The changing epitome of species identification - DNA barcoding

Genus Bithynia: morphological classification to molecular identification

Snails of the genus Bithynia, whose primary habitat is slow-flowing ponds and ditches, serve as the first intermediate hosts of liver fluke. Currently, approximately 200 million individuals worldwide are at risk of liver fluke infection, yet questions still persist regarding the taxonomic identification of Bithynia genus, a crucial player in the transmission of this disease. Accurate taxonomic classification of the Bithynia genus could significantly enhance current understanding of the disease's transmission mechanisms. In this article we comprehensively review the extensive research conducted on Bithynia genus, spanning past inquiries up to the latest findings. The primary emphasis is placed on exploring the taxonomic identification of this genus within various technological settings. We then present a consolidated analysis of the morphological taxonomic identification methods, highlighting their strengths and limitations. We also introduce a novel perspective on the future direction of identification and classification efforts for the members of this genus, emphasizing the crucial role Bithynia plays in the epidemiological cycle of liver fluke transmission. We conclude by urging researchers to prioritize the significance of the members of this genus in the epidemiological cycle of liver fluke transmission and in control measures for disease dissemination, within the context of the vector organisms.

Comparison of Universal mtDNA Primers in Species Identification of Animals in a Sample with Severely Degraded DNA

Analysis of mitochondrial DNA, specifically the cytochrome b gene (cyt b), has become an essential tool for species identification. In the case of degraded samples, in which DNA is fractionated, universal primers, which are highly effective at amplifying the target region, are necessary. The material analysed in this study was a keychain made of bone, which was secured at a border crossing due to the suspicion that it was made of ivory. Due to processing of the bone and the likelihood of DNA degradation, five pairs of universal primers with different product lengths (from 148 to 990 base pairs) were used for species identification. Fragments of mtDNA from the cyt b and the 12S rRNA and 16S rRNA subunits were analysed. The analysis showed that only one pair of primers (L15601/H15748) enabled identification of the species, which is very common in samples with highly degraded DNA. The material was bone tissue belonging to the species Bos taurus (cattle). Species identification by molecular methods is extremely important in analysis of material when the species cannot be identified on the basis of morphological characteristics.

The buzz about honey-based biosurveys

Approximately 1.8 million metric tonnes of honey are produced globally every year. The key source behind this output, the honey bee (Apis mellifera), works tirelessly to create the delicious condiment that is consumed worldwide. The honey that finds its way into jars on store shelves contains a myriad of information about its biogeographical origins, such as the bees that produced it, the botanical constituents, and traces of other organisms or pathogens that have come in contact with the product or its producer. With the ongoing threat of honey bee decline and overall global biodiversity loss, access to ecological information has become an key factor in preventing the loss of species. This review delves into the various molecular techniques developed to characterize the collective DNA harnessed within honey samples, and how it can be used to elucidate the ecological interactions between honey bees and the environment. We also explore how these DNA-based methods can be used for large-scale biogeographical studies through the environmental DNA collected by foraging honey bees. Further development of these techniques can assist in the conservation of biodiversity by detecting ecosystem perturbations, with the potential to be expanded towards other critical flying pollinators.

Genetic, haplotype and phylogenetic analysis of Ligula intestinalis by using mt-CO1 gene marker: ecological implications, climate change and eco-genetic diversity

Abstract Ligula intestinalis is a cestode parasite that affects freshwater fish in different countries of the world. The current study aims to reveal the phylogenetic, genetic and haplotype diversity of mt-CO1 gene sequences sent to the NCBI database from different countries by using in-silico analysis. The 105 mt-CO1 (371 bp) gene sequences of L. intestinalis obtained from NCBI were used for bioinformatics analyses. Sequences were subjected to phylogenetic and haplotype analysis. As a result of the haplotype analysis of L. intestinalis, 38 haplotypes were obtained from 13 different countries. Hap24 constituted 44.76% of the obtained haplotype network. Changes in nucleotides between haplotypes occurred at 1-84 different points. China and Turkey have highest fixation index (Fst) values of 0.59761, while the lowest (-0.10526) was found between Russia and Turkey. This study provides a baseline for future studies on extensive scale on the epidemiology, ecological aspects, distribution pattern, transmission dynamics and population dispersion of L. intestinalis worldwide.

Universal mtDNA fragment for Cervidae barcoding species identification using phylogeny and preliminary analysis of machine learning approach

The aim of the study was to use total DNA obtained from bone material to identify species of free-living animals based on the analysis of mtDNA fragments by molecular methods using accurate bioinformatics tools Bayesian approach and the machine learning approach. In our research, we present a case study of successful species identification based on degraded samples of bone, with the use of short mtDNA fragments. For better barcoding, we used molecular and bioinformatics methods. We obtained a partial sequence of the mitochondrial cytochrome b (Cytb) gene for Capreolus capreolus, Dama dama, and Cervus elaphus, that can be used for species affiliation. The new sequences have been deposited in GenBank, enriching the existing Cervidae mtDNA base. We have also analysed the effect of barcodes on species identification from the perspective of the machine learning approach. Machine learning approaches of BLOG and WEKA were compared with distance-based (TaxonDNA) and tree-based (NJ tree) methods based on the discrimination accuracy of the single barcodes. The results indicated that BLOG and WEKAs SMO classifier and NJ tree performed better than TaxonDNA in discriminating Cervidae species, with BLOG and WEKAs SMO classifier performing the best.

Development of a DNA Metabarcoding Method for the Identification of Insects in Food

Insects have the potential to become an efficient and reliable food source for humans in the future and could contribute to solving problems with the current food chain. Analytical methods to verify the authenticity of foods are essential for consumer acceptance. We present a DNA metabarcoding method that enables the identification and differentiation of insects in food. The method, developed on Illumina platforms, is targeting a 200 bp mitochondrial 16S rDNA fragment, which we found to be suitable for distinguishing more than 1000 insect species. We designed a novel universal primer pair for a singleplex PCR assay. Individual DNA extracts from reference samples, DNA extracts from model foods and food products commercially available were investigated. In all of the samples investigated, the insect species were correctly identified. The developed DNA metabarcoding method has a high potential to identify and differentiate insect DNA in the context of food authentication in routine analysis.

Genetic Characterization of Some Saudi Arabia's Accessions from Commiphora gileadensis Using Physio-Biochemical Parameters, Molecular Markers, DNA Barcoding Analysis and Relative Gene Expression

Commiphora gileadensis L. is a medicinal plant, known as balsam, with pharmaceutical potential for its phytochemical activities and chemical constituents. Genetic diversity is a genetic tool used in medicinal plant evolution and conservation. Three accessions from C. gileadensis were collected from three localities in Saudi Arabia (Jeddah, Jizan and Riyadh). Genetic characterization was carried out using physio-biochemical parameters, molecular markers (inter-simple sequence repeat (ISSR) and start codon targeted (SCoT)), DNA barcoding (18 S rRNA and ITS rDNA regions), relative gene expressions (phenylalanine ammonia-lyase 1 (PAL1), defensin (PR-12)) and pathogenesis-related protein (AFPRT). The results of this study showed that C. gileadensis accession C3, collected from Riyadh, had the highest content from the physio-biochemical parameters perspective, with values of 92.54 mg/g and 77.13 mg/g for total phenolic content (TPC) and total flavonoid content (TFC), respectively. Furthermore, the highest content of antioxidant enzyme activity was present in accession C3 with values of 16.87, 60.87, 35.76 and 27.98 U mg-1 for superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) (mol/min/mg FW) and ascorbate peroxidase (APX) (U mg-1 protein), respectively. The highest total number of bands and number of unique bands were 138 and 59, respectively, for the SCoT marker. The SCoT marker was the most efficient for the genetic diversity of C. gileadensis by producing the highest polymorphism (75.63%). DNA barcoding using 18 S and ITS showed the nearby Commiphora genus and clustered C. gileadensis accessions from Jeddah and Jizan in one clade and the C. gileadensis accession from Ryiadh in a separate cluster. Moreover, relative gene expression of the PAL1, defensin (PR-12) and AFPRT (PR1) genes was upregulated in the C. gileadensis accession from Ryiadh. In conclusion, ecological and environmental conditions in each locality affect the genomic expression and genetic diversity, which can help the evolution of important medicinal plants and improve breeding and conservation systems.

Endorsement and phylogenetic analysis of some Fabaceae plants based on DNA barcoding

Background

DNA barcoding have been considered as a tool to facilitate species identification based on its simplicity and high-level accuracy in compression to the complexity and subjective biases linked to morphological identification of taxa. MaturaseK gene (MatK gene) of the chloroplast is very vital in the plant system which is involved in the group II intron splicing. The main objective of this study is to determine the relative utility of the “MatK” chloroplast gene for barcoding in 15 legume as a tool to facilitate species identification based on their simplicity and high-level accuracy linked to morphological identification of taxa.

Methods and Results

MatK gene sequences were submitted to GenBank and the accession numbers were obtained with sequence length ranging from 730 to 1545 nucleotides. These DNA sequences were aligned with database sequence using PROMALS server, Clustal Omega server and Bioedit program. Maximum likelihood and neighbor-joining algorithms were employed for constructing phylogeny. Overall, these results indicated that the phylogenetic tree analysis and the evolutionary distances of an individual dataset of each species were agreed with a phylogenetic tree of all each other consisting of two clades, the first clade comprising (Enterolobium contortisiliquum, Albizia lebbek), Acacia saligna, Leucaena leucocephala, Dichrostachys Cinerea, (Delonix regia, Parkinsonia aculeata), (Senna surattensis, Cassia fistula, Cassia javanica) and Schotia brachypetala were more closely to each other, respectively. The remaining four species of Erythrina humeana, (Sophora secundiflora, Dalbergia Sissoo, Tipuana Tipu) constituted the second clade.

Conclusion

Moreover, their sequences could be successfully utilized in single nucleotide polymorphism or as part of the sequence as DNA fragment analysis utilizing polymerase chain reaction in plant systematic. Therefore, MatK gene is considered promising a candidate for DNA barcoding in the plant family Fabaceae and provides a clear relationship between the families.

Polymorphism in a Neotropical toad species: ontogenetic, populational and geographic approaches to chromatic variation in Proceratophrys cristiceps (Müller, 1883) (Amphibia, Anura, Odontophrynidae)

Quantifying variability is important for understanding how evolution operates in polymorphic species such as those of the genus Proceratophrys Miranda-Ribeiro, 1920, which is widely distributed in South America. P. cristiceps distribution is limited to the Caatinga biome in Brazil. We examined its chromatic variation from a populational perspective, looking at different phenetic polymorphism levels and probable chromotypic association by applying statistical and GIS tools that could facilitate future taxonomic research regarding this and other species. We characterized P. cristiceps colour patterns and re-evaluated its geographic variation, highlighting potential consequences for the taxonomy of the genus. Our results revealed six principle chromotypes whose frequencies varied among sex and ontogenetic classes. Phenotypic expression appeared to respect defined proportions and evidenced selective value for the species. We conclude that individual variation, together with typological traditionalism may overestimate the polymorphic magnitude at the population level and cause taxonomic inflation. Our data support the usefulness of P. cristiceps as a model for microevolutionary studies.

Identification of Vicia Species Native to South Korea Using Molecular and Morphological Characteristics

Recently, within the Fabaceae family, the Vicia genus has been recognized for its vital role in sustainable agriculture. Vicia species are economically important grain and forage crops. However, the presence of complex morphological characteristics makes identification and recognition of native species difficult. In this study, the possibility of using DNA barcoding regions (ITS2, matK, and rbcL) to distinguish among 19 Vicia taxa (59 accessions) found in South Korea was evaluated. The sequence alignment analysis revealed considerable nucleotide diversity (π) between the loci, in which ITS2 showed the highest mean interspecific distance, whereas there was no intraspecific variability among the barcode regions in 12 of the 19 taxa. Phylogenetic analysis of combined barcoding regions revealed well-resolved phylogeny with the highest species level discrimination. Combinations of barcode loci were also used in classification at the subgenera and section levels. The results revealed that the combined barcoding regions can be used effectively to differentiate the following species: Vicia angustifolia var. segetilis, Vicia bungei, Vicia villosa, Vicia cracca, Vicia dasycarpa, Vicia hirsuta, Vicia tetrasperma, Vicia amurensis, Vicia hirticalycina, and Vicia chosenensis. However, it is difficult to differentiate the species of Vicia unijuga, Vicia unijuga var. kaussanensis, Vicia linearifolia, Vicia unijuga f. angustifolia, Vicia nipponica, Vicia amoena, Vicia venosa var. cuspidata, Vicia pseudo-orobus, and Vicia japonica with the tested barcode regions. These species come under sect. Vicilla and are found to be closely related or species that have recently undergone speciation; thus, it has limitation to distinguish with recommended barcodes. Hence, to differentiate the unclassified species, 39 morphological characteristics were investigated, in which 16 useful characteristics were selected for efficient classification. Finally, the 16 selected morphological useful traits efficiently differentiated all the Vicia species. In conclusion, a combination of barcoding loci together with morphological characteristics of this study efficiently discriminated all the Korean Vicia species.

ITS2: An Ideal DNA Barcode for the Arid Medicinal Plant Rhazya Stricta

INTRODUCTION

In Saudi Arabia, Rhazya stricta is a widely used folkloric plant because of its various therapeutic properties. It is sold in herbal markets as a dried powder; however, the absence of visible phenotypic traits in the powder can mask its authenticity. Potential misidentification of this substance threatens consumer health. DNA barcoding could accurately identify this plant regardless of its physical state, however barcoding presents the challenge of variations in marker loci.

OBJECTIVES

The objective of this work was to assess barcode markers from the chloroplast and nuclear regions to determine their taxonomic accuracy in R. stricta barcoding, and select the best marker for this species that could fulfill the authentication test for its fresh and dried samples.

METHOD

In this study, we assessed seven barcode markers from the chloroplast (psbA-trnH, matK, rbcL, rpoB, and rpoC1) and nuclear regions (ITS1and ITS2). We compared DNA sequences of R. stricta from 50 fresh locally collected samples and 10 dried ground samples from the herbal market with the database sequences of R. stricta, R. orientalis, and eight other related species as controls. We utilized three methods (BLAST, nearest distance, and neighbor-joining tree) in this analysis.

RESULT

With the exception of psbA-trnH, all the chloroplast markers determined high similarity with other taxa. However, nuclear ITS2 best distinguished between R. stricta, R. orientalis, and other related species because of its secondary structures, which allowed for more accurate distinctions. A two-locus marker of ITS1 + ITS2 sequences also showed promising results. A two-dimensional image of our proposed marker was generated to more easily handle DNA barcoding applications.

CONCLUSION

Our study indicates that ITS2 is a cost-effective barcoding marker capable of verifying the authenticity of R. stricta and other medicinal plants in order to protect consumer health.

Promising Perspectives for Detection, Identification, and Quantification of Plant Pathogenic Fungi and Oomycetes through Targeting Mitochondrial DNA

Fungi and oomycetes encompass many pathogens affecting crops worldwide. Their effective control requires screening pathogens across the local and international trade networks along with the monitoring of pathogen inocula in the field. Fundamentals to all of these concerns are their efficient detection, identification, and quantification. The use of molecular markers showed the best promise in the field of plant pathogen diagnostics. However, despite the unquestionable benefits of DNA-based methods, two significant limitations are associated with their use. The first limitation concerns the insufficient level of sensitivity due to the very low and uneven distribution of pathogens in plant material. The second limitation pertains to the inability of widely used diagnostic assays to detect cryptic species. Targeting mtDNA appears to provide a solution to these challenges. Its high copy number in microbial cells makes mtDNA an attractive target for developing highly sensitive assays. In addition, previous studies on different pathogen taxa indicated that mitogenome sequence variation could improve cryptic species delimitation accuracy. This review sheds light on the potential application of mtDNA for pathogen diagnostics. This paper covers a brief description of qPCR and DNA barcoding as two major strategies enabling the diagnostics of plant pathogenic fungi and oomycetes. Both strategies are discussed along with the potential use of mtDNA, including their strengths and weaknesses.

A Novel PCR-Based Approach for Rapid Identification of Morchella sextelata Using Species-Specific Primers

Morels are precious and rare edible mushroom, which contain 61 species. It is difficult to identify the species of morels based on morphological characteristics. In recent years, morels cultivation technology has made great progress, Morchella sextelata has been cultivated in China widely. In this study, a PCR-based approach was developed for identification of Morchella sextelata, based on a 190-bp segment of internal transcribed spacer (ITS). The species-specific primer, MS1F/MS1R, was designed based on the alignment of sequence obtained from the 20 representative cultivated body fruit of Morchella sextelata as well as 10 sequence data available in Genbank. Verifying the species-specific primer pair demonstrated generation of an amplicon from extracted DNA of Morchella sextelata. The primer pair was also applied and tested for five other species of morels and eight common mushrooms from other genus. This novel PCR assay allowed a rapid and effective quality evaluation of Morchella sextelata.

Development of species-specific chloroplast markers for the authentication of Gynostemma pentaphyllum and their distribution in the Korean peninsula

Gynostemma pentaphyllum is a traditional oriental medicinal herb used as tea since ancient time. Among Gynostemma species, G. pentaphyllum has more active chemical components and better therapeutic effect. It is used to cure depression, diabetes, anxiety, hyperlipidemia, fatigue, immunity, cancer, and oxidative stress. Overexploitation of G. pentaphyllum for its medicinal benefits has been on a rise, due to which they are adulterated or mistakenly identified with other members of Gynostemma species. Hence, we used chloroplast universal regions such as ycf3, accD, petD, psbB and their polymorphism to distinguish G. pentaphyllum from other Gynostemma species. By using the species-specific primers derived from the above regions, we established a multiplex allele-specific PCR for the authentication of G. pentaphyllum from other species. Thus the PCR reaction produced unique amplicons of size 244 bp and 438 bp for G. pentaphyllum amplified by the primers flanking ycf3, and accD regions respectively. While a 607 bp, and 787 bp amplicons from the primers targeting psbB, and petD regions distinguished G. longipes, G. burmanicum, and G. pubescens species. Moreover, these primers were successful to analyze the dried tea samples of Gynostemma as well. Thus, the developed molecular markers could authenticate different Gynostemma species as well as its products thereby preventing the mistaken-identity of this medicinal herb.

Evaluation of five regions as DNA barcodes for identification of Lepista species (Tricholomataceae, Basidiomycota) from China

Background

Distinguishing among species in the genus Lepista is difficult because of their similar morphologies.

Methods

To identify a suitable DNA barcode for identification of Lepista species, we assessed the following five regions: internal transcribed spacer (ITS), the intergenic spacer (IGS), nuclear ribosomal RNA subunit, mitochondrial small subunit rDNA, and tef1. A total of 134 sequences from 34 samples belong to eight Lepista species were analyzed. The utility of each region as a DNA barcode was assessed based on the success rates of its PCR amplification and sequencing, and on its intra- and inter-specific variations.

Results

The results indicated that the ITS region could distinguish all species tested. We therefore propose that the ITS region can be used as a DNA barcode for the genus Lepista. In addition, a phylogenetic tree based on the ITS region showed that the tested eight Lepista species, including two unrecognized species, formed eight separate and well-supported clades.

Host DNA integrity within blood meals of hematophagous larval gnathiid isopods (Crustacea, Isopoda, Gnathiidae)

BACKGROUND

Juvenile gnathiid isopods are common ectoparasites of marine fishes. Each of the three juvenile stages briefly attach to a host to obtain a blood meal but spend most of their time living in the substrate, thus making it difficult to determine patterns of host exploitation. Sequencing of host blood meals from wild-caught specimens is a promising tool to determine host identity. Although established protocols for this approach exist, certain challenges must be overcome when samples are subjected to typical field conditions that may contribute to DNA degradation. The goal of this study was to address a key methodological issue associated with molecular-based host identification from free-living, blood-engorged gnathiid isopods-the degradation of host DNA within blood meals. Here we have assessed the length of time host DNA within gnathiid blood meals can remain viable for positive host identification.

METHODS

Juvenile gnathiids were allowed to feed on fish of known species and subsets were preserved at 4-h intervals over 24 h and then every 24 h up to 5 days post-feeding. Host DNA extracted from gnathiid blood meals was sequenced to validate the integrity of host DNA at each time interval. DNA was also extracted from blood meals of wild-fed gnathiids for comparison. Attempts were also made to extract host DNA from metamorphosed juveniles.

RESULTS

Using a cox1 universal fish primer set, known fish host DNA sequences were successfully identified for nearly 100% of third-stage juvenile gnathiid blood meals, digested for up to 5 days post-feeding. For second-stage juveniles, host identification was 100% successful when gnathiids were preserved within 24 h of collection. Fish hosts were positively identified for 69% of sequences from wild-fed gnathiid isopods. Of the 31% of sequences not receiving a ≥ 98 % match to a sequence in GenBank, 25 sequences were of possible invertebrate origin.

CONCLUSIONS

To our knowledge, this is the first study to examine the degradation rate of gnathiid isopod blood meals. Determining the rate at which gnathiids digest their blood meal is an important step in ensuring the successful host identification by DNA-based methods in large field studies.

Dynamic Chloroplast Genome Rearrangement and DNA Barcoding for Three Apiaceae Species Known as the Medicinal Herb "Bang-Poong"

Three Apiaceae species Ledebouriella seseloides, Peucedanum japonicum, and Glehnia littoralis are used as Asian herbal medicines, with the confusingly similar common name "Bang-poong". We characterized the complete chloroplast (cp) genomes and 45S nuclear ribosomal DNA (45S nrDNA) sequences of two accessions for each species. The complete cp genomes of G. littoralis, L. seseloides, and P. japonicum were 147,467, 147,830, and 164,633 bp, respectively. Compared to the other species, the P. japonicum cp genome had a huge inverted repeat expansion and a segmental inversion. The 45S nrDNA cistron sequences of the three species were almost identical in size and structure. Despite the structural variation in the P. japonicum cp genome, phylogenetic analysis revealed that G. littoralis diverged 5-6 million years ago (Mya), while P. japonicum diverged from L. seseloides only 2-3 Mya. Abundant copy number variations including tandem repeats, insertion/deletions, and single nucleotide polymorphisms, were found at the interspecies level. Intraspecies-level polymorphism was also found for L. seseloides and G. littoralis. We developed nine PCR barcode markers to authenticate all three species. This study characterizes the genomic differences between L. seseloides, P. japonicum, and G. littoralis; provides a method of species identification; and sheds light on the evolutionary history of these three species.

Complete Chloroplast Genome Sequence of Malus hupehensis: Genome Structure, Comparative Analysis, and Phylogenetic Relationships

Malus hupehensis belongs to the Malus genus (Rosaceae) and is an indigenous wild crabapple of China. This species has received more and more attention, due to its important medicinal, and excellent ornamental and economical, values. In this study, the whole chloroplast (cp) genome of Malus hupehensis, using a Hiseq X Ten sequencing platform, is reported. The M. hupehensis cp genome is 160,065 bp in size, containing a large single copy region (LSC) of 88,166 bp and a small single copy region (SSC) of 19,193 bp, separated by a pair of inverted repeats (IRs) of 26,353 bp. It contains 112 genes, including 78 protein-coding genes (PCGs), 30 transfer RNA genes (tRNAs), and four ribosomal RNA genes (rRNAs). The overall nucleotide composition is 36.6% CG. A total of 96 simple sequence repeats (SSRs) were identified, most of them were found to be mononucleotide repeats composed of A/T. In addition, a total of 49 long repeats were identified, including 24 forward repeats, 21 palindromic repeats, and four reverse repeats. Comparisons of the IR boundaries of nine Malus complete chloroplast genomes presented slight variations at IR/SC boundaries regions. A phylogenetic analysis, based on 26 chloroplast genomes using the maximum likelihood (ML) method, indicates that M. hupehensis clustered closer ties with M. baccata, M. micromalus, and M. prunifolia than with M. tschonoskii. The availability of the complete chloroplast genome using genomics methods is reported here and provides reliable genetic information for future exploration on the taxonomy and phylogenetic evolution of the Malus and related species.

Species-specific molecular signature of Commiphora species of Saudi Arabia inferred from internal transcribed spacer sequences of nuclear ribosomal DNA

The deciduous habit and tendency to produce flowers prior to developing leaves, and a predominantly dioecious system of breeding in the genus Commiphora leads to difficulties in its taxonomic identification at species level. The characteristics of easy amplification by universal primer, shorter length and higher discrimination power at the species level makes the internal transcribed spacer (ITS) sequence of nuclear ribosomal DNA (nrDNA) to a smart gene for generating species-specific phylogenetic inferences in most of the plants groups. The present study deals the ITS sequence of nrDNA based molecular genotyping of seven species of the genus Commiphora of Saudi Arabia. The molecular phylogenetic analysis of ITS sequences of nrDNA of Commiphora species distributed in Saudi Arabia reveals the the occurrence of C. madagascariens in Saudi Arabia.

Advances in DNA Barcoding of Toxic Marine Organisms

There are more than 200,000 marine species worldwide. These include many important economic species, such as large yellow croaker, ribbonfish, tuna, and salmon, but also many potentially toxic species, such as blue-green algae, diatoms, cnidarians, ctenophores, Nassarius spp., and pufferfish. However, some edible and toxic species may look similar, and the correct identification of marine species is thus a major issue. The failure of traditional classification methods in certain species has promoted the use of DNA barcoding, which uses short, standard DNA fragments to assist with species identification. In this review, we summarize recent advances in DNA barcoding of toxic marine species such as jellyfish and pufferfish, using genes including cytochrome oxidase I gene (COI), cytochrome b gene (cytb), 16S rDNA, internal transcribed spacer (ITS), and Ribulose-1,5-bisphosphate carboxylase oxygenase gene (rbcL). We also discuss the application of this technique for improving the identification of marine species. The use of DNA barcoding can benefit the studies of biological diversity, biogeography, food safety, and the detection of both invasive and new species. However, the technique has limitations, particularly for the analysis of complex objects and the selection of standard DNA barcodes. The development of high-throughput methods may offer solutions to some of these issues.

Molecular authentication of Anthemis deserti Boiss. (Asteraceae) based on ITS2 region of nrDNA gene sequence

The dried plant material of medicinally important Anthemis deserti Boiss. (family: Asteraceae) especially when it remains in the powdered form often look similar to Anthemis melampodina Del.; and therefore, difficult to distinguish, finally lead to chances of adulteration. The adulteration in medicinal plants effects on the efficacy of the drugs. The molecular authentication of herbal plant materials such as based on the internal transcribed spacer 2 (ITS2) sequences of nuclear ribosomal DNA (nrDNA) is considered as more reliable method compared to other the biochemical or histological methods. The present study aims to molecular authentication ofA. deserti based on molecular phylogenetic analyses of ITS2 gene sequence of nrDNA region. The ITS2 region of nrDNA of A. deserti were sequenced, and the molecular phylogenetic analyses were performed together with the GenBank sequences. The Maximum Parsimony tree revealed the close relationships of A. deserti with A. melampodina; however, the Neighbor-Joining and Maximum Likelihood tree clearly revealed that A. deserti is distinct from A. melampodina, which is also supported by the differences in nucleotides at five diffident positions (i.e. 22, 28, 87, 175 and 198) in the DNA sequence alignment.

Authentication of the Herbal Medicine Angelicae Dahuricae Radix Using an ITS Sequence-Based Multiplex SCAR Assay

The accurate identification of plant species is of great concern for the quality control of herbal medicines. The Korean Pharmacopoeia and the Pharmacopoeia of the People's Republic of China define Angelicae Dahuricae Radix (Baek-Ji in Korean and Bai-zhi in Chinese) as the dried roots of Angelica dahurica or A. dahurica var. formosana belonging to the family Apiaceae. Discrimination among Angelica species on the basis of morphological characteristics is difficult due to their extremely polymorphic traits and controversial taxonomic history. Furthermore, dried roots processed for medicinal applications are indistinguishable using conventional methods. DNA barcoding is a useful and reliable method for the identification of species. In this study, we sequenced the internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes in A. dahurica, A. dahurica var. formosana, and the related species A. anomala and A. japonica. Using these sequences, we designed species-specific primers, and developed and optimized a multiplex sequence-characterized amplified region (SCAR) assay that can simply and rapidly identify respective species, and verify the contamination of adulterant depending on the polymerase chain reaction (PCR) amplification without sequencing analysis in a single PCR reaction. This assay successfully identified commercial samples of Angelicae Dahuricae Radix collected from Korean and Chinese herbal markets, and distinguished them from adulterants. This multiplex SCAR assay shows a great potential in reducing the time and cost involved in the identification of genuine Angelicae Dahuricae Radix and adulterant contamination.

Identification of processed Chinese medicinal materials using DNA mini-barcoding

Most of Chinese medicinal herbs are subjected to traditional processing procedures, including stir-frying, charring, steaming, boiling, and calcining before they are released into dispensaries. The marketing and identification of processed medicinal materials is a growing issue in the marketplace. However, conventional methods of identification have limitations, while DNA mini-barcoding, based on the sequencing of a short-standardized region, has received considerable attention as a new potential means to identify processed medicinal materials. In the present study, six DNA barcode loci including ITS2, psbA-trnH, rbcL, matK, trnL (UAA) intron and its P6 loop, were employed for the authentication of 45 processed samples belonging to 15 species. We evaluated the amplification efficiency of each locus. We also examined the identification accuracy of the potential mini-barcode locus, of trnL (UAA) intron P6 loop. Our results showed that the five primary barcode loci were successfully amplified in only 8.89%-20% of the processed samples, while the amplification rates of the trnL (UAA) intron P6 loop were higher, at 75.56% successful amplification. We compared the mini-barcode sequences with Genbank using the Blast program. The analysis showed that 45.23% samples could be identified to genus level, while only one sample could be identified to the species level. We conclude that trnL (UAA) p6 loop is a candidate mini-barcode that has shown its potential and may become a universal mini-barcode as complementary barcode for authenticity testing and will play an important role in medicinal materials control.

Identification of effective DNA barcodes for Triticum plants through chloroplast genome-wide analysis

The Egyptian flora is rich with a large number of Triticum plants, which are very difficult to discriminate between in the early developmental stages. This study assesses the significance of using two DNA Barcoding loci (matK and rbcL) in distinguishing between 18 different Triticum accessions in Egypt. We isolated and sequenced 15 rbcL and six matK fragments, but our analysis of the resultant sequences demonstrated a limited ability of matK and rbcL in distinguishing between Triticum accessions. Therefore, we pursued a bioinformatics approach to determine the most useful loci which may be used as DNA barcodes for the Triticum spp. We obtained the 10 available chloroplast genomes of the 10 Triticum species and sub-species from NCBI, and performed chloroplast genome-wide analysis to find the potential barcode loci. A total of 134 chloroplast genes, gene combinations, intergenic regions and intergenic region combinations were tested using a Tree-based method. We were unable to discriminate between Triticum species by using chloroplast genes, gene combinations and intergenic regions. However, a combination of the intergenic region (trnfM-trnT) with either (trnD-psbM), (petN-trnC), (matK-rps16) or (rbcL-psaI) demonstrated a very high discrimination capacity, suggesting their utilization as DNA barcodes for the Triticum plants. Furthermore, our novel DNA barcodes demonstrated high discrimination capacity for other Poaceae members.

Detection of Ophiocordyceps sinensis and Its Common Adulterates Using Species-Specific Primers

Ophiocordyceps sinensis is a fungus that infects Hepialidae caterpillars, mummifying the larvae and producing characteristic fruiting bodies (stromata) that are processed into one of the most valued traditional Chinese medicines (TCM). The product commands a very high price due to a high demand but a very limited supply. Adulteration with other fungi is a common problem and there is a need to test preparation for the presence of the correct fungus. In the current study, a PCR-based approach for the identification of O. sinensis based on a segment of the internal transcribed spacer (ITS) region was developed. The segments is 146-bp in size and is likely to be amplified even in materials where processing led to DNA fragmentation. Primer development was based on the alignment of sequence data generated from a total of 89 samples of O. sinensis and potential adulterants as well as sequences date from 41 Ophiocordyceps species and 26 Cordyceps species available in GenBank. Tests with primer pair, DCF4/DCR4, demonstrated generation of an amplicon from DNA extracted from O. sinensis stromata, but not from extracts derived from adulterants. Species-specific primer pairs were also developed and tested for detection of the common adulterants, Cordyceps gunnii, Cordyceps cicadae, Cordyceps militaris, Cordyceps liangshanensis and Ophiocordyceps nutans. The collection of primers developed in the present study will be useful for the authentication of preparation claiming to only contain O. sinensis and for the detection of fungi used as adulterants in these preparations.

Discriminatory power of rbcL barcode locus for authentication of some of United Arab Emirates (UAE) native plants

DNA barcoding of United Arab Emirates (UAE) native plants is of high practical and scientific value as the plants adapt to very harsh environmental conditions that challenge their identification. Fifty-one plant species belonged to 22 families, 2 monocots, and 20 eudicots; a maximum number of species being legumes and grasses were collected. To authenticate the morphological identification of the wild plant taxa, rbcL and matK regions were used in the study. The primer universality and discriminatory power of rbcL is 100%, while it is 35% for matK locus for these plant species. The sequences were submitted to GenBank; accession numbers were obtained for all the rbcL sequences and for 6 of matK sequences. We suggest rbcL as a promising barcode locus for the tested group of 51 plants. In the present study, an inexpensive, simple method of identification of rare desert plant taxa through rbcL barcode is being reported.

Review: DNA Barcoding and Chromatography Fingerprints for the Authentication of Botanicals in Herbal Medicinal Products

In the last two decades, there has been a tremendous increase in the global use of herbal medicinal products (HMPs) due to their claimed health benefits. This has led to increase in their demand and consequently, also, resulted in massive adulteration. This is due to the fact that most of the traditional methods cannot identify closely related species in a process product form. Therefore the urgent need for simple and rapid identification methods resulted in the discovery of a novel technique. DNA barcoding is a process that uses short DNA sequence from the standard genome for species identification. This technique is reliable and is not affected by external factors such as climates, age, or plant part. The difficulties in isolation of DNA of high quality in addition to other factors are among the challenges encountered using the DNA barcoding in the authentication of HMP. These limitations indicated that using DNA barcoding alone may ineffectively authenticate the HMP. Therefore, the combination of DNA barcoding with chromatographic fingerprint, a popular and generally accepted technique for the assessment and quality control of HMP, will offer an efficient solution to effectively evaluate the authenticity and quality consistency of HMP. Detailed and quality information about the main composition of the HMPs will help to ascertain their efficacy and safety as these are very important for quality control.

The marker choice: Unexpected resolving power of an unexplored CO1 region for layered DNA barcoding approaches

The potential of DNA barcoding approaches to identify single species and characterize species compositions strongly depends on the marker choice. The prominent “Folmer region”, a 648 basepair fragment at the 5’ end of the mitochondrial CO1 gene, has been traditionally applied as a universal DNA barcoding region for metazoans. In order to find a suitable marker for biomonitoring odonates (dragonflies and damselflies), we here explore a new region of the CO1 gene (CO1B) for DNA barcoding in 51 populations of 23 dragonfly and damselfly species. We compare the “Folmer region”, the mitochondrial ND1 gene (NADH dehydrogenase 1) and the new CO1 region with regard to (i) speed and reproducibility of sequence generation, (ii) levels of homoplasy and (iii) numbers of diagnostic characters for discriminating closely related sister taxa and populations. The performances of the gene regions regarding these criteria were quite different. Both, the amplification of CO1B and ND1 was highly reproducible and CO1B showed the highest potential for discriminating sister taxa at different taxonomic levels. In contrast, the amplification of the “Folmer region” using the universal primers was difficult and the third codon positions of this fragment have experienced nucleotide substitution saturation. Most important, exploring this new barcode region of the CO1 gene identified a higher discriminating power between closely related sister taxa. Together with the design of layered barcode approaches adapted to the specific taxonomic “environment”, this new marker will further enhance the discrimination power at the species level.

The first initiative of DNA barcoding of ornamental plants from Egypt and potential applications in horticulture industry

DNA barcoding relies on short and standardized gene regions to identify species. The agricultural and horticultural applications of barcoding such as for marketplace regulation and copyright protection remain poorly explored. This study examines the effectiveness of the standard plant barcode markers (matK and rbcL) for the identification of plant species in private and public nurseries in northern Egypt. These two markers were sequenced from 225 specimens of 161 species and 62 plant families of horticultural importance. The sequence recovery was similar for rbcL (96.4%) and matK (84%), but the number of specimens assigned correctly to the respective genera and species was lower for rbcL (75% and 29%) than matK (85% and 40%). The combination of rbcL and matK brought the number of correct generic and species assignments to 83.4% and 40%, respectively. Individually, the efficiency of both markers varied among different plant families; for example, all palm specimens (Arecaceae) were correctly assigned to species while only one individual of Asteraceae was correctly assigned to species. Further, barcodes reliably assigned ornamental horticultural and medicinal plants correctly to genus while they showed a lower or no success in assigning these plants to species and cultivars. For future, we recommend the combination of a complementary barcode (e.g. ITS or trnH-psbA) with rbcL + matK to increase the performance of taxa identification. By aiding species identification of horticultural crops and ornamental palms, the analysis of the barcode regions will have large impact on horticultural industry.

Role of DNA barcoding in marine biodiversity assessment and conservation: An update

More than two third area of our planet is covered by oceans and assessment of marine biodiversity is a challenging task. With the increasing global population, there is a tendency to exploit marine resources for food, energy and other requirements. This puts pressure on the fragile marine environment and necessitates sustainable conservation efforts. Marine species identification using traditional taxonomical methods is often burdened with taxonomic controversies. Here we discuss the comparatively new concept of DNA barcoding and its significance in marine perspective. This molecular technique can be useful in the assessment of cryptic species which is widespread in marine environment and linking the different life cycle stages to the adult which is difficult to accomplish in the marine ecosystem. Other advantages of DNA barcoding include authentication and safety assessment of seafood, wildlife forensics, conservation genetics and detection of invasive alien species (IAS). Global DNA barcoding efforts in the marine habitat include MarBOL, CeDAMar, CMarZ, SHARK-BOL, etc. An overview on DNA barcoding of different marine groups ranging from the microbes to mammals is revealed. In conjugation with newer and faster techniques like high-throughput sequencing, DNA barcoding can serve as an effective modern tool in marine biodiversity assessment and conservation.

Rapid Authentication of the Herbal Medicine Plant Species Aralia continentalis Kitag. and Angelica biserrata C.Q. Yuan and R.H. Shan Using ITS2 Sequences and Multiplex-SCAR Markers

Accurate identification of the plant species that are present in herbal medicines is important for quality control. Although the dried roots of Aralia continentalis (Araliae Continentalis Radix) and Angelica biserrata (Angelicae Pubescentis Radix) are used in the same traditional medicine, namely Dok-Hwal in Korean and Du-Huo in Chinese, the medicines are described differently in the national pharmacopeia. Further confusion arises from the distribution of dried Levisticum officinale and Heracleum moellendorffii roots as the same medicine. Medicinal ingredients from all four plants are morphologically similar, and discrimination is difficult using conventional methods. Molecular identification methods offer rapidity and accuracy. The internal transcribed spacer 2 (ITS2) region of the nuclear ribosomal RNA gene (rDNA) was sequenced in all four plant species, and the sequences were used to design species-specific primers. Primers for each species were then combined to allow sample analysis in a single PCR reaction. Commercial herbal medicine samples were obtained from Korea and China and analyzed using the multiplex assay. The assay successfully identified authentic medicines and also identified inauthentic or adulterated samples. The multiplex assay will be a useful tool for identification of authentic Araliae Continentalis Radix and/or Angelicae Pubescentis Radix preparations in Korea and China.

Botanical Integrity: The Importance of the Integration of Chemical, Biological, and Botanical Analyses, and the Role of DNA Barcoding

Raw materials, ingredients, and products derived from plants are commonly referred to as herbs or botanicals in both the biomedical literature and the natural products health industry. This overarching term includes the breadth of crude herbs, plant parts, and the ingredients made from them, and also covers finished products such as botanical dietary supplements. Botanical dietary supplements are intended to supplement the human diet and are composed primarily of powdered plant parts, their extracts, or other preparations derived from crude herbal material; some formulations include other ingredients such as vitamins, minerals, and amino acids. Botanical dietary supplements are highly complex mixtures reflecting the diverse chemical constituents that comprise the source plant's raw material. Botanical analysis is an intricate analytical challenge requiring specialized skills and instrumentation that is different from those required for quality control of chemically simpler pharmaceuticals, or for the safety assessment of many conventional food or other products that are generally regarded as safe (GRAS).