scholarly journals Feasibility of nuclear ribosomal region ITS1 over ITS2 in barcoding taxonomically challenging genera of subtribe Cassiinae (Fabaceae)

2016 ◽  
Author(s):  
Priyanka Mishra ◽  
Amit Kumar ◽  
Vereena Rodrigues ◽  
Ashutosh K Shukla ◽  
Velusamy Sundaesan
Keyword(s):  
Dna Barcoding ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Its Region ◽  
Genetic Distances ◽  
Discrimination Power ◽  
Distance Method ◽  
Tree Reconciliation ◽  
Its1 Region ◽  
Barcoding Gap

Premise of the Study. The internal transcribed spacer (ITS) region is situated between 18S and 26S in a polycistronic rRNA precursor transcript. It had been proved to be the most commonly sequenced region across plant species to resolve phylogenetic relationships ranging from shallow to deep taxonomic levels. Despite several taxonomical revisions in Cassiinae, a stable phylogeny remains elusive at the molecular level, particularly concerning the delineation of species in the genera Cassia, Senna and Chamaecrista. This study addresses the comparative potential of ITS datasets (ITS1, ITS2 and concatenated) in resolving the underlying morphological disparity in the highly complex genera, to assess their discriminatory power as potential barcode candidates in Cassiinae. Methodology. A combination of experimental data and an in-silico approach based on threshold genetic distances, sequence similarity based and hierarchical tree-based methods was performed to decipher the discriminating power of ITS datasets on 18 different species of Cassiinae complex. Lab-generated sequences were compared against those available in the GenBank using BLAST and were aligned through MUSCLE 3.8.31 and analysed in PAUP 4.0 and BEAST1.8 using parsimony ratchet, maximum likelihood and Bayesian inference (BI) methods of gene and species tree reconciliation with bootstrapping. DNA barcoding gap was realized based on the Kimura two-parameter distance model (K2P) in TaxonDNA and MEGA. Principal Findings. Based on the K2P distance, significant divergences between the inter- and intra-specific genetic distances were observed, while the presence of a DNA barcoding gap was obvious. The ITS1 region efficiently identified 81.63% and 90% of species using TaxonDNA and BI methods, respectively. The PWG-distance method based on simple pairwise matching indicated the significance of ITS1 whereby highest number of variable (210) and informative sites (206) were obtained. The BI tree-based methods outperformed the similarity-based methods producing well-resolved phylogenetic trees with many nodes well supported by bootstrap analyses. Conclusion. The reticulated phylogenetic hypothesis using the ITS1 region mainly supported the relationship between the species of Cassiinae established by traditional morphological methods. The ITS1 region showed a higher discrimination power and desirable characteristics as compared to ITS2 and ITS1+2 there by concluding to be the locus of choice. Considering the complexity of the group and the underlying biological ambiguities, the results presented here are encouraging for developing DNA barcoding as a useful tool for resolving taxonomical challenges in corroboration with morphological framework.

scholarly journals Feasibility of nuclear ribosomal region ITS1 over ITS2 in barcoding taxonomically challenging genera of subtribe Cassiinae (Fabaceae)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2638 ◽  
Author(s):  
Priyanka Mishra ◽  
Amit Kumar ◽  
Vereena Rodrigues ◽  
Ashutosh K. Shukla ◽  
Velusamy Sundaresan
Keyword(s):  
Dna Barcoding ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Its Region ◽  
Genetic Distances ◽  
Discrimination Power ◽  
Distance Method ◽  
Tree Reconciliation ◽  
Its1 Region ◽  
Barcoding Gap

Premise of the StudyThe internal transcribed spacer (ITS) region is situated between 18S and 26S in a polycistronic rRNA precursor transcript. It had been proved to be the most commonly sequenced region across plant species to resolve phylogenetic relationships ranging from shallow to deep taxonomic levels. Despite several taxonomical revisions in Cassiinae, a stable phylogeny remains elusive at the molecular level, particularly concerning the delineation of species in the generaCassia, SennaandChamaecrista. This study addresses the comparative potential of ITS datasets (ITS1, ITS2 and concatenated) in resolving the underlying morphological disparity in the highly complex genera, to assess their discriminatory power as potential barcode candidates in Cassiinae.MethodologyA combination of experimental data and an in-silico approach based on threshold genetic distances, sequence similarity based and hierarchical tree-based methods was performed to decipher the discriminating power of ITS datasets on 18 different species of Cassiinae complex. Lab-generatedsequences were compared against those available in the GenBank using BLAST and were aligned through MUSCLE 3.8.31 and analysed in PAUP 4.0 and BEAST1.8 using parsimony ratchet, maximum likelihood and Bayesian inference (BI) methods of gene and species tree reconciliation with bootstrapping. DNA barcoding gap was realized based on the Kimura two-parameter distance model (K2P) in TaxonDNA and MEGA.Principal FindingsBased on the K2P distance, significant divergences between the inter- and intra-specific genetic distances were observed, while the presence of a DNA barcoding gap was obvious. The ITS1 region efficiently identified 81.63% and 90% of species using TaxonDNA and BI methods, respectively. The PWG-distance method based on simple pairwise matching indicated the significance of ITS1 whereby highest number of variable (210) and informative sites (206) were obtained. The BI tree-based methods outperformed the similarity-based methods producing well-resolved phylogenetic trees with many nodes well supported by bootstrap analyses.ConclusionThe reticulated phylogenetic hypothesis using the ITS1 region mainly supported the relationship between the species of Cassiinae established by traditional morphological methods. The ITS1 region showed a higher discrimination power and desirable characteristics as compared to ITS2 and ITS1 + 2, thereby concluding to be the locus of choice. Considering the complexity of the group and the underlying biological ambiguities, the results presented here are encouraging for developing DNA barcoding as a useful tool for resolving taxonomical challenges in corroboration with morphological framework.

scholarly journals Feasibility of nuclear ribosomal region ITS1 over ITS2 in barcoding taxonomically challenging genera of subtribe Cassiinae (Fabaceae)

2017 ◽  
Author(s):  
Priyanka Mishra ◽  
Amit Kumar ◽  
Vereena Rodrigues ◽  
Ashutosh K Shukla ◽  
Velusamy Sundaesan
Keyword(s):  
Dna Barcoding ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Genetic Distances ◽  
Discrimination Power ◽  
Distance Method ◽  
Tree Reconciliation ◽  
Barcoding Gap ◽  
Discriminating Power ◽  
Distance Model

Premise of the Study. The internal transcribed spacer (ITS) region is situated between 18S and 26S in a polycistronic rRNA precursor transcript. It had been proved to be the most commonly sequenced region across plant species to resolve phylogenetic relationships ranging from shallow to deep taxonomic levels. Despite several taxonomical revisions in Cassiinae, a stable phylogeny remains elusive at the molecular level, particularly concerning the delineation of species in the genera Cassia, Senna and Chamaecrista. This study addresses the comparative potential of ITS datasets (ITS1, ITS2 and concatenated) in resolving the underlying morphological disparity in the highly complex genera, to assess their discriminatory power as potential barcode candidates in Cassiinae. Methodology. A combination of experimental data and an in-silico approach based on threshold genetic distances, sequence similarity based and hierarchical tree-based methods was performed to decipher the discriminating power of ITS datasets on 18 different species of Cassiinae complex. Lab-generated sequences were compared against those available in the GenBank using BLAST and were aligned through MUSCLE 3.8.31 and analysed in PAUP 4.0 and BEAST1.8 using parsimony ratchet, maximum likelihood and Bayesian inference (BI) methods of gene and species tree reconciliation with bootstrapping. DNA barcoding gap was realized based on the Kimura two-parameter distance model (K2P) in TaxonDNA and MEGA. Principal Findings. Based on the K2P distance, significant divergences between the inter- and intraspecific genetic distances were observed, while the presence of a DNA barcoding gap was obvious. The ITS1 region efficiently identified 81.63% and 90% of species using TaxonDNA and BI methods, respectively. The PWG-distance method based on simple pairwise matching indicated the significance of ITS1 whereby highest number of variable (210) and informative sites (206) were obtained. The BI tree based methods outperformed the similarity-based methods producing well-resolved phylogenetic trees with many nodes well supported by bootstrap analyses. Conclusion. The reticulated phylogenetic hypothesis using the ITS1 region mainly supported the relationship between the species of Cassiinae established by traditional morphological methods. The ITS1 region showed a higher discrimination power and desirable characteristics as compared to ITS2 and ITS1+2, thereby concluding to be the locus of choice. Considering the complexity of the group and the underlying biological ambiguities, the results presented here are encouraging for developing DNA barcoding as a useful tool for resolving taxonomical challenges in corroboration with morphological framework.

scholarly journals Feasibility of nuclear ribosomal region ITS1 over ITS2 in barcoding taxonomically challenging genera of subtribe Cassiinae (Fabaceae)

2017 ◽  
Author(s):  
Priyanka Mishra ◽  
Amit Kumar ◽  
Vereena Rodrigues ◽  
Ashutosh K Shukla ◽  
Velusamy Sundaesan
Keyword(s):  
Dna Barcoding ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Genetic Distances ◽  
Discrimination Power ◽  
Distance Method ◽  
Tree Reconciliation ◽  
Barcoding Gap ◽  
Discriminating Power ◽  
Distance Model

Premise of the Study. The internal transcribed spacer (ITS) region is situated between 18S and 26S in a polycistronic rRNA precursor transcript. It had been proved to be the most commonly sequenced region across plant species to resolve phylogenetic relationships ranging from shallow to deep taxonomic levels. Despite several taxonomical revisions in Cassiinae, a stable phylogeny remains elusive at the molecular level, particularly concerning the delineation of species in the genera Cassia, Senna and Chamaecrista. This study addresses the comparative potential of ITS datasets (ITS1, ITS2 and concatenated) in resolving the underlying morphological disparity in the highly complex genera, to assess their discriminatory power as potential barcode candidates in Cassiinae. Methodology. A combination of experimental data and an in-silico approach based on threshold genetic distances, sequence similarity based and hierarchical tree-based methods was performed to decipher the discriminating power of ITS datasets on 18 different species of Cassiinae complex. Lab-generated sequences were compared against those available in the GenBank using BLAST and were aligned through MUSCLE 3.8.31 and analysed in PAUP 4.0 and BEAST1.8 using parsimony ratchet, maximum likelihood and Bayesian inference (BI) methods of gene and species tree reconciliation with bootstrapping. DNA barcoding gap was realized based on the Kimura two-parameter distance model (K2P) in TaxonDNA and MEGA. Principal Findings. Based on the K2P distance, significant divergences between the inter- and intraspecific genetic distances were observed, while the presence of a DNA barcoding gap was obvious. The ITS1 region efficiently identified 81.63% and 90% of species using TaxonDNA and BI methods, respectively. The PWG-distance method based on simple pairwise matching indicated the significance of ITS1 whereby highest number of variable (210) and informative sites (206) were obtained. The BI tree based methods outperformed the similarity-based methods producing well-resolved phylogenetic trees with many nodes well supported by bootstrap analyses. Conclusion. The reticulated phylogenetic hypothesis using the ITS1 region mainly supported the relationship between the species of Cassiinae established by traditional morphological methods. The ITS1 region showed a higher discrimination power and desirable characteristics as compared to ITS2 and ITS1+2, thereby concluding to be the locus of choice. Considering the complexity of the group and the underlying biological ambiguities, the results presented here are encouraging for developing DNA barcoding as a useful tool for resolving taxonomical challenges in corroboration with morphological framework.

scholarly journals Assessing universality of DNA barcoding in geographically isolated selected desert medicinal species of Fabaceae and Poaceae

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4499 ◽  
Author(s):  
Aisha Tahir ◽  
Fatma Hussain ◽  
Nisar Ahmed ◽  
Abdolbaset Ghorbani ◽  
Amer Jamil
Keyword(s):  
Dna Barcoding ◽  
Species Identification ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Sequence Divergence ◽  
Species Level ◽  
Practical Implementation ◽  
Medicinal Species ◽  
Level Identification ◽  
Geographically Isolated

In pursuit of developing fast and accurate species-level molecular identification methods, we tested six DNA barcodes, namely ITS2, matK, rbcLa, ITS2+matK, ITS2+rbcLa, matK+rbcLa and ITS2+matK+rbcLa, for their capacity to identify frequently consumed but geographically isolated medicinal species of Fabaceae and Poaceae indigenous to the desert of Cholistan. Data were analysed by BLASTn sequence similarity, pairwise sequence divergence in TAXONDNA, and phylogenetic (neighbour-joining and maximum-likelihood trees) methods. Comparison of six barcode regions showed that ITS2 has the highest number of variable sites (209/360) for tested Fabaceae and (106/365) Poaceae species, the highest species-level identification (40%) in BLASTn procedure, distinct DNA barcoding gap, 100% correct species identification in BM and BCM functions of TAXONDNA, and clear cladding pattern with high nodal support in phylogenetic trees in both families. ITS2+matK+rbcLa followed ITS2 in its species-level identification capacity. The study was concluded with advocating the DNA barcoding as an effective tool for species identification and ITS2 as the best barcode region in identifying medicinal species of Fabaceae and Poaceae. Current research has practical implementation potential in the fields of pharmaco-vigilance, trade of medicinal plants and biodiversity conservation.

scholarly journals Single molecule, near full-length genome sequencing of dengue virus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Thiruni N. Adikari ◽  
Nasir Riaz ◽  
Chathurani Sigera ◽  
Preston Leung ◽  
Braulio M. Valencia ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Single Molecule ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
Sequence Similarity ◽  
Genetic Distances ◽  
Full Length ◽  
Denv Serotypes ◽  
Consensus Sequences ◽  
Pairwise Sequence Similarity

Abstract Current methods for dengue virus (DENV) genome amplification, amplify parts of the genome in at least 5 overlapping segments and then combine the output to characterize a full genome. This process is laborious, costly and requires at least 10 primers per serotype, thus increasing the likelihood of PCR bias. We introduce an assay to amplify near full-length dengue virus genomes as intact molecules, sequence these amplicons with third generation “nanopore” technology without fragmenting and use the sequence data to differentiate within-host viral variants with a bioinformatics tool (Nano-Q). The new assay successfully generated near full-length amplicons from DENV serotypes 1, 2 and 3 samples which were sequenced with nanopore technology. Consensus DENV sequences generated by nanopore sequencing had over 99.5% pairwise sequence similarity to Illumina generated counterparts provided the coverage was > 100 with both platforms. Maximum likelihood phylogenetic trees generated from nanopore consensus sequences were able to reproduce the exact trees made from Illumina sequencing with a conservative 99% bootstrapping threshold (after 1000 replicates and 10% burn-in). Pairwise genetic distances of within host variants identified from the Nano-Q tool were less than that of between host variants, thus enabling the phylogenetic segregation of variants from the same host.

LSU rDNA D5 region: the DNA barcode for molecular classification and identification of Demodex

Genome ◽  
2019 ◽  
Vol 62 (5) ◽  
pp. 295-304 ◽  
Author(s):  
Li Hu ◽  
Yae Zhao ◽  
Yuanjun Yang ◽  
Dongling Niu ◽  
Rui Yang
Keyword(s):  
Phylogenetic Trees ◽  
Dna Barcode ◽  
Sequence Divergence ◽  
Its Region ◽  
Molecular Classification ◽  
Ribosomal Genes ◽  
Lsu Rdna ◽  
Dna Barcodes ◽  
Barcoding Gap ◽  
Demodex Folliculorum

Whether ribosomal genes can be used as DNA barcodes for molecular identification of Demodex (Acariformes: Demodicidae) is unclear. To examine this, Demodex folliculorum, D. brevis, D. canis, and D. caprae were collected for DNA extraction, rDNA fragments amplification, sequencing, and analysis. The V2 and V4 regions of SSU rDNA; D5, D6, and D8 regions of LSU rDNA; and ITS region were obtained from the four morphospecies. BLAST analysis showed that the obtained sequences matched those of Demodex or Aplonobia (Acariformes: Tetranychidae) in Raphignathae. Phylogenetic trees derived from V2, V4, D5, D6, and D8 regions, but not from ITS region, showed that the four species of Demodex clustered independently. Sequence divergence analysis further demonstrated that D5, D6, and D8 regions had obvious barcoding gap between intraspecific and interspecific divergences, with the gap of D5 (16.91%) larger than that of D6 (11.82%) and D8 (4.66%). The V2 and V4 regions did not have a barcoding gap, as the intraspecific and interspecific divergences partially overlapped. For the ITS region, intraspecific and interspecific divergences completely overlapped. These results suggest that the D5, D6, and D8 regions of LSU rDNA, especially D5, are suitable DNA barcodes for Demodex.

scholarly journals Assessing universality of DNA barcoding in geographically isolated selected desert medicinal species of Fabaceae and Poaceae

2018 ◽  
Author(s):  
Aisha Tahir ◽  
Fatma Hussain ◽  
Nisar Ahmed ◽  
Abdolbaset Ghorbani ◽  
Amer Jamil
Keyword(s):  
Dna Barcoding ◽  
Species Identification ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Sequence Divergence ◽  
Species Level ◽  
Practical Implementation ◽  
Medicinal Species ◽  
Level Identification ◽  
Geographically Isolated

In pursuit of developing fast and accurate species level molecular identification methods, we tested six DNA barcodes viz. ITS2, matK, rbcLa, ITS2+matK, ITS2+rbcLa, matK+rbcLa, ITS2+matK+rbcLa for their capacity to identify frequently consumed but geographically isolated medicinal species of Fabaceae and Poaceae indigenous to the desert of Cholistan. Data were analysed by BLASTn sequence similarity, pairwise sequence divergence in TAXONDNA, and phylogenetic (neighbour-joining and maximum-likelihood trees) methods. Comparison of six barcode regions showed that ITS2 has the highest number of variable sites (209/360) for tested Fabaceae and (106/365) Poaceae species, the highest species level identification (40%) in BLASTn procedure, distinct DNA barcoding gap, 100% correct species identification in BM and BCM functions of TAXONDNA, and clear cladding pattern with high nodal support in phylogenetic trees in both families. ITS2+matK+rbcLa followed ITS2 in its species level identification capacity. The study was concluded with advocating the DNA barcoding as an effective tool for species identification and ITS2 as the best barcode region in identifying medicinal species of Fabaceae and Poaceae. Current research has practical implementation potential in the fields of pharmaco-vigilance, trade of medicinal plants and biodiversity conservation.

scholarly journals Assessing universality of DNA barcoding in geographically isolated selected desert medicinal species of Fabaceae and Poaceae

2018 ◽  
Author(s):  
Aisha Tahir ◽  
Fatma Hussain ◽  
Nisar Ahmed ◽  
Abdolbaset Ghorbani ◽  
Amer Jamil
Keyword(s):  
Dna Barcoding ◽  
Species Identification ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Sequence Divergence ◽  
Species Level ◽  
Practical Implementation ◽  
Medicinal Species ◽  
Level Identification ◽  
Geographically Isolated

In pursuit of developing fast and accurate species level molecular identification methods, we tested six DNA barcodes viz. ITS2, matK, rbcLa, ITS2+matK, ITS2+rbcLa, matK+rbcLa, ITS2+matK+rbcLa for their capacity to identify frequently consumed but geographically isolated medicinal species of Fabaceae and Poaceae indigenous to the desert of Cholistan. Data were analysed by BLASTn sequence similarity, pairwise sequence divergence in TAXONDNA, and phylogenetic (neighbour-joining and maximum-likelihood trees) methods. Comparison of six barcode regions showed that ITS2 has the highest number of variable sites (209/360) for tested Fabaceae and (106/365) Poaceae species, the highest species level identification (40%) in BLASTn procedure, distinct DNA barcoding gap, 100% correct species identification in BM and BCM functions of TAXONDNA, and clear cladding pattern with high nodal support in phylogenetic trees in both families. ITS2+matK+rbcLa followed ITS2 in its species level identification capacity. The study was concluded with advocating the DNA barcoding as an effective tool for species identification and ITS2 as the best barcode region in identifying medicinal species of Fabaceae and Poaceae. Current research has practical implementation potential in the fields of pharmaco-vigilance, trade of medicinal plants and biodiversity conservation.

scholarly journals Morpho-molecular identification and first report of Fusarium equiseti in causing chilli wilt from Kashmir (Northern Himalayas)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ammarah Hami ◽  
Rovidha S. Rasool ◽  
Nisar A. Khan ◽  
Sheikh Mansoor ◽  
Mudasir A. Mir ◽  
...  
Keyword(s):  
Dna Barcoding ◽  
Pcr Amplification ◽  
Its Region ◽  
Fungal Species ◽  
Pathogenicity Test ◽  
Kashmir Valley ◽  
Fusarium Equiseti ◽  
Infected Root ◽  
Fusarium Sp ◽  
High Degree

AbstractChilli (Capsicum annuum L.) is one of the most significant vegetable and spice crop. Wilt caused by Fusarium Sp. has emerged as a serious problem in chilli production. Internal transcribed spacer (ITS) region is widely used as a DNA barcoding marker to characterize the diversity and composition of Fusarium communities. ITS regions are heavily used in both molecular methods and ecological studies of fungi, because of its high degree of interspecific variability, conserved primer sites and multiple copy nature in the genome. In the present study we focused on morphological and molecular characterization of pathogen causing chilli wilt. Chilli plants were collected from four districts of Kashmir valley of Himalayan region. Pathogens were isolated from infected root and stem of the plants. Isolated pathogens were subjected to DNA extraction and PCR amplification. The amplified product was sequenced and three different wilt causing fungal isolates were obtained which are reported in the current investigation. In addition to Fusarium oxysporum and Fusarium solani, a new fungal species was found in association with the chilli wilt in Kashmir valley viz., Fusarium equiseti that has never been reported before from this region. The studies were confirmed by pathogenicity test and re-confirmation by DNA barcoding.

scholarly journals Identification of Epidemiological Traits by Analysis of SARS−CoV−2 Sequences

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 764
Author(s):  
Bohu Pan ◽  
Zuowei Ji ◽  
Sugunadevi Sakkiah ◽  
Wenjing Guo ◽  
Jie Liu ◽  
...  
Keyword(s):  
Clustering Analysis ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Host Age ◽  
Hierarchical Clustering Analysis ◽  
Genome Sequences ◽  
Geographic Patterns ◽  
Rapid Spread ◽  
Pairwise Sequence Similarity ◽  
Sequence Similarity Analysis

Severe acute respiratory syndrome coronavirus 2 (SARS−CoV−2) has caused the ongoing global COVID-19 pandemic that began in late December 2019. The rapid spread of SARS−CoV−2 is primarily due to person-to-person transmission. To understand the epidemiological traits of SARS−CoV−2 transmission, we conducted phylogenetic analysis on genome sequences from >54K SARS−CoV−2 cases obtained from two public databases. Hierarchical clustering analysis on geographic patterns in the resulting phylogenetic trees revealed a co-expansion tendency of the virus among neighboring countries with diverse sources and transmission routes for SARS−CoV−2. Pairwise sequence similarity analysis demonstrated that SARS−CoV−2 is transmitted locally and evolves during transmission. However, no significant differences were seen among SARS−CoV−2 genomes grouped by host age or sex. Here, our identified epidemiological traits provide information to better prevent transmission of SARS−CoV−2 and to facilitate the development of effective vaccines and therapeutics against the virus.

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