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1.
DNA metabarcoding enables efficient characterization of species composition in environmental DNA or bulk biodiversity samples, and this approach is making significant and unique contributions in the field of ecology. In metabarcoding of animals, the cytochrome c oxidase subunit I (COI) gene is frequently used as the marker of choice because no other genetic region can be found in taxonomically verified databases with sequences covering so many taxa. However, the accuracy of metabarcoding datasets is dependent on recovery of the targeted taxa using conserved amplification primers. We argue that COI does not contain suitably conserved regions for most amplicon-based metabarcoding applications. Marker selection deserves increased scrutiny and available marker choices should be broadened in order to maximize potential in this exciting field of research.  相似文献   

2.
冯芸芝  孙栋  邵倩文  王春生 《生态学报》2022,42(21):8544-8554
浮游动物是海洋生态系统的关键类群,其覆盖门类广泛,多样性高。传统形态鉴定技术需要检测人员具备专业的形态鉴定知识,且费时费力。宏条形码技术无需分离生物个体,而是提取拖网采集到的浮游动物混合样本的总DNA,或者水体中的环境DNA (eDNA),依托高通量测序平台测序,能够实现对大规模样本快速、准确、经济的分析,在海洋浮游动物生态学研究中得到越来越广泛的应用。分析了DNA宏条形码技术常用的核糖体和线粒体分子标记,在浮游动物多样性和数量研究中的可靠性和不足,并给出在海洋浮游动物群落监测,食物关系分析及生物入侵早期预警等研究中的应用。未来,开发多基因片段组合条形码,发展完备的参考数据库及实现准确的量化研究是DNA宏条形码技术发展的重要方向。  相似文献   

3.
There is urgent need for effective and efficient monitoring of marine fish populations. Monitoring eggs and larval fish may be more informative than that traditional fish surveys since ichthyoplankton surveys reveal the reproductive activities of fish populations, which directly impact their population trajectories. Ichthyoplankton surveys have turned to molecular methods (DNA barcoding & metabarcoding) for identification of eggs and larval fish due to challenges of morphological identification. In this study, we examine the effectiveness of using metabarcoding methods on mock communities of known fish egg DNA. We constructed six mock communities with known ratios of species. In addition, we analyzed two samples from a large field collection of fish eggs and compared metabarcoding results with traditional DNA barcoding results. We examine the ability of our metabarcoding methods to detect species and relative proportion of species identified in each mock community. We found that our metabarcoding methods were able to detect species at very low input proportions; however, levels of successful detection depended on the markers used in amplification, suggesting that the use of multiple markers is desirable. Variability in our quantitative results may result from amplification bias as well as interspecific variation in mitochondrial DNA copy number. Our results demonstrate that there remain significant challenges to using metabarcoding for estimating proportional species composition; however, the results provide important insights into understanding how to interpret metabarcoding data. This study will aid in the continuing development of efficient molecular methods of biological monitoring for fisheries management.  相似文献   

4.
DNA条形码及其在海洋浮游动物生态学研究中的应用   总被引:2,自引:1,他引:2  
浮游动物的准确鉴定是浮游动物生态学研究的基础.传统的基于形态特征的鉴定不仅费时费力,而且部分类群特别是浮游幼体由于形态差异细微,鉴定存在困难,导致物种多样性被低估.DNA条形码(DNA barcodes)技术为浮游动物物种鉴定提供了一个有力工具,已迅速应用于海洋浮游动物生态学研究.本文介绍了DNA条形码的基本概念、优势及局限性,总结了该技术(主要是基于线粒体细胞色素C氧化酶第一亚基(mtCOI)基因序列片段的DNA条形码)在海洋浮游动物物种快速鉴定、隐种发现、营养关系研究、生物入侵种监测、群落历史演变反演、种群遗传学以及生物地理学中的成功应用.随着DNA条形码数据库信息量覆盖率的不断提高和新一代测序技术的快速发展,DNA条形码将提供除了种类鉴定外更加丰富的信息,从而帮助人们更好地理解海洋浮游动物的多样性及其在生态系统中的功能,推动海洋浮游动物生态学的发展.  相似文献   

5.
研究使用环境DNA宏条形码技术(eDNA metabarcoding)检测辽东湾东北部河口区围海养殖池塘水母种类多样性,探索适用于水母种类物种鉴定和监测的新方法。利用环境DNA宏条形码技术,分别基于18S rDNA和COI宏条形码检测了辽东湾东北部河口区围海养殖池塘水母种类多样性,通过水样采集、过滤、eDNA提取、遗传标记扩增、测序与生物信息分析的环境DNA宏条形码标准化分析流程,从围海养殖池塘7个采样点中获得可检测的采样点数据。结果显示,基于18S rDNA宏条形码检测出8种水母种类,其中钵水母纲大型水母2种、水螅水母总纲小型水母6种;基于COI宏条形码技术共检测出19种水母种类,其中钵水母纲大型水母5种、水螅水母总纲小型水母14种;两种DNA条形码标记都显示养殖种类海蜇(Rhopilema esculentum)为优势种。研究结果表明,环境DNA宏条形码技术作为一种新兴的生物多样性监测手段可用于快速检测水母种类多样性,在水母类物种鉴定、监测及早期预警中有较大的应用潜能。  相似文献   

6.
Oysters (family Ostreidae), with high levels of phenotypic plasticity and wide geographic distribution, are a challenging group for taxonomists and phylogenetics. As a useful tool for molecular species identification, DNA barcoding might offer significant potential for oyster identification and taxonomy. This study used two mitochondrial fragments, cytochrome c oxidase I (COI) and the large ribosomal subunit (16S rDNA), to assess whether oyster species could be identified by phylogeny and distance-based DNA barcoding techniques. Relationships among species were estimated by the phylogenetic analyses of both genes, and then pairwise inter- and intraspecific genetic divergences were assessed. Species forming well-differentiated clades in the molecular phylogenies were identical for both genes even when the closely related species were included. Intraspecific variability of 16S rDNA overlapped with interspecific divergence. However, average intra- and interspecific genetic divergences for COI were 0-1.4% (maximum 2.2%) and 2.6-32.2% (minimum 2.2%), respectively, indicating the existence of a barcoding gap. These results confirm the efficacy of species identification in oysters via DNA barcodes and phylogenetic analysis.  相似文献   

7.
为评价宏DNA条形码技术在我国海洋生物多样性监测中的应用潜力,采集了22份鸭绿江口浮游动物样品,分别利用宏条形码分子鉴定和形态鉴定方法对优势类群桡足类进行多样性的比较研究。结果显示:(1)利用宏条形码分子鉴定方法共鉴定出4目23科32属229个操作分类单元(Operational Taxonomic Units, OTUs),形态方法共鉴定出3目5科5属6种;同时,利用形态鉴定得到的分类阶元多数(目:100%、科:80%、属:80%)能用宏条形码分子鉴定方法鉴定出来,而宏条形码分子鉴定方法鉴定得到的分类阶元多数(目:25%、科:83%、属:88%)却未能用形态鉴定出来,表明宏条形码分子鉴定方法在鉴定物种丰富度方面具有明显优势。(2)利用宏条形码分子鉴定与形态鉴定桡足类的多样性指数呈显著的一致性(r=0.524,P=0.024),表明宏条形码鉴定方法与形态方法在评价物种多样性方面具有较好的可比性。本研究表明宏条形码分子鉴定方法在我国海洋浮游动物业务化监测中具有较高的应用潜力。  相似文献   

8.
Metabarcode surveys of DNA extracted from environmental samples are increasingly popular for biodiversity assessment in natural communities. Such surveys rely heavily on robust genetic markers. Therefore, analysis of PCR efficiency and subsequent biodiversity estimation for different types of genetic markers and their corresponding primers is important. Here, we test the PCR efficiency and biodiversity recovery potential of three commonly used genetic markers – nuclear small subunit ribosomal DNA (18S), mitochondrial cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (mt16S) – using 454 pyrosequencing of a zooplankton community collected from Hamilton Harbour, Ontario. We found that biodiversity detection power and PCR efficiency varied widely among these markers. All tested primers for COI failed to provide high‐quality PCR products for pyrosequencing, but newly designed primers for 18S and 16S passed all tests. Furthermore, multiple analyses based on large‐scale pyrosequencing (i.e. 1/2 PicoTiter plate for each marker) showed that primers for 18S recover more (38 orders) groups than 16S (10 orders) across all taxa, and four vs. two orders and nine vs. six families for Crustacea. Our results showed that 18S, using newly designed primers, is an efficient and powerful tool for profiling biodiversity in largely unexplored communities, especially when amplification difficulties exist for mitochondrial markers such as COI. Universal primers for higher resolution markers such as COI are still needed to address the possible low resolution of 18S for species‐level identification.  相似文献   

9.
Freshwater ecosystems face multiple threats to their stability globally. Poyang Lake is the largest lake in China, but its habitat has been seriously degraded because of human activities and natural factors (e.g. climate change), resulting in a decline in freshwater biodiversity. Zooplankton are useful indicators of environmental stressors because they are sensitive to external perturbations. DNA metabarcoding is an approach that has gained significant traction by aiding ecosystem conservation and management. Here, the seasonal and spatial variability in the zooplankton diversity were analyzed in the Poyang Lake Basin using DNA metabarcoding. The results showed that the community structure of zooplankton exhibited significant seasonal and spatial variability using DNA metabarcoding, where the community structure was correlated with turbidity, water temperature, pH, total phosphorus, and chlorophyll‐a. These results indicated habitat variations affected by human activities and seasonal change could be the main driving factors for the variations of zooplankton community. This study also provides an important reference for the management of aquatic ecosystem health and conservation of aquatic biodiversity.  相似文献   

10.
Predation on early life stages of Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus (ATS) may be a constraint to species recovery. Due to the difficulty in assessing consumption of early life stages with traditional diet analysis methods, we pursued an alternative DNA-based approach. We extracted total gut content from gastrointestinal tracts of 23 fish species (593 samples) within the tidal-fresh Pamunkey River fish assemblage collected from known ATS spawning grounds during prime spawning periods (September-October) in 2016. High-throughput DNA sequencing was used to amplify two markers for each sample: mitochondrial cytochrome c oxidase I (COI) and nuclear 18S ribosomal RNA gene. DNA sequences were compared to custom, SILVA 132, and NCBI databases. Results showed presence of ATS DNA in 22 samples (4%) across multiple native and nonnative tidal-fresh fishes. The highest percentage of consumption occurred in samples from Common Carp Cyprinus carpio (11.5) and Striped Bass Morone saxatilis (12.5). Six percent of Blue Catfish Ictalurus furcatus samples had target DNA. Considering there were no bony structures or tissue resembling ATS during morphological evaluation, DNA detections were likely from partially-fully digested eggs or early developing days-old larvae. High-throughput sequencing is capable of detecting consumption of ATS.  相似文献   

11.
The green lacewing Chrysoperla carnea is a complex of cryptic species whose differentiation has been so far based upon morphology, ecophysiology, behaviour and preliminary mitochondrial DNA data using cytochrome oxidase subunit II (COII) and NADH dehydrogenase subunit II. In this work we extended the DNA data by screening nucleotide sequences of COII, cytochrome oxidase I, cytochrome b and the large ribosomal subunit of the mtDNA. These new data suggest that C. carnea s.s. is a well-supported, separate taxon, but that other taxa of the complex are not consistently differentiated by the current DNA data.  相似文献   

12.
Environmental DNA (eDNA) is the DNA suspended in the environment (e.g., water column), which includes cells, gametes, and other material derived from but not limited to shedding of tissue, scales, mucus, and fecal matter. Amplifying and sequencing marker genes (i.e., metabarcoding) from eDNA can reveal the wide range of taxa present in an ecosystem through analysis of a single water sample. Metabarcoding of eDNA provides higher resolution data than visual surveys, aiding in assessments of ecosystem health. This study conducted eDNA metabarcoding of two molecular markers (cytochrome c oxidase I (COI) and 18S ribosomal RNA (rRNA) genes) to survey eukaryotic diversity across multiple trophic levels in surface water samples collected at three sites along the coral reef tract within the Florida Keys National Marine Sanctuary (FKNMS) during four research cruises in 2015. The 18S rRNA gene sequences recovered 785 genera while the COI gene sequences recovered 115 genera, with only 33 genera shared between the two datasets, emphasizing the complementarity of these marker genes. Community composition for both genetic markers clustered by month of sample collection, suggesting that temporal variation has a larger effect on biodiversity than spatial variability in the FKNMS surface waters. Sequences from both marker genes were dominated by copepods, but each marker recovered distinct phytoplankton groups, with 18S rRNA gene sequences dominated by dinoflagellates and COI sequences dominated by coccolithophores. Although eDNA samples were collected from surface waters, many benthic species such as sponges, crustaceans, and corals were identified. These results show the utility of eDNA metabarcoding for cataloging biodiversity to establish an ecosystem baseline against which future samples can be compared in order to monitor community changes.  相似文献   

13.
The phylogenic relationships existing among 14 parasitic Platyhelminthes in the Republic of Korea were investigated via the use of the partial 28S ribosomal DNA (rDNA) D1 region and the partial mitochondrial cytochrome c oxidase subunit 1 (mCOI) DNA sequences. The nucleotide sequences were analyzed by length, G + C %, nucleotide differences and gaps in order to determine the analyzed phylogenic relationships. The phylogenic patterns of the 28S rDNA D1 and mCOI regions were closely related within the same class and order as analyzed by the PAUP 4.0 program, with the exception of a few species. These findings indicate that the 28S rDNA gene sequence is more highly conserved than are the mCOI gene sequences. The 28S rDNA gene may prove useful in studies of the systematics and population genetic structures of parasitic Platyhelminthes.  相似文献   

14.
Anthropogenic impacts are an increasing threat to the diversity of fishes, especially in areas around large urban centres, and many effective conservation actions depend on accurate species identification. Considering the utility of DNA barcoding as a global system for species identification and discovery, this study aims to assemble a DNA barcode reference sequence library for marine fishes from the coastal region of São Paulo State, Brazil. The standard 652 bp ‘barcode’ fragment of the cytochrome c oxidase subunit I (COI) gene was PCR amplified and bidirectionally sequenced from 678 individuals belonging to 135 species. A neighbour‐joining analysis revealed that this approach can unambiguously discriminate 97% of the species surveyed. Most species exhibited low intraspecific genetic distances (0.31%), about 43‐fold less than the distance among species within a genus. Four species showed higher intraspecific divergences ranging from 2.2% to 7.6%, suggesting overlooked diversity. Notably, just one species‐pair exhibited barcode divergences of <1%. This library is a first step to better know the molecular diversity of marine fish species from São Paulo, providing a basis for further studies of this fauna – extending the ability to identify these species from all life stages and even fragmentary remains, setting the stage for a better understanding of interactions among species, calibrating the estimations about species composition and richness in an ecosystem, and providing tools for authenticating bioproducts and monitoring illegal species exploitation.  相似文献   

15.
In diet metabarcoding analyses, insufficient taxonomic coverage of PCR primer sets generates false negatives that may dramatically distort biodiversity estimates. In this paper, we investigated the taxonomic coverage and complementarity of three cytochrome c oxidase subunit I gene (COI) primer sets based on in silico analyses and we conducted an in vivo evaluation using fecal and spider web samples from different invertivores, environments, and geographic locations. Our results underline the lack of predictability of both the coverage and complementarity of individual primer sets: (a) sharp discrepancies exist observed between in silico and in vivo analyses (to the detriment of in silico analyses); (b) both coverage and complementarity depend greatly on the predator and on the taxonomic level at which preys are considered; (c) primer sets’ complementarity is the greatest at fine taxonomic levels (molecular operational taxonomic units [MOTUs] and variants). We then formalized the “one‐locus‐several‐primer‐sets” (OLSP) strategy, that is, the use of several primer sets that target the same locus (here the first part of the COI gene) and the same group of taxa (here invertebrates). The proximal aim of the OLSP strategy is to minimize false negatives by increasing total coverage through multiple primer sets. We illustrate that the OLSP strategy is especially relevant from this perspective since distinct variants within the same MOTUs were not equally detected across all primer sets. Furthermore, the OLSP strategy produces largely overlapping and comparable sequences, which cannot be achieved when targeting different loci. This facilitates the use of haplotypic diversity information contained within metabarcoding datasets, for example, for phylogeography and finer analyses of prey–predator interactions.  相似文献   

16.
Coleoids are part of the Cephalopoda class, which occupy an important position in most oceans both at an ecological level and at a commercial level. Nevertheless, some coleoid species are difficult to distinguish with traditional morphological identification in cases when specimens are heavily damaged during collection or when closely related taxa are existent. As a useful tool for rapid species assignment, DNA barcoding may offer significant potential for coleoid identification. Here, we used two mitochondrial fragments, cytochrome c oxidase I and the large ribosomal subunit (16S rRNA), to assess whether 34 coleoids accounting for about one-third of the Chinese coleoid fauna could be identified by DNA barcoding technique. The pairwise intra- and interspecific distances were assessed, and relationships among species were estimated by NJ and bayesian analyses. High levels of genetic differentiation within Loliolus beka led to an overlap between intra- and interspecific distances. All remaining species forming well-differentiated clades in the NJ and bayesian trees were identical for both fragments. Loliolus beka possessed two mitochondrial lineages with high levels of intraspecific distances, suggesting the occurrence of cryptic species. This study confirms the efficacy of DNA barcoding for identifying species as well as discovering cryptic diversity of Chinese coleoids. It also lays a foundation for other ecological and biological studies of Coleoidea.  相似文献   

17.
The distribution of Octopus vulgaris has not yet been completely clarified. For a long time, a cosmopolitan distribution with unknown distribution limits had been assumed. This assumption has recently been questioned and it has been postulated that the distribution is restricted to the Mediterranean and the northeastern Atlantic. However, as our previous studies show, the existence of O. vulgaris can be confirmed for the Mediterranean and the whole eastern Atlantic, and evidence is provided for its occurrence in the western Atlantic. The aim of the present work is to extend our previous data matrix and to clarify whether O. vulgaris exists in the northwestern Pacific. Therefore, the sequence variation in ostensible O. vulgaris from 13 localities in the Mediterranean (France), the Atlantic Ocean [Lanzarote, Senegal, South Africa (Atlantic, Indian Ocean), Tristan da Cunha, north, middle and south Brazil], the Caribbean Sea (Venezuela) and the Pacific Ocean (Taiwan, Japan and Costa Rica) was examined using the mitochondrial genes coding for the 16S rRNA and cytochrome oxidase subunit III (COIII). Sequence divergence was relatively low between populations of O. vulgaris from the Mediterranean, the eastern and western Atlantic (except north Brazil), Venezuela, Taiwan and Japan compared with other species of the genus Octopus . Trees constructed by using maximum likelihood, neighbour joining and maximum parsimony algorithms (PAUP) show the above-mentioned populations from the Mediterranean, the western and eastern Atlantic, Venezuela and the northwestern Pacific (Japan and Taiwan) as a monophyletic cluster. Thus, even if the Octopus vulgaris -like octopus from north Brazil should turn out a cryptic species, the data of this work not only support our hypothesis of the distribution of O. vulgaris in the Mediterranean, the eastern and western Atlantic but also show that O. vulgaris is present in the northwestern Pacific, namely in the waters of Taiwan and Japan.  相似文献   

18.
Recent advances in molecular techniques allow us to resolve the diet of unstudied taxa. Odonates are potentially important top‐down regulators of many insects. Yet, to date, our knowledge of odonate prey use is based mainly on limited observations of odonates catching or eating their prey. In this study, we examine the potential use of metabarcoding in establishing the diet of three adult odonate species (Lestes sponsa, Enallagma cyathigerum, and Sympetrum danae) at a site in southwestern Finland. To this purpose, we compared three different methods for extracting DNA from fecal samples: the Macherey‐Nagel Nucleospin XS kit, a traditional salt extraction, and the Zymo Research Fecal Microprep kit. From these extracts, we amplified group‐specific mitochondrial markers (COI and 16S rRNA) from altogether 72 odonate individuals, and compared them to comprehensive reference libraries. The three odonate species show major overlap in diet, with no significant differences between individuals of different size and/or gender, reflecting opportunistic foraging of adult odonates. Of a total of 41 different prey species detected, the most frequently consumed ones were Diptera, with additional records of six other orders. Based on our data, the best DNA extraction method is the traditional salt extraction, as it provides the most information on prey content while also being the most economical. To our knowledge, this is the first study to resolve the species‐level diet of adult odonates. Armed with the appropriate methodological caveats, we are ready to examine the ecological role of odonates in both terrestrial and aquatic food webs, and in transferring subsidies between these two realms.  相似文献   

19.
Environmental DNA (eDNA) analysis has seen rapid development in the last decade, as a novel biodiversity monitoring method. Previous studies have evaluated optimal strategies, at several experimental steps of eDNA metabarcoding, for the simultaneous detection of fish species. However, optimal sampling strategies, especially the season and the location of water sampling, have not been evaluated thoroughly. To identify optimal sampling seasons and locations, we performed sampling monthly or at two‐monthly intervals throughout the year in three dam reservoirs. Water samples were collected from 15 and nine locations in the Miharu and Okawa dam reservoirs in Fukushima Prefecture, respectively, and five locations in the Sugo dam reservoir in Hyogo Prefecture, Japan. One liter of water was filtered with glass‐fiber filters, and eDNA was extracted. By performing MiFish metabarcoding, we successfully detected a total of 21, 24, and 22 fish species in Miharu, Okawa, and Sugo reservoirs, respectively. From these results, the eDNA metabarcoding method had a similar level of performance compared to conventional long‐term data. Furthermore, it was found to be effective in evaluating entire fish communities. The number of species detected by eDNA survey peaked in May in Miharu and Okawa reservoirs, and in March and June in Sugo reservoir, which corresponds with the breeding seasons of many of fish species inhabiting the reservoirs. In addition, the number of detected species was significantly higher in shore, compared to offshore samples in the Miharu reservoir, and a similar tendency was found in the other two reservoirs. Based on these results, we can conclude that the efficiency of species detection by eDNA metabarcoding could be maximized by collecting water from shore locations during the breeding seasons of the inhabiting fish. These results will contribute in the determination of sampling seasons and locations for fish fauna survey via eDNA metabarcoding, in the future.  相似文献   

20.
对21种帘蛤科贝类线粒体细胞色素c氧化酶亚基Ⅰ(cytochrome c oxidase subunit I,COI)基因核苷酸序列进行了分析,以探讨这一序列在种质鉴定、分子系统发生研究中的应用价值。测序结果表明,所有物种扩增片段长度均为707 bp(含引物),序列A+T含量(62.4%—67.8%)明显高于G+C含量。物种间共有变异位点379个,其中简约信息位点334个;此区段共编码235个氨基酸,种间共有氨基酸变异位点100个。以COI基因片段序列为标记,用中国蛤蜊(Mactra chinensis)作外群,构建了35种帘蛤科贝类(其中14种贝类COI序列从GenBank下载)的系统发生树,结合拓扑结构分析和序列比对分析,结果表明:支持将短文蛤(Meretrix petechinalis)和丽文蛤(M.lusoria)订为文蛤(M.meretrix)的同物异名的观点,建议将丽文蛤和短文蛤订为文蛤的地理亚种;支持将薄片镜蛤(Dosinia corrugata)和D.angulosa订为2个独立种的观点;认为将波纹巴非蛤(Paphia undulata)和织锦巴非蛤(P.textile)订为2个独立种是合适的。COI基因序列含有丰富的遗传信息,适合作为帘蛤科贝类种群遗传结构和系统发生研究的分子标记。  相似文献   

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