43 resultados para POPULATION VIABILITY ANALYSIS

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Background: Previously reported evidence indicates that pigs were independently domesticated in multiple places throughout the world. However, a detailed picture of the origin and dispersal of domestic pigs in East Asia has not yet been reported. Results:

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The numbers of spawning sites for Chinese sturgeon have been drastically reduced since the construction of the Gezhouba Dam across the Yangtze River. This dam has blocked migration of Chinese sturgeon to their historic spawning ground causing a significant decline of the Chinese sturgeon population. We conducted a VORTEX population viability analysis to estimate the sustainability of the population and to quantify the efficiency of current and alternative conservation procedures. The model predicted the observed decline of Chinese sturgeon, resulting from the effect of the Gezhouba Dam. These simulations demonstrated the potential interest of two conservation measures: increasing spawning area and reducing predation on sturgeon eggs. The simulations also demonstrated that the actual restocking program is not sufficient to sustain sturgeon population as the artificial reproduction program induce the loss of more wild mature adults that the recruitment expected by the artificial reproduction.

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据2003年9月至2005年9月,对云南中部无量山大寨子黑长臂猿种群(5个群体)进行了观察,获得了群体大小、配偶体制、繁殖间隔、环境容纳量、死亡率、灾害的发生频率等种群参数,并结合近缘种的一些相关数据,利用旋涡模型(Vortex 914),对无量山大寨子地区黑长臂猿亚种群的动态进行了模拟分析.结果显示:大寨子亚种群是一个具有很强的潜在繁殖力的种群,如果没有偷猎,亚种群在100a之内不会灭绝,并且能迅速达到环境容纳量.但是每年如果有1只成年雄性和1只成年雌性被猎杀,该种群将会在第78年灭绝,且灭绝概率为100%.不同程度的死亡率对种群影响不大,但高死亡率显著延缓了种群到达环境容纳量的时间.环境容纳量对种群遗传多样性损失具有重要的影响,在没有猎杀的情况下,种群的长期存活需要一个较大的环境容纳量.因此,在黑长臂猿受到严格保护、且栖息地主要在保护区内的今天,严密监控火灾的发生,限制牲畜进入林区等人为干扰的影响,保护好黑长臂猿栖息地是首要工作之一.但如果能使其栖息地周围的森林植被得到恢复,增加其栖息范围,将有利于该地区黑长臂猿的发展.

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National Key Technology R&D Program of China [2008BAK50B05]; Chinese Academy of Sciences [KZCX-YW-Q06, KZCX2-YW-Q03-06]

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根据黑白仰鼻猴( Rhinopithecus bieti ) 的相关参数, 借助漩涡模型(Vortex 9142) , 对黑白仰鼻猴的 种群动态进行了模拟分析。结果表明, 在没有近亲繁殖和偷猎影响的情况下, 各亚种群100 年间均持续增长, 即使数量较少的攀天阁和白济讯亚种群的灭绝概率也只有3 %和6 %。在加入近亲繁殖和偷猎因素时, 有5 个亚 种群(小昌都、乌牙普牙、金丝厂、富合山和格花箐) 保持增长态势, 3 亚种群(茨卡通、各摩茸及响姑箐) 数量保持稳定, 其他5 个亚种群(米拉卡、巴美、龙马山、攀天阁和白济讯) 呈下降趋势。在其他条件相同的 情况下, 大的环境容纳量能够促进亚种群的增长, 因此, 保护生境是保护该物种的根本途径。偷猎对整个异质 种群增长有负作用, 所以杜绝偷猎发生是保护该物种的重要条件。近亲繁殖率随种群减小和时间推移逐渐增 加, 也对猴群的长期存活有负面影响。

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Amplified fragment length polymorphism (AFLP) was used to analyse the genetic structure of 45 individuals of Gymnocypris przewalskii (Kessler, 1876), an endangered and state-protected rare fish species, from three areas [the Heima (HM), Buha (BH) and Shaliu rivers (SL), all draining into Qinghai Lake]. A total of 563 polymorphic loci were detected. The HM, BH and SL populations have 435, 433 and 391 loci, respectively (Zhu and Wu, 1975), which account for 77.26%, 76.91% and 69.45% of the total number of polymorphic loci of each population, respectively. The Nei indices of genetic diversities (H) of the three populations were calculated to be 0.2869 (HM), 0.2884 (BH) and 0.2663 (SL), respectively. Their Shannon informative indices are 0.4244, 0.4251 and 0.3915, respectively. Research results show that the mean genetic distance between HM and BH is the smallest (0.0511), between BH and SL is the second shortest (0.0608), and between HM and SL is the largest (0.0713), with the mean genetic distance among the three populations being over 0.05. Data mentioned above indicate that the three populations have a certain genetic differentiation. The total genetic diversity (H-t = 0.3045) and the mean value of genetic diversity within the population (H-s = 0.2786) indicate that the variations have mainly come from within the population.

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The population genetic structure of the crimson snapper Lutjanus erythropterus in East Asia was examined with a 427-bp hypervariable portion of the mtDNA control region. A total of 262 samples were collected and 75 haplotypes were obtained. Neutrality tests (Tajima's and Fu's) suggested that Lutjanus erythropterus in East Asia had experienced a bottleneck followed by population expansion since the late Pleistocene. Despite the low phylogeographic structures in mtDNA haplotypes, a hierarchical examination of populations in 11 localities from four geographical regions using analysis of molecular variance (AMOVA) indicated significant genetic differentiation among regions (Phi(CT) = 0.08564, p < 0.01). Limited gene flow between the eastern region (including a locality in the western Pacific Ocean and two localities in the East Sea) and three geographic regions of the South China Sea largely contributed to the genetic subdivision. However, comparisons among three geographic regions of the South China Sea showed little to no genetic difference. Populations of Lutjanus erythropterus in East Asia are inferred to be divided into two major groups: an eastern group, including populations of the western Pacific Ocean and the East Sea, and a South China Sea group, consisting of populations from northern Malaysia to South China. The results suggest that fishery management should reflect the genetic differentiation and diversity in East Asia. (c) 2006 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.

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Mitochondrial DNA, purified from 36 samples of 23 local populations which are widely distributed in Vietnam, Burma, and 10 provinces of China, has been analyzed to model the phylogeny of rhesus monkeys. The 20 local populations of China may represent nearly all major populations in China. Using 20 restriction endonucleases of 6-bp recognition, we observed a total of 50-61 sites in the various samples. By combining the cleavage patterns for each enzyme, the 36 samples were classified into 23 restriction types, each of which was found exclusively in the respective population from which samples were obtained By combining the earlier study of Indian rhesus monkeys, phylogenetic trees, which have been constructed on the basis of genetic distance, indicate that rhesus monkeys in China, Vietnam, India, and Burma can be divided into seven groups. Integrating morphological and geographical data, we suggest that rhesus monkeys in China, Vietnam, and Burma may be classified into six subspecies-M. m. mulatta, M. m. brevicaudus, M. m. lasiotis, M. m. littoralis, M. m. vestita, and M. m. tcheliensis-and rhesus monkeys in India may be another valid subspecies. M. m. tcheliensis is the most endangered subspecies in China. Divergence among subspecies may have begun 0.9-1.6 Ma. The radiation of rhesus monkeys in China may have spread from the southwest toward the east. The taxonomic status of the Hainan monkey and the Taiwan monkey require further investigation.

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The anadromous Chinese sturgeon (Acipenser sinensis), mainly endemic to the Yangtze River in China, is an endangered fish species. The natural population has declined since the Gezhouba Dam blocked its migratory route to the spawning grounds in 1981. In the near future, the completion of the Three Gorges Dam, the world's largest hydroelectric project, may further impact this species by altering the water flow of the Yangtze River. Little is currently known about the population genetic structure of the Chinese sturgeon. In this study, DNA sequence data were determined from the control region (D-loop) of the mitochondrial genome of adult sturgeons (n = 106) that were collected between 1995-2000. The molecular data were used to investigate genetic variation, effective female population size and population history of the Chinese sturgeon in the Yangtze River. Our results indicate that the reduction in abundance did not change genetic variation of the Chinese sturgeon, and that the population underwent an expansion in the past. AMOVA analysis indicated that 98.7% of the genetic variability occurred within each year's spawning populations, the year of collection had little influence on the diversity of annual temporary samples. The relative large effective female population size (N-ef) indicates that good potential exists for the recovery of this species in the future. Strikingly, the ratio of N-ef to the census female population size (N-f) is unusually high (0.77-0.93). This may be the result of a current bottleneck in the population of the Chinese sturgeon that is likely caused by human intervention.

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Twenty-five chipmunk species occur in the world, of which only the Siberian chipmunk, Tamias sibiricus, inhabits Asia. To investigate mitochondrial cytochrome b sequence variations and population structure of the Siberian chipmunk in northeastern Asia, we

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Mitochondrial disease currently received an increasing concern. However, the case-control design commonly adopted in this field is vulnerable to genetic background, population stratification and poor data quality. Although the phylogenetic analysis could

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Many fluorescent probes excited by visible light have been used to assess sperm quality by flow cytometry. Developing a viability evaluation method using UV excited stains would be useful for multiparameter analysis of sperm function. This investigation was conducted to determine the efficacy of Hoechst 33342 (H342) and propidium iodide (PI) dual staining for evaluating rhesus monkey sperm viability through use of flow cytometry and excited by a single UV laser. The results showed that the live cells stained only with H342 strongly correlated with expected sperm viability, and flow cytometric analyses were highly correlated with fluorescence microscopic observation. Using H342/PI/SYBR-14 triple staining method, it was found that the live/dead sperm distributions were completely concordant in both H342/PI and SYBR-14/PI assays. In addition, this dual staining was extended with fluorescein isothiocyanate-conjugated peanut agglutinin (FITC-PNA) to simultaneously analyze viability and acrosome integrity of sperm cryopreserved using two different extenders, TTE and TEST, and indicated that TTE offered better Preservation of plasma and acrosome integrity than TEST Therefore, the H342/PI dual staining provides an accurate technique for evaluating viability of rhesus monkey sperm and should be valuable for multiparameter flow cytometric analysis of sperm function.