microsatellite

微卫星
  • 文章类型: Journal Article
    野生动物物种的易位成为全球范围内重建濒临灭绝的当地种群的普遍做法。考古数据证实,羚羊曾经生活在比奥科沃山,但是,在1960年代重新引入之前,没有书面证据表明他们最近在该地区存在。人口在1964-1969年期间重新引入,当时波斯尼亚和黑塞哥维那邻近山区的48名巴尔干人被释放。这项研究的主要目的是确定有关Biokovo山的巴尔干羚羊种群起源的现有历史数据的准确性,并评估重新引入56年后来源和易位种群的遗传多样性和种群结构。使用16个微卫星基因座分析了来自Prenj的三个源羚羊种群的遗传结构,并来自比科沃山。结构分析和GENELAND分析均显示,比奥科沃重新引入的种群与Prenj\的仓鼠有明显的分离,并且比奥科沃种群与cvrsnica-cabulja种群之间具有相当大的遗传相似性。这表明Biokovo种群的当前遗传组成并非完全来自Prenj,正如现有文献和个人访谈所建议的那样,但也来自于加vrsnica和加abulja。GENELAND分析认为来自Prenj的巴尔干羚羊是一个单独的集群,与CVrsnica和Cabulja的人口不同。因此,我们的结果强调了需要对濒危巴尔干羚羊的重新引入和来源种群进行遗传监测,以告知可持续管理和保护策略,以最大程度地提高种群持续存在的机会。
    The translocation of wild animal species became a common practice worldwide to re-establish local populations threatened with extinction. Archaeological data confirm that chamois once lived in the Biokovo Mountain but, prior to their reintroduction in the 1960s, there was no written evidence of their recent existence in the area. The population was reintroduced in the period 1964-1969, when 48 individuals of Balkan chamois from the neighbouring mountains in Bosnia and Herzegovina were released. The main objective of this study was to determine the accuracy of the existing historical data on the origin of the Balkan chamois population from the Biokovo Mountain and to assess the genetic diversity and population structure of the source and translocated populations 56 years after reintroduction. Sixteen microsatellite loci were used to analyse the genetic structure of three source chamois populations from Prenj, Čvrsnica and Čabulja Mountains and from Biokovo Mountain. Both STRUCTURE and GENELAND analyses showed a clear separation of the reintroduced population on Biokovo from Prenj\'s chamois and considerable genetic similarity between the Biokovo population and the Čvrsnica-Čabulja population. This suggests that the current genetic composition of the Biokovo population does not derive exclusively from Prenj, as suggested by the available literature and personal interviews, but also from Čvrsnica and Čabulja. GENELAND analysis recognised the Balkan chamois from Prenj as a separate cluster, distinct from the populations of Čvrsnica and Čabulja. Our results thus highlight the need to implement genetic monitoring of both reintroduced and source populations of endangered Balkan chamois to inform sustainable management and conservation strategies in order to maximise the chances of population persistence.
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  • 文章类型: Case Reports
    BACKGROUND: Colorectal cancer (CRC) is the third most prevalent cancer worldwide and poses a serious challenge for clinicians. Previous studies have shown promising results in patients with Microsatellite Stable microsatellite-stable CRC refractory to chemotherapy upon treating with (Programmed Cell Death Protein 1) PD-1 inhibitor combined with regorafenib. Herein, we report a unique case of a patient for whom the conventional chemotherapy and radiotherapy were ineffective, but showed a prolonged stable disease with third-line treatment with regorafenib and PD-1 inhibitor, sintilimab.
    METHODS: A 64-year-old East Asian female patient was admitted to a regional cancer hospital presenting with abdominal unease due to increased stool frequency and bloody stool. Digital anal examination revealed adenocarcinoma, while genetic profiling of the tumor resections detected wild-type KRAS mutations in codon 12 and 13. Microsatellite instability (MSI) analysis for detecting germline mutations of (Mismatch-repair) MMR genes showed stable phenotype. In December 2016, Miles\' resection for intestinal adhesion release and iliac vessel exploration in the rectum was performed (Tumor, Node, Metastasis [TNM]: T3N0M0; stage IIA). The adjuvant chemotherapeutic regimen consisted of a combination of capecitabine at 1.5 g (twice daily) and oxaliplatin therapy at 200 mg for three cycles from February 2016; followed by administering capecitabine tablets orally (1.5 g bid) for five cycles as post-operative palliative care. The patient tested positive for hepatic C virus, which was managed by oral antiviral agents. Following recurrence of rectal adenocarcinoma after 4 years and disease progression with a previous chemotherapeutic regimen, regorafenib was administered at 120 mg once daily combined with sintilimab 200 mg, and the patient\'s progress was monitored. A follow-up computerized tomography imaging in March 2020 showed disease progression, additionally presented nodule formation (TNM: T3NxM1b; stage IVB). According to Response Evaluation Criteria in Solid Tumors criteria (RECIST), the patient showed a complete response (CR) after treatment with regorafenib and sintilimab immunotherapy.
    CONCLUSIONS: Data from this clinical case report support future exploration of combination treatment of the oral multi-kinase inhibitor regorafenib with PD-1 targeted monoclonal antibodies in patients with metastatic microsatellite-stable CRC.
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  • 文章类型: Journal Article
    动物园管理着少量濒临灭绝的大型猫科动物,如老虎,狮子,和豹子展示,研究,和保护性育种。这些种群的基因管理对于确保长期生存和保护效用至关重要。在这里,我们提出了一种简单且经济有效的基于微卫星的协议,用于圈养大型猫的遗传管理。我们从首尔大公园动物园(大韩民国)采样了36只大猫,并扩增了33个已发布的微卫星基因座。总的来说,发现豹子的等位基因丰富度和基因多样性最高,其次是狮子和老虎。在所有目标物种中,33个标记中有12个显示出高度的多态性。这些微卫星为老虎提供了高度的辨别力(1.45×10-8),狮子(1.54×10-10),和豹子(1.88×10-12),因此可用于全球认可动物园中大型猫的遗传表征。在圈养繁殖期间,动物园当局依靠保存在研究簿中的血统记录来确保与基因无关的个体交配。一些研究报告了大猫物种的研究簿记录中的错误。微卫星是简单且具有成本效益的DNA指纹识别工具,遗传多样性的估计,和亲子鉴定.我们针对大型猫科动物的统一微型卫星面板(12丛)非常高效,可以很容易地被动物园当局采用以进行常规种群管理。
    The zoos manage small populations of endangered big cat species like tiger, lion, and leopard for display, research, and conservation breeding. Genetic management of these populations is essential to ensure long term survival and conservation utility. Here we propose a simple and cost effective microsatellite based protocol for the genetic management of captive big cats. We sampled 36 big cat individuals from Seoul Grand Park Zoo (Republic of Korea) and amplified 33 published microsatellite loci. Overall, allelic richness and gene diversity was found highest for leopards, followed by lions and tigers. Twelve of the thirty-three markers showed a high degree of polymorphism across all target species. These microsatellites provide a high degree of discrimination for tiger (1.45 × 10-8), lion (1.54 × 10-10), and leopard (1.88 × 10-12) and thus can be adopted for the genetic characterization of big cats in accredited zoos globally. During captive breeding, zoo authorities rely on pedigree records maintained in studbooks to ensure mating of genetically fit unrelated individuals. Several studies have reported errors in studbook records of big cat species. Microsatellites are simple and cost effective tool for DNA fingerprinting, estimation of genetic diversity, and paternity assessment. Our unified microsatellite panel (12-plex) for big cats is efficient and can easily be adopted by zoo authorities for regular population management.
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  • 文章类型: Journal Article
    We report a case study wherein we established the putative cause of the death of three leopards by identifying the species and number of individual prey species from the gut contents using molecular tools. In a National Park within Northern part of India, the suspicious death of three leopards (Panthera pardus) was reported from different localities on the same day. The gut contents from the three leopard carcasses were collected during postmortem and sent to us to confirm the prey species. We used mitochondrial DNA cytochrome b (Cyt b) and control region (CR), and nuclear microsatellites for molecular identification of species and individual identification, respectively, from the gut contents. Mitochondrial sequences confirmed that the undigested remnants collected from the gut contents were of the domestic dog (Canis lupus familiaris). Furthermore, the microsatellite analysis of the gut contents highlighted the consumption of the same dog by all the three deceased leopards. Since the National Park was one of the major human-wildlife interaction zones, consuming the same dog by the leopards implies suspicious poisoning for revenge. The use of dog carcass for the possible poisoning for the mass-scale killing of the protected species is a severe wildlife offense.
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  • 文章类型: Journal Article
    Most species exist as subdivided ex situ daughter population(s) derived from a single original group of individuals. Such subdivision occurs for many reasons both natural and manmade. Traditional British and Irish pony breeds were introduced to North America (U.S.A. and Canada) within the last 150 years, and subsequently equivalent breed societies were established. We have analyzed selected U.K. and North American equivalent pony populations as a case study for understanding the relationship between putative source and derived subpopulations. Diversity was measured using mitochondrial DNA and a panel of microsatellite markers. Genetic signatures differed between the North American subpopulations according to historical management processes. Founder effect and stochastic drift was apparent, particularly pronounced in some breeds, with evidence of admixture of imported mares of different North American breeds. This demonstrates the importance of analysis of subpopulations to facilitate understanding the genetic effects of past management practices and to lead to informed future conservation strategies.
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  • 文章类型: Journal Article
    水稻是一种主要和广泛种植的作物,具有丰富的遗传多样性。由于很难根据视觉观察准确区分各种水稻品种的种子,收获的种子和随后的加工产品极易被不诚实的商人掺假,与外观相似和质量低的种子掺假。保护进口国和消费者的利益,在过去的几十年中,已经采用了几种方法来明确区分品种,准确量化掺假物,并用于确定栽培地理区域。随着生物技术的最新进展,基于DNA的技术发展迅速,并被证明比传统的非基于DNA的方法成功,以消除商业水平的掺假问题。在当前的审查中,我们试图通过提供Basmati作为案例研究来全面总结现有的掺假检测和量化方法,以使交易者在选择适当的方法以消除全球大米行业的掺假做法时能够快速解决问题。
    Rice is a staple and widely grown crop endowed with rich genetic diversity. As it is difficult to differentiate seeds of various rice varieties based on visual observation accurately, the harvested seeds and subsequent processed products are highly prone to adulteration with look-alike and low quality seeds by the dishonest traders. To protect the interests of importing countries and consumers, several methods have been employed over the last few decades for unambiguous discrimination of cultivars, accurate quantification of the adulterants, and for determination of cultivated geographical area. With recent advances in biotechnology, DNA based techniques evolved rapidly and proved successful over conventional non-DNA based methods to purge the problem of adulteration at commercial level. In the current review, we made an attempt to summarize the existing methods of adulteration detection and quantification in a comprehensive manner by providing Basmati as a case study to enable the traders to arrive at a quick resolution in choosing the apt method to eliminate the adulteration practice in the global rice industry.
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  • 文章类型: Journal Article
    鲑鱼表现出高度的种群分化。特别是,褐鳟鱼(SalmotruttaL.)在河流排水遗传结构中表现出复杂性。越来越多,这些模式可以与潜在的进化模型相关,其中三种情况(成员-流浪者假设,种群模型和panmixia)有助于对种群结构进行可测试的预测。我们分析了从飞镖河收集的1225条鳟鱼,一条75公里长的河流,位于英格兰西南部。在连续三个夏天(2001-2003年)从22个样本站点收集了样本,并在9个微卫星位点检查了遗传变异。分子变异的层次分析表明,可忽略的遗传变异归因于时间样本。最高的分化水平发生在隔离在鱼类运动障碍之上的样本中,一旦这些样本被取出,观察到隔离距离的显着影响。这些结果表明,至少在短期内,生态事件比随机灭绝事件更重要,当然也不会与成员流浪汉假设的期望相矛盾。此外,个体水平的空间自相关分析支持先前关于保护整个支流系统中分布的许多产卵点的建议,以保护在鲑鱼物种中发现的高水平遗传变异。
    Salmonid fishes exhibit high levels of population differentiation. In particular, the brown trout (Salmo trutta L.) demonstrates complex within river drainage genetic structure. Increasingly, these patterns can be related to the underlying evolutionary models, of which three scenarios (member-vagrant hypothesis, metapopulation model and panmixia) facilitate testable predictions for investigations into population structure. We analysed 1225 trout collected from the River Dart, a 75 km long river located in southwest England. Specimens were collected from 22 sample sites across three consecutive summers (2001-2003) and genetic variation was examined at nine microsatellite loci. A hierarchical analysis of molecular variance revealed that negligible genetic variation was attributed among temporal samples. The highest levels of differentiation occurred among samples isolated above barriers to fish movement, and once these samples were removed, a significant effect of isolation-by-distance was observed. These results suggest that, at least in the short-term, ecological events are more important in shaping the population structure of Dart trout than stochastic extinction events, and certainly do not contradict the expectations of a member-vagrant hypothesis. Furthermore, individual-level spatial autocorrelation analyses support previous recommendations for the preservation of a number of spawning sites spaced throughout the tributary system to conserve the high levels of genetic variation identified in salmonid species.
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  • 文章类型: Journal Article
    Inferences about introduction histories of invasive species remain challenging because of the stochastic demographic processes involved. Approximate Bayesian computation (ABC) can help to overcome these problems, but such method requires a prior understanding of population structure over the study area, necessitating the use of alternative methods and an intense sampling design. In this study, we made inferences about the worldwide invasion history of the ladybird Harmonia axyridis by various population genetics statistical methods, using a large set of sampling sites distributed over most of the species\' native and invaded areas. We evaluated the complementarity of the statistical methods and the consequences of using different sets of site samples for ABC inferences. We found that the H. axyridis invasion has involved two bridgehead invasive populations in North America, which have served as the source populations for at least six independent introductions into other continents. We also identified several situations of genetic admixture between differentiated sources. Our results highlight the importance of coupling ABC methods with more traditional statistical approaches. We found that the choice of site samples could affect the conclusions of ABC analyses comparing possible scenarios. Approaches involving independent ABC analyses on several sample sets constitute a sensible solution, complementary to standard quality controls based on the analysis of pseudo-observed data sets, to minimize erroneous conclusions. This study provides biologists without expertise in this area with detailed methodological and conceptual guidelines for making inferences about invasion routes when dealing with a large number of sampling sites and complex population genetic structures.
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  • 文章类型: Journal Article
    来自分布在五个生物地理区域的19个位置的>2300Haliotislaevigata(greenlip鲍鱼)的分层采样和随后的微卫星基因分型大大增进了我们对这一商业重要物种的种群结构和连通性的了解。该研究发现了H.laevigata的种群结构与同胞和同类Haliotisrubra(黑唇鲍鱼)的主要差异,并为针对具有小尺度空间结构特征的物种的渔业管理(即S型渔业)提供了宝贵的见解。和H.Rubra一样,H.laevigata包括一系列自我招募能力很强的群体。然而,H.laevigata综合种群的空间范围(约30km(2);长达135km的距离是幼虫扩散的有效障碍)大大大于H.rubra的空间范围(Miller等人。2009).人口过程的动态和规模的差异,即使在这项研究中很明显的是同类牛耳之间,暗示对于S-渔业,很难概括生活史共性的潜在后果。因此,反映目标物种种群结构的特定物种管理仍然尤为重要。这可能需要将有关种群结构和连通性的信息与生活史和种群动态数据相结合,以确定必要的输入(例如,渔民数量,捕捞努力量)和产量(例如,最小法定规模,总允许渔获量)的控制措施,以支持其可持续管理。
    Hierarchical sampling and subsequent microsatellite genotyping of >2300 Haliotis laevigata (greenlip abalone) from 19 locations distributed across five biogeographic regions have substantially advanced our knowledge of population structure and connectivity in this commercially important species. The study has found key differences in stock structure of H. laevigata compared with the sympatric and congeneric Haliotis rubra (blacklip abalone) and yielded valuable insights into the management of fisheries targeting species characterized by spatial structure at small scales (i.e. S-fisheries). As with H. rubra, H. laevigata comprise a series of metapopulations with strong self-recruitment. However, the spatial extent of H. laevigata metapopulations (reefal areas around 30 km(2) ; distances of up to 135 km are effective barriers to larval dispersal) was substantially greater than that identified for H. rubra (Miller et al. 2009). Differences in the dynamics and scale of population processes, even between congeneric haliotids as made evident in this study, imply that for S-fisheries, it is difficult to generalize about the potential consequences of life history commonalities. Consequently, species-specific management reflective of the population structure of the target species remains particularly important. This will likely require integration of information about stock structure and connectivity with data on life history and population dynamics to determine the necessary input (e.g. number of fishers, fishing effort) and output (e.g. minimum legal size, total allowable catch) controls to underpin their sustainable management.
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  • 文章类型: Journal Article
    Many plant species combine sexual and clonal reproduction. Clonal propagation has ecological costs mainly related to inbreeding depression and pollen discounting; at the same time, species able to reproduce clonally have ecological and evolutionary advantages being able to persist when conditions are not favorable for sexual reproduction. The presence of clonality has profound consequences on the genetic structure of populations, especially when it represents the predominant reproductive strategy in a population. Theoretical studies suggest that high rate of clonal propagation should increase the effective number of alleles and heterozygosity in a population, while an opposite effect is expected on genetic differentiation among populations and on genotypic diversity. In this study, we ask how clonal propagation affects the genetic diversity of rare insular species, which are often characterized by low levels of genetic diversity, hence at risk of extinction. We used eight polymorphic microsatellite markers to study the genetic structure of the critically endangered insular endemic Ruta microcarpa. We found that clonality appears to positively affect the genetic diversity of R. microcarpa by increasing allelic diversity, polymorphism, and heterozygosity. Moreover, clonal propagation seems to be a more successful reproductive strategy in small, isolated population subjected to environmental stress. Our results suggest that clonal propagation may benefit rare species. However, the advantage of clonal growth may be only short-lived for prolonged clonal growth could ultimately lead to monoclonal populations. Some degree of sexual reproduction may be needed in a predominantly clonal species to ensure long-term viability.
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