Identifying Canadian mosquito species through DNA barcodes

A short fragment of mt DNA from the cytochrome c oxidase 1 (CO1) region was used to provide the first CO1 barcodes for 37 species of Canadian mosquitoes (Diptera: Culicidae) from the provinces Ontario and New Brunswick. Sequence variation was analysed in a 617-bp fragment from the 5' end of the CO1 region. Sequences of each mosquito species formed barcode clusters with tight cohesion that were usually clearly distinct from those of allied species. CO1 sequence divergences were, on average, nearly 20 times higher for congeneric species than for members of a species; divergences between congeneric species averaged 10.4% (range 0.2-17.2%), whereas those for conspecific individuals averaged 0.5% (range 0.0-3.9%).     

Molecular characterization of marine and coastal fishes of Bangladesh through DNA barcodes

This study describes the molecular characterization of marine and coastal fishes of Bangladesh based on the mitochondrial cytochrome c oxidase subunit I (COI) gene as a marker. A total of 376 mitochondrial COI barcode sequences were obtained from 185 species belonging to 146 genera, 74 families, 21 orders, and two classes of fishes. The mean length of the sequences was 652 base pairs. In Elasmobranchii (Sharks and rays), the average Kimura two parameter (K2P) distances within species, genera, families, and orders were 1.20%, 6.07%, 11.08%, and 14.68%, respectively, and for Actinopterygii, the average K2P distances within species, genera, families, and orders were 0.40%, 6.36%, 14.10%, and 24.07%, respectively. The mean interspecies distance was 16‐fold higher than the mean intraspecies distance. The K2P neighbor‐joining (NJ) trees based on the sequences generally clustered species in accordance with their taxonomic position. A total of 21 species were newly recorded in Bangladesh. High efficiency and fidelity in species identification and discrimination were demonstrated in the present study by DNA barcoding, and we conclude that COI sequencing can be used as an authentic identification marker for Bangladesh marine fish species.     

DNA barcodes of Philippine accipitrids

DNA barcoding is a molecular method that rapidly identifies an individual to a known taxon or its closest relative based on a 650-bp fragment of the cytochrome c oxidase subunit I (COI). In this study, DNA barcodes of members of the family Accipitridae, including Haliastur indus (brahminy kite), Haliaeetus leucogaster (white-bellied sea eagle), Ichthyophaga ichthyaetus (grey-headed fish eagle), Spilornis holospilus (crested serpent-eagle), Spizaetus philippensis (Philippine hawk-eagle), and Pithecophaga jefferyi (Philippine eagle), are reported for the first time. All individuals sampled are kept at the Philippine Eagle Center in Davao City, Philippines. Basic local alignment search tool results demonstrated that the COI sequences for these species were unique. The COI gene trees constructed using the maximum-likelihood and neighbour-joining (NJ) methods supported the monophyly of the booted eagles of the Aquilinae and the sea eagles of the Haliaeetinae but not the kites of the Milvinae.     

Fungal pathogen (mis-) identifications: A case study with DNA barcodes on Melampsora rusts of aspen and white poplar

Wide variation and overlap in morphological characters have led to confusion in species identification within the fungal rust genus Melampsora. The Melampsora species with uredinial–telial stages on white poplar and aspens are especially prone to misidentification. This group includes the Melampsora populnea species complex and the highly destructive pine twisting rust, Melampsora pinitorqua, which alternates between hosts in Populus section Populus and Pinus. Our objective was to compare morphologically based identification to genetic material extracted from Melampsora species pathogenic to aspen and white poplar. We compared morphometric traits and DNA barcodes obtained from internal transcribed spacer (ITS), large ribosomal RNA subunit (28S), and mitochondrial cytochrome oxidase 1 (CO1) sequences to delimit within this taxonomically difficult group. Eight different Melampsora species were initially defined based on host specificity and morphometric data. DNA barcodes were then overlaid on these initial species definitions. The DNA barcodes, specifically those defined on ITS and 28S sequences, provided a highly accurate means of identifying and resolving Melampsora taxa. We highlighted species misidentification in specimens from Canadian herbaria related to either Melampsora medusae f. sp. tremuloidae or Melampsora aecidioides. Finally, we evidenced that the north-American species found on Populus alba, M. aecidioides is closely related but distinct from the four species of the M. populnea complex (Melampsora larici-tremulae, Melampsora magnusiana, Melampsora pinitorqua, and Melampsora rostrupii) found in Eurasia.     

Species identification of aphids (Insecta: Hemiptera: Aphididae) through DNA barcodes

A 658-bp fragment of mitochondrial DNA from the 5' region of the mitochondrial cytochrome c oxidase 1 (COI) gene has been adopted as the standard DNA barcode region for animal life. In this study, we test its effectiveness in the discrimination of over 300 species of aphids from more than 130 genera. Most (96%) species were well differentiated, and sequence variation within species was low, averaging just 0.2%. Despite the complex life cycles and parthenogenetic reproduction of aphids, DNA barcodes are an effective tool for identification.     

植物DNA条形码在系统发育研究中的应用

<正>1常用植物DNA条形码物种的准确鉴定是开展科学研究和生物多样性保护的先决条件,但根据形态学特征进行物种鉴定对非专业人员而言比较困难。即使是专业人员,面对纷繁复杂的物种,要想逐一鉴定也难以实现。DNA条形码技术(DNA barcoding)为物种的快速、准确鉴定提供了可能(Hebert et al.,2003)。线粒体COI基因作为动物的DNA条形码已得到广泛应用。但对     

DNA barcodes expose unexpected diversity in Canadian mites

Mites (Arachnida: Acariformes, Parasitiformes) are the most abundant and species‐rich group of arthropods in soil, but are also diverse in freshwater habitats, on plants, and as symbionts of larger animals. However, assessment of their diversity has been impeded by their small size and often cryptic morphology. As a consequence, published estimates of their species richness span more than two orders of magnitude (0.4–114 million). In this study we employ DNA barcoding and the Barcode Index Number (BIN) system to investigate mite diversity at over 1,800 sites across Canada, primarily from soil and litter habitats with smaller contributions from freshwater, plants, and animal hosts. Barcodes from 73,394 specimens revealed 7,077 BINs with representatives from all four orders (Ixodida, Mesostigmata, Sarcoptiformes, Trombidiformes) and 60% (186) of the known families. The BIN total is 2.4 times the number of species previously recorded from Canada (2,999), reflecting the unexpectedly high richness of several families. Richness projections suggest that more than 28,000 BINs occur at the sampled locations, indicating that the Canadian mite fauna almost certainly includes more than 30,000 species—a total similar to that for the most diverse insect order in Canada, Diptera. This unexpected diversity was partitioned into highly dissimilar, spatially‐structured assemblages that likely reflect dispersal limitation and environmental heterogeneity. Further sampling of a greater diversity of habitats will refine understanding of mite diversity in Canada, but similar analyses in other geographic regions will be essential to ascertain their diversity at a global scale.     

植物DNA条形码、物种形成和分类学

<正>DNA条形码最大的特点是用一段标准DNA序列就可以鉴定生物材料(特别是不具有分类特征的残缺或来自幼小个体的材料)和生物产品的物种来源(Hebert et al.,2003)。已有研究发现,动物中线粒体基因组的COI基因序列能鉴定多个动物类群的物种,被认为是理想的DNA条形码片段(Ward et al.,2005;TavaresBaker,2008)。而植物DNA条形码序列的确定还存在争议,例如应选择一个片段还是多     

DNA barcodes for marine fungal identification and discovery

We employed DNA barcodes for identification of fungal species in marine sediments. Sediments were collected seasonally along the Southeast coast of India from which a culturable fungal library was constructed. All cultured species were morphologically documented using microscopical analysis. A maximum population density of 19.3 × 10³ CFU/g was recorded in monsoon and minimum of 3 × 10³ CFU/g in premonsoon season. Two-way analysis of variance suggests that the fungal community varied significantly between the seasons (F = 9.543, P < 0.001) and at various depths sampled (F = 4.655, P < 0.05). In total, 54 fungal species belonging to 13 different families were documented and all species were sequenced for internal transcribed spacer genes. Each species was represented by at least two specimens constituting a total of 171 specimens for DNA barcoding. Twelve species of a marine fungi were sequenced for the first time. Branching patterns of phylogenetic tree strongly supported the sequence variations within and between all species barcoded. Based on the pairwise distance model we suggest barcode gaps of 15 %, 21 %, 30 %, 35 % and 51 % for genera, family, order, class and phyla respectively.     

DNA barcodes for biosecurity: invasive species identification

Biosecurity encompasses protecting against any risk through 'biological harm', not least being the economic impact from the spread of pest insects. Molecular diagnostic tools provide valuable support for the rapid and accurate identification of morphologically indistinct alien species. However, these tools currently lack standardization. They are not conducive to adaptation by multiple sectors or countries, or to coping with changing pest priorities. The data presented here identifies DNA barcodes as a very promising opportunity to address this. DNA of tussock moth and fruit fly specimens intercepted at the New Zealand border over the last decade were reanalysed using the cox1 sequence barcode approach. Species identifications were compared with the historical dataset obtained by PCR-RFLP of nuclear rDNA. There was 90 and 96% agreement between the methods for these species, respectively. Improvements included previous tussock moth 'unknowns' being placed to family, genera or species and further resolution within fruit fly species complexes. The analyses highlight several advantages of DNA barcodes, especially their adaptability and predictive value. This approach is a realistic platform on which to build a much more flexible system, with the potential to be adopted globally for the rapid and accurate identification of invasive alien species.     

DNA barcodes of eight species in genus Sebastes

DNA barcode is effective for biological taxonomy and is able to identify species from any life-history stage. In the present study, eight species which belong to four different subgenera of genus Sebastes found in China sea waters were identified by cytochrome c oxidase I (COI) barcode. The results indicated that the intra-species variation in DNA barcode was less than inter-species variation. When the phylogenetic trees were reconstructed by neighbor joining (NJ), maximum parsimony (MP), maximum likelihood (ML) and Bayesian methods, all the species clustered in their groups distinguishable by high bootstrap values, which proved that COI barcode is a powerful means to differentiate species of Sebastes and supports their identification. When the molecular tree was compared to the morphological tree, only Sebastes trivittatus in subgenus Sebastocles settled in the different positions. It is suggested that S. trivittatus is one of the shallowest occurring species in the Northwest Pacific due to its life characters.     

Exploring community assembly among Javanese and Balinese freshwater shrimps (Atyidae,Palaemonidae) through DNA barcodes

Hydrobiologia - Species proliferate through evolutionary mechanisms but coexist through ecological dynamics. As such, it might be expected that mechanisms of speciation and species maintenance...     

Identification of herbal medicinal materials using DNA barcodes

Herbal medicinal materials have been used worldwide for centuries to maintain health and to treat disease. However, adulteration of herbal medicines remains a major concern of users and industry for reasons of safety and efficacy. Identification of herbal medicinal materials by DNA technology has been widely applied,started from the mid-1990s. In recent years, DNA barcoding of global plant species using four standard barcodes (rbcL, matK, trnH-psbA and ITS) has been a major focus in the fields of biodiversity and conservation. These DNA barcodes can also be used as reliable tools to facilitate the identification of herbal medicinal materials for the safe use of herbs, quality control, and forensic investigation. Many studies have applied these DNA barcodes for the identification of herbal medicinal species and their adulterants. The present article reviews efforts in the identification of herbal medicinal materials using the standard DNA barcodes and other DNA sequence-based markers.     

New DNA barcodes for identification of Korean birds

DNA barcode is a short sequence of standardized genomic region that is specific to a species and therefore, helps in species identification. According to studies of animal species, the 648-bp sequence of the mitochondrial gene encoding cytochrome c oxidase 1 (CO1) is extremely useful for species identification. Several studies of birds have already ascertained the reliability of CO1 barcodes. In this study, we investigated the validity of DNA barcoding in Korean bird species by using additional barcode records. We analyzed the CO1 barcodes of 154 species of Korean birds, and discovered that the average genetic distance between congeneric species was 25 times higher than the average genetic distance within species. Most (98.7 %) bird species possessed a barcode distinct from that of other bird species. However, among the remaining 1.3 %, species had overlapping barcode clusters. Thus, we reemphasize that CO1 barcodes are an effective identification tool for Korean bird species.     

Logic Gate Operation by DNA Translocation through Biological Nanopores

Logical operations using biological molecules, such as DNA computing or programmable diagnosis using DNA, have recently received attention. Challenges remain with respect to the development of such systems, including label-free output detection and the rapidity of operation. Here, we propose integration of biological nanopores with DNA molecules for development of a logical operating system. We configured outputs “1” and “0” as single-stranded DNA (ssDNA) that is or is not translocated through a nanopore; unlabeled DNA was detected electrically. A negative-AND (NAND) operation was successfully conducted within approximately 10 min, which is rapid compared with previous studies using unlabeled DNA. In addition, this operation was executed in a four-droplet network. DNA molecules and associated information were transferred among droplets via biological nanopores. This system would facilitate linking of molecules and electronic interfaces. Thus, it could be applied to molecular robotics, genetic engineering, and even medical diagnosis and treatment.     

Design and applicability of DNA arrays and DNA barcodes in biodiversity monitoring

Background  

The rapid and accurate identification of species is a critical component of large-scale biodiversity monitoring programs. DNA arrays (micro and macro) and DNA barcodes are two molecular approaches that have recently garnered much attention. Here, we compare these two platforms for identification of an important group, the mammals.     

Neotropical bats: estimating species diversity with DNA barcodes

DNA barcoding using the cytochrome c oxidase subunit 1 gene (COI) is frequently employed as an efficient method of species identification in animal life and may also be used to estimate species richness, particularly in understudied faunas. Despite numerous past demonstrations of the efficiency of this technique, few studies have attempted to employ DNA barcoding methodologies on a large geographic scale, particularly within tropical regions. In this study we survey current and potential species diversity using DNA barcodes with a collection of more than 9000 individuals from 163 species of Neotropical bats (order Chiroptera). This represents one of the largest surveys to employ this strategy on any animal group and is certainly the largest to date for land vertebrates. Our analysis documents the utility of this tool over great geographic distances and across extraordinarily diverse habitats. Among the 163 included species 98.8% possessed distinct sets of COI haplotypes making them easily recognizable at this locus. We detected only a single case of shared haplotypes. Intraspecific diversity in the region was high among currently recognized species (mean of 1.38%, range 0-11.79%) with respect to birds, though comparable to other bat assemblages. In 44 of 163 cases, well-supported, distinct intraspecific lineages were identified which may suggest the presence of cryptic species though mean and maximum intraspecific divergence were not good predictors of their presence. In all cases, intraspecific lineages require additional investigation using complementary molecular techniques and additional characters such as morphology and acoustic data. Our analysis provides strong support for the continued assembly of DNA barcoding libraries and ongoing taxonomic investigation of bats.     

DNA条形码在鞘翅目昆虫分子系统学研究中的应用

近年来,DNA条形码(DNA Barcoding)技术已经成为生物分类学研究中备受关注的新型技术,并在鞘翅目昆虫系统发育研究中得到广泛应用。本文总结了鞘翅目昆虫DNA条形码研究所用COⅠ基因序列,概述了DNA条形码在鞘翅目昆虫的物种分类鉴定、发现新种和隐存种、系统发育关系研究等方面的应用,并对DNA条形码研究技术新进展和标准序列筛选需要注意的问题进行了讨论。