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
The Yangtze vole(Microtus fortis Buechner,1889)is a small herbivore species that inhabits lake beaches in the Dongting Lake region along the Yangtze River in Southern China.Its population shows strong oscillations dur...The Yangtze vole(Microtus fortis Buechner,1889)is a small herbivore species that inhabits lake beaches in the Dongting Lake region along the Yangtze River in Southern China.Its population shows strong oscillations during the wet season due to summer precipitation-induced immigration away from the lake into adjacent rice fields.The effect of El Niño-Southern Oscillation-driven precipitation on population abundance and growth of the vole species is not fully understood.We undertook an analysis of the combined data of 4 time series covering 1981–2006 from 4 different sites and a separate analysis on a single time series(1981–2006)from one site.Our results demonstrate that a dual effect of El Niño-Southern Oscillation-driven precipitation on the population abundance of voles is timedependent:precipitation in the current year has a positive effect,whereas precipitation in the previous year has a negative effect.The dual effect of precipitation on vole population is well explained by the unique interactions among vole population,precipitation water level and the lake beach habitat around Dongting Lake.We found that drier than average weather of the previous year benefited voles because their breeding habitats,lake beaches,were exposed for long stretches of time.Wet weather was found to increase the number of voles inhabiting rice fields because as the water level of the lake rose they were forced from beaches into surrounding rice fields.Summer precipitation in the Dongting Lake region was found to be positively associated with the sea surface temperature(SST)of the eastern tropical Pacific Ocean of the previous year and winter SST and spring SST of the current year.Annual rates of increase in the vole population of the reconstructed time series are negatively associated with the vole abundance and autumn precipitation of the previous year and winter precipitation of the current years.These results suggest that both extrinsic and density-dependent intrinsic factors may affect population dynamics of the Yangtze voles.展开更多
Microtus fortis calamorum inhabit on the beach of Dongting Lake from winter to spring, and hereafter are forced to migrate into rice field by flood and live there until autumn usually. We had compared the viscera indi...Microtus fortis calamorum inhabit on the beach of Dongting Lake from winter to spring, and hereafter are forced to migrate into rice field by flood and live there until autumn usually. We had compared the viscera indices (viscera indices=viscera weight/body weight×100g, including heart, lung, liver, spleen, kidney, stomach without content and testis) and intestinal tract length of M.fortis calamorum from the beach of Dongting Lake in spring, the rice field in autumn and laboratory populations. There were significant differences in the indices of liver, spleen, kidney and stomach of females among the three habitats, and so were the indices of heart, spleen, kidney, stomach and testis of males. The spleen indices of wild voles from the beach of Dongting Lake and rice field were conspicuously bigger than that of laboratory ones. The length of caecum, large+small intestine and total intestinal tract of wild voles were significantly longer than that of laboratory ones, and the length of caecum of voles from the beach of Dongting Lake were significantly longer than that of animals from the rice field. The results suggest that the bigger spleen of wild voles is probably an immunoreation to the infection of the animalcule and schistosome, and that the intestinal tract length is related to the food quality and the requirement of energy and nutrition. The caecum length extends with the increase of the cellulose in the food.展开更多
为了解东方田鼠(Microtusfortis)筑巢行为在不同环境条件下的适应性进化。在实验室内采用48 h等级法和连续144 h巢材获取重量法,比较了东方田鼠长江亚种(M. f. calamorumt)和指名亚种(M. f. fortis)筑巢行为。结果表明,东方田鼠指名亚...为了解东方田鼠(Microtusfortis)筑巢行为在不同环境条件下的适应性进化。在实验室内采用48 h等级法和连续144 h巢材获取重量法,比较了东方田鼠长江亚种(M. f. calamorumt)和指名亚种(M. f. fortis)筑巢行为。结果表明,东方田鼠指名亚种和长江亚种皆能主动获取巢材并建筑质量良好的巢,具有稳定的筑巢行为;东方田鼠两个亚种的筑巢行为在利用巢材能力(P <0.01)和获取巢材能力(P <0.05)上皆具有显著性差异;指名亚种雌雄个体在利用巢材(P <0.05)和获取巢材的能力(P<0.05)上皆具有显著差异,而长江亚种在这两个方面都不存在性别差异。展开更多
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 State Basic Research Program of Ministry of Science and Technology(2007CB109100)CAS project(GJHZ 200810)the ISZS international research program Biological Consequences of Global Change(BCGC)sponsored by Bureau of International Cooperation,Chinese Academy of Sciences(GJHZ200810).
文摘The Yangtze vole(Microtus fortis Buechner,1889)is a small herbivore species that inhabits lake beaches in the Dongting Lake region along the Yangtze River in Southern China.Its population shows strong oscillations during the wet season due to summer precipitation-induced immigration away from the lake into adjacent rice fields.The effect of El Niño-Southern Oscillation-driven precipitation on population abundance and growth of the vole species is not fully understood.We undertook an analysis of the combined data of 4 time series covering 1981–2006 from 4 different sites and a separate analysis on a single time series(1981–2006)from one site.Our results demonstrate that a dual effect of El Niño-Southern Oscillation-driven precipitation on the population abundance of voles is timedependent:precipitation in the current year has a positive effect,whereas precipitation in the previous year has a negative effect.The dual effect of precipitation on vole population is well explained by the unique interactions among vole population,precipitation water level and the lake beach habitat around Dongting Lake.We found that drier than average weather of the previous year benefited voles because their breeding habitats,lake beaches,were exposed for long stretches of time.Wet weather was found to increase the number of voles inhabiting rice fields because as the water level of the lake rose they were forced from beaches into surrounding rice fields.Summer precipitation in the Dongting Lake region was found to be positively associated with the sea surface temperature(SST)of the eastern tropical Pacific Ocean of the previous year and winter SST and spring SST of the current year.Annual rates of increase in the vole population of the reconstructed time series are negatively associated with the vole abundance and autumn precipitation of the previous year and winter precipitation of the current years.These results suggest that both extrinsic and density-dependent intrinsic factors may affect population dynamics of the Yangtze voles.
文摘Microtus fortis calamorum inhabit on the beach of Dongting Lake from winter to spring, and hereafter are forced to migrate into rice field by flood and live there until autumn usually. We had compared the viscera indices (viscera indices=viscera weight/body weight×100g, including heart, lung, liver, spleen, kidney, stomach without content and testis) and intestinal tract length of M.fortis calamorum from the beach of Dongting Lake in spring, the rice field in autumn and laboratory populations. There were significant differences in the indices of liver, spleen, kidney and stomach of females among the three habitats, and so were the indices of heart, spleen, kidney, stomach and testis of males. The spleen indices of wild voles from the beach of Dongting Lake and rice field were conspicuously bigger than that of laboratory ones. The length of caecum, large+small intestine and total intestinal tract of wild voles were significantly longer than that of laboratory ones, and the length of caecum of voles from the beach of Dongting Lake were significantly longer than that of animals from the rice field. The results suggest that the bigger spleen of wild voles is probably an immunoreation to the infection of the animalcule and schistosome, and that the intestinal tract length is related to the food quality and the requirement of energy and nutrition. The caecum length extends with the increase of the cellulose in the food.
文摘为了解东方田鼠(Microtusfortis)筑巢行为在不同环境条件下的适应性进化。在实验室内采用48 h等级法和连续144 h巢材获取重量法,比较了东方田鼠长江亚种(M. f. calamorumt)和指名亚种(M. f. fortis)筑巢行为。结果表明,东方田鼠指名亚种和长江亚种皆能主动获取巢材并建筑质量良好的巢,具有稳定的筑巢行为;东方田鼠两个亚种的筑巢行为在利用巢材能力(P <0.01)和获取巢材能力(P <0.05)上皆具有显著性差异;指名亚种雌雄个体在利用巢材(P <0.05)和获取巢材的能力(P<0.05)上皆具有显著差异,而长江亚种在这两个方面都不存在性别差异。
