Search

Metabarcoding is revolutionizing fundamental research in ecology by enabling large‐scale detection of species and producing data that are rich with community context. However, the benefits of metabarcoding have yet to be fully realized in fields of applied ecology, especially those such as classical biological control (CBC) research that involve hyperdiverse taxa. Here, we discuss some of the opportunities that metabarcoding provides CBC and solutions to the main methodological challenges that have limited the integration of metabarcoding in existing CBC workflows. We focus on insect parasitoids, which are popular and effective biological control agents (BCAs) of invasive species and agricultural pests. Accurately identifying native, invasive and BCA species is paramount, since misidentification can undermine control efforts and lead to large negative socio‐economic impacts. Unfortunately, most existing publicly accessible genetic databases cannot be used to reliably identify parasitoid species, thereby limiting the accuracy of metabarcoding in CBC research. To address this issue, we argue for the establishment of authoritative genetic databases that link metabarcoding data to taxonomically identified specimens. We further suggest using multiple genetic markers to reduce primer bias and increase taxonomic resolution. We also provide suggestions for biological control‐specific metabarcoding workflows intended to track the long‐term effectiveness of introduced BCAs. Finally, we use the example of an invasive pest, Drosophila suzukii, in a reflective "what if" thought experiment to explore the potential power of community metabarcoding in CBC. [ABSTRACT FROM AUTHOR]

Assembling DNA barcode reference libraries for various taxonomic groups allows researchers to use metabarcoding or environmental DNA approaches to gain a rapid understanding of diversity in given environments. However, our ability to use reference libraries depends on how accurately DNA barcodes are able to recover taxonomic boundaries and identify species, which is rarely considered. We constructed an extensive COI barcoding library for amphibians of the Western Palearctic and successfully recovered barcodes from 60 urodele and 73 anuran species (representing 94% and 98% of the nominal anuran and urodele species in the Western Palearctic, respectively), covering the intraspecific diversity of the majority of species in this region. We tested the effectiveness of our assembled DNA barcode dataset for species identification using barcoding gap, efficiency analyses, and two phylogenetic species delimitation methods. We obtained DNA barcodes for 1251 specimens (691 anurans and 560 urodeles) with a high success rate (92-96%) of species identification. The absence of a barcoding gap in a number of samples was linked to species misidentifications, which suggest incipient speciation or cryptic diversity, or previously described mitochondrial introgression events. The phylogenetic species delimitation methods resulted in substantial oversplitting of currently accepted taxonomy. This COI barcoding library provides an almost complete and reliable reference library for Western Palearctic amphibians. We highlight the importance of generating comprehensive and well curated reference libraries that include intra- and interspecific genetic variability and the need of detailed taxonomic revision when ambiguous or incorrect DNA barcodes exist. [ABSTRACT FROM AUTHOR]

DNA barcoding is a well‐established tool for rapid species identification and biodiversity monitoring. A reliable and traceable DNA barcode reference library with extensive coverage is necessary but unavailable for many geographical regions. The arid region in northwestern China, a vast area of about 2.5 million km2, is ecologically fragile and often overlooked in biodiversity studies. In particular, DNA barcode data from the arid region in China are lacking. We develop and evaluate the efficacy of an extensive DNA barcode library for native flowering plants in the arid region of northwestern China. Plant specimens were collected, identified and vouchered for this purpose. The database utilized four DNA barcode markers, namely rbcL, matK, ITS and ITS2, for 1816 accessions (representing 890 species from 385 genera and 72 families), and consisted of 5196 barcode sequences. Individual barcodes varied in resolution rates: species‐ and genus‐level rates for rbcL, matK, ITS and ITS2 were 79.9%–51.1%/76.1%, 79.9%–67.2%/88.9%, 85.0%–72.0%/88.2% and 81.0%–67.4%/84.9%, respectively. The three‐barcode combination of rbcL + matK + ITS (RMI) revealed a higher species‐ and genus‐level resolution (75.5%/92.1%, respectively). A total of 110 plastomes were newly generated as super‐barcodes to increase species resolution for seven species‐rich genera, namely Astragalus, Caragana, Lactuca, Lappula, Lepidium, Silene and Zygophyllum. Plastomes revealed higher species resolution compared to standard DNA barcodes and their combination. We suggest future databases include super‐barcodes, especially for species‐rich and complex genera. The plant DNA barcode library in the current study provides a valuable resource for future biological investigations in the arid regions of China. [ABSTRACT FROM AUTHOR]

Simple Summary: One-third of shark and ray species are threatened due to overfishing, but a lack of information on each species makes conservation decisions difficult. To address this issue, we conducted a study to identify the different species of sharks and rays in Malaysian waters using DNA barcoding of the CO1 gene, which is akin to DNA fingerprinting for species. We collected 175 individuals between June 2015 and June 2022, randomly selecting up to six specimens from each species. We successfully generated DNA barcodes for 67 species, belonging to 44 genera, 20 families, and 11 orders. Accurate species identification will improve species-specific catch landing data and accelerate the identification of use and illegal trade in Malaysia. The data provided in this article are partial fragments of the Cytochrome c oxidase subunit 1 mitochondrial gene (CO1) sequences of 175 tissues sampled from sharks and batoids collected from Malaysian waters, from June 2015 to June 2022. The barcoding was done randomly for six specimens from each species, so as to authenticate the code. We generated barcodes for 67 different species in 20 families and 11 orders. DNA was extracted from the tissue samples following the Chelex protocols and amplified by polymerase chain reaction (PCR) using the barcoding universal primers FishF2 and FishR2. A total of 654 base pairs (bp) of barcode CO1 gene from 175 samples were sequenced and analysed. The genetic sequences were blasted into the NCBI GenBank and Barcode of Life Data System (BOLD). A review of the blast search confirmed that there were 68 valid species of sharks and batoids that occurred in Malaysian waters. We provided the data of the COI gene mid-point rooting phylogenetic relation trees and analysed the genetic distances among infra-class and order, intra-species, inter-specific, inter-genus, inter-familiar, and inter-order. We confirmed the addition of Squalus edmundsi, Carcharhinus amboinensis, Alopias superciliosus, and Myliobatis hamlyni as new records for Malaysia. The establishment of a comprehensive CO1 database for sharks and batoids will help facilitate the rapid monitoring and assessment of elasmobranch fisheries using environmental DNA methods. [ABSTRACT FROM AUTHOR]

We present an extensive DNA barcoding study of the fish species of the Lake Edward system, including information on intraspecific variation. The DNA barcode gene, cytochrome c oxidase I (COI), failed to discriminate the 35 species of the genus Haplochromis analysed. For the non-Haplochromis species, the reference library had a near complete coverage of 91.2%, with 31 out of the 34 known species of the system sequenced. With the recent morphology-based review of the ichthyofauna of the system as a backbone, the DNA barcoding library proved to be very effective for future species identifications. High identification successes were obtained based on Best Match (98.2%), Best Close Match (97.9%), and All Species Barcode (95.0%) criteria. Surprisingly, Laciris pelagicus and Micropanchax vitschumbaensis, two morphologically distinct species, had very similar and even identical COI haplotypes, whilst in Enteromius the existence of possible cryptic species was revealed. Few species occurring in the Lake Edward system were already represented in the global database Genbank. For some widespread species, regional genetic differences were found, highlighting the value of basin-specific information in reference databases. The provided reference library of DNA barcodes is a valuable tool for future conservation actions, which is certainly relevant in a system where the fisheries are under pressure. [ABSTRACT FROM AUTHOR]

The data provided in this article are partial fragments of the Cytochrome c oxidase subunit 1 mitochondrial gene (CO1) sequences of 175 tissues sampled from sharks and batoids collected from Malaysian waters, from June 2015 to June 2022. The barcoding was done randomly for six specimens from each species, so as to authenticate the code. We generated barcodes for 67 different species in 20 families and 11 orders. DNA was extracted from the tissue samples following the Chelex protocols and amplified by polymerase chain reaction (PCR) using the barcoding universal primers FishF2 and FishR2. A total of 654 base pairs (bp) of barcode CO1 gene from 175 samples were sequenced and analysed. The genetic sequences were blasted into the NCBI GenBank and Barcode of Life Data System (BOLD). A review of the blast search confirmed that there were 68 valid species of sharks and batoids that occurred in Malaysian waters. We provided the data of the COI gene mid-point rooting phylogenetic relation trees and analysed the genetic distances among infra-class and order, intra-species, inter-specific, inter-genus, inter-familiar, and inter-order. We confirmed the addition of Squalus edmundsi, Carcharhinus amboinensis, Alopias superciliosus, and Myliobatis hamlyni as new records for Malaysia. The establishment of a comprehensive CO1 database for sharks and batoids will help facilitate the rapid monitoring and assessment of elasmobranch fisheries using environmental DNA methods.

To associate specimens identified by molecular characters to other biological knowledge, we need reference sequences annotated by Linnaean taxonomy. In this study, we (1) report the creation of a comprehensive reference library of DNA barcodes for the arthropods of an entire country (Finland), (2) publish this library, and (3) deliver a new identification tool for insects and spiders, as based on this resource. The reference library contains mtDNA COI barcodes for 11,275 (43%) of 26,437 arthropod species known from Finland, including 10,811 (45%) of 23,956 insect species. To quantify the improvement in identification accuracy enabled by the current reference library, we ran 1000 Finnish insect and spider species through the Barcode of Life Data system (BOLD) identification engine. Of these, 91% were correctly assigned to a unique species when compared to the new reference library alone, 85% were correctly identified when compared to BOLD with the new material included, and 75% with the new material excluded. To capitalize on this resource, we used the new reference material to train a probabilistic taxonomic assignment tool, FinPROTAX, scoring high success. For the full‐length barcode region, the accuracy of taxonomic assignments at the level of classes, orders, families, subfamilies, tribes, genera, and species reached 99.9%, 99.9%, 99.8%, 99.7%, 99.4%, 96.8%, and 88.5%, respectively. The FinBOL arthropod reference library and FinPROTAX are available through the Finnish Biodiversity Information Facility (www.laji.fi) at https://laji.fi/en/theme/protax. Overall, the FinBOL investment represents a massive capacity‐transfer from the taxonomic community of Finland to all sectors of society. [ABSTRACT FROM AUTHOR]

L’articolo è dedicato al libro di Giovanni Solimine Introduzione allo studio della biblioteconomia, pubblicato nel 1995, articolato intorno al modello biblioteca/mediazione/organizzazione, che definì i fondamenti della ‘biblioteconomia gestionale’, radicati nel modello paradigmatico della reference library. La rilettura mette in luce i complessi fattori di mutamento attuali, e lo slittamento di paradigma in corso, le cui ‘anomalie’, secondo il lessico di Thomas Kuhn, si manifestano nelle eterogenee prospettive biblioteconomiche delineate, da quella ‘digitale’ a quella ‘sociale’ e ‘partecipativa’. Le considerazioni finali rimandano alla necessità di valorizzare le energie e le intelligenze che si muovono nei campi delle discipline del libro, dell’informazione, delle biblioteche, delle culture documentarie, orientandole all’interpretazione critica del cambiamento in atto, cercandone il radicamento nelle invarianti profonde su cui la tradizione disciplinare si è costituita.

Abstract DNA barcoding opens new perspectives on the way we document biodiversity. Initially proposed to circumvent the limits of morphological characters to assign unknown individuals to known species, DNA barcoding has been used in a wide array of studies where collecting species identity constitutes a crucial step. The assignment of unknowns to knowns assumes that species are already well identified and delineated, making the assignment performed reliable. Here, we used DNA‐based species delimitation and specimen assignment methods iteratively to tackle the inventory of the Indo‐Australian Archipelago grey mullets, a notorious case of taxonomic complexity that requires DNA‐based identification methods considering that traditional morphological identifications are usually not repeatable and sequence mislabeling is common in international sequence repositories. We first revisited a DNA barcode reference library available at the global scale for Mugilidae through different DNA‐based species delimitation methods to produce a robust consensus scheme of species delineation. We then used this curated library to assign unknown specimens collected throughout the Indo‐Australian Archipelago to known species. A second iteration of OTU delimitation and specimen assignment was then performed. We show the benefits of using species delimitation and specimen assignment methods iteratively to improve the accuracy of specimen identification and propose a workflow to do so.

Abstract The Coral Triangle (CT), a region spanning across Indonesia and Philippines, is home to about 4,350 marine fish species and is among the world's most emblematic regions in terms of conservation. Threatened by overfishing and oceans warming, the CT fisheries have faced drastic declines over the last decades. Usually monitored through a biomass‐based approach, fisheries trends have rarely been characterized at the species level due to the high number of taxa involved and the difficulty to accurately and routinely identify individuals to the species level. Biomass, however, is a poor proxy of species richness, and automated methods of species identification are required to move beyond biomass‐based approaches. Recent meta‐analyses have demonstrated that species richness peaks at intermediary levels of biomass. Consequently, preserving biomass is not equal to preserving biodiversity. We present the results of a survey to estimate the shore fish diversity retailed at the harbor of Ambon Island, an island located at the center of the CT that display exceptionally high biomass despite high levels of threat, while building a DNA barcode reference library of CT shore fishes targeted by artisanal fisheries. We sampled 1,187 specimens and successfully barcoded 696 of the 760 selected specimens that represent 202 species. Our results show that DNA barcodes were effective in capturing species boundaries for 96% of the species examined, which opens new perspectives for the routine monitoring of the CT fisheries.

The accuracy and reliability of DNA metabarcoding analyses depend on the breadth and quality of the reference libraries that underpin them. However, there are limited options available to obtain and curate the huge volumes of sequence data that are available on public repositories such as NCBI and BOLD. Here, we provide a pipeline to download, clean and annotate mitochondrial DNA sequence data for a given list of fish species. Features of this pipeline include (a) support for multiple metabarcode markers; (b) searches on species synonyms and taxonomic name validation; (c) phylogeny assisted quality control for identification and removal of misannotated sequences; (d) automatically generated coverage reports for each new GenBank release update; and (e) citable, versioned DOIs. As an example we provide a ready‐to‐use curated reference library for the marine and freshwater fishes of the U.K. To augment this reference library for environmental DNA metabarcoding specifically, we generated 241 new MiFish‐12S sequences for 88 U.K. marine species, and make available new primer sets useful for sequencing these. This brings the coverage of common U.K. species for the MiFish‐12S fragment to 93%, opening new avenues for scaling up fish metabarcoding across wide spatial gradients. The Meta‐Fish‐Lib reference library and pipeline is hosted at https://github.com/genner-lab/meta-fish-lib. [ABSTRACT FROM AUTHOR]

Background Dragonflies and damselflies (Odonata) are important components in biomonitoring due to their amphibiotic lifecycle and specific habitat requirements. They are charismatic and popular insects, but can be challenging to identify despite large size and often distinct coloration, especially the immature stages. DNA-based assessment tools rely on validated DNA barcode reference libraries evaluated in a supraregional context to minimize taxonomic incongruence and identification mismatches. Methods This study reports on findings from the analysis of the most comprehensive DNA barcode dataset for Central European Odonata to date, with 103 out of 145 recorded European species included and publicly deposited in the Barcode of Life Data System (BOLD). The complete dataset includes 697 specimens (548 adults, 108 larvae) from 274 localities in 16 countries with a geographic emphasis on Central Europe. We used BOLD to generate sequence divergence metrics and to examine the taxonomic composition of the DNA barcode clusters within the dataset and in comparison with all data on BOLD. Results Over 88% of the species included can be readily identified using their DNA barcodes and the reference dataset provided. Considering the complete European dataset, unambiguous identification is hampered in 12 species due to weak mitochondrial differentiation and partial haplotype sharing. However, considering the known species distributions only two groups of five species possibly co-occur, leading to an unambiguous identification of more than 95% of the analysed Odonata via DNA barcoding in real applications. The cases of small interspecific genetic distances and the observed deep intraspecific variation in Cordulia aenea (Linnaeus, 1758) are discussed in detail and the corresponding taxa in the public reference database are highlighted. They should be considered in future applications of DNA barcoding and metabarcoding and represent interesting evolutionary biological questions, which call for in depth analyses of the involved taxa throughout their distribution ranges.

Metabarcoding is an emerging method in which DNA barcoding is combined with next-generation sequencing to determine the biodiversity of taxonomically complex samples. We assessed the current state of DNA barcode reference databases for marine zooplankton in South Africa and undertook a metabarcoding analysis to determine the species composition of samples collected with plankton tow nets. Analysis of DNA sequences mined from the literature and in online barcode reference databases revealed incomplete records for all taxa examined. Barcode records were dominated by meroplanktonic species with commercially important life-history phases (fishes and decapod crustaceans) and by species occurring in easily accessible nearshore habitats. Holoplanktonic species were underrepresented, despite making up the bulk of zooplankton biodiversity, including most potential indicator species. Metabarcoding analysis of plankton samples could identify 45% of amplicon sequence variants to species level based on BOLD databases (123 species) and similar numbers using GenBank and the MIDORI COI classifier. Morphological analysis of samples could not achieve comparable resolution at species level, but with some exceptions it recovered similar classes of organisms to those found by metabarcoding. The need for integrative molecular/morphological studies to increase and validate barcode reference databases of key zooplankton taxa is recognised. Metabarcoding of marine zooplankton in South Africa has now been successfully undertaken and the methodology is expected to facilitate high-resolution monitoring of zooplankton biodiversity in pelagic ecosystems and accelerate the discovery of new species. [ABSTRACT FROM AUTHOR]

Background. Dragonflies and damselflies (Odonata) are important components in biomonitoring due to their amphibiotic lifecycle and specific habitat requirements. They are charismatic and popular insects, but can be challenging to identify despite large size and often distinct coloration, especially the immature stages. DNA-based assessment tools rely on validated DNA barcode reference libraries evaluated in a supraregional context to minimize taxonomic incongruence and identification mismatches. Methods. This study reports on findings from the analysis of the most comprehensive DNA barcode dataset for Central European Odonata to date, with 103 out of 145 recorded European species included and publicly deposited in the Barcode of Life Data System (BOLD). The complete dataset includes 697 specimens (548 adults, 108 larvae) from 274 localities in 16 countries with a geographic emphasis on Central Europe. We used BOLD to generate sequence divergence metrics and to examine the taxonomic composition of the DNA barcode clusters within the dataset and in comparison with all data on BOLD. Results. Over 88% of the species included can be readily identified using their DNA barcodes and the reference dataset provided. Considering the complete European dataset, unambiguous identification is hampered in 12 species due to weak mitochondrial differentiation and partial haplotype sharing. However, considering the known species distributions only two groups of five species possibly co-occur, leading to an unambiguous identification of more than 95% of the analysed Odonata via DNA barcoding in real applications. The cases of small interspecific genetic distances and the observed deep intraspecific variation in Cordulia aenea (Linnaeus, 1758) are discussed in detail and the corresponding taxa in the public reference database are highlighted. They should be considered in future applications of DNA barcoding and metabarcoding and represent interesting evolutionary biological questions, which call for in depth analyses of the involved taxa throughout their distribution ranges. [ABSTRACT FROM AUTHOR]

DNA barcoding has tremendous potential for advancing species knowledge for many diverse groups of insects, potentially paving way for machine identification and semi-automated monitoring of whole insect faunas. Here, I review the current state of DNA barcoding of the superfamily Sciaroidea (Diptera), a diverse group consisting of eight understudied fly families where the described species in the world makes up some 10% (≈16,000 species) of all Diptera. World data of Sciaroidea were extracted from the Barcode of Life online database BoldSystems (BOLD) and contrasted with results and experiences from a Nordic project to build the reference library. Well over 1.2 million (1,224,877) Sciaroidea specimens have been submitted for barcoding, giving barcode-compliant sequences resulting in 56,648 so-called barcode index numbers (BINs, machine-generated proxies for species). Although the BINs on BOLD already represent 3.5 times the number of described species, merely some 2850 named species (described or interim names, 5% of the BINs) currently have been assigned a BIN. The other 95% remain as dark taxa figuring in many frontier publications as statistics representing proxies for species diversity within a family. In the Nordic region, however, substantial progress has been made towards building a complete reference library, currently making up 55% of all named Sciaroidea BINs on BOLD. Another major source (31%) of named Sciaroidea BINs on BOLD comes from COI sequences mined from GenBank, generated through phylogenetic and integrative studies outside of BOLD. Building a quality reference library for understudied insects such as Sciaroidea requires heavy investment, both pre sequence and post sequence, by trained taxonomists to build and curate voucher collections, to continually improve the quality of the data and describe new species. Only when the BINs are properly calibrated by a rigorously quality-checked reference library can the great potential of both classical taxonomic barcoding, metabarcoding, and eDNA ecology be realized.

DNA barcoding opens new perspectives on the way we document biodiversity. Initially proposed to circumvent the limits of morphological characters to assign unknown individuals to known species, DNA barcoding has been used in a wide array of studies where collecting species identity constitutes a crucial step. The assignment of unknowns to knowns assumes that species are already well identified and delineated, making the assignment performed reliable. Here, we used DNA‐based species delimitation and specimen assignment methods iteratively to tackle the inventory of the Indo‐Australian Archipelago grey mullets, a notorious case of taxonomic complexity that requires DNA‐based identification methods considering that traditional morphological identifications are usually not repeatable and sequence mislabeling is common in international sequence repositories. We first revisited a DNA barcode reference library available at the global scale for Mugilidae through different DNA‐based species delimitation methods to produce a robust consensus scheme of species delineation. We then used this curated library to assign unknown specimens collected throughout the Indo‐Australian Archipelago to known species. A second iteration of OTU delimitation and specimen assignment was then performed. We show the benefits of using species delimitation and specimen assignment methods iteratively to improve the accuracy of specimen identification and propose a workflow to do so. [ABSTRACT FROM AUTHOR]

The Coral Triangle (CT), a region spanning across Indonesia and Philippines, is home to about 4,350 marine fish species and is among the world's most emblematic regions in terms of conservation. Threatened by overfishing and oceans warming, the CT fisheries have faced drastic declines over the last decades. Usually monitored through a biomass‐based approach, fisheries trends have rarely been characterized at the species level due to the high number of taxa involved and the difficulty to accurately and routinely identify individuals to the species level. Biomass, however, is a poor proxy of species richness, and automated methods of species identification are required to move beyond biomass‐based approaches. Recent meta‐analyses have demonstrated that species richness peaks at intermediary levels of biomass. Consequently, preserving biomass is not equal to preserving biodiversity. We present the results of a survey to estimate the shore fish diversity retailed at the harbor of Ambon Island, an island located at the center of the CT that display exceptionally high biomass despite high levels of threat, while building a DNA barcode reference library of CT shore fishes targeted by artisanal fisheries. We sampled 1,187 specimens and successfully barcoded 696 of the 760 selected specimens that represent 202 species. Our results show that DNA barcodes were effective in capturing species boundaries for 96% of the species examined, which opens new perspectives for the routine monitoring of the CT fisheries. [ABSTRACT FROM AUTHOR]

Copyright of Diadora is the property of Archaeological Museum in Zadar and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microbial source tracking can determine fecal contamination but requires a relevant, sizable reference library for analysis. We provide a reference library of 100+ fecal microbiome samples relevant to mid-Atlantic United States ecosystems. Included are wild and domesticated fauna, wastewater, and septic samples applicable to Delaware source tracking studies., Competing Interests: The authors declare no conflict of interest.

Effective identification of species using short DNA fragments (DNA barcoding and DNA metabarcoding) requires reliable sequence reference libraries of known taxa. Both taxonomically comprehensive coverage and content quality are important for sufficient accuracy. For aquatic ecosystems in Europe, reliable barcode reference libraries are particularly important if molecular identification tools are to be implemented in biomonitoring and reports in the context of the EU Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD). We analysed gaps in the two most important reference databases, Barcode of Life Data Systems (BOLD) and NCBI GenBank, with a focus on the taxa most frequently used in WFD and MSFD. Our analyses show that coverage varies strongly among taxonomic groups, and among geographic regions. In general, groups that were actively targeted in barcode projects (e.g. fish, true bugs, caddisflies and vascular plants) are well represented in the barcode libraries, while others have fewer records (e.g. marine molluscs, ascidians, and freshwater diatoms). We also found that species monitored in several countries often are represented by barcodes in reference libraries, while species monitored in a single country frequently lack sequence records. A large proportion of species (up to 50%) in several taxonomic groups are only represented by private data in BOLD. Our results have implications for the future strategy to fill existing gaps in barcode libraries, especially if DNA metabarcoding is to be used in the monitoring of European aquatic biota under the WFD and MSFD. For example, missing species relevant to monitoring in multiple countries should be prioritized for future collaborative programs. We also discuss why a strategy for quality control and quality assurance of barcode reference libraries is needed and recommend future steps to ensure full utilisation of metabarcoding in aquatic biomonitoring. Unlabelled Image • DNA barcode representation in public databases of 28,000 aquatic species is analysed. • Gaps in barcode reference libraries are largest for diatoms and invertebrates. • Sequence coverage varies considerably among invertebrate groups. • Species monitored by one or few countries more frequently lack reference barcodes. • Strategies should be implemented to maintain quality of barcode reference libraries. [ABSTRACT FROM AUTHOR]

Reliable wood identification and proof of the provenance of trees is the first step for combating illegal logging. DNA barcoding belongs to the promising tools in this regard, for which reliable methods and reference libraries are needed. Machine learning approaches (MLAs) are tailored to the necessities of DNA barcoding, which are based on mathematical multivaried analysis. In the present study, eight Dalbergia timber species were investigated in terms of their DNA sequences focusing on four barcodes (ITS2, matK, trnH-psbA and trnL) by means of the MLAs BLOG and WEKA for wood species identification. The data material downloaded from NCBI (288 sequences) and taken from a previous study of the authors (153 DNA sequences) was taken as dataset for calibration. The MLAs' effectivity was verified through identification of non-vouchered wood specimens. The results indicate that the SMO classifier as part of the WEKA approach performed the best (98%~100%) for discriminating the eight Dalbergia timber species. Moreover, the two-locus combination ITS2+trnH-psbA showed the highest success rate. Furthermore, the non-vouchered wood specimens were successfully identified by means of ITS2+trnH-psbA with the SMO classifier. The MLAs are successful in combi- nation with DNA barcode reference libraries for the identification of endangered Dalbergia timber species. [ABSTRACT FROM AUTHOR]

Reference spectral library searching, while widely used to identify compounds in other areas of mass spectrometry, is not commonly used in glycomics. Building on a study by Cotter and coworkers on analysis of sialylated oligosaccharides using atmospheric pressure-matrix-assisted laser-induced tandem mass spectrometry (MS/MS), we show that library search methods enable the automated differentiation of such sialylated oligosaccharide isomers using MS/MS derived from electrospray collision-induced dissociation in ion trap and beam-type fragmentation mass spectrometers. We compare MS/MS spectra of five sets of native sialylated oligosaccharide isomers and show a spectral library search method that can distinguish between these isomers using the precursor ion [M+2X-H]+, where X=Li, Na, or K. Sialic acid linkage (α2,3 vs. α2,6) is known to have a dramatic effect on the fragmentation of the sialylated compounds. We found that 2,4A3 cross-ring fragment at the terminal monosaccharide in sialyllactoses, sialyllactosamines, and sialyl pentasaccharides is highly abundant in the MS/MS spectra of [M+2X-H]+ species of α2,6-NeuAc glycans, while (2,4A3-H2O) fragment is highly abundant in α2,3-NeuAc moiety. The 2,4A3-H2O peak is specific to NeuAc-α2,3-Gal-β1,4-Y (Y=GlcNAc or Glc). To our knowledge, this observation was not reported previously. Theoretical calculations reveal major conformational differences between α2,6-NeuAc and α2,3-NeuAc structures that provide reasonable explanations for the observed fragmentation patterns. Other singly-charged ions ([M+X]+) do not show similar cross-ring cleavages. Implemented in a searchable library, these spectral differences provide a facile method to distinguish sialyl isomers without derivatization. We also found good spectral matching across instruments. MS/MS spectra and tools are available at http://chemdata.nist.gov/glycan/spectra.Graphical Abstract [ABSTRACT FROM AUTHOR]

Herbal drug authentication is an important task in traditional medicine; however, it is challenged by the limitations of traditional authentication methods and the lack of trained experts. DNA barcoding is conspicuous in almost all areas of the biological sciences and has already been added to the British pharmacopeia and Chinese pharmacopeia for routine herbal drug authentication. However, DNA barcoding for the Korean pharmacopeia still requires significant improvements. Here, we present a DNA barcode reference library for herbal drugs in the Korean pharmacopeia and developed a species identification engine named KP-IDE to facilitate the adoption of this DNA reference library for the herbal drug authentication. Using taxonomy records, specimen records, sequence records, and reference records, KP-IDE can identify an unknown specimen. Currently, there are 6,777 taxonomy records, 1,054 specimen records, 30,744 sequence records (ITS2 and psbA-trnH) and 285 reference records. Moreover, 27 herbal drug materials were collected from the Seoul Yangnyeongsi herbal medicine market to give an example for real herbal drugs authentications. Our study demonstrates the prospects of the DNA barcode reference library for the Korean pharmacopeia and provides future directions for the use of DNA barcoding for authenticating herbal drugs listed in other modern pharmacopeias.

Thin sections, resin blocks, pressed pellets, fused beads, milled powders, solutions and digested residues are several key sample formats used in the invasive scientific analysis of ancient ceramics. They are crucial tools that enable researchers to characterise the mineralogical, geochemical, molecular and microstructural composition of pottery and other ceramic artefacts, in order to interpret their raw materials, manufacturing technology, production locations and functions. Despite the importance of such preparations, key issues about their status, such as whether they are still artefacts or not, who owns them and where they should reside after analysis, are rarely addressed in the archaeological or archaeometric literature. These questions have implications for the long-term future of thin sections, resin blocks and other sample formats, as well as their accessibility for future research. The present paper highlights the above problem and assess the roles, perspectives and needs of ceramic analysts, field archaeologists, commercial units, curators, policy makers, professional bodies, special interest groups and funding agencies. Finally, guidelines are put forward that can be taken into account when deciding on the value and research potential of scientific specimens of archaeological ceramics, as well as strategies for their curation. [ABSTRACT FROM AUTHOR]

In recent years, large-scale DNA barcoding campaigns have generated an enormous amount of COI barcodes, which are usually stored in NCBI's GenBank and the official Barcode of Life database ( BOLD). BOLD data are generally associated with more detailed and better curated meta-data, because a great proportion is based on expert-verified and vouchered material, accessible in public collections. In the course of the initiative German Barcode of Life data were generated for the reference library of 2,846 species of Coleoptera from 13,516 individuals., Confronted with the high effort associated with the identification, verification and data validation, a bioinformatic pipeline, 'Tax CI' was developed that (1) identifies taxonomic inconsistencies in a given tree topology (optionally including a reference dataset), (2) discriminates between different cases of incongruence in order to identify contamination or misidentified specimens, (3) graphically marks those cases in the tree, which finally can be checked again and, if needed, corrected or removed from the dataset. For this, 'Tax CI' may use DNA-based species delimitations from other approaches (e.g. mPTP) or may perform implemented threshold-based clustering., The data-processing pipeline was tested on a newly generated set of barcodes, using the available BOLD records as a reference. A data revision based on the first run of the Tax CI tool resulted in the second Tax CI analysis in a taxonomic match ratio very similar to the one recorded from the reference set (92% vs. 94%). The revised dataset improved by nearly 20% through this procedure compared to the original, uncorrected one., Overall, the new processing pipeline for DNA barcode data allows for the rapid and easy identification of inconsistencies in large datasets, which can be dealt with before submitting them to public data repositories like BOLD or GenBank. Ultimately, this will increase the quality of submitted data and the speed of data submission, while primarily avoiding the deterioration of the accuracy of the data repositories due to ambiguously identified or contaminated specimens. [ABSTRACT FROM AUTHOR]

Citrus (Citrus spp.) production continues to decline in East Africa, particularly in Kenya and Tanzania, the two major producers in the region. This decline is attributed to pests and diseases including infestation by the African citrus triozid, Trioza erytreae (Del Guercio) (Hemiptera: Triozidae). Besides direct feeding damage by adults and immature stages, T. erytreae is the main vector of ‘Candidatus Liberibacter africanus’, the causative agent of Greening disease in Africa, closely related to Huanglongbing. This study aimed to generate a novel barcode reference library for T. erytreae in order to use DNA barcoding as a rapid tool for accurate identification of the pest to aid phytosanitary measures. Triozid samples were collected from citrus orchards in Kenya, Tanzania, and South Africa and from alternative host plants. Sequences generated from populations in the study showed very low variability within acceptable ranges of species. All samples analyzed were linked to T. erytreae of GenBank accession number KU517195. Phylogeny of samples in this study and other Trioza reference species was inferred using the Maximum Likelihood method. The phylogenetic tree was paraphyletic with two distinct branches. The first branch had two clusters: 1) cluster of all populations analyzed with GenBank accession of T. erytreae and 2) cluster of all the other GenBank accession of Trioza species analyzed except T. incrustata Percy, 2016 (KT588307.1), T. eugeniae Froggatt (KY294637.1), and T. grallata Percy, 2016 (KT588308.1) that occupied the second branch as outgroups forming sister clade relationships. These results were further substantiated with genetic distance values and principal component analyses. [ABSTRACT FROM AUTHOR]

A large-scale comprehensive reference library of DNA barcodes for European marine fishes was assembled, allowing the evaluation of taxonomic uncertainties and species genetic diversity that were otherwise hidden in geographically restricted studies. A total of 4118 DNA barcodes were assigned to 358 species generating 366 Barcode Index Numbers ( BIN). Initial examination revealed as much as 141 BIN discordances (more than one species in each BIN). After implementing an auditing and five-grade (A-E) annotation protocol, the number of discordant species BINs was reduced to 44 (13% grade E), while concordant species BINs amounted to 271 (78% grades A and B) and 14 other had insufficient data (grade D). Fifteen species displayed comparatively high intraspecific divergences ranging from 2·6 to 18·5% (grade C), which is biologically paramount information to be considered in fish species monitoring and stock assessment. On balance, this compilation contributed to the detection of 59 European fish species probably in need of taxonomic clarification or re-evaluation. The generalized implementation of an auditing and annotation protocol for reference libraries of DNA barcodes is recommended. [ABSTRACT FROM AUTHOR]

Biodiversity loss is mainly driven by human activity. While concern grows over the fate of hot spots of biodiversity, contemporary species losses still prevail in industrialized nations. Therefore, strategies were formulated to halt or reverse the loss, driven by evidence for its value for ecosystem services. Maintenance of the latter through conservation depends on correctly identified species. To this aim, the German Federal Ministry of Education and Research is funding the GBOL project, a consortium of natural history collections, botanic gardens, and universities working on a barcode reference database for the country's fauna and flora. Several noticeable findings could be useful for future campaigns: ( i) validating taxon lists to serve as a taxonomic backbone is time-consuming, but without alternative; ( ii) offering financial incentives to taxonomic experts, often citizen scientists, is indispensable; ( iii) completion of the libraries for widespread species enables analyses of environmental samples, but the process may not hold pace with technological advancements; ( iv) discoveries of new species are among the best stories for the media; ( v) a commitment to common data standards and repositories is needed, as well as transboundary cooperation between nations; ( vi) after validation, all data should be published online via the BOLD to make them searchable for external users and to allow cross-checking with data from other countries. [ABSTRACT FROM AUTHOR]

Copyright of Genome is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)