbreak frequency and peak population density were significantly correlated with the proportion of land covered by suitable habitat(r=0.68,P=0.04 and r=0.76,P=0.03,respectively).The Yangtze vole population tends to migrate approximately 10 km in outbreak years.Here,we propose a practical method for habitat evaluation that can be used to create integrated pest management plans for rodent pests when combined with basic information on the biology,ecology and behavior of the target species.
