Sanger sequencing as a first-line approach for molecular diagnosis of Andersen-Tawil syndrome [version 1; referees: 2 approved

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Armando Totomoch-Serra

2017-06-01

Full Text Available In 1977, Frederick Sanger developed a new method for DNA sequencing based on the chain termination method, now known as the Sanger sequencing method (SSM.  Recently, massive parallel sequencing, better known as next-generation sequencing (NGS,  is replacing the SSM for detecting mutations in cardiovascular diseases with a genetic background. The present opinion article wants to remark that “targeted” SSM is still effective as a first-line approach for the molecular diagnosis of some specific conditions, as is the case for Andersen-Tawil syndrome (ATS. ATS is described as a rare multisystemic autosomal dominant channelopathy syndrome caused mainly by a heterozygous mutation in the KCNJ2 gene. KCJN2 has particular characteristics that make it attractive for “directed” SSM. KCNJ2 has a sequence of 17,510 base pairs (bp, and a short coding region with two exons (exon 1=166 bp and exon 2=5220 bp, half of the mutations are located in the C-terminal cytosolic domain, a mutational hotspot has been described in residue Arg218, and this gene explains the phenotype in 60% of ATS cases that fulfill all the clinical criteria of the disease. In order to increase the diagnosis of ATS we urge cardiologists to search for facial and muscular abnormalities in subjects with frequent ventricular arrhythmias (especially bigeminy and prominent U waves on the electrocardiogram.

[Sensitivity and specificity of nested PCR pyrosequencing in hepatitis B virus drug resistance gene testing].

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Sun, Shumei; Zhou, Hao; Zhou, Bin; Hu, Ziyou; Hou, Jinlin; Sun, Jian

2012-05-01

To evaluate the sensitivity and specificity of nested PCR combined with pyrosequencing in the detection of HBV drug-resistance gene. RtM204I (ATT) mutant and rtM204 (ATG) nonmutant plasmids mixed at different ratios were detected for mutations using nested-PCR combined with pyrosequencing, and the results were compared with those by conventional PCR pyrosequencing to analyze the linearity and consistency of the two methods. Clinical specimens with different viral loads were examined for drug-resistant mutations using nested PCR pyrosequencing and nested PCR combined with dideoxy sequencing (Sanger) for comparison of the detection sensitivity and specificity. The fitting curves demonstrated good linearity of both conventional PCR pyrosequencing and nested PCR pyrosequencing (R(2)>0.99, PNested PCR showed a better consistency with the predicted value than conventional PCR, and was superior to conventional PCR for detection of samples containing 90% mutant plasmid. In the detection of clinical specimens, Sanger sequencing had a significantly lower sensitivity than nested PCR pyrosequencing (92% vs 100%, Pnested PCR and Sanger sequencing method, nested PCR pyrosequencing has a higher sensitivity especially in clinical specimens with low viral copies, which can be important for early detection of HBV mutant strains and hence more effective clinical management.

Genome Sequencing

DEFF Research Database (Denmark)

Sato, Shusei; Andersen, Stig Uggerhøj

2014-01-01

The current Lotus japonicus reference genome sequence is based on a hybrid assembly of Sanger TAC/BAC, Sanger shotgun and Illumina shotgun sequencing data generated from the Miyakojima-MG20 accession. It covers nearly all expressed L. japonicus genes and has been annotated mainly based on transcr......The current Lotus japonicus reference genome sequence is based on a hybrid assembly of Sanger TAC/BAC, Sanger shotgun and Illumina shotgun sequencing data generated from the Miyakojima-MG20 accession. It covers nearly all expressed L. japonicus genes and has been annotated mainly based...

Detection of MPL mutations by a novel allele-specific PCR-based strategy.

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Furtado, Larissa V; Weigelin, Helmut C; Elenitoba-Johnson, Kojo S J; Betz, Bryan L

2013-11-01

MPL mutation testing is recommended in patients with suspected primary myelofibrosis or essential thrombocythemia who lack the JAK2 V617F mutation. MPL mutations can occur at allelic levels below 15%, which may escape detection by commonly used mutation screening methods such as Sanger sequencing. We developed a novel multiplexed allele-specific PCR assay capable of detecting most recurrent MPL exon 10 mutations associated with primary myelofibrosis and essential thrombocythemia (W515L, W515K, W515A, and S505N) down to a sensitivity of 2.5% mutant allele. Test results were reviewed from 15 reference cases and 1380 consecutive specimens referred to our laboratory for testing. Assay performance was compared to Sanger sequencing across a series of 58 specimens with MPL mutations. Positive cases consisted of 45 with W515L, 6 with S505N, 5 with W515K, 1 with W515A, and 1 with both W515L and S505N. Seven cases had mutations below 5% that were undetected by Sanger sequencing. Ten additional cases had mutation levels between 5% and 15% that were not consistently detected by sequencing. All results were easily interpreted in the allele-specific test. This assay offers a sensitive and reliable solution for MPL mutation testing. Sanger sequencing appears insufficiently sensitive for robust MPL mutation detection. Our data also suggest the relative frequency of S505N mutations may be underestimated, highlighting the necessity for inclusion of this mutation in MPL test platforms. Copyright © 2013 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

KRAS mutation detection in colorectal cancer by a commercially available gene chip array compares well with Sanger sequencing.

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French, Deborah; Smith, Andrew; Powers, Martin P; Wu, Alan H B

2011-08-17

Binding of a ligand to the epidermal growth factor receptor (EGFR) stimulates various intracellular signaling pathways resulting in cell cycle progression, proliferation, angiogenesis and apoptosis inhibition. KRAS is involved in signaling pathways including RAF/MAPK and PI3K and mutations in this gene result in constitutive activation of these pathways, independent of EGFR activation. Seven mutations in codons 12 and 13 of KRAS comprise around 95% of the observed human mutations, rendering monoclonal antibodies against EGFR (e.g. cetuximab and panitumumab) useless in treatment of colorectal cancer. KRAS mutation testing by two different methodologies was compared; Sanger sequencing and AutoGenomics INFINITI® assay, on DNA extracted from colorectal cancers. Out of 29 colorectal tumor samples tested, 28 were concordant between the two methodologies for the KRAS mutations that were detected in both assays with the INFINITI® assay detecting a mutation in one sample that was indeterminate by Sanger sequencing and a third methodology; single nucleotide primer extension. This study indicates the utility of the AutoGenomics INFINITI® methodology in a clinical laboratory setting where technical expertise or access to equipment for DNA sequencing does not exist. Copyright © 2011 Elsevier B.V. All rights reserved.

Screening for duplications, deletions and a common intronic mutation detects 35% of second mutations in patients with USH2A monoallelic mutations on Sanger sequencing.

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Steele-Stallard, Heather B; Le Quesne Stabej, Polona; Lenassi, Eva; Luxon, Linda M; Claustres, Mireille; Roux, Anne-Francoise; Webster, Andrew R; Bitner-Glindzicz, Maria

2013-08-08

Usher Syndrome is the leading cause of inherited deaf-blindness. It is divided into three subtypes, of which the most common is Usher type 2, and the USH2A gene accounts for 75-80% of cases. Despite recent sequencing strategies, in our cohort a significant proportion of individuals with Usher type 2 have just one heterozygous disease-causing mutation in USH2A, or no convincing disease-causing mutations across nine Usher genes. The purpose of this study was to improve the molecular diagnosis in these families by screening USH2A for duplications, heterozygous deletions and a common pathogenic deep intronic variant USH2A: c.7595-2144A>G. Forty-nine Usher type 2 or atypical Usher families who had missing mutations (mono-allelic USH2A or no mutations following Sanger sequencing of nine Usher genes) were screened for duplications/deletions using the USH2A SALSA MLPA reagent kit (MRC-Holland). Identification of USH2A: c.7595-2144A>G was achieved by Sanger sequencing. Mutations were confirmed by a combination of reverse transcription PCR using RNA extracted from nasal epithelial cells or fibroblasts, and by array comparative genomic hybridisation with sequencing across the genomic breakpoints. Eight mutations were identified in 23 Usher type 2 families (35%) with one previously identified heterozygous disease-causing mutation in USH2A. These consisted of five heterozygous deletions, one duplication, and two heterozygous instances of the pathogenic variant USH2A: c.7595-2144A>G. No variants were found in the 15 Usher type 2 families with no previously identified disease-causing mutations. In 11 atypical families, none of whom had any previously identified convincing disease-causing mutations, the mutation USH2A: c.7595-2144A>G was identified in a heterozygous state in one family. All five deletions and the heterozygous duplication we report here are novel. This is the first time that a duplication in USH2A has been reported as a cause of Usher syndrome. We found that 8 of

Use of amplicon sequencing to improve sensitivity in PCR-based detection of microbial pathogen in environmental samples.

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Saingam, Prakit; Li, Bo; Yan, Tao

2018-06-01

DNA-based molecular detection of microbial pathogens in complex environments is still plagued by sensitivity, specificity and robustness issues. We propose to address these issues by viewing them as inadvertent consequences of requiring specific and adequate amplification (SAA) of target DNA molecules by current PCR methods. Using the invA gene of Salmonella as the model system, we investigated if next generation sequencing (NGS) can be used to directly detect target sequences in false-negative PCR reaction (PCR-NGS) in order to remove the SAA requirement from PCR. False-negative PCR and qPCR reactions were first created using serial dilutions of laboratory-prepared Salmonella genomic DNA and then analyzed directly by NGS. Target invA sequences were detected in all false-negative PCR and qPCR reactions, which lowered the method detection limits near the theoretical minimum of single gene copy detection. The capability of the PCR-NGS approach in correcting false negativity was further tested and confirmed under more environmentally relevant conditions using Salmonella-spiked stream water and sediment samples. Finally, the PCR-NGS approach was applied to ten urban stream water samples and detected invA sequences in eight samples that would be otherwise deemed Salmonella negative. Analysis of the non-target sequences in the false-negative reactions helped to identify primer dime-like short sequences as the main cause of the false negativity. Together, the results demonstrated that the PCR-NGS approach can significantly improve method sensitivity, correct false-negative detections, and enable sequence-based analysis for failure diagnostics in complex environmental samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Introduction of the hybcell-based compact sequencing technology and comparison to state-of-the-art methodologies for KRAS mutation detection.

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Zopf, Agnes; Raim, Roman; Danzer, Martin; Niklas, Norbert; Spilka, Rita; Pröll, Johannes; Gabriel, Christian; Nechansky, Andreas; Roucka, Markus

2015-03-01

The detection of KRAS mutations in codons 12 and 13 is critical for anti-EGFR therapy strategies; however, only those methodologies with high sensitivity, specificity, and accuracy as well as the best cost and turnaround balance are suitable for routine daily testing. Here we compared the performance of compact sequencing using the novel hybcell technology with 454 next-generation sequencing (454-NGS), Sanger sequencing, and pyrosequencing, using an evaluation panel of 35 specimens. A total of 32 mutations and 10 wild-type cases were reported using 454-NGS as the reference method. Specificity ranged from 100% for Sanger sequencing to 80% for pyrosequencing. Sanger sequencing and hybcell-based compact sequencing achieved a sensitivity of 96%, whereas pyrosequencing had a sensitivity of 88%. Accuracy was 97% for Sanger sequencing, 85% for pyrosequencing, and 94% for hybcell-based compact sequencing. Quantitative results were obtained for 454-NGS and hybcell-based compact sequencing data, resulting in a significant correlation (r = 0.914). Whereas pyrosequencing and Sanger sequencing were not able to detect multiple mutated cell clones within one tumor specimen, 454-NGS and the hybcell-based compact sequencing detected multiple mutations in two specimens. Our comparison shows that the hybcell-based compact sequencing is a valuable alternative to state-of-the-art methodologies used for detection of clinically relevant point mutations.

A new trilocus sequence-based multiplex-PCR to detect major Acinetobacter baumannii clones.

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Martins, Natacha; Picão, Renata Cristina; Cerqueira-Alves, Morgana; Uehara, Aline; Barbosa, Lívia Carvalho; Riley, Lee W; Moreira, Beatriz Meurer

2016-08-01

A collection of 163 Acinetobacter baumannii isolates detected in a large Brazilian hospital, was potentially related with the dissemination of four clonal complexes (CC): 113/79, 103/15, 109/1 and 110/25, defined by University of Oxford/Institut Pasteur multilocus sequence typing (MLST) schemes. The urge of a simple multiplex-PCR scheme to specify these clones has motivated the present study. The established trilocus sequence-based typing (3LST, for ompA, csuE and blaOXA-51-like genes) multiplex-PCR rapidly identifies international clones I (CC109/1), II (CC118/2) and III (CC187/3). Thus, the system detects only one (CC109/1) out of four main CC in Brazil. We aimed to develop an alternative multiplex-PCR scheme to detect these clones, known to be present additionally in Africa, Asia, Europe, USA and South America. MLST, performed in the present study to complement typing our whole collection of isolates, confirmed that all isolates belonged to the same four CC detected previously. When typed by 3LST-based multiplex-PCR, only 12% of the 163 isolates were classified into groups. By comparative sequence analysis of ompA, csuE and blaOXA-51-like genes, a set of eight primers was designed for an alternative multiplex-PCR to distinguish the five CC 113/79, 103/15, 109/1, 110/25 and 118/2. Study isolates and one CC118/2 isolate were blind-tested with the new alternative PCR scheme; all were correctly clustered in groups of the corresponding CC. The new multiplex-PCR, with the advantage of fitting in a single reaction, detects five leading A. baumannii clones and could help preventing the spread in healthcare settings. Copyright © 2016 Elsevier B.V. All rights reserved.

[Clinical utility of real-time fluorescent PCR for combined detection of anaplastic lymphoma kinase and c-ros oncogene 1 receptor tyrosine kinase in non-small cell lung cancer].

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Bai, D Y; Zhang, H P; Zhong, S; Suo, W H; Gao, D H; Ding, Y; Tu, J H

2016-12-23

Objective: To investigate the clinical application value of combined detection of ALK fusion gene and c-ros oncogene 1 receptor tyrosine kinase (ROS1) fusion gene in non-small cell lung cancer (NSCLC) using real-time fluorescent PCR. Methods: A kit for combined detection of ALK fusion gene and ROS1 fusion gene based on fluorescent PCR was used to simultaneously detect the two fusion genes in 302 cases of NSCLC specimens. The results were validated through Sanger sequencing. The consistency of the two detection methods was analyzed. Results: All 302 cases of NSCLC specimens were successfully analyzed through fluorescent PCR (302/302). 12 cases (4.0%) were found to contain ALK fusion gene, including 3 cases with ALK-M1, 3 with ALK-M2, 3 with ALK-M3, 1 with ALK-M4, and 2 with ALK-M6 fusion gene.12 cases (4.0%) were found to contain ROS1 fusion gene, including 1 case with ROS1-M7, 8 cases with ROS1-M8, 1 case with ROS1-M12, 1 case with ROS1-M14, and 1 case with double-positive ROS1-M3 and ROS1-M8 fusion genes. The total detection rate of ALK fusion gene and ROS1 fusion gene was 7.9% (24/302) and 278 cases showed to be negative for ALK fusion gene and ROS1 fusion gene. The successful detection rates for Sanger DNA sequencing were also 100%. The positive, negative and total coincidence rates obtained by real-time fluorescent PCR and by Sanger DNA sequencing were all 100%. Conclusions: The results of Sanger DNA sequencing demonstrate that the real-time fluorescent PCR assay is equally effective in detecting ALK and ROS1 fusion genes in NSCLC tissues. Furthermore, real-time fluorescent PCR assay can be used to detect trace ALK and ROS1 fusion gene simultaneously in tiny samples, and can save time and avoid repeated sampling. It is worthy of recommendation as a rapid and reliable detection technique.

Non-invasive prenatal diagnosis of multiple endocrine neoplasia type 2A using COLD-PCR combined with HRM genotyping analysis from maternal serum.

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Macher, Hada C; Martinez-Broca, Maria A; Rubio-Calvo, Amalia; Leon-Garcia, Cristina; Conde-Sanchez, Manuel; Costa, Alzenira; Navarro, Elena; Guerrero, Juan M

2012-01-01

The multiple endocrine neoplasia type 2A (MEN2A) is a monogenic disorder characterized by an autosomal dominant pattern of inheritance which is characterized by high risk of medullary thyroid carcinoma in all mutation carriers. Although this disorder is classified as a rare disease, the patients affected have a low life quality and a very expensive and continuous treatment. At present, MEN2A is diagnosed by gene sequencing after birth, thus trying to start an early treatment and by reduction of morbidity and mortality. We first evaluated the presence of MEN2A mutation (C634Y) in serum of 25 patients, previously diagnosed by sequencing in peripheral blood leucocytes, using HRM genotyping analysis. In a second step, we used a COLD-PCR approach followed by HRM genotyping analysis for non-invasive prenatal diagnosis of a pregnant woman carrying a fetus with a C634Y mutation. HRM analysis revealed differences in melting curve shapes that correlated with patients diagnosed for MEN2A by gene sequencing analysis with 100% accuracy. Moreover, the pregnant woman carrying the fetus with the C634Y mutation revealed a melting curve shape in agreement with the positive controls in the COLD-PCR study. The mutation was confirmed by sequencing of the COLD-PCR amplification product. In conclusion, we have established a HRM analysis in serum samples as a new primary diagnosis method suitable for the detection of C634Y mutations in MEN2A patients. Simultaneously, we have applied the increase of sensitivity of COLD-PCR assay approach combined with HRM analysis for the non-invasive prenatal diagnosis of C634Y fetal mutations using pregnant women serum.

[Rapid detection of hot spot mutations of FGFR3 gene with PCR-high resolution melting assay].

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Li, Shan; Wang, Han; Su, Hua; Gao, Jinsong; Zhao, Xiuli

2017-08-10

To identify the causative mutations in five individuals affected with dyschondroplasia and develop an efficient procedure for detecting hot spot mutations of the FGFR3 gene. Genomic DNA was extracted from peripheral blood samples with a standard phenol/chloroform method. PCR-Sanger sequencing was used to analyze the causative mutations in the five probands. PCR-high resolution melting (HRM) was developed to detect the identified mutations. A c.1138G>A mutation in exon 8 was found in 4 probands, while a c.1620C>G mutation was found in exon 11 of proband 5 whom had a mild phenotype. All patients were successfully distinguished from healthy controls with the PCR-HRM method. The results of HRM analysis were highly consistent with that of Sanger sequencing. The Gly380Arg and Asn540Lys are hot spot mutations of the FGFR3 gene among patients with ACH/HCH. PCR-HRM analysis is more efficient for detecting hot spot mutations of the FGFR3 gene.

Non-invasive prenatal diagnosis of multiple endocrine neoplasia type 2A using COLD-PCR combined with HRM genotyping analysis from maternal serum.

Directory of Open Access Journals (Sweden)

Hada C Macher

Full Text Available The multiple endocrine neoplasia type 2A (MEN2A is a monogenic disorder characterized by an autosomal dominant pattern of inheritance which is characterized by high risk of medullary thyroid carcinoma in all mutation carriers. Although this disorder is classified as a rare disease, the patients affected have a low life quality and a very expensive and continuous treatment. At present, MEN2A is diagnosed by gene sequencing after birth, thus trying to start an early treatment and by reduction of morbidity and mortality. We first evaluated the presence of MEN2A mutation (C634Y in serum of 25 patients, previously diagnosed by sequencing in peripheral blood leucocytes, using HRM genotyping analysis. In a second step, we used a COLD-PCR approach followed by HRM genotyping analysis for non-invasive prenatal diagnosis of a pregnant woman carrying a fetus with a C634Y mutation. HRM analysis revealed differences in melting curve shapes that correlated with patients diagnosed for MEN2A by gene sequencing analysis with 100% accuracy. Moreover, the pregnant woman carrying the fetus with the C634Y mutation revealed a melting curve shape in agreement with the positive controls in the COLD-PCR study. The mutation was confirmed by sequencing of the COLD-PCR amplification product. In conclusion, we have established a HRM analysis in serum samples as a new primary diagnosis method suitable for the detection of C634Y mutations in MEN2A patients. Simultaneously, we have applied the increase of sensitivity of COLD-PCR assay approach combined with HRM analysis for the non-invasive prenatal diagnosis of C634Y fetal mutations using pregnant women serum.

Clinical Application of Picodroplet Digital PCR Technology for Rapid Detection of EGFR T790M in Next-Generation Sequencing Libraries and DNA from Limited Tumor Samples.

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Borsu, Laetitia; Intrieri, Julie; Thampi, Linta; Yu, Helena; Riely, Gregory; Nafa, Khedoudja; Chandramohan, Raghu; Ladanyi, Marc; Arcila, Maria E

2016-11-01

Although next-generation sequencing (NGS) is a robust technology for comprehensive assessment of EGFR-mutant lung adenocarcinomas with acquired resistance to tyrosine kinase inhibitors, it may not provide sufficiently rapid and sensitive detection of the EGFR T790M mutation, the most clinically relevant resistance biomarker. Here, we describe a digital PCR (dPCR) assay for rapid T790M detection on aliquots of NGS libraries prepared for comprehensive profiling, fully maximizing broad genomic analysis on limited samples. Tumor DNAs from patients with EGFR-mutant lung adenocarcinomas and acquired resistance to epidermal growth factor receptor inhibitors were prepared for Memorial Sloan-Kettering-Integrated Mutation Profiling of Actionable Cancer Targets sequencing, a hybrid capture-based assay interrogating 410 cancer-related genes. Precapture library aliquots were used for rapid EGFR T790M testing by dPCR, and results were compared with NGS and locked nucleic acid-PCR Sanger sequencing (reference high sensitivity method). Seventy resistance samples showed 99% concordance with the reference high sensitivity method in accuracy studies. Input as low as 2.5 ng provided a sensitivity of 1% and improved further with increasing DNA input. dPCR on libraries required less DNA and showed better performance than direct genomic DNA. dPCR on NGS libraries is a robust and rapid approach to EGFR T790M testing, allowing most economical utilization of limited material for comprehensive assessment. The same assay can also be performed directly on any limited DNA source and cell-free DNA. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Targeted resequencing and variant validation using pxlence PCR assays

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Frauke Coppieters

2016-01-01

Full Text Available The advent of next-generation sequencing technologies had a profound impact on molecular diagnostics. PCR is a popular method for target enrichment of disease gene panels. Using our proprietary primer-design pipeline, primerXL, we have created almost one million assays covering over 98% of the human exome. Here we describe the assay specification and both in silico and wet-lab validation of a selected set of 2294 assays using both next-generation sequencing and Sanger sequencing. Using a universal PCR protocol without optimization, these assays result in high coverage uniformity and limited non-specific coverage. In addition, data indicates a positive correlation between the predictive in silico specificity score and the amount of assay non-specific coverage.

Highly sensitive KRAS mutation detection from formalin-fixed paraffin-embedded biopsies and circulating tumour cells using wild-type blocking polymerase chain reaction and Sanger sequencing.

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Huang, Meggie Mo Chao; Leong, Sai Mun; Chua, Hui Wen; Tucker, Steven; Cheong, Wai Chye; Chiu, Lily; Li, Mo-Huang; Koay, Evelyn Siew-Chuan

2014-08-01

Among patients with colorectal cancer (CRC), KRAS mutations were reported to occur in 30-51 % of all cases. CRC patients with KRAS mutations were reported to be non-responsive to anti-epidermal growth factor receptor (EGFR) monoclonal antibody (MoAb) treatment in many clinical trials. Hence, accurate detection of KRAS mutations would be critical in guiding the use of anti-EGFR MoAb therapies in CRC. In this study, we carried out a detailed investigation of the efficacy of a wild-type (WT) blocking real-time polymerase chain reaction (PCR), employing WT KRAS locked nucleic acid blockers, and Sanger sequencing, for KRAS mutation detection in rare cells. Analyses were first conducted on cell lines to optimize the assay protocol which was subsequently applied to peripheral blood and tissue samples from patients with CRC. The optimized assay provided a superior sensitivity enabling detection of as little as two cells with mutated KRAS in the background of 10(4) WT cells (0.02 %). The feasibility of this assay was further investigated to assess the KRAS status of 45 colorectal tissue samples, which had been tested previously, using a conventional PCR sequencing approach. The analysis showed a mutational discordance between these two methods in 4 of 18 WT cases. Our results present a simple, effective, and robust method for KRAS mutation detection in both paraffin embedded tissues and circulating tumour cells, at single-cell level. The method greatly enhances the detection sensitivity and alleviates the need of exhaustively removing co-enriched contaminating lymphocytes.

Electrostatic Potential Maps and Natural Bond Orbital Analysis: Visualization and Conceptualization of Reactivity in Sanger's Reagent

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Mottishaw, Jeffery D.; Erck, Adam R.; Kramer, Jordan H.; Sun, Haoran; Koppang, Miles

2015-01-01

Frederick Sanger's early work on protein sequencing through the use of colorimetric labeling combined with liquid chromatography involves an important nucleophilic aromatic substitution (S[subscript N]Ar) reaction in which the N-terminus of a protein is tagged with Sanger's reagent. Understanding the inherent differences between this S[subscript…

A next generation semiconductor based sequencing approach for the identification of meat species in DNA mixtures.

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Francesca Bertolini

Full Text Available The identification of the species of origin of meat and meat products is an important issue to prevent and detect frauds that might have economic, ethical and health implications. In this paper we evaluated the potential of the next generation semiconductor based sequencing technology (Ion Torrent Personal Genome Machine for the identification of DNA from meat species (pig, horse, cattle, sheep, rabbit, chicken, turkey, pheasant, duck, goose and pigeon as well as from human and rat in DNA mixtures through the sequencing of PCR products obtained from different couples of universal primers that amplify 12S and 16S rRNA mitochondrial DNA genes. Six libraries were produced including PCR products obtained separately from 13 species or from DNA mixtures containing DNA from all species or only avian or only mammalian species at equimolar concentration or at 1:10 or 1:50 ratios for pig and horse DNA. Sequencing obtained a total of 33,294,511 called nucleotides of which 29,109,688 with Q20 (87.43% in a total of 215,944 reads. Different alignment algorithms were used to assign the species based on sequence data. Error rate calculated after confirmation of the obtained sequences by Sanger sequencing ranged from 0.0003 to 0.02 for the different species. Correlation about the number of reads per species between different libraries was high for mammalian species (0.97 and lower for avian species (0.70. PCR competition limited the efficiency of amplification and sequencing for avian species for some primer pairs. Detection of low level of pig and horse DNA was possible with reads obtained from different primer pairs. The sequencing of the products obtained from different universal PCR primers could be a useful strategy to overcome potential problems of amplification. Based on these results, the Ion Torrent technology can be applied for the identification of meat species in DNA mixtures.

Development of allele-specific multiplex PCR to determine the length of poly-T in intron 8 of CFTR

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Neng Chen

2014-07-01

Full Text Available Cystic fibrosis transmembrane conductance regulator (CFTR gene mutation analysis has been implemented for Cystic Fibrosis (CF carrier screening, and molecular diagnosis of CF and congenital bilateral absence of the vas deferens (CBAVD. Although poly-T allele analysis in intron 8 of CFTR is required when a patient is positive for R117H, it is not recommended for routine carrier screening. Therefore, commercial kits for CFTR mutation analysis were designed either to mask the poly-T allele results, unless a patient is R117H positive, or to have the poly-T analysis as a standalone reflex test using the same commercial platform. There are other standalone assays developed to detect poly-T alleles, such as heteroduplex analysis, High Resolution Melting (HRM curve analysis, allele-specific PCR (AS-PCR and Sanger sequencing. In this report, we developed a simple and easy-to-implement multiplex AS-PCR assay using unlabeled standard length primers, which can be used as a reflex or standalone test for CFTR poly-T track analysis. Out of 115 human gDNA samples tested, results from our new AS-PCR matched to the previous known poly-T results or results from Sanger sequencing.

A machine learning model to determine the accuracy of variant calls in capture-based next generation sequencing.

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van den Akker, Jeroen; Mishne, Gilad; Zimmer, Anjali D; Zhou, Alicia Y

2018-04-17

Next generation sequencing (NGS) has become a common technology for clinical genetic tests. The quality of NGS calls varies widely and is influenced by features like reference sequence characteristics, read depth, and mapping accuracy. With recent advances in NGS technology and software tools, the majority of variants called using NGS alone are in fact accurate and reliable. However, a small subset of difficult-to-call variants that still do require orthogonal confirmation exist. For this reason, many clinical laboratories confirm NGS results using orthogonal technologies such as Sanger sequencing. Here, we report the development of a deterministic machine-learning-based model to differentiate between these two types of variant calls: those that do not require confirmation using an orthogonal technology (high confidence), and those that require additional quality testing (low confidence). This approach allows reliable NGS-based calling in a clinical setting by identifying the few important variant calls that require orthogonal confirmation. We developed and tested the model using a set of 7179 variants identified by a targeted NGS panel and re-tested by Sanger sequencing. The model incorporated several signals of sequence characteristics and call quality to determine if a variant was identified at high or low confidence. The model was tuned to eliminate false positives, defined as variants that were called by NGS but not confirmed by Sanger sequencing. The model achieved very high accuracy: 99.4% (95% confidence interval: +/- 0.03%). It categorized 92.2% (6622/7179) of the variants as high confidence, and 100% of these were confirmed to be present by Sanger sequencing. Among the variants that were categorized as low confidence, defined as NGS calls of low quality that are likely to be artifacts, 92.1% (513/557) were found to be not present by Sanger sequencing. This work shows that NGS data contains sufficient characteristics for a machine-learning-based model to

Fusion primer and nested integrated PCR (FPNI-PCR: a new high-efficiency strategy for rapid chromosome walking or flanking sequence cloning

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Wang Zhen

2011-11-01

Full Text Available Abstract Background The advent of genomics-based technologies has revolutionized many fields of biological enquiry. However, chromosome walking or flanking sequence cloning is still a necessary and important procedure to determining gene structure. Such methods are used to identify T-DNA insertion sites and so are especially relevant for organisms where large T-DNA insertion libraries have been created, such as rice and Arabidopsis. The currently available methods for flanking sequence cloning, including the popular TAIL-PCR technique, are relatively laborious and slow. Results Here, we report a simple and effective fusion primer and nested integrated PCR method (FPNI-PCR for the identification and cloning of unknown genomic regions flanked known sequences. In brief, a set of universal primers was designed that consisted of various 15-16 base arbitrary degenerate oligonucleotides. These arbitrary degenerate primers were fused to the 3' end of an adaptor oligonucleotide which provided a known sequence without degenerate nucleotides, thereby forming the fusion primers (FPs. These fusion primers are employed in the first step of an integrated nested PCR strategy which defines the overall FPNI-PCR protocol. In order to demonstrate the efficacy of this novel strategy, we have successfully used it to isolate multiple genomic sequences namely, 21 orthologs of genes in various species of Rosaceace, 4 MYB genes of Rosa rugosa, 3 promoters of transcription factors of Petunia hybrida, and 4 flanking sequences of T-DNA insertion sites in transgenic tobacco lines and 6 specific genes from sequenced genome of rice and Arabidopsis. Conclusions The successful amplification of target products through FPNI-PCR verified that this novel strategy is an effective, low cost and simple procedure. Furthermore, FPNI-PCR represents a more sensitive, rapid and accurate technique than the established TAIL-PCR and hiTAIL-PCR procedures.

Phylogenetic analysis of Fusobacterium prausnitzii based upon the 16S rRNA gene sequence and PCR confirmation.

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Wang, R F; Cao, W W; Cerniglia, C E

1996-01-01

In order to develop a PCR method to detect Fusobacterium prausnitzii in human feces and to clarify the phylogenetic position of this species, its 16S rRNA gene sequence was determined. The sequence described in this paper is different from the 16S rRNA gene sequence is specific for F. prausnitzii, and the results of this assay confirmed that F. prausnitzii is the most common species in human feces. However, a PCR assay based on the original GenBank sequence was negative when it was performed with two strains of F. prausnitzii obtained from the American Type Culture Collection. A phylogenetic tree based on the new 16S rRNA gene sequence was constructed. On this tree F. prausnitzii was not a member of the Fusobacterium group but was closer to some Eubacterium spp. and located between Clostridium "clusters III and IV" (M.D. Collins, P.A. Lawson, A. Willems, J.J. Cordoba, J. Fernandez-Garayzabal, P. Garcia, J. Cai, H. Hippe, and J.A.E. Farrow, Int. J. Syst. Bacteriol. 44:812-826, 1994).

Detection of Anti-Hepatitis B Virus Drug Resistance Mutations Based on Multicolor Melting Curve Analysis.

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Mou, Yi; Athar, Muhammad Ammar; Wu, Yuzhen; Xu, Ye; Wu, Jianhua; Xu, Zhenxing; Hayder, Zulfiqar; Khan, Saeed; Idrees, Muhammad; Nasir, Muhammad Israr; Liao, Yiqun; Li, Qingge

2016-11-01

Detection of anti-hepatitis B virus (HBV) drug resistance mutations is critical for therapeutic decisions for chronic hepatitis B virus infection. We describe a real-time PCR-based assay using multicolor melting curve analysis (MMCA) that could accurately detect 24 HBV nucleotide mutations at 10 amino acid positions in the reverse transcriptase region of the HBV polymerase gene. The two-reaction assay had a limit of detection of 5 copies per reaction and could detect a minor mutant population (5% of the total population) with the reverse transcriptase M204V amino acid mutation in the presence of the major wild-type population when the overall concentration was 10 4 copies/μl. The assay could be finished within 3 h, and the cost of materials for each sample was less than $10. Clinical validation studies using three groups of samples from both nucleos(t)ide analog-treated and -untreated patients showed that the results for 99.3% (840/846) of the samples and 99.9% (8,454/8,460) of the amino acids were concordant with those of Sanger sequencing of the PCR amplicon from the HBV reverse transcriptase region (PCR Sanger sequencing). HBV DNA in six samples with mixed infections consisting of minor mutant subpopulations was undetected by the PCR Sanger sequencing method but was detected by MMCA, and the results were confirmed by coamplification at a lower denaturation temperature-PCR Sanger sequencing. Among the treated patients, 48.6% (103/212) harbored viruses that displayed lamivudine monoresistance, adefovir monoresistance, entecavir resistance, or lamivudine and adefovir resistance. Among the untreated patients, the Chinese group had more mutation-containing samples than did the Pakistani group (3.3% versus 0.56%). Because of its accuracy, rapidness, wide-range coverage, and cost-effectiveness, the real-time PCR assay could be a robust tool for the detection if anti-HBV drug resistance mutations in resource-limited countries. Copyright © 2016, American Society for

Generation and analysis of blueberry transcriptome sequences from leaves, developing fruit, and flower buds from cold acclimation through deacclimation.

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Rowland, Lisa J; Alkharouf, Nadim; Darwish, Omar; Ogden, Elizabeth L; Polashock, James J; Bassil, Nahla V; Main, Dorrie

2012-04-02

There has been increased consumption of blueberries in recent years fueled in part because of their many recognized health benefits. Blueberry fruit is very high in anthocyanins, which have been linked to improved night vision, prevention of macular degeneration, anti-cancer activity, and reduced risk of heart disease. Very few genomic resources have been available for blueberry, however. Further development of genomic resources like expressed sequence tags (ESTs), molecular markers, and genetic linkage maps could lead to more rapid genetic improvement. Marker-assisted selection could be used to combine traits for climatic adaptation with fruit and nutritional quality traits. Efforts to sequence the transcriptome of the commercial highbush blueberry (Vaccinium corymbosum) cultivar Bluecrop and use the sequences to identify genes associated with cold acclimation and fruit development and develop SSR markers for mapping studies are presented here. Transcriptome sequences were generated from blueberry fruit at different stages of development, flower buds at different stages of cold acclimation, and leaves by next-generation Roche 454 sequencing. Over 600,000 reads were assembled into approximately 15,000 contigs and 124,000 singletons. The assembled sequences were annotated and functionally mapped to Gene Ontology (GO) terms. Frequency of the most abundant sequences in each of the libraries was compared across all libraries to identify genes that are potentially differentially expressed during cold acclimation and fruit development. Real-time PCR was performed to confirm their differential expression patterns. Overall, 14 out of 17 of the genes examined had differential expression patterns similar to what was predicted from their reads alone. The assembled sequences were also mined for SSRs. From these sequences, 15,886 blueberry EST-SSR loci were identified. Primers were designed from 7,705 of the SSR-containing sequences with adequate flanking sequence. One hundred

Generation and analysis of blueberry transcriptome sequences from leaves, developing fruit, and flower buds from cold acclimation through deacclimation

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Rowland Lisa J

2012-04-01

with adequate flanking sequence. One hundred primer pairs were tested for amplification and polymorphism among parents of two blueberry populations currently being used for genetic linkage map construction. The tetraploid mapping population was based on a cross between the highbush cultivars Draper and Jewel (V. darrowii is also in the background of 'Jewel'. The diploid mapping population was based on a cross between an F1 hybrid of V. darrowii and diploid V. corymbosum and another diploid V. corymbosum. The overall amplification rate of the SSR primers was 68% and the polymorphism rate was 43%. Conclusions These results indicate that this large collection of 454 ESTs will be a valuable resource for identifying genes that are potentially differentially expressed and play important roles in flower bud development, cold acclimation, chilling unit accumulation, and fruit development in blueberry and related species. In addition, the ESTs have already proved useful for the development of SSR and EST-PCR markers, and are currently being used for construction of genetic linkage maps in blueberry.

Generation and analysis of blueberry transcriptome sequences from leaves, developing fruit, and flower buds from cold acclimation through deacclimation

Science.gov (United States)

2012-01-01

sequence. One hundred primer pairs were tested for amplification and polymorphism among parents of two blueberry populations currently being used for genetic linkage map construction. The tetraploid mapping population was based on a cross between the highbush cultivars Draper and Jewel (V. darrowii is also in the background of 'Jewel'). The diploid mapping population was based on a cross between an F1 hybrid of V. darrowii and diploid V. corymbosum and another diploid V. corymbosum. The overall amplification rate of the SSR primers was 68% and the polymorphism rate was 43%. Conclusions These results indicate that this large collection of 454 ESTs will be a valuable resource for identifying genes that are potentially differentially expressed and play important roles in flower bud development, cold acclimation, chilling unit accumulation, and fruit development in blueberry and related species. In addition, the ESTs have already proved useful for the development of SSR and EST-PCR markers, and are currently being used for construction of genetic linkage maps in blueberry. PMID:22471859

Enrichment of methylated molecules using enhanced-ice-co-amplification at lower denaturation temperature-PCR (E-ice-COLD-PCR) for the sensitive detection of disease-related hypermethylation.

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Mauger, Florence; Kernaleguen, Magali; Lallemand, Céline; Kristensen, Vessela N; Deleuze, Jean-François; Tost, Jörg

2018-05-01

The detection of specific DNA methylation patterns bears great promise as biomarker for personalized management of cancer patients. Co-amplification at lower denaturation temperature-PCR (COLD-PCR) assays are sensitive methods, but have previously only been able to analyze loss of DNA methylation. Enhanced (E)-ice-COLD-PCR reactions starting from 2 ng of bisulfite-converted DNA were developed to analyze methylation patterns in two promoters with locked nucleic acid (LNA) probes blocking amplification of unmethylated CpGs. The enrichment of methylated molecules was compared to quantitative (q)PCR and quantified using serial dilutions. E-ice-COLD-PCR allowed the multiplexed enrichment and quantification of methylated DNA. Assays were validated in primary breast cancer specimens and circulating cell-free DNA from cancer patients. E-ice-COLD-PCR could prove a useful tool in the context of DNA methylation analysis for personalized medicine.

Directed PCR-free engineering of highly repetitive DNA sequences

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Preissler Steffen

2011-09-01

Full Text Available Abstract Background Highly repetitive nucleotide sequences are commonly found in nature e.g. in telomeres, microsatellite DNA, polyadenine (poly(A tails of eukaryotic messenger RNA as well as in several inherited human disorders linked to trinucleotide repeat expansions in the genome. Therefore, studying repetitive sequences is of biological, biotechnological and medical relevance. However, cloning of such repetitive DNA sequences is challenging because specific PCR-based amplification is hampered by the lack of unique primer binding sites resulting in unspecific products. Results For the PCR-free generation of repetitive DNA sequences we used antiparallel oligonucleotides flanked by restriction sites of Type IIS endonucleases. The arrangement of recognition sites allowed for stepwise and seamless elongation of repetitive sequences. This facilitated the assembly of repetitive DNA segments and open reading frames encoding polypeptides with periodic amino acid sequences of any desired length. By this strategy we cloned a series of polyglutamine encoding sequences as well as highly repetitive polyadenine tracts. Such repetitive sequences can be used for diverse biotechnological applications. As an example, the polyglutamine sequences were expressed as His6-SUMO fusion proteins in Escherichia coli cells to study their aggregation behavior in vitro. The His6-SUMO moiety enabled affinity purification of the polyglutamine proteins, increased their solubility, and allowed controlled induction of the aggregation process. We successfully purified the fusions proteins and provide an example for their applicability in filter retardation assays. Conclusion Our seamless cloning strategy is PCR-free and allows the directed and efficient generation of highly repetitive DNA sequences of defined lengths by simple standard cloning procedures.

An enhanced method for sequence walking and paralog mining: TOPO® Vector-Ligation PCR

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Davis Thomas M

2010-03-01

Full Text Available Abstract Background Although technological advances allow for the economical acquisition of whole genome sequences, many organisms' genomes remain unsequenced, and fully sequenced genomes may contain gaps. Researchers reliant upon partial genomic or heterologous sequence information require methods for obtaining unknown sequences from loci of interest. Various PCR based techniques are available for sequence walking - i.e., the acquisition of unknown DNA sequence adjacent to known sequence. Many such methods require rigid, elaborate protocols and/or impose narrowly confined options in the choice of restriction enzymes for necessary genomic digests. We describe a new method, TOPO® Vector-Ligation PCR (or TVL-PCR that innovatively integrates available tools and familiar concepts to offer advantages as a means of both targeted sequence walking and paralog mining. Findings TVL-PCR exploits the ligation efficiency of the pCR®4-TOPO® (Invitrogen, Carlsbad, California vector system to capture fragments of unknown sequence by creating chimeric molecules containing defined priming sites at both ends. Initially, restriction enzyme-digested genomic DNA is end-repaired to create 3' adenosine overhangs and is then ligated to pCR4-TOPO vectors. The ligation product pool is used directly as a template for nested PCR, using specific primers to target orthologous sequences, or degenerate primers to enable capture of paralogous gene family members. We demonstrated the efficacy of this method by capturing entire coding and partial promoter sequences of several strawberry Superman-like genes. Conclusions TVL-PCR is a convenient and efficient method for DNA sequence walking and paralog mining that is applicable to any organism for which relevant DNA sequence is available as a basis for primer design.

Prevalence of Hepatitis C Virus Subgenotypes 1a and 1b in Japanese Patients: Ultra-Deep Sequencing Analysis of HCV NS5B Genotype-Specific Region

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Wu, Shuang; Kanda, Tatsuo; Nakamoto, Shingo; Jiang, Xia; Miyamura, Tatsuo; Nakatani, Sueli M.; Ono, Suzane Kioko; Takahashi-Nakaguchi, Azusa; Gonoi, Tohru; Yokosuka, Osamu

2013-01-01

Background Hepatitis C virus (HCV) subgenotypes 1a and 1b have different impacts on the treatment response to peginterferon plus ribavirin with direct-acting antivirals (DAAs) against patients infected with HCV genotype 1, as the emergence rates of resistance mutations are different between these two subgenotypes. In Japan, almost all of HCV genotype 1 belongs to subgenotype 1b. Methods and Findings To determine HCV subgenotype 1a or 1b in Japanese patients infected with HCV genotype 1, real-time PCR-based method and Sanger method were used for the HCV NS5B region. HCV subgenotypes were determined in 90% by real-time PCR-based method. We also analyzed the specific probe regions for HCV subgenotypes 1a and 1b using ultra-deep sequencing, and uncovered mutations that could not be revealed using direct-sequencing by Sanger method. We estimated the prevalence of HCV subgenotype 1a as 1.2-2.5% of HCV genotype 1 patients in Japan. Conclusions Although real-time PCR-based HCV subgenotyping method seems fair for differentiating HCV subgenotypes 1a and 1b, it may not be sufficient for clinical practice. Ultra-deep sequencing is useful for revealing the resistant strain(s) of HCV before DAA treatment as well as mixed infection with different genotypes or subgenotypes of HCV. PMID:24069214

Comparison of the quantification of KRAS mutations by digital PCR and E-ice-COLD-PCR in circulating-cell-free DNA from metastatic colorectal cancer patients.

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Sefrioui, David; Mauger, Florence; Leclere, Laurence; Beaussire, Ludivine; Di Fiore, Frédéric; Deleuze, Jean-François; Sarafan-Vasseur, Nasrin; Tost, Jörg

2017-02-01

Circulating cell-free DNA (ccfDNA) bears great promise as biomarker for personalized medicine, but ccfDNA is present only at low levels in the plasma or serum of cancer patients. E-ice-COLD-PCR is a recently developed enrichment method to detect and identify mutations present at low-abundance in clinical samples. However, recent studies have shown the importance to accurately quantify low-abundance mutations as clinically important decisions will depend on certain mutation thresholds. The possibility for an enrichment method to accurately quantify the mutation levels remains a point of concern and might limit its clinical applicability. In the present study, we compared the quantification of KRAS mutations in ccfDNA from metastatic colorectal cancer patients by E-ice-COLD-PCR with two digital PCR approaches. For the quantification of mutations by E-ice-COLD-PCR, cell lines with known mutations diluted into WT genomic DNA were used for calibration. E-ice-COLD-PCR and the two digital PCR approaches showed the same range of the mutation level and were concordant for mutation levels below the clinical relevant threshold. E-ice-COLD-PCR can accurately detect and quantify low-abundant mutations in ccfDNA and has a shorter time to results making it compatible with the requirements of analyses in a clinical setting without the loss of quantitative accuracy. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

The use of coded PCR primers enables high-throughput sequencing of multiple homolog amplification products by 454 parallel sequencing.

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Jonas Binladen

2007-02-01

Full Text Available The invention of the Genome Sequence 20 DNA Sequencing System (454 parallel sequencing platform has enabled the rapid and high-volume production of sequence data. Until now, however, individual emulsion PCR (emPCR reactions and subsequent sequencing runs have been unable to combine template DNA from multiple individuals, as homologous sequences cannot be subsequently assigned to their original sources.We use conventional PCR with 5'-nucleotide tagged primers to generate homologous DNA amplification products from multiple specimens, followed by sequencing through the high-throughput Genome Sequence 20 DNA Sequencing System (GS20, Roche/454 Life Sciences. Each DNA sequence is subsequently traced back to its individual source through 5'tag-analysis.We demonstrate that this new approach enables the assignment of virtually all the generated DNA sequences to the correct source once sequencing anomalies are accounted for (miss-assignment rate<0.4%. Therefore, the method enables accurate sequencing and assignment of homologous DNA sequences from multiple sources in single high-throughput GS20 run. We observe a bias in the distribution of the differently tagged primers that is dependent on the 5' nucleotide of the tag. In particular, primers 5' labelled with a cytosine are heavily overrepresented among the final sequences, while those 5' labelled with a thymine are strongly underrepresented. A weaker bias also exists with regards to the distribution of the sequences as sorted by the second nucleotide of the dinucleotide tags. As the results are based on a single GS20 run, the general applicability of the approach requires confirmation. However, our experiments demonstrate that 5'primer tagging is a useful method in which the sequencing power of the GS20 can be applied to PCR-based assays of multiple homologous PCR products. The new approach will be of value to a broad range of research areas, such as those of comparative genomics, complete mitochondrial

Sources of PCR-induced distortions in high-throughput sequencing data sets

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Kebschull, Justus M.; Zador, Anthony M.

2015-01-01

PCR permits the exponential and sequence-specific amplification of DNA, even from minute starting quantities. PCR is a fundamental step in preparing DNA samples for high-throughput sequencing. However, there are errors associated with PCR-mediated amplification. Here we examine the effects of four important sources of error—bias, stochasticity, template switches and polymerase errors—on sequence representation in low-input next-generation sequencing libraries. We designed a pool of diverse PCR amplicons with a defined structure, and then used Illumina sequencing to search for signatures of each process. We further developed quantitative models for each process, and compared predictions of these models to our experimental data. We find that PCR stochasticity is the major force skewing sequence representation after amplification of a pool of unique DNA amplicons. Polymerase errors become very common in later cycles of PCR but have little impact on the overall sequence distribution as they are confined to small copy numbers. PCR template switches are rare and confined to low copy numbers. Our results provide a theoretical basis for removing distortions from high-throughput sequencing data. In addition, our findings on PCR stochasticity will have particular relevance to quantification of results from single cell sequencing, in which sequences are represented by only one or a few molecules. PMID:26187991

Microfluidic PCR Amplification and MiSeq Amplicon Sequencing Techniques for High-Throughput Detection and Genotyping of Human Pathogenic RNA Viruses in Human Feces, Sewage, and Oysters

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Mamoru Oshiki

2018-04-01

Full Text Available Detection and genotyping of pathogenic RNA viruses in human and environmental samples are useful for monitoring the circulation and prevalence of these pathogens, whereas a conventional PCR assay followed by Sanger sequencing is time-consuming and laborious. The present study aimed to develop a high-throughput detection-and-genotyping tool for 11 human RNA viruses [Aichi virus; astrovirus; enterovirus; norovirus genogroup I (GI, GII, and GIV; hepatitis A virus; hepatitis E virus; rotavirus; sapovirus; and human parechovirus] using a microfluidic device and next-generation sequencer. Microfluidic nested PCR was carried out on a 48.48 Access Array chip, and the amplicons were recovered and used for MiSeq sequencing (Illumina, Tokyo, Japan; genotyping was conducted by homology searching and phylogenetic analysis of the obtained sequence reads. The detection limit of the 11 tested viruses ranged from 100 to 103 copies/μL in cDNA sample, corresponding to 101–104 copies/mL-sewage, 105–108 copies/g-human feces, and 102–105 copies/g-digestive tissues of oyster. The developed assay was successfully applied for simultaneous detection and genotyping of RNA viruses to samples of human feces, sewage, and artificially contaminated oysters. Microfluidic nested PCR followed by MiSeq sequencing enables efficient tracking of the fate of multiple RNA viruses in various environments, which is essential for a better understanding of the circulation of human pathogenic RNA viruses in the human population.

Application of PCR-based DNA sequencing technique for the detection of Leptospira in peripheral blood of septicemia patients

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Ram, S.

2012-01-01

Full Text Available Aim: Isolation, dark field detection and microscopic agglutination test (MAT are considered ―gold standard‖ tests for diagnosis of Leptospirosis. Several PCR assays are reported but very few have been evaluated for detection of Leptospirosis. Therefore, this study was undertaken. This study aims to design and standardize polymerase chain reaction (PCR - based DNA sequencing technique for the detection of pathogenic Leptospira from peripheral blood of patients clinically diagnosed with septicemia. Methodology and Results: Two hundred and seven (207 blood samples from patients were diagnosed with septicemia which includes 100 bacterial (other than Leptospira culture positive and 107 bacterial culture negative samples were studied. Primers for Nested PCR targeting LipL32 gene of Leptospira interrogans were designed and the specificity of primers was tested against serum samples positive/negative by either MAT or dark field microscopy. PCR amplified products were further confirmed by DNA sequencing. The standardized nPCR was sensitive and specific to Leptospira interrogans. Twenty-one (21% out of 100 culture positive blood samples, three (2.8% out of 107 culture negative samples showed nPCR positivity and were confirmed as Leptospira interrogans by DNA sequencing (p<0.001. A sensitive nPCR specific to Leptospira interrogans was developed. Conclusion, significance and impact of study: The p value (<0.001 signifies that Leptospira is commonly associated with other bacteria circulating in blood indicating that a decreased immune status is created primarily by a bacterium with enhanced possibility of development of Leptospiral infection probably be of an endogenous origin.

Digital PCR provides sensitive and absolute calibration for high throughput sequencing

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Fan H Christina

2009-03-01

Full Text Available Abstract Background Next-generation DNA sequencing on the 454, Solexa, and SOLiD platforms requires absolute calibration of the number of molecules to be sequenced. This requirement has two unfavorable consequences. First, large amounts of sample-typically micrograms-are needed for library preparation, thereby limiting the scope of samples which can be sequenced. For many applications, including metagenomics and the sequencing of ancient, forensic, and clinical samples, the quantity of input DNA can be critically limiting. Second, each library requires a titration sequencing run, thereby increasing the cost and lowering the throughput of sequencing. Results We demonstrate the use of digital PCR to accurately quantify 454 and Solexa sequencing libraries, enabling the preparation of sequencing libraries from nanogram quantities of input material while eliminating costly and time-consuming titration runs of the sequencer. We successfully sequenced low-nanogram scale bacterial and mammalian DNA samples on the 454 FLX and Solexa DNA sequencing platforms. This study is the first to definitively demonstrate the successful sequencing of picogram quantities of input DNA on the 454 platform, reducing the sample requirement more than 1000-fold without pre-amplification and the associated bias and reduction in library depth. Conclusion The digital PCR assay allows absolute quantification of sequencing libraries, eliminates uncertainties associated with the construction and application of standard curves to PCR-based quantification, and with a coefficient of variation close to 10%, is sufficiently precise to enable direct sequencing without titration runs.

Assessment of real-time PCR method for detection of EGFR mutation using both supernatant and cell pellet of malignant pleural effusion samples from non-small-cell lung cancer patients.

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Shin, Saeam; Kim, Juwon; Kim, Yoonjung; Cho, Sun-Mi; Lee, Kyung-A

2017-10-26

EGFR mutation is an emerging biomarker for treatment selection in non-small-cell lung cancer (NSCLC) patients. However, optimal mutation detection is hindered by complications associated with the biopsy procedure, tumor heterogeneity and limited sensitivity of test methodology. In this study, we evaluated the diagnostic utility of real-time PCR using malignant pleural effusion samples. A total of 77 pleural fluid samples from 77 NSCLC patients were tested using the cobas EGFR mutation test (Roche Molecular Systems). Pleural fluid was centrifuged, and separated cell pellets and supernatants were tested in parallel. Results were compared with Sanger sequencing and/or peptide nucleic acid (PNA)-mediated PCR clamping of matched tumor tissue or pleural fluid samples. All samples showed valid real-time PCR results in one or more DNA samples extracted from cell pellets and supernatants. Compared with other molecular methods, the sensitivity of real-time PCR method was 100%. Concordance rate of real-time PCR and Sanger sequencing plus PNA-mediated PCR clamping was 98.7%. We have confirmed that real-time PCR using pleural fluid had a high concordance rate compared to conventional methods, with no failed samples. Our data demonstrated that the parallel real-time PCR testing using supernatant and cell pellet could offer reliable and robust surrogate strategy when tissue is not available.

A dual PCR-based sequencing approach for the identification and discrimination of Echinococcus and Taenia taxa.

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Boubaker, Ghalia; Marinova, Irina; Gori, Francesca; Hizem, Amani; Müller, Norbert; Casulli, Adriano; Jerez Puebla, Luis Enrique; Babba, Hamouda; Gottstein, Bruno; Spiliotis, Markus

2016-08-01

Reliable and rapid molecular tools for the genetic identification and differentiation of Echinococcus species and/or genotypes are crucial for studying spatial and temporal transmission dynamics. Here, we describe a novel dual PCR targeting regions in the small (rrnS) and large (rrnL) subunits of mitochondrial ribosomal RNA (rRNA) genes, which enables (i) the specific identification of species and genotypes of Echinococcus (rrnS + L-PCR) and/or (ii) the identification of a range of taeniid cestodes, including different species of Echinococcus, Taenia and some others (17 species of diphyllidean helminths). This dual PCR approach was highly sensitive, with an analytical detection limit of 1 pg for genomic DNA of Echinococcus. Using concatenated sequence data derived from the two gene markers (1225 bp), we identified five unique and geographically informative single nucleotide polymorphisms (SNPs) that allowed genotypes (G1 and G3) of Echinococcus granulosus sensu stricto to be distinguished, and 25 SNPs that allowed differentiation within Echinococcus canadensis (G6/7/8/10). In conclusion, we propose that this dual PCR-based sequencing approach can be used for molecular epidemiological studies of Echinococcus and other taeniid cestodes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of PCR-based DNA sequencing technique for the detection of Leptospira in peripheral blood of septicemia patients

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Ram, S.; Vimalin, J.M.; Jambulingam, M.; Tiru, V.; Gopalakrishnan, R.K.; Madhavan, H.N.

2012-01-01

Aim: Isolation, dark field detection and microscopic agglutination test (MAT) are considered ―gold standard‖ tests for diagnosis of Leptospirosis. Several PCR assays are reported but very few have been evaluated for detection of Leptospirosis. Therefore, this study was undertaken. This study aims to design and standardize polymerase chain reaction (PCR) - based DNA sequencing technique for the detection of pathogenic Leptospira from peripheral blood of patients clinically diagnosed with septi...

Molecular Properties of Poliovirus Isolates: Nucleotide Sequence Analysis, Typing by PCR and Real-Time RT-PCR.

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Burns, Cara C; Kilpatrick, David R; Iber, Jane C; Chen, Qi; Kew, Olen M

2016-01-01

Virologic surveillance is essential to the success of the World Health Organization initiative to eradicate poliomyelitis. Molecular methods have been used to detect polioviruses in tissue culture isolates derived from stool samples obtained through surveillance for acute flaccid paralysis. This chapter describes the use of realtime PCR assays to identify and serotype polioviruses. In particular, a degenerate, inosine-containing, panpoliovirus (panPV) PCR primer set is used to distinguish polioviruses from NPEVs. The high degree of nucleotide sequence diversity among polioviruses presents a challenge to the systematic design of nucleic acid-based reagents. To accommodate the wide variability and rapid evolution of poliovirus genomes, degenerate codon positions on the template were matched to mixed-base or deoxyinosine residues on both the primers and the TaqMan™ probes. Additional assays distinguish between Sabin vaccine strains and non-Sabin strains. This chapter also describes the use of generic poliovirus specific primers, along with degenerate and inosine-containing primers, for routine VP1 sequencing of poliovirus isolates. These primers, along with nondegenerate serotype-specific Sabin primers, can also be used to sequence individual polioviruses in mixtures.

Combined use of real-time PCR and nested sequence-based typing in survey of human Legionella infection.

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Qin, T; Zhou, H; Ren, H; Shi, W; Jin, H; Jiang, X; Xu, Y; Zhou, M; Li, J; Wang, J; Shao, Z; Xu, X

2016-07-01

Legionnaires' disease (LD) is a globally distributed systemic infectious disease. The burden of LD in many regions is still unclear, especially in Asian countries including China. A survey of Legionella infection using real-time PCR and nested sequence-based typing (SBT) was performed in two hospitals in Shanghai, China. A total of 265 bronchoalveolar lavage fluid (BALF) specimens were collected from hospital A between January 2012 and December 2013, and 359 sputum specimens were collected from hospital B throughout 2012. A total of 71 specimens were positive for Legionella according to real-time PCR focusing on the 5S rRNA gene. Seventy of these specimens were identified as Legionella pneumophila as a result of real-time PCR amplification of the dotA gene. Results of nested SBT revealed high genetic polymorphism in these L. pneumophila and ST1 was the predominant sequence type. These data revealed that the burden of LD in China is much greater than that recognized previously, and real-time PCR may be a suitable monitoring technology for LD in large sample surveys in regions lacking the economic and technical resources to perform other methods, such as urinary antigen tests and culture methods.

Automated degenerate PCR primer design for high-throughput sequencing improves efficiency of viral sequencing

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Li Kelvin

2012-11-01

Full Text Available Abstract Background In a high-throughput environment, to PCR amplify and sequence a large set of viral isolates from populations that are potentially heterogeneous and continuously evolving, the use of degenerate PCR primers is an important strategy. Degenerate primers allow for the PCR amplification of a wider range of viral isolates with only one set of pre-mixed primers, thus increasing amplification success rates and minimizing the necessity for genome finishing activities. To successfully select a large set of degenerate PCR primers necessary to tile across an entire viral genome and maximize their success, this process is best performed computationally. Results We have developed a fully automated degenerate PCR primer design system that plays a key role in the J. Craig Venter Institute’s (JCVI high-throughput viral sequencing pipeline. A consensus viral genome, or a set of consensus segment sequences in the case of a segmented virus, is specified using IUPAC ambiguity codes in the consensus template sequence to represent the allelic diversity of the target population. PCR primer pairs are then selected computationally to produce a minimal amplicon set capable of tiling across the full length of the specified target region. As part of the tiling process, primer pairs are computationally screened to meet the criteria for successful PCR with one of two described amplification protocols. The actual sequencing success rates for designed primers for measles virus, mumps virus, human parainfluenza virus 1 and 3, human respiratory syncytial virus A and B and human metapneumovirus are described, where >90% of designed primer pairs were able to consistently successfully amplify >75% of the isolates. Conclusions Augmenting our previously developed and published JCVI Primer Design Pipeline, we achieved similarly high sequencing success rates with only minor software modifications. The recommended methodology for the construction of the consensus

Sequence characterisation of deletion breakpoints in the dystrophin gene by PCR

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Abbs, S.; Sandhu, S.; Bobrow, M. [Guy`s Hospital, London (United Kingdom)

1994-09-01

Partial deletions of the dystrophin gene account for 65% of cases of Duchenne muscular dystrophy. A high proportion of these structural changes are generated by new mutational events, and lie predominantly within two `hotspot` regions, yet the underlying reasons for this are not known. We are characterizing and sequencing the regions surrounding deletion breakpoints in order to: (i) investigate the mechanisms of deletion mutation, and (ii) enable the design of PCR assays to specifically amplify mutant and normal sequences, allowing us to search for the presence of somatic mosaicism in appropriate family members. Using this approach we have been able to demonstrate the presence of somatic mosaicism in a maternal grandfather of a DMD-affected male, deleted for exons 49-50. Three deletions, namely of exons 48-49, 49-50, and 50, have been characterized using a PCR approach that avoids any cloning procedures. Breakpoints were initially localized to within regions of a few kilobases using Southern blot restriction analyses with exon-specific probes and PCR amplification of exonic and intronic loci. Sequencing was performed directly on PCR products: (i) mutant sequences were obtained from long-range or inverse-PCR across the deletion junction fragments, and (ii) normal sequences were obtained from the products of standard PCR, vectorette PCR, or inverse-PCR performed on YACs. Further characterization of intronic sequences will allow us to amplify and sequence across other deletion breakpoints and increase our knowledge of the mechanisms of mutation in the dystophin gene.

Multiplex Amplification Refractory Mutation System PCR (ARMS-PCR) provides sequencing independent typing of canine parvovirus.

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Chander, Vishal; Chakravarti, Soumendu; Gupta, Vikas; Nandi, Sukdeb; Singh, Mithilesh; Badasara, Surendra Kumar; Sharma, Chhavi; Mittal, Mitesh; Dandapat, S; Gupta, V K

2016-12-01

Canine parvovirus-2 antigenic variants (CPV-2a, CPV-2b and CPV-2c) ubiquitously distributed worldwide in canine population causes severe fatal gastroenteritis. Antigenic typing of CPV-2 remains a prime focus of research groups worldwide in understanding the disease epidemiology and virus evolution. The present study was thus envisioned to provide a simple sequencing independent, rapid, robust, specific, user-friendly technique for detecting and typing of presently circulating CPV-2 antigenic variants. ARMS-PCR strategy was employed using specific primers for CPV-2a, CPV-2b and CPV-2c to differentiate these antigenic types. ARMS-PCR was initially optimized with reference positive controls in two steps; where first reaction was used to differentiate CPV-2a from CPV-2b/CPV-2c. The second reaction was carried out with CPV-2c specific primers to confirm the presence of CPV-2c. Initial validation of the ARMS-PCR was carried out with 24 sequenced samples and the results were matched with the sequencing results. ARMS-PCR technique was further used to screen and type 90 suspected clinical samples. Randomly selected 15 suspected clinical samples that were typed with this technique were sequenced. The results of ARMS-PCR and the sequencing matched exactly with each other. The developed technique has a potential to become a sequencing independent method for simultaneous detection and typing of CPV-2 antigenic variants in veterinary disease diagnostic laboratories globally. Copyright © 2016 Elsevier B.V. All rights reserved.

Droplet Digital™ PCR Next-Generation Sequencing Library QC Assay.

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Heredia, Nicholas J

2018-01-01

Digital PCR is a valuable tool to quantify next-generation sequencing (NGS) libraries precisely and accurately. Accurately quantifying NGS libraries enable accurate loading of the libraries on to the sequencer and thus improve sequencing performance by reducing under and overloading error. Accurate quantification also benefits users by enabling uniform loading of indexed/barcoded libraries which in turn greatly improves sequencing uniformity of the indexed/barcoded samples. The advantages gained by employing the Droplet Digital PCR (ddPCR™) library QC assay includes the precise and accurate quantification in addition to size quality assessment, enabling users to QC their sequencing libraries with confidence.

Event-specific qualitative and quantitative PCR detection of the GMO carnation (Dianthus caryophyllus) variety Moonlite based upon the 5'-transgene integration sequence.

Science.gov (United States)

Li, P; Jia, J W; Jiang, L X; Zhu, H; Bai, L; Wang, J B; Tang, X M; Pan, A H

2012-04-27

To ensure the implementation of genetically modified organism (GMO)-labeling regulations, an event-specific detection method was developed based on the junction sequence of an exogenous integrant in the transgenic carnation variety Moonlite. The 5'-transgene integration sequence was isolated by thermal asymmetric interlaced PCR. Based upon the 5'-transgene integration sequence, the event-specific primers and TaqMan probe were designed to amplify the fragments, which spanned the exogenous DNA and carnation genomic DNA. Qualitative and quantitative PCR assays were developed employing the designed primers and probe. The detection limit of the qualitative PCR assay was 0.05% for Moonlite in 100 ng total carnation genomic DNA, corresponding to about 79 copies of the carnation haploid genome; the limit of detection and quantification of the quantitative PCR assay were estimated to be 38 and 190 copies of haploid carnation genomic DNA, respectively. Carnation samples with different contents of genetically modified components were quantified and the bias between the observed and true values of three samples were lower than the acceptance criterion (GMO detection method. These results indicated that these event-specific methods would be useful for the identification and quantification of the GMO carnation Moonlite.

Fast detection of deletion breakpoints using quantitative PCR

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Gulshara Abildinova

2016-01-01

Full Text Available Abstract The routine detection of large and medium copy number variants (CNVs is well established. Hemizygotic deletions or duplications in the large Duchenne muscular dystrophy DMD gene responsible for Duchenne and Becker muscular dystrophies are routinely identified using multiple ligation probe amplification and array-based comparative genomic hybridization. These methods only map deleted or duplicated exons, without providing the exact location of breakpoints. Commonly used methods for the detection of CNV breakpoints include long-range PCR and primer walking, their success being limited by the deletion size, GC content and presence of DNA repeats. Here, we present a strategy for detecting the breakpoints of medium and large CNVs regardless of their size. The hemizygous deletion of exons 45-50 in the DMD gene and the large autosomal heterozygous PARK2 deletion were used to demonstrate the workflow that relies on real-time quantitative PCR to narrow down the deletion region and Sanger sequencing for breakpoint confirmation. The strategy is fast, reliable and cost-efficient, making it amenable to widespread use in genetic laboratories.

Development of Prevotella intermedia-specific PCR primers based on the nucleotide sequences of a DNA probe Pig27.

Science.gov (United States)

Kim, Min Jung; Hwang, Kyung Hwan; Lee, Young-Seok; Park, Jae-Yoon; Kook, Joong-Ki

2011-03-01

The aim of this study was to develop Prevotella intermedia-specific PCR primers based on the P. intermedia-specific DNA probe. The P. intermedia-specific DNA probe was screened by inverted dot blot hybridization and confirmed by Southern blot hybridization. The nucleotide sequences of the species-specific DNA probes were determined using a chain termination method. Southern blot analysis showed that the DNA probe, Pig27, detected only the genomic DNA of P. intermedia strains. PCR showed that the PCR primers, Pin-F1/Pin-R1, had species-specificity for P. intermedia. The detection limits of the PCR primer sets were 0.4pg of the purified genomic DNA of P. intermedia ATCC 49046. These results suggest that the PCR primers, Pin-F1/Pin-R1, could be useful in the detection of P. intermedia as well as in the development of a PCR kit in epidemiological studies related to periodontal diseases. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

A Comparison of Molecular Typing Methods Applied to Enterobacter cloacae complex: hsp60 Sequencing, Rep-PCR, and MLST

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Roberto Viau

2017-02-01

Full Text Available Molecular typing using repetitive sequenced-based PCR (rep-PCR and hsp60 sequencing were applied to a collection of diverse Enterobacter cloacae complex isolates. To determine the most practical method for reference laboratories, we analyzed 71 E. cloacae complex isolates from sporadic and outbreak occurrences originating from 4 geographic areas. While rep-PCR was more discriminating, hsp60 sequencing provided a broader and a more objective geographical tracking method similar to multilocus sequence typing (MLST. In addition, we suggest that MLST may have higher discriminative power compared to hsp60 sequencing, although rep-PCR remains the most discriminative method for local outbreak investigations. In addition, rep-PCR can be an effective and inexpensive method for local outbreak investigation.

Polyadenylated Sequencing Primers Enable Complete Readability of PCR Amplicons Analyzed by Dideoxynucleotide Sequencing

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Martin Beránek

2012-01-01

Full Text Available Dideoxynucleotide DNA sequencing is one of the principal procedures in molecular biology. Loss of an initial part of nucleotides behind the 3' end of the sequencing primer limits the readability of sequenced amplicons. We present a method which extends the readability by using sequencing primers modified by polyadenylated tails attached to their 5' ends. Performing a polymerase chain reaction, we amplified eight amplicons of six human genes (AMELX, APOE, HFE, MBL2, SERPINA1 and TGFB1 ranging from 106 bp to 680 bp. Polyadenylation of the sequencing primers minimized the loss of bases in all amplicons. Complete sequences of shorter products (AMELX 106 bp, SERPINA1 121 bp, HFE 208 bp, APOE 244 bp, MBL2 317 bp were obtained. In addition, in the case of TGFB1 products (366 bp, 432 bp, and 680 bp, respectively, the lengths of sequencing readings were significantly longer if adenylated primers were used. Thus, single strand dideoxynucleotide sequencing with adenylated primers enables complete or near complete readability of short PCR amplicons.

Long-PCR based next generation sequencing of the whole mitochondrial genome of the peacock skate Pavoraja nitida (Elasmobranchii: Arhynchobatidae).

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Yang, Lei; Naylor, Gavin J P

2016-01-01

We determined the complete mitochondrial genome sequence (16,760 bp) of the peacock skate Pavoraja nitida using a long-PCR based next generation sequencing method. It has 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 control region in the typical vertebrate arrangement. Primers, protocols, and procedures used to obtain this mitogenome are provided. We anticipate that this approach will facilitate rapid collection of mitogenome sequences for studies on phylogenetic relationships, population genetics, and conservation of cartilaginous fishes.

Generic Amplicon Deep Sequencing to Determine Ilarvirus Species Diversity in Australian Prunus.

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Kinoti, Wycliff M; Constable, Fiona E; Nancarrow, Narelle; Plummer, Kim M; Rodoni, Brendan

2017-01-01

The distribution of Ilarvirus species populations amongst 61 Australian Prunus trees was determined by next generation sequencing (NGS) of amplicons generated using a genus-based generic RT-PCR targeting a conserved region of the Ilarvirus RNA2 component that encodes the RNA dependent RNA polymerase (RdRp) gene. Presence of Ilarvirus sequences in each positive sample was further validated by Sanger sequencing of cloned amplicons of regions of each of RNA1, RNA2 and/or RNA3 that were generated by species specific PCRs and by metagenomic NGS. Prunus necrotic ringspot virus (PNRSV) was the most frequently detected Ilarvirus , occurring in 48 of the 61 Ilarvirus -positive trees and Prune dwarf virus (PDV) and Apple mosaic virus (ApMV) were detected in three trees and one tree, respectively. American plum line pattern virus (APLPV) was detected in three trees and represents the first report of APLPV detection in Australia. Two novel and distinct groups of Ilarvirus -like RNA2 amplicon sequences were also identified in several trees by the generic amplicon NGS approach. The high read depth from the amplicon NGS of the generic PCR products allowed the detection of distinct RNA2 RdRp sequence variant populations of PNRSV, PDV, ApMV, APLPV and the two novel Ilarvirus -like sequences. Mixed infections of ilarviruses were also detected in seven Prunus trees. Sanger sequencing of specific RNA1, RNA2, and/or RNA3 genome segments of each virus and total nucleic acid metagenomics NGS confirmed the presence of PNRSV, PDV, ApMV and APLPV detected by RNA2 generic amplicon NGS. However, the two novel groups of Ilarvirus -like RNA2 amplicon sequences detected by the generic amplicon NGS could not be associated to the presence of sequence from RNA1 or RNA3 genome segments or full Ilarvirus genomes, and their origin is unclear. This work highlights the sensitivity of genus-specific amplicon NGS in detection of virus sequences and their distinct populations in multiple samples, and the

Generic Amplicon Deep Sequencing to Determine Ilarvirus Species Diversity in Australian Prunus

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Wycliff M. Kinoti

2017-06-01

Full Text Available The distribution of Ilarvirus species populations amongst 61 Australian Prunus trees was determined by next generation sequencing (NGS of amplicons generated using a genus-based generic RT-PCR targeting a conserved region of the Ilarvirus RNA2 component that encodes the RNA dependent RNA polymerase (RdRp gene. Presence of Ilarvirus sequences in each positive sample was further validated by Sanger sequencing of cloned amplicons of regions of each of RNA1, RNA2 and/or RNA3 that were generated by species specific PCRs and by metagenomic NGS. Prunus necrotic ringspot virus (PNRSV was the most frequently detected Ilarvirus, occurring in 48 of the 61 Ilarvirus-positive trees and Prune dwarf virus (PDV and Apple mosaic virus (ApMV were detected in three trees and one tree, respectively. American plum line pattern virus (APLPV was detected in three trees and represents the first report of APLPV detection in Australia. Two novel and distinct groups of Ilarvirus-like RNA2 amplicon sequences were also identified in several trees by the generic amplicon NGS approach. The high read depth from the amplicon NGS of the generic PCR products allowed the detection of distinct RNA2 RdRp sequence variant populations of PNRSV, PDV, ApMV, APLPV and the two novel Ilarvirus-like sequences. Mixed infections of ilarviruses were also detected in seven Prunus trees. Sanger sequencing of specific RNA1, RNA2, and/or RNA3 genome segments of each virus and total nucleic acid metagenomics NGS confirmed the presence of PNRSV, PDV, ApMV and APLPV detected by RNA2 generic amplicon NGS. However, the two novel groups of Ilarvirus-like RNA2 amplicon sequences detected by the generic amplicon NGS could not be associated to the presence of sequence from RNA1 or RNA3 genome segments or full Ilarvirus genomes, and their origin is unclear. This work highlights the sensitivity of genus-specific amplicon NGS in detection of virus sequences and their distinct populations in multiple samples

Single base pair mutation analysis by PNA directed PCR clamping

DEFF Research Database (Denmark)

Ørum, H.; Nielsen, P.E.; Egholm, M.

1993-01-01

A novel method that allows direct analysis of single base mutation by the polymerase chain reaction (PCR) is described. The method utilizes the finding that PNAs (peptide nucleic acids) recognize and bind to their complementary nucleic acid sequences with higher thermal stability and specificity...... allows selective amplification/suppression of target sequences that differ by only one base pair. Finally we show that PNAs can be designed in such a way that blockage can be accomplished when the PNA target sequence is located between the PCR primers....

Discovery of Escherichia coli CRISPR sequences in an undergraduate laboratory.

Science.gov (United States)

Militello, Kevin T; Lazatin, Justine C

2017-05-01

Clustered regularly interspaced short palindromic repeats (CRISPRs) represent a novel type of adaptive immune system found in eubacteria and archaebacteria. CRISPRs have recently generated a lot of attention due to their unique ability to catalog foreign nucleic acids, their ability to destroy foreign nucleic acids in a mechanism that shares some similarity to RNA interference, and the ability to utilize reconstituted CRISPR systems for genome editing in numerous organisms. In order to introduce CRISPR biology into an undergraduate upper-level laboratory, a five-week set of exercises was designed to allow students to examine the CRISPR status of uncharacterized Escherichia coli strains and to allow the discovery of new repeats and spacers. Students started the project by isolating genomic DNA from E. coli and amplifying the iap CRISPR locus using the polymerase chain reaction (PCR). The PCR products were analyzed by Sanger DNA sequencing, and the sequences were examined for the presence of CRISPR repeat sequences. The regions between the repeats, the spacers, were extracted and analyzed with BLASTN searches. Overall, CRISPR loci were sequenced from several previously uncharacterized E. coli strains and one E. coli K-12 strain. Sanger DNA sequencing resulted in the discovery of 36 spacer sequences and their corresponding surrounding repeat sequences. Five of the spacers were homologous to foreign (non-E. coli) DNA. Assessment of the laboratory indicates that improvements were made in the ability of students to answer questions relating to the structure and function of CRISPRs. Future directions of the laboratory are presented and discussed. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(3):262-269, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

De Novo Transcriptome Sequencing in Passiflora edulis Sims to Identify Genes and Signaling Pathways Involved in Cold Tolerance

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Sian Liu

2017-11-01

Full Text Available The passion fruit (Passiflora edulis Sims, also known as the purple granadilla, is widely cultivated as the new darling of the fruit market throughout southern China. This exotic and perennial climber is adapted to warm and humid climates, and thus is generally intolerant of cold. There is limited information about gene regulation and signaling pathways related to the cold stress response in this species. In this study, two transcriptome libraries (KEDU_AP vs. GX_AP were constructed from the aerial parts of cold-tolerant and cold-susceptible varieties of P. edulis, respectively. Overall, 126,284,018 clean reads were obtained, and 86,880 unigenes with a mean size of 1449 bp were assembled. Of these, there were 64,067 (73.74% unigenes with significant similarity to publicly available plant protein sequences. Expression profiles were generated, and 3045 genes were found to be significantly differentially expressed between the KEDU_AP and GX_AP libraries, including 1075 (35.3% up-regulated and 1970 (64.7% down-regulated. These included 36 genes in enriched pathways of plant hormone signal transduction, and 56 genes encoding putative transcription factors. Six genes involved in the ICE1–CBF–COR pathway were induced in the cold-tolerant variety, and their expression levels were further verified using quantitative real-time PCR. This report is the first to identify genes and signaling pathways involved in cold tolerance using high-throughput transcriptome sequencing in P. edulis. These findings may provide useful insights into the molecular mechanisms regulating cold tolerance and genetic breeding in Passiflora spp.

Automated purification of Borrelia burgdorferi s.l. PCR products with KingFisherTM magnetic particle processor prior to genome sequencing

International Nuclear Information System (INIS)

Maekinen, Johanna; Marttila, Harri; Viljanen, Matti K.

2001-01-01

Borrelia burgdorferi sensu lato genospecies were differentiated by PCR-based sequencing of the borrelial flagellin gene. To evaluate the usefulness of KingFisher TM magnetic particle processor in PCR product purification, borrelia PCR products were purified with KingFisher TM magnetic particle processor prior to cycle sequencing and the quality of the sequence data received was analyzed. KingFisher was found to offer a rapid and reliable alternative for borrelial PCR product purification

Development of a Species-specific PCR Assay for Three Xanthomonas Species, Causing Bulb and Flower Diseases, Based on Their Genome Sequences

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Chang-Gi Back

2015-09-01

Full Text Available In this study, we developed a species-specific PCR assay for rapid and accurate detection of three Xanthomonas species, X. axonopodis pv. poinsettiicola (XAP, X. hyacinthi (XH and X. campestris pv. zantedeschiae (XCZ, based on their draft genome sequences. XAP, XH and XCZ genomes consist of single chromosomes that contain 5,221, 4,395 and 7,986 protein coding genes, respectively. Species-specific primers were designed from variable regions of the draft genome sequence data and assessed by a PCR-based detection method. These primers were also tested for specificity against 17 allied Xanthomonas species as well as against the host DNA and the microbial community of the host surface. Three primer sets were found to be very specific and no amplification product was obtained with the host DNA and the microbial community of the host surface. In addition, a detection limit of 1 pg/μl per PCR reaction was detected when these primer sets were used to amplify corresponding bacterial DNAs. Therefore, these primer sets and the developed species-specific PCR assay represent a valuable, sensitive, and rapid diagnostic tool that can be used to detect three specific pathogens at early stages of infection and may help control diseases.

Identification and molecular epidemiology of dermatophyte isolates by repetitive-sequence-PCR-based DNA fingerprinting using the DiversiLab system in Turkey.

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Koc, A Nedret; Atalay, Mustafa A; Inci, Melek; Sariguzel, Fatma M; Sav, Hafize

2017-05-01

Dermatophyte species, isolation and identification in clinical samples are still difficult and take a long time. The identification and molecular epidemiology of dermatophytes commonly isolated in a clinical laboratory in Turkey by repetitive sequence-based PCR (rep-PCR) were assessed by comparing the results with those of reference identification. A total of 44 dermatophytes isolated from various clinical specimens of 20 patients with superficial mycoses in Kayseri and 24 patients in Hatay were studied. The identification of dermatophyte isolates was based on the reference identification and rep-PCR using the DiversiLab System (BioMerieux). The genotyping of dermatophyte isolates from different patients was determined by rep-PCR. In the identification of dermatophyte isolates, agreement between rep-PCR and conventional methods was 87.8 % ( 36 of 41). The dermatophyte strains belonged to four clones (A -D) which were determined by the use of rep-PCR. The dermatophyte strains in Clone B, D showed identical patterns with respect to the region. In conclusion, rep-PCR appears to be useful for evaluation of the identification and clonal relationships between Trichophyton rubrum species complex and Trichophyton mentagrophytes species complex isolates. The similarity and diversity of these isolates may be assessed according to different regions by rep-PCR. © 2017 Blackwell Verlag GmbH.

RUCS: Rapid identification of PCR primers for unique core sequences

DEFF Research Database (Denmark)

Thomsen, Martin Christen Frølund; Hasman, Henrik; Westh, Henrik

2017-01-01

Designing PCR primers to target a specific selection of whole genome sequenced strains can be a long, arduous, and sometimes impractical task. Such tasks would benefit greatly from an automated tool to both identify unique targets, and to validate the vast number of potential primer pairs...... for the targets in silico . Here we present RUCS, a program that will find PCR primer pairs and probes for the unique core sequences of a positive genome dataset complement to a negative genome dataset. The resulting primer pairs and probes are in addition to simple selection also validated through a complex...... in silico PCR simulation. We compared our method, which identifies the unique core sequences, against an existing tool called ssGeneFinder, and found that our method was 6.5-20 times more sensitive. We used RUCS to design primer pairs that would target a set of genomes known to contain the mcr-1 colistin...

The use of coded PCR primers enables high-throughput sequencing of multiple homolog amplification products by 454 parallel sequencing

DEFF Research Database (Denmark)

Binladen, Jonas; Gilbert, M Thomas P; Bollback, Jonathan P

2007-01-01

BACKGROUND: The invention of the Genome Sequence 20 DNA Sequencing System (454 parallel sequencing platform) has enabled the rapid and high-volume production of sequence data. Until now, however, individual emulsion PCR (emPCR) reactions and subsequent sequencing runs have been unable to combine...... primers that is dependent on the 5' nucleotide of the tag. In particular, primers 5' labelled with a cytosine are heavily overrepresented among the final sequences, while those 5' labelled with a thymine are strongly underrepresented. A weaker bias also exists with regards to the distribution...

Identification of genomic insertion and flanking sequence of G2-EPSPS and GAT transgenes in soybean using whole genome sequencing method

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Bingfu Guo

2016-07-01

Full Text Available Molecular characterization of sequences flanking exogenous fragment insertions is essential for safety assessment and labeling of genetically modified organisms (GMO. In this study, the T-DNA insertion sites and flanking sequences were identified in two newly developed transgenic glyphosate-tolerant soybeans GE-J16 and ZH10-6 based on whole genome sequencing (WGS method. About 21 Gb sequence data (~21× coverage for each line was generated on Illumina HiSeq 2500 platform. The junction reads mapped to boundary of T-DNA and flanking sequences in these two events were identified by comparing all sequencing reads with soybean reference genome and sequence of transgenic vector. The putative insertion loci and flanking sequences were further confirmed by PCR amplification, Sanger sequencing, and co-segregation analysis. All these analyses supported that exogenous T-DNA fragments were integrated in positions of Chr19: 50543767-50543792 and Chr17: 7980527-7980541 in these two transgenic lines. Identification of the genomic insertion site of the G2-EPSPS and GAT transgenes will facilitate the use of their glyphosate-tolerant traits in soybean breeding program. These results also demonstrated that WGS is a cost-effective and rapid method of identifying sites of T-DNA insertions and flanking sequences in soybean.

Towards clinical molecular diagnosis of inherited cardiac conditions: a comparison of bench-top genome DNA sequencers.

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Xinzhong Li

Full Text Available Molecular genetic testing is recommended for diagnosis of inherited cardiac disease, to guide prognosis and treatment, but access is often limited by cost and availability. Recently introduced high-throughput bench-top DNA sequencing platforms have the potential to overcome these limitations.We evaluated two next-generation sequencing (NGS platforms for molecular diagnostics. The protein-coding regions of six genes associated with inherited arrhythmia syndromes were amplified from 15 human samples using parallelised multiplex PCR (Access Array, Fluidigm, and sequenced on the MiSeq (Illumina and Ion Torrent PGM (Life Technologies. Overall, 97.9% of the target was sequenced adequately for variant calling on the MiSeq, and 96.8% on the Ion Torrent PGM. Regions missed tended to be of high GC-content, and most were problematic for both platforms. Variant calling was assessed using 107 variants detected using Sanger sequencing: within adequately sequenced regions, variant calling on both platforms was highly accurate (Sensitivity: MiSeq 100%, PGM 99.1%. Positive predictive value: MiSeq 95.9%, PGM 95.5%. At the time of the study the Ion Torrent PGM had a lower capital cost and individual runs were cheaper and faster. The MiSeq had a higher capacity (requiring fewer runs, with reduced hands-on time and simpler laboratory workflows. Both provide significant cost and time savings over conventional methods, even allowing for adjunct Sanger sequencing to validate findings and sequence exons missed by NGS.MiSeq and Ion Torrent PGM both provide accurate variant detection as part of a PCR-based molecular diagnostic workflow, and provide alternative platforms for molecular diagnosis of inherited cardiac conditions. Though there were performance differences at this throughput, platforms differed primarily in terms of cost, scalability, protocol stability and ease of use. Compared with current molecular genetic diagnostic tests for inherited cardiac arrhythmias

Conserved PCR primer set designing for closely-related species to complete mitochondrial genome sequencing using a sliding window-based PSO algorithm.

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Cheng-Hong Yang

Full Text Available BACKGROUND: Complete mitochondrial (mt genome sequencing is becoming increasingly common for phylogenetic reconstruction and as a model for genome evolution. For long template sequencing, i.e., like the entire mtDNA, it is essential to design primers for Polymerase Chain Reaction (PCR amplicons which are partly overlapping each other. The presented chromosome walking strategy provides the overlapping design to solve the problem for unreliable sequencing data at the 5' end and provides the effective sequencing. However, current algorithms and tools are mostly focused on the primer design for a local region in the genomic sequence. Accordingly, it is still challenging to provide the primer sets for the entire mtDNA. METHODOLOGY/PRINCIPAL FINDINGS: The purpose of this study is to develop an integrated primer design algorithm for entire mt genome in general, and for the common primer sets for closely-related species in particular. We introduce ClustalW to generate the multiple sequence alignment needed to find the conserved sequences in closely-related species. These conserved sequences are suitable for designing the common primers for the entire mtDNA. Using a heuristic algorithm particle swarm optimization (PSO, all the designed primers were computationally validated to fit the common primer design constraints, such as the melting temperature, primer length and GC content, PCR product length, secondary structure, specificity, and terminal limitation. The overlap requirement for PCR amplicons in the entire mtDNA is satisfied by defining the overlapping region with the sliding window technology. Finally, primer sets were designed within the overlapping region. The primer sets for the entire mtDNA sequences were successfully demonstrated in the example of two closely-related fish species. The pseudo code for the primer design algorithm is provided. CONCLUSIONS/SIGNIFICANCE: In conclusion, it can be said that our proposed sliding window-based PSO

DNA Fingerprinting of Lactobacillus crispatus Strain CTV-05 by Repetitive Element Sequence-Based PCR Analysis in a Pilot Study of Vaginal Colonization

OpenAIRE

Antonio, May A. D.; Hillier, Sharon L.

2003-01-01

Lactobacillus crispatus is one of the predominant hydrogen peroxide (H2O2)-producing species found in the vagina and is under development as a probiotic for the treatment of bacterial vaginosis. In this study, we assessed whether DNA fingerprinting by repetitive element sequence-based PCR (rep-PCR) can be used to distinguish the capsule strain of L. crispatus (CTV-05) from other endogenous strains as well as other species of vaginal lactobacilli. Vaginal and rectal lactobacilli were identifie...

Whole Genome Sequencing of Enterovirus species C Isolates by High-throughput Sequencing: Development of Generic Primers

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Maël Bessaud

2016-08-01

Full Text Available Enteroviruses are among the most common viruses infecting humans and can cause diverse clinical syndromes ranging from minor febrile illness to severe and potentially fatal diseases. Enterovirus species C (EV-C consists of more than 20 types, among which the 3 serotypes of polioviruses, the etiological agents of poliomyelitis, are included. Biodiversity and evolution of EV-C genomes are shaped by frequent recombination events. Therefore, identification and characterization of circulating EV-C strains require the sequencing of different genomic regions.A simple method was developed to sequence quickly the entire genome of EV-C isolates. Four overlapping fragments were produced separately by RT-PCR performed with generic primers. The four amplicons were then pooled and purified prior to be sequenced by high-throughput technique.The method was assessed on a panel of EV-Cs belonging to a wide-range of types. It can be used to determine full-length genome sequences through de novo assembly of thousands of reads. It was also able to discriminate reads from closely related viruses in mixtures.By decreasing the workload compared to classical Sanger-based techniques, this method will serve as a precious tool for sequencing large panels of EV-Cs isolated in cell cultures during environmental surveillance or from patients, including vaccine-derived polioviruses.

Efficacy of Pulsed-Field Gel Electrophoresis and Repetitive Element Sequence-Based PCR in Typing of Salmonella Isolates from Assam, India.

Science.gov (United States)

Gogoi, Purnima; Borah, Probodh; Hussain, Iftikar; Das, Leena; Hazarika, Girin; Tamuly, Shantanu; Barkalita, Luit Moni

2018-05-01

A total of 12 Salmonella isolates belonging to different serovars, viz , Salmonella enterica serovar Enteritidis ( n = 4), Salmonella enterica serovar Weltevreden ( n = 4), Salmonella enterica serovar Newport ( n = 1), Salmonella enterica serovar Litchifield ( n = 1), and untypeable strains ( n = 2) were isolated from 332 diarrheic fecal samples collected from animals, birds, and humans. Of the two molecular typing methods applied, viz , repetitive element sequence-based PCR (REP-PCR) and pulsed-field gel electrophoresis (PFGE), PFGE could clearly differentiate the strains belonging to different serovars as well as differentiate between strains of the same serovar with respect to their source of isolation, whereas REP-PCR could not differentiate between strains of the same serovar. Thus, it can be suggested that PFGE is more useful and appropriate for molecular typing of Salmonella isolates during epidemiological investigations than REP-PCR. Copyright © 2018 American Society for Microbiology.

Development of a pan-Simbu real-time reverse transcriptase PCR for the detection of Simbu serogroup viruses and comparison with SBV diagnostic PCR systems.

Science.gov (United States)

Fischer, Melina; Schirrmeier, Horst; Wernike, Kerstin; Wegelt, Anne; Beer, Martin; Hoffmann, Bernd

2013-11-05

Schmallenberg virus (SBV), a novel orthobunyavirus of the Simbu serogroup, was first identified in October 2011 in dairy cattle in Germany, where it caused fever, diarrhea and a drop in milk yield. Since then, SBV additionally has been detected in adult sheep and goats. Although symptoms of acute infection were not observed, infection during a vulnerable phase of pregnancy caused congenital malformations and stillbirths. In view of the current situation and the possible emergence of further Simbu serogroup members, a pan-Simbu real-time reverse transcriptase (RT) PCR system for the reliable detection of Simbu serogroup viruses should be developed. In this study a pan-Simbu real-time RT-PCR system was established and compared to several SBV real-time RT-PCR assays. All PCR-systems were tested using a panel of different Simbu serogroup viruses as well as several field samples from diseased cattle, sheep and goats originating from all over Germany. Several pan-Simbu real-time RT-PCR products were sequenced via Sanger sequencing. Furthermore, in silico analyses were performed to investigate suitability for the detection of further orthobunyaviruses. All tested members of the Simbu serogroup (n = 14) as well as most of the field samples were successfully detected by the pan-Simbu real-time RT-PCR system. The comparison of this intercalating dye assay with different TaqMan probe-based assays developed for SBV diagnostics confirmed the functionality of the pan-Simbu assay for screening purposes. However, the SBV-TaqMan-assay SBV-S3 delivered the highest analytical sensitivity of less than ten copies per reaction for duplex systems including an internal control. In addition, for confirmation of SBV-genome detection the highly specific SBV-M1 assay was established. The pan-Simbu real-time RT-PCR system was able to detect all tested members of the Simbu serogroup, most of the SBV field samples as well as three tested Bunyamwera serogroup viruses with a suitable

A comparison of EGFR mutation testing methods in lung carcinoma: direct sequencing, real-time PCR and immunohistochemistry.

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Bárbara Angulo

Full Text Available The objective of this study is to compare two EGFR testing methodologies (a commercial real-time PCR kit and a specific EGFR mutant immunohistochemistry, with direct sequencing and to investigate the limit of detection (LOD of both PCR-based methods. We identified EGFR mutations in 21 (16% of the 136 tumours analyzed by direct sequencing. Interestingly, the Therascreen EGFR Mutation Test kit was able to characterize as wild-type one tumour that could not be analyzed by direct sequencing of the PCR product. We then compared the LOD of the kit and that of direct sequencing using the available mutant tumours. The kit was able to detect the presence of a mutation in a 1% dilution of the total DNA in nine of the 18 tumours (50%, which tested positive with the real-time quantitative PCR method. In all cases, EGFR mutation was identified at a dilution of 5%. Where the mutant DNA represented 30% of the total DNA, sequencing was able to detect mutations in 12 out of 19 cases (63%. Additional experiments with genetically defined standards (EGFR ΔE746-A750/+ and EGFR L858R/+ yielded similar results. Immunohistochemistry (IHC staining with exon 19-specific antibody was seen in eight out of nine cases with E746-A750del detected by direct sequencing. Neither of the two tumours with complex deletions were positive. Of the five L858R-mutated tumours detected by the PCR methods, only two were positive for the exon 21-specific antibody. The specificity was 100% for both antibodies. The LOD of the real-time PCR method was lower than that of direct sequencing. The mutation specific IHC produced excellent specificity.

Next-generation sequencing can reveal in vitro-generated PCR crossover products: some artifactual sequences correspond to HLA alleles in the IMGT/HLA database.

Science.gov (United States)

Holcomb, C L; Rastrou, M; Williams, T C; Goodridge, D; Lazaro, A M; Tilanus, M; Erlich, H A

2014-01-01

The high-resolution human leukocyte antigen (HLA) genotyping assay that we developed using 454 sequencing and Conexio software uses generic polymerase chain reaction (PCR) primers for DRB exon 2. Occasionally, we observed low abundance DRB amplicon sequences that resulted from in vitro PCR 'crossing over' between DRB1 and DRB3/4/5. These hybrid sequences, revealed by the clonal sequencing property of the 454 system, were generally observed at a read depth of 5%-10% of the true alleles. They usually contained at least one mismatch with the IMGT/HLA database, and consequently, were easily recognizable and did not cause a problem for HLA genotyping. Sometimes, however, these artifactual sequences matched a rare allele and the automatic genotype assignment was incorrect. These observations raised two issues: (1) could PCR conditions be modified to reduce such artifacts? and (2) could some of the rare alleles listed in the IMGT/HLA database be artifacts rather than true alleles? Because PCR crossing over occurs during late cycles of PCR, we compared DRB genotypes resulting from 28 and (our standard) 35 cycles of PCR. For all 21 cell line DNAs amplified for 35 cycles, crossover products were detected. In 33% of the cases, these hybrid sequences corresponded to named alleles. With amplification for only 28 cycles, these artifactual sequences were not detectable. To investigate whether some rare alleles in the IMGT/HLA database might be due to PCR artifacts, we analyzed four samples obtained from the investigators who submitted the sequences. In three cases, the sequences were generated from true alleles. In one case, our 454 sequencing revealed an error in the previously submitted sequence. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of ELISA, nested PCR and sequencing and a novel qPCR for detection of Giardia isolates from Jordan.

Science.gov (United States)

Hijjawi, Nawal; Yang, Rongchang; Hatmal, Ma'mon; Yassin, Yasmeen; Mharib, Taghrid; Mukbel, Rami; Mahmoud, Sameer Alhaj; Al-Shudifat, Abdel-Ellah; Ryan, Una

2018-02-01

Little is known about the prevalence of Giardia duodenalis in human patients in Jordan and all previous studies have used direct microscopy, which lacks sensitivity. The present study developed a novel quantitative PCR (qPCR) assay at the β-giardin (bg) locus and evaluated its use as a frontline test for the diagnosis of giardiasis in comparison with a commercially available ELISA using nested PCR and sequencing of the glutamate dehydrogenase (gdh) locus (gdh nPCR) as the gold standard. A total of 96 human faecal samples were collected from 96 patients suffering from diarrhoea from 5 regions of Jordan and were screened using the ELISA and qPCR. The analytical specificity of the bg qPCR assay revealed no cross-reactions with other genera and detected all the Giardia isolates tested. Analytical sensitivity was 1 Giardia cyst per μl of DNA extract. The overall prevalence of Giardia was 64.6%. The clinical sensitivity and specificity of the bg qPCR was 89.9% and 82.9% respectively compared to 76.5 and 68.0% for the ELISA. This study is the first to compare three different methods (ELISA, bg qPCR, nested PCR and sequencing at the gdh locus) to diagnose Jordanian patients suffering from giardiasis and to analyze their demographic data. Copyright © 2018 Elsevier Inc. All rights reserved.

Ribosomal PCR and DNA sequencing for detection and identification of bacteria

DEFF Research Database (Denmark)

Jensen, Kristine Helander; Dargis, Rimtas; Christensen, Jens Jørgen

2014-01-01

-haemolytic streptococci, especially within the mitis group. The data show that ribosomal PCR with subsequent DNA sequencing of the PCR product is a most valuable supplement to culture for identifying bacterial agents of both acute and prolonged infections. However, some bacteria, including non-haemolytic streptococci...

Why barcode? High-throughput multiplex sequencing of mitochondrial genomes for molecular systematics.

Science.gov (United States)

Timmermans, M J T N; Dodsworth, S; Culverwell, C L; Bocak, L; Ahrens, D; Littlewood, D T J; Pons, J; Vogler, A P

2010-11-01

Mitochondrial genome sequences are important markers for phylogenetics but taxon sampling remains sporadic because of the great effort and cost required to acquire full-length sequences. Here, we demonstrate a simple, cost-effective way to sequence the full complement of protein coding mitochondrial genes from pooled samples using the 454/Roche platform. Multiplexing was achieved without the need for expensive indexing tags ('barcodes'). The method was trialled with a set of long-range polymerase chain reaction (PCR) fragments from 30 species of Coleoptera (beetles) sequenced in a 1/16th sector of a sequencing plate. Long contigs were produced from the pooled sequences with sequencing depths ranging from ∼10 to 100× per contig. Species identity of individual contigs was established via three 'bait' sequences matching disparate parts of the mitochondrial genome obtained by conventional PCR and Sanger sequencing. This proved that assembly of contigs from the sequencing pool was correct. Our study produced sequences for 21 nearly complete and seven partial sets of protein coding mitochondrial genes. Combined with existing sequences for 25 taxa, an improved estimate of basal relationships in Coleoptera was obtained. The procedure could be employed routinely for mitochondrial genome sequencing at the species level, to provide improved species 'barcodes' that currently use the cox1 gene only.

Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR

Energy Technology Data Exchange (ETDEWEB)

D`Souza, T.M.; Boominathan, K.; Reddy, C.A. [Michigan State Univ., East Lansing, MI (United States)

1996-10-01

Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequences of each of the PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum, Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. 36 refs., 6 figs., 2 tabs.

A Ribeiroia spp. (Class: Trematoda) - Specific PCR-based diagnostic

Science.gov (United States)

Reinitz, David M.; Yoshino, T.P.; Cole, Rebecca A.

2007-01-01

Increased reporting of amphibian malformations in North America has been noted with concern in light of reports that amphibian numbers and species are declining worldwide. Ribeiroia ondatrae has been shown to cause a variety of types of malformations in amphibians. However, little is known about the prevalence of R. ondatrae in North America. To aid in conducting field studies of Ribeiroia spp., we have developed a polymerase chain reaction (PCR)-based diagnostic. Herein, we describe the development of an accurate, rapid, simple, and cost-effective diagnostic for detection of Ribeiroia spp. infection in snails (Planorbella trivolvis). Candidate oligonucleotide primers for PCR were designed via DNA sequence analyses of multiple ribosomal internal transcribed spacer-2 regions from Ribeiroia spp. and Echinostoma spp. Comparison of consensus sequences determined from both genera identified areas of sequence potentially unique to Ribeiroia spp. The PCR reliably produced a diagnostic 290-base pair (bp) product in the presence of a wide concentration range of snail or frog DNA. Sensitivity was examined with DNA extracted from single R. ondatrae cercaria. The single-tube PCR could routinely detect less than 1 cercariae equivalent, because DNA isolated from a single cercaria could be diluted at least 1:50 and still yield a positive result via gel electrophoresis. An even more sensitive nested PCR also was developed that routinely detected 100 fg of the 290-bp fragment. The assay did not detect furcocercous cercariae of certain Schistosomatidae, Echinostoma sp., or Sphaeridiotrema globulus nor adults of Clinostomum sp. or Cyathocotyle bushiensis. Field testing of 137 P. trivolvis identified 3 positives with no overt environmental cross-reactivity, and results concurred with microscopic examinations in all cases. ?? American Society of Parasitologists 2007.

Development and Evaluation of a PCR and Mass Spectroscopy-based (PCR-MS) Method for Quantitative, Type-specific Detection of Human Papillomavirus

Science.gov (United States)

Patel, Divya A.; Shih, Yang-Jen; Newton, Duane W.; Michael, Claire W.; Oeth, Paul A.; Kane, Michael D.; Opipari, Anthony W.; Ruffin, Mack T.; Kalikin, Linda M.; Kurnit, David M.

2010-01-01

Knowledge of the central role of high-risk human papillomavirus (HPV) in cervical carcinogenesis, coupled with an emerging need to monitor the efficacy of newly introduced HPV vaccines, warrant development and evaluation of type-specific, quantitative HPV detection methods. In the present study, a prototype PCR and mass spectroscopy (PCR-MS)-based method to detect and quantitate 13 high-risk HPV types is compared to the Hybrid Capture 2 High Risk HPV DNA test (HC2; Digene Corp., Gaithersburg, MD) in 199 cervical scraping samples and to DNA sequencing in 77 cervical tumor samples. High-risk HPV types were detected in 76/77 (98.7%) cervical tumor samples by PCR-MS. Degenerate and type-specific sequencing confirmed the types detected by PCR-MS. In 199 cervical scraping samples, all 13 HPV types were detected by PCR-MS. Eighteen (14.5%) of 124 cervical scraping samples that were positive for high-risk HPV by HC2 were negative by PCR-MS. In all these cases, degenerate DNA sequencing failed to detect any of the 13 high-risk HPV types. Nearly half (46.7%) of the 75 cervical scraping samples that were negative for high-risk HPV by the HC2 assay were positive by PCR-MS. Type-specific sequencing in a subset of these samples confirmed the HPV type detected by PCR-MS. Quantitative PCR-MS results demonstrated that 11/75 (14.7%) samples contained as much HPV copies/cell as HC2-positive samples. These findings suggest that this prototype PCR-MS assay performs at least as well as HC2 for HPV detection, while offering the additional, unique advantages of type-specific identification and quantitation. Further validation work is underway to define clinically meaningful HPV detection thresholds and to evaluate the potential clinical application of future generations of the PCR-MS assay. PMID:19410602

Development and evaluation of a PCR and mass spectroscopy (PCR-MS)-based method for quantitative, type-specific detection of human papillomavirus.

Science.gov (United States)

Patel, Divya A; Shih, Yang-Jen; Newton, Duane W; Michael, Claire W; Oeth, Paul A; Kane, Michael D; Opipari, Anthony W; Ruffin, Mack T; Kalikin, Linda M; Kurnit, David M

2009-09-01

Knowledge of the central role of high-risk human papillomavirus (HPV) in cervical carcinogenesis, coupled with an emerging need to monitor the efficacy of newly introduced HPV vaccines, warrant development and evaluation of type-specific, quantitative HPV detection methods. In the present study, a prototype PCR and mass spectroscopy (PCR-MS)-based method to detect and quantitate 13 high-risk HPV types is compared to the Hybrid Capture 2 High-Risk HPV DNA test (HC2; Digene Corp., Gaithersburg, MD) in 199 cervical scraping samples and to DNA sequencing in 77 cervical tumor samples. High-risk HPV types were detected in 76/77 (98.7%) cervical tumor samples by PCR-MS. Degenerate and type-specific sequencing confirmed the types detected by PCR-MS. In 199 cervical scraping samples, all 13 HPV types were detected by PCR-MS. Eighteen (14.5%) of 124 cervical scraping samples that were positive for high-risk HPV by HC2 were negative by PCR-MS. In all these cases, degenerate DNA sequencing failed to detect any of the 13 high-risk HPV types. Nearly half (46.7%) of the 75 cervical scraping samples that were negative for high-risk HPV by the HC2 assay were positive by PCR-MS. Type-specific sequencing in a subset of these samples confirmed the HPV type detected by PCR-MS. Quantitative PCR-MS results demonstrated that 11/75 (14.7%) samples contained as much HPV copies/cell as HC2-positive samples. These findings suggest that this prototype PCR-MS assay performs at least as well as HC2 for HPV detection, while offering the additional, unique advantages of type-specific identification and quantitation. Further validation work is underway to define clinically meaningful HPV detection thresholds and to evaluate the potential clinical application of future generations of the PCR-MS assay.

PCR amplification and DNA sequencing of Demodex injai from otic secretions of a dog.

Science.gov (United States)

Milosevic, Milivoj A; Frank, Linda A; Brahmbhatt, Rupal A; Kania, Stephen A

2013-04-01

The identification of Demodex mites from dogs is usually based on morphology and location. Mites with uncharacteristic features or from unusual locations, hosts or disease manifestations could represent new species not previously described; however, this is difficult to determine based on morphology alone. The goal of this study was to identify and confirm Demodex injai in association with otitis externa in a dog using PCR amplification and DNA sequencing. Otic samples were obtained from a beagle in which a long-bodied Demodex mite was identified. For comparison, Demodex mite samples were collected from a swab and scraping of the dorsal skin of a wire-haired fox terrier and an otic sample from a dog with generalized and otic demodicosis. To identify the Demodex mite, DNA was extracted, and 16S rRNA was amplified by PCR, sequenced and compared with Demodex sequences available in public databases and from separate samples morphologically diagnosed as D. injai and Demodex canis. PCR amplification of the long-bodied mite rRNA DNA obtained from otic samples was approximately 330 bp and was identical to that from the mite morphologically identified as D. injai obtained from the dorsal skin of a dog. Furthermore, the examined mite did not have any significant homology to any of the reported genes from Demodex spp. These results confirmed that the demodex mites in this case were D. injai. © 2013 The Authors. Veterinary Dermatology © 2013 ESVD and ACVD.

Genomic GC-content affects the accuracy of 16S rRNA gene sequencing bsed microbial profiling due to PCR bias

DEFF Research Database (Denmark)

Laursen, Martin F.; Dalgaard, Marlene Danner; Bahl, Martin Iain

2017-01-01

Profiling of microbial community composition is frequently performed by partial 16S rRNA gene sequencing on benchtop platforms following PCR amplification of specific hypervariable regions within this gene. Accuracy and reproducibility of this strategy are two key parameters to consider, which may...... be influenced during all processes from sample collection and storage, through DNA extraction and PCR based library preparation to the final sequencing. In order to evaluate both the reproducibility and accuracy of 16S rRNA gene based microbial profiling using the Ion Torrent PGM platform, we prepared libraries...... be explained partly by premature read truncation, but to larger degree their genomic GC-content, which correlated negatively with the observed relative abundances, suggesting a PCR bias against GC-rich species during library preparation. Increasing the initial denaturation time during the PCR amplification...

Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR.

Science.gov (United States)

D'Souza, T M; Boominathan, K; Reddy, C A

1996-01-01

Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum, Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. PMID:8837429

Genetic Diversity and Phylogenetic Analysis of the Iranian Leishmania Parasites Based on HSP70 Gene PCR-RFLP and Sequence Analysis.

Science.gov (United States)

Nemati, Sara; Fazaeli, Asghar; Hajjaran, Homa; Khamesipour, Ali; Anbaran, Mohsen Falahati; Bozorgomid, Arezoo; Zarei, Fatah

2017-08-01

Despite the broad distribution of leishmaniasis among Iranians and animals across the country, little is known about the genetic characteristics of the causative agents. Applying both HSP70 PCR-RFLP and sequence analyses, this study aimed to evaluate the genetic diversity and phylogenetic relationships among Leishmania spp. isolated from Iranian endemic foci and available reference strains. A total of 36 Leishmania isolates from almost all districts across the country were genetically analyzed for the HSP70 gene using both PCR-RFLP and sequence analysis. The original HSP70 gene sequences were aligned along with homologous Leishmania sequences retrieved from NCBI, and subjected to the phylogenetic analysis. Basic parameters of genetic diversity were also estimated. The HSP70 PCR-RFLP presented 3 different electrophoretic patterns, with no further intraspecific variation, corresponding to 3 Leishmania species available in the country, L. tropica, L. major, and L. infantum. Phylogenetic analyses presented 5 major clades, corresponding to 5 species complexes. Iranian lineages, including L. major, L. tropica, and L. infantum, were distributed among 3 complexes L. major, L. tropica, and L. donovani. However, within the L. major and L. donovani species complexes, the HSP70 phylogeny was not able to distinguish clearly between the L. major and L. turanica isolates, and between the L. infantum, L. donovani, and L. chagasi isolates, respectively. Our results indicated that both HSP70 PCR-RFLP and sequence analyses are medically applicable tools for identification of Leishmania species in Iranian patients. However, the reduced genetic diversity of the target gene makes it inevitable that its phylogeny only resolves the major groups, namely, the species complexes.

Identification of rat genes by TWINSCAN gene prediction, RT-PCR, and direct sequencing

DEFF Research Database (Denmark)

Wu, Jia Qian; Shteynberg, David; Arumugam, Manimozhiyan

2004-01-01

an alternative approach: reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing based on dual-genome de novo predictions from TWINSCAN. We tested 444 TWINSCAN-predicted rat genes that showed significant homology to known human genes implicated in disease but that were partially...... in the single-intron experiment. Spliced sequences were amplified in 46 cases (34%). We conclude that this procedure for elucidating gene structures with native cDNA sequences is cost-effective and will become even more so as it is further optimized.......The publication of a draft sequence of a third mammalian genome--that of the rat--suggests a need to rethink genome annotation. New mammalian sequences will not receive the kind of labor-intensive annotation efforts that are currently being devoted to human. In this paper, we demonstrate...

Exome sequencing and genetic testing for MODY.

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Stefan Johansson

Full Text Available Genetic testing for monogenic diabetes is important for patient care. Given the extensive genetic and clinical heterogeneity of diabetes, exome sequencing might provide additional diagnostic potential when standard Sanger sequencing-based diagnostics is inconclusive.The aim of the study was to examine the performance of exome sequencing for a molecular diagnosis of MODY in patients who have undergone conventional diagnostic sequencing of candidate genes with negative results.We performed exome enrichment followed by high-throughput sequencing in nine patients with suspected MODY. They were Sanger sequencing-negative for mutations in the HNF1A, HNF4A, GCK, HNF1B and INS genes. We excluded common, non-coding and synonymous gene variants, and performed in-depth analysis on filtered sequence variants in a pre-defined set of 111 genes implicated in glucose metabolism.On average, we obtained 45 X median coverage of the entire targeted exome and found 199 rare coding variants per individual. We identified 0-4 rare non-synonymous and nonsense variants per individual in our a priori list of 111 candidate genes. Three of the variants were considered pathogenic (in ABCC8, HNF4A and PPARG, respectively, thus exome sequencing led to a genetic diagnosis in at least three of the nine patients. Approximately 91% of known heterozygous SNPs in the target exomes were detected, but we also found low coverage in some key diabetes genes using our current exome sequencing approach. Novel variants in the genes ARAP1, GLIS3, MADD, NOTCH2 and WFS1 need further investigation to reveal their possible role in diabetes.Our results demonstrate that exome sequencing can improve molecular diagnostics of MODY when used as a complement to Sanger sequencing. However, improvements will be needed, especially concerning coverage, before the full potential of exome sequencing can be realized.

Quantitation of next generation sequencing library preparation protocol efficiencies using droplet digital PCR assays - a systematic comparison of DNA library preparation kits for Illumina sequencing.

Science.gov (United States)

Aigrain, Louise; Gu, Yong; Quail, Michael A

2016-06-13

The emergence of next-generation sequencing (NGS) technologies in the past decade has allowed the democratization of DNA sequencing both in terms of price per sequenced bases and ease to produce DNA libraries. When it comes to preparing DNA sequencing libraries for Illumina, the current market leader, a plethora of kits are available and it can be difficult for the users to determine which kit is the most appropriate and efficient for their applications; the main concerns being not only cost but also minimal bias, yield and time efficiency. We compared 9 commercially available library preparation kits in a systematic manner using the same DNA sample by probing the amount of DNA remaining after each protocol steps using a new droplet digital PCR (ddPCR) assay. This method allows the precise quantification of fragments bearing either adaptors or P5/P7 sequences on both ends just after ligation or PCR enrichment. We also investigated the potential influence of DNA input and DNA fragment size on the final library preparation efficiency. The overall library preparations efficiencies of the libraries show important variations between the different kits with the ones combining several steps into a single one exhibiting some final yields 4 to 7 times higher than the other kits. Detailed ddPCR data also reveal that the adaptor ligation yield itself varies by more than a factor of 10 between kits, certain ligation efficiencies being so low that it could impair the original library complexity and impoverish the sequencing results. When a PCR enrichment step is necessary, lower adaptor-ligated DNA inputs leads to greater amplification yields, hiding the latent disparity between kits. We describe a ddPCR assay that allows us to probe the efficiency of the most critical step in the library preparation, ligation, and to draw conclusion on which kits is more likely to preserve the sample heterogeneity and reduce the need of amplification.

Artemis and ACT: viewing, annotating and comparing sequences stored in a relational database

Science.gov (United States)

Carver, Tim; Berriman, Matthew; Tivey, Adrian; Patel, Chinmay; Böhme, Ulrike; Barrell, Barclay G.; Parkhill, Julian; Rajandream, Marie-Adèle

2008-01-01

Motivation: Artemis and Artemis Comparison Tool (ACT) have become mainstream tools for viewing and annotating sequence data, particularly for microbial genomes. Since its first release, Artemis has been continuously developed and supported with additional functionality for editing and analysing sequences based on feedback from an active user community of laboratory biologists and professional annotators. Nevertheless, its utility has been somewhat restricted by its limitation to reading and writing from flat files. Therefore, a new version of Artemis has been developed, which reads from and writes to a relational database schema, and allows users to annotate more complex, often large and fragmented, genome sequences. Results: Artemis and ACT have now been extended to read and write directly to the Generic Model Organism Database (GMOD, http://www.gmod.org) Chado relational database schema. In addition, a Gene Builder tool has been developed to provide structured forms and tables to edit coordinates of gene models and edit functional annotation, based on standard ontologies, controlled vocabularies and free text. Availability: Artemis and ACT are freely available (under a GPL licence) for download (for MacOSX, UNIX and Windows) at the Wellcome Trust Sanger Institute web sites: http://www.sanger.ac.uk/Software/Artemis/ http://www.sanger.ac.uk/Software/ACT/ Contact: artemis@sanger.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online. PMID:18845581

A second generation framework for the analysis of microsatellites in expressed sequence tags and the development of EST-SSR markers for a conifer, Cryptomeria japonica

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Ueno Saneyoshi

2012-04-01

Full Text Available Abstract Background Microsatellites or simple sequence repeats (SSRs in expressed sequence tags (ESTs are useful resources for genome analysis because of their abundance, functionality and polymorphism. The advent of commercial second generation sequencing machines has lead to new strategies for developing EST-SSR markers, necessitating the development of bioinformatic framework that can keep pace with the increasing quality and quantity of sequence data produced. We describe an open scheme for analyzing ESTs and developing EST-SSR markers from reads collected by Sanger sequencing and pyrosequencing of sugi (Cryptomeria japonica. Results We collected 141,097 sequence reads by Sanger sequencing and 1,333,444 by pyrosequencing. After trimming contaminant and low quality sequences, 118,319 Sanger and 1,201,150 pyrosequencing reads were passed to the MIRA assembler, generating 81,284 contigs that were analysed for SSRs. 4,059 SSRs were found in 3,694 (4.54% contigs, giving an SSR frequency lower than that in seven other plant species with gene indices (5.4–21.9%. The average GC content of the SSR-containing contigs was 41.55%, compared to 40.23% for all contigs. Tri-SSRs were the most common SSRs; the most common motif was AT, which was found in 655 (46.3% di-SSRs, followed by the AAG motif, found in 342 (25.9% tri-SSRs. Most (72.8% tri-SSRs were in coding regions, but 55.6% of the di-SSRs were in non-coding regions; the AT motif was most abundant in 3′ untranslated regions. Gene ontology (GO annotations showed that six GO terms were significantly overrepresented within SSR-containing contigs. Forty–four EST-SSR markers were developed from 192 primer pairs using two pipelines: read2Marker and the newly-developed CMiB, which combines several open tools. Markers resulting from both pipelines showed no differences in PCR success rate and polymorphisms, but PCR success and polymorphism were significantly affected by the expected PCR product size

A second generation framework for the analysis of microsatellites in expressed sequence tags and the development of EST-SSR markers for a conifer, Cryptomeria japonica

Science.gov (United States)

2012-01-01

Background Microsatellites or simple sequence repeats (SSRs) in expressed sequence tags (ESTs) are useful resources for genome analysis because of their abundance, functionality and polymorphism. The advent of commercial second generation sequencing machines has lead to new strategies for developing EST-SSR markers, necessitating the development of bioinformatic framework that can keep pace with the increasing quality and quantity of sequence data produced. We describe an open scheme for analyzing ESTs and developing EST-SSR markers from reads collected by Sanger sequencing and pyrosequencing of sugi (Cryptomeria japonica). Results We collected 141,097 sequence reads by Sanger sequencing and 1,333,444 by pyrosequencing. After trimming contaminant and low quality sequences, 118,319 Sanger and 1,201,150 pyrosequencing reads were passed to the MIRA assembler, generating 81,284 contigs that were analysed for SSRs. 4,059 SSRs were found in 3,694 (4.54%) contigs, giving an SSR frequency lower than that in seven other plant species with gene indices (5.4–21.9%). The average GC content of the SSR-containing contigs was 41.55%, compared to 40.23% for all contigs. Tri-SSRs were the most common SSRs; the most common motif was AT, which was found in 655 (46.3%) di-SSRs, followed by the AAG motif, found in 342 (25.9%) tri-SSRs. Most (72.8%) tri-SSRs were in coding regions, but 55.6% of the di-SSRs were in non-coding regions; the AT motif was most abundant in 3′ untranslated regions. Gene ontology (GO) annotations showed that six GO terms were significantly overrepresented within SSR-containing contigs. Forty–four EST-SSR markers were developed from 192 primer pairs using two pipelines: read2Marker and the newly-developed CMiB, which combines several open tools. Markers resulting from both pipelines showed no differences in PCR success rate and polymorphisms, but PCR success and polymorphism were significantly affected by the expected PCR product size and number of SSR

FastCloning: a highly simplified, purification-free, sequence- and ligation-independent PCR cloning method

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Lu Jia

2011-10-01

Full Text Available Abstract Background Although a variety of methods and expensive kits are available, molecular cloning can be a time-consuming and frustrating process. Results Here we report a highly simplified, reliable, and efficient PCR-based cloning technique to insert any DNA fragment into a plasmid vector or into a gene (cDNA in a vector at any desired position. With this method, the vector and insert are PCR amplified separately, with only 18 cycles, using a high fidelity DNA polymerase. The amplified insert has the ends with ~16-base overlapping with the ends of the amplified vector. After DpnI digestion of the mixture of the amplified vector and insert to eliminate the DNA templates used in PCR reactions, the mixture is directly transformed into competent E. coli cells to obtain the desired clones. This technique has many advantages over other cloning methods. First, it does not need gel purification of the PCR product or linearized vector. Second, there is no need of any cloning kit or specialized enzyme for cloning. Furthermore, with reduced number of PCR cycles, it also decreases the chance of random mutations. In addition, this method is highly effective and reproducible. Finally, since this cloning method is also sequence independent, we demonstrated that it can be used for chimera construction, insertion, and multiple mutations spanning a stretch of DNA up to 120 bp. Conclusion Our FastCloning technique provides a very simple, effective, reliable, and versatile tool for molecular cloning, chimera construction, insertion of any DNA sequences of interest and also for multiple mutations in a short stretch of a cDNA.

Development of a real-time PCR for detection of Staphylococcus pseudintermedius using a novel automated comparison of whole-genome sequences.

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Koen M Verstappen

Full Text Available Staphylococcus pseudintermedius is an opportunistic pathogen in dogs and cats and occasionally causes infections in humans. S. pseudintermedius is often resistant to multiple classes of antimicrobials. It requires a reliable detection so that it is not misidentified as S. aureus. Phenotypic and currently-used molecular-based diagnostic assays lack specificity or are labour-intensive using multiplex PCR or nucleic acid sequencing. The aim of this study was to identify a specific target for real-time PCR by comparing whole genome sequences of S. pseudintermedius and non-pseudintermedius.Genome sequences were downloaded from public repositories and supplemented by isolates that were sequenced in this study. A Perl-script was written that analysed 300-nt fragments from a reference genome sequence of S. pseudintermedius and checked if this sequence was present in other S. pseudintermedius genomes (n = 74 and non-pseudintermedius genomes (n = 138. Six sequences specific for S. pseudintermedius were identified (sequence length between 300-500 nt. One sequence, which was located in the spsJ gene, was used to develop primers and a probe. The real-time PCR showed 100% specificity when testing for S. pseudintermedius isolates (n = 54, and eight other staphylococcal species (n = 43. In conclusion, a novel approach by comparing whole genome sequences identified a sequence that is specific for S. pseudintermedius and provided a real-time PCR target for rapid and reliable detection of S. pseudintermedius.

A Retrospective Examination of Feline Leukemia Subgroup Characterization: Viral Interference Assays to Deep Sequencing.

Science.gov (United States)

Chiu, Elliott S; Hoover, Edward A; VandeWoude, Sue

2018-01-10

Feline leukemia virus (FeLV) was the first feline retrovirus discovered, and is associated with multiple fatal disease syndromes in cats, including lymphoma. The original research conducted on FeLV employed classical virological techniques. As methods have evolved to allow FeLV genetic characterization, investigators have continued to unravel the molecular pathology associated with this fascinating agent. In this review, we discuss how FeLV classification, transmission, and disease-inducing potential have been defined sequentially by viral interference assays, Sanger sequencing, PCR, and next-generation sequencing. In particular, we highlight the influences of endogenous FeLV and host genetics that represent FeLV research opportunities on the near horizon.

Non PCR-amplified Transcripts and AFLP fragments as reduced representations of the quail genome for 454 Titanium sequencing

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Leterrier Christine

2010-07-01

Full Text Available Abstract Background SNP (Single Nucleotide Polymorphism discovery is now routinely performed using high-throughput sequencing of reduced representation libraries. Our objective was to adapt 454 GS FLX based sequencing methodologies in order to obtain the largest possible dataset from two reduced representations libraries, produced by AFLP (Amplified Fragment Length Polymorphism for genomic DNA, and EST (Expressed Sequence Tag for the transcribed fraction of the genome. Findings The expressed fraction was obtained by preparing cDNA libraries without PCR amplification from quail embryo and brain. To optimize the information content for SNP analyses, libraries were prepared from individuals selected in three quail lines and each individual in the AFLP library was tagged. Sequencing runs produced 399,189 sequence reads from cDNA and 373,484 from genomic fragments, covering close to 250 Mb of sequence in total. Conclusions Both methods used to obtain reduced representations for high-throughput sequencing were successful after several improvements. The protocols may be used for several sequencing applications, such as de novo sequencing, tagged PCR fragments or long fragment sequencing of cDNA.

Linear and exponential TAIL-PCR: a method for efficient and quick amplification of flanking sequences adjacent to Tn5 transposon insertion sites.

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Jia, Xianbo; Lin, Xinjian; Chen, Jichen

2017-11-02

Current genome walking methods are very time consuming, and many produce non-specific amplification products. To amplify the flanking sequences that are adjacent to Tn5 transposon insertion sites in Serratia marcescens FZSF02, we developed a genome walking method based on TAIL-PCR. This PCR method added a 20-cycle linear amplification step before the exponential amplification step to increase the concentration of the target sequences. Products of the linear amplification and the exponential amplification were diluted 100-fold to decrease the concentration of the templates that cause non-specific amplification. Fast DNA polymerase with a high extension speed was used in this method, and an amplification program was used to rapidly amplify long specific sequences. With this linear and exponential TAIL-PCR (LETAIL-PCR), we successfully obtained products larger than 2 kb from Tn5 transposon insertion mutant strains within 3 h. This method can be widely used in genome walking studies to amplify unknown sequences that are adjacent to known sequences.

A dated molecular phylogeny of manta and devil rays (Mobulidae) based on mitogenome and nuclear sequences

NARCIS (Netherlands)

Poortvliet, Marloes; Olsen, Jeanine; Croll, Donald A.; Bernardi, Giacomo; Newton, Kelly; Kollias, Spyros; O'Sullivan, John; Fernando, Daniel; Stevens, Guy; Galván Magaña, Felipe; Seret, Bernard; Wintner, Sabine; Hoarau, Galice

Manta and devil rays are an iconic group of globally distributed pelagic filter feeders, yet their evolutionary history remains enigmatic. We employed next generation sequencing of mitogenomes for nine of the 11 recognized species and two outgroups; as well as additional Sanger sequencing of two

Data Analysis of Sequences and qPCR for Microbial Communities during Algal Blooms

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A training opportunity is open to a highly microbial-research-motivated student to conduct sequence analysis, explore novel genes and metabolic pathways, validate resultant findings using qPCR/RT-qPCR and summarize the findings

Characterization of bovine ruminal epithelial bacterial communities using 16S rRNA sequencing, PCR-DGGE, and qRT-PCR analysis.

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Li, Meiju; Zhou, Mi; Adamowicz, Elizabeth; Basarab, John A; Guan, Le Luo

2012-02-24

Currently, knowledge regarding the ecology and function of bacteria attached to the epithelial tissue of the rumen wall is limited. In this study, the diversity of the bacterial community attached to the rumen epithelial tissue was compared to the rumen content bacterial community using 16S rRNA gene sequencing, PCR-DGGE, and qRT-PCR analysis. Sequence analysis of 2785 randomly selected clones from six 16S rDNA (∼1.4kb) libraries showed that the community structures of three rumen content libraries clustered together and were separated from the rumen tissue libraries. The diversity index of each library revealed that ruminal content bacterial communities (4.12/4.42/4.88) were higher than ruminal tissue communities (2.90/2.73/3.23), based on 97% similarity. The phylum Firmicutes was predominant in the ruminal tissue communities, while the phylum Bacteroidetes was predominant in the ruminal content communities. The phyla Fibrobacteres, Planctomycetes, and Verrucomicrobia were only detected in the ruminal content communities. PCR-DGGE analysis of the bacterial profiles of the rumen content and ruminal epithelial tissue samples from 22 steers further confirmed that there is a distinct bacterial community that inhibits the rumen epithelium. The distinctive epimural bacterial communities suggest that Firmicutes, together with other epithelial-specific species, may have additional functions other than food digestion. Copyright © 2011 Elsevier B.V. All rights reserved.

Practical tools to implement massive parallel pyrosequencing of PCR products in next generation molecular diagnostics.

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Kim De Leeneer

Full Text Available Despite improvements in terms of sequence quality and price per basepair, Sanger sequencing remains restricted to screening of individual disease genes. The development of massively parallel sequencing (MPS technologies heralded an era in which molecular diagnostics for multigenic disorders becomes reality. Here, we outline different PCR amplification based strategies for the screening of a multitude of genes in a patient cohort. We performed a thorough evaluation in terms of set-up, coverage and sequencing variants on the data of 10 GS-FLX experiments (over 200 patients. Crucially, we determined the actual coverage that is required for reliable diagnostic results using MPS, and provide a tool to calculate the number of patients that can be screened in a single run. Finally, we provide an overview of factors contributing to false negative or false positive mutation calls and suggest ways to maximize sensitivity and specificity, both important in a routine setting. By describing practical strategies for screening of multigenic disorders in a multitude of samples and providing answers to questions about minimum required coverage, the number of patients that can be screened in a single run and the factors that may affect sensitivity and specificity we hope to facilitate the implementation of MPS technology in molecular diagnostics.

[Whole Genome Sequencing of Human mtDNA Based on Ion Torrent PGM™ Platform].

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Cao, Y; Zou, K N; Huang, J P; Ma, K; Ping, Y

2017-08-01

To analyze and detect the whole genome sequence of human mitochondrial DNA （mtDNA） by Ion Torrent PGM™ platform and to study the differences of mtDNA sequence in different tissues. Samples were collected from 6 unrelated individuals by forensic postmortem examination, including chest blood, hair, costicartilage, nail, skeletal muscle and oral epithelium. Amplification of whole genome sequence of mtDNA was performed by 4 pairs of primer. Libraries were constructed with Ion Shear™ Plus Reagents kit and Ion Plus Fragment Library kit. Whole genome sequencing of mtDNA was performed using Ion Torrent PGM™ platform. Sanger sequencing was used to determine the heteroplasmy positions and the mutation positions on HVⅠ region. The whole genome sequence of mtDNA from all samples were amplified successfully. Six unrelated individuals belonged to 6 different haplotypes. Different tissues in one individual had heteroplasmy difference. The heteroplasmy positions and the mutation positions on HVⅠ region were verified by Sanger sequencing. After a consistency check by the Kappa method, it was found that the results of mtDNA sequence had a high consistency in different tissues. The testing method used in present study for sequencing the whole genome sequence of human mtDNA can detect the heteroplasmy difference in different tissues, which have good consistency. The results provide guidance for the further applications of mtDNA in forensic science. Copyright© by the Editorial Department of Journal of Forensic Medicine

Detection of hepatitis A virus by the nucleic acid sequence-based amplification technique and comparison with reverse transcription-PCR.

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Jean, J; Blais, B; Darveau, A; Fliss, I

2001-12-01

A nucleic acid sequence-based amplification (NASBA) technique for the detection of hepatitis A virus (HAV) in foods was developed and compared to the traditional reverse transcription (RT)-PCR technique. Oligonucleotide primers targeting the VP1 and VP2 genes encoding the major HAV capsid proteins were used for the amplification of viral RNA in an isothermal process resulting in the accumulation of RNA amplicons. Amplicons were detected by hybridization with a digoxigenin-labeled oligonucleotide probe in a dot blot assay format. Using the NASBA, as little as 0.4 ng of target RNA/ml was detected per comparison to 4 ng/ml for RT-PCR. When crude HAV viral lysate was used, a detection limit of 2 PFU (4 x 10(2) PFU/ml) was obtained with NASBA, compared to 50 PFU (1 x 10(4) PFU/ml) obtained with RT-PCR. No interference was encountered in the amplification of HAV RNA in the presence of excess nontarget RNA or DNA. The NASBA system successfully detected HAV recovered from experimentally inoculated samples of waste water, lettuce, and blueberries. Compared to RT-PCR and other amplification techniques, the NASBA system offers several advantages in terms of sensitivity, rapidity, and simplicity. This technique should be readily adaptable for detection of other RNA viruses in both foods and clinical samples.

Draft genome sequence of pigeonpea (Cajanus cajan), an orphan legume crop of resource-poor farmers

DEFF Research Database (Denmark)

Varshney, Rajeev K.; Chen, Wenbin; Li, Yupeng

2012-01-01

Pigeonpea is an important legume food crop grown primarily by smallholder farmers in many semi-arid tropical regions of the world. We used the Illumina next-generation sequencing platform to generate 237.2 Gb of sequence, which along with Sanger-based bacterial artificial chromosome end sequences...

Next-generation phylogeography: a targeted approach for multilocus sequencing of non-model organisms.

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Jonathan B Puritz

Full Text Available The field of phylogeography has long since realized the need and utility of incorporating nuclear DNA (nDNA sequences into analyses. However, the use of nDNA sequence data, at the population level, has been hindered by technical laboratory difficulty, sequencing costs, and problematic analytical methods dealing with genotypic sequence data, especially in non-model organisms. Here, we present a method utilizing the 454 GS-FLX Titanium pyrosequencing platform with the capacity to simultaneously sequence two species of sea star (Meridiastra calcar and Parvulastra exigua at five different nDNA loci across 16 different populations of 20 individuals each per species. We compare results from 3 populations with traditional Sanger sequencing based methods, and demonstrate that this next-generation sequencing platform is more time and cost effective and more sensitive to rare variants than Sanger based sequencing. A crucial advantage is that the high coverage of clonally amplified sequences simplifies haplotype determination, even in highly polymorphic species. This targeted next-generation approach can greatly increase the use of nDNA sequence loci in phylogeographic and population genetic studies by mitigating many of the time, cost, and analytical issues associated with highly polymorphic, diploid sequence markers.

Development of Quantitative Competitive PCR and Absolute Based Real-Time PCR Assays for Quantification of The Butyrate Producing Bacterium: Butyrivibrio fibrisolvens

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Mojtaba Tahmoorespur

2016-04-01

Full Text Available Introduction Butyrivibrio fibrisolvens strains are presently recognized as the major butyrate-producing bacteria found in the rumen and digestive track of many animals and also in the human gut. In this study we reported the development of two DNA based techniques, quantitative competitive (QC PCR and absolute based Real-Time PCR, for enumerating Butyrivibrio fibrisolvens strains. Despite the recent introduction of real-time PCR method for the rapid quantification of the target DNA sequences, use of quantitative competitive PCR (QC-PCR technique continues to play an important role in nucleic acid quantification since it is more cost effective. The procedure relies on the co-amplification of the sequence of interest with a serially diluted synthetic DNA fragment of the known concentration (competitor, using the single set primers. A real-time polymerase chain reaction is a laboratory technique of molecular biology based on the polymerase chain reaction (PCR. It monitors the amplification of a targeted DNA molecule during the PCR. Materials and Methods At first reported species-specific primers targeting the 16S rDNA region of the bacterium Butyrivibrio fibrisolvens were used for amplifying a 213 bp fragment. A DNA competitor differing by 50 bp in length from the 213 bp fragment was constructed and cloned into pTZ57R/T vector. The competitor was quantified by NanoDrop spectrophotometer and serially diluted and co-amplified by PCR with total extracted DNA from rumen fluid samples. PCR products were quantified by photographing agarose gels and analyzed with Image J software and the amount of amplified target DNA was log plotted against the amount of amplified competitor. Coefficient of determination (R2 was used as a criterion of methodology precision. For developing the Real-time PCR technique, the 213 bp fragment was amplified and cloned into pTZ57R/T was used to draw a standard curve. Results and Discussion The specific primers of Butyrivibrio

Assessment of metagenomic assembly using simulated next generation sequencing data

DEFF Research Database (Denmark)

Mende, Daniel R; Waller, Alison S; Sunagawa, Shinichi

2012-01-01

with platform-specific (Sanger, pyrosequencing, Illumina) base-error models, and simulated metagenomes of differing community complexities. We first evaluated the effect of rigorous quality control on Illumina data. Although quality filtering removed a large proportion of the data, it greatly improved...... the accuracy and contig lengths of resulting assemblies. We then compared the quality-trimmed Illumina assemblies to those from Sanger and pyrosequencing. For the simple community (10 genomes) all sequencing technologies assembled a similar amount and accurately represented the expected functional composition...... the Sanger reads still represented the overall functional composition reasonably well. We further examined the effect of scaffolding of contigs using paired-end Illumina reads. It dramatically increased contig lengths of the simple community and yielded minor improvements to the more complex communities...

Real-time PCR systems targeting giant viruses of amoebae and their virophages.

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Ngounga, Tatsiana; Pagnier, Isabelle; Reteno, Dorine-Gaelle Ikanga; Raoult, Didier; La Scola, Bernard; Colson, Philippe

2013-01-01

Giant viruses that infect amoebae, including mimiviruses and marseilleviruses, were first described in 2003. Virophages were subsequently described that infect mimiviruses. Culture isolation with Acanthamoeba spp. and metagenomic studies have shown that these giant viruses are common inhabitants of our biosphere and have enabled the recent detection of these viruses in human samples. However, the genomes of these viruses display substantial genetic diversity, making it a challenge to examine their presence in environmental and clinical samples using conventional and real-time PCR. We designed and evaluated the performance of PCR systems capable of detecting all currently isolated mimiviruses, marseilleviruses and virophages to assess their prevalence in various samples. Our real-time PCR assays accurately detected all or most of the members of the currently delineated lineages of giant viruses infecting acanthamoebae as well as the mimivirus virophages, and enabled accurate classification of the mimiviruses of amoebae in lineages A, B or C. We were able to detect four new mimiviruses directly from environmental samples and correctly classified these viruses within mimivirus lineage C. This was subsequently confirmed by culture on amoebae followed by partial Sanger sequencing. PCR systems such as those implemented here may contribute to an improved understanding of the prevalence of mimiviruses, their virophages and marseilleviruses in humans.

Next-Generation Sequencing-Based Detection of Germline Copy Number Variations in BRCA1/BRCA2

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Schmidt, Ane Y; Hansen, Thomas V O; Ahlborn, Lise B

2017-01-01

Genetic testing of BRCA1/2 includes screening for single nucleotide variants and small insertions/deletions and for larger copy number variations (CNVs), primarily by Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). With the advent of next-generation sequencing (NGS)...

A Retrospective Examination of Feline Leukemia Subgroup Characterization: Viral Interference Assays to Deep Sequencing

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Elliott S. Chiu

2018-01-01

Full Text Available Feline leukemia virus (FeLV was the first feline retrovirus discovered, and is associated with multiple fatal disease syndromes in cats, including lymphoma. The original research conducted on FeLV employed classical virological techniques. As methods have evolved to allow FeLV genetic characterization, investigators have continued to unravel the molecular pathology associated with this fascinating agent. In this review, we discuss how FeLV classification, transmission, and disease-inducing potential have been defined sequentially by viral interference assays, Sanger sequencing, PCR, and next-generation sequencing. In particular, we highlight the influences of endogenous FeLV and host genetics that represent FeLV research opportunities on the near horizon.

[Molecular and prenatal diagnosis of a family with Fanconi anemia by next generation sequencing].

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Gong, Zhuwen; Yu, Yongguo; Zhang, Qigang; Gu, Xuefan

2015-04-01

To provide prenatal diagnosis for a pregnant woman who had given birth to a child with Fanconi anemia with combined next-generation sequencing (NGS) and Sanger sequencing. For the affected child, potential mutations of the FANCA gene were analyzed with NGS. Suspected mutation was verified with Sanger sequencing. For prenatal diagnosis, genomic DNA was extracted from cultured fetal amniotic fluid cells and subjected to analysis of the same mutations. A low-frequency frameshifting mutation c.989_995del7 (p.H330LfsX2, inherited from his father) and a truncating mutation c.3971C>T (p.P1324L, inherited from his mother) have been identified in the affected child and considered to be pathogenic. The two mutations were subsequently verified by Sanger sequencing. Upon prenatal diagnosis, the fetus was found to carry two mutations. The combined next-generation sequencing and Sanger sequencing can reduce the time for diagnosis and identify subtypes of Fanconi anemia and the mutational sites, which has enabled reliable prenatal diagnosis of this disease.

PCR Assays for Identification of Coccidioides posadasii Based on the Nucleotide Sequence of the Antigen 2/Proline-Rich Antigen

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Bialek, Ralf; Kern, Jan; Herrmann, Tanja; Tijerina, Rolando; Ceceñas, Luis; Reischl, Udo; González, Gloria M.

2004-01-01

A conventional nested PCR and a real-time LightCycler PCR assay for detection of Coccidioides posadasii DNA were designed and tested in 120 clinical strains. These had been isolated from 114 patients within 10 years in Monterrey, Nuevo Leon, Mexico, known to be endemic for coccidioidomycosis. The gene encoding the specific antigen 2/proline-rich antigen (Ag2/PRA) was used as a target. All strains were correctly identified, whereas DNA from related members of the family Onygenaceae remained negative. Melting curve analysis by LightCycler and sequencing of the 526-bp product of the first PCR demonstrated either 100% identity to the GenBank sequence of the Silveira strain, now known to be C. posadasii (accession number AF013256), or a single silent mutation at position 1228. Length determination of two microsatellite-containing loci (GAC and 621) identified all 120 isolates as C. posadasii. Specific DNA was amplified by conventional nested PCR from three microscopically spherule-positive paraffin-embedded tissue samples, whereas 20 human tissue samples positive for other dimorphic fungi remained negative. Additionally, the safety of each step of a modified commercially available DNA extraction procedure was evaluated by using 10 strains. At least three steps of the protocol were demonstrated to sufficiently kill arthroconidia. This safe procedure is applicable to cultures and to clinical specimens. PMID:14766853

[Influence of PCR cycle number on microbial diversity analysis through next generation sequencing].

Science.gov (United States)

An, Yunhe; Gao, Lijuan; Li, Junbo; Tian, Yanjie; Wang, Jinlong; Zheng, Xuejuan; Wu, Huijuan

2016-08-25

Using of high throughput sequencing technology to study the microbial diversity in complex samples has become one of the hottest issues in the field of microbial diversity research. In this study, the soil and sheep rumen chyme samples were used to extract DNA, respectively. Then the 25 ng total DNA was used to amplify the 16S rRNA V3 region with 20, 25, 30 PCR cycles, and the final sequencing library was constructed by mixing equal amounts of purified PCR products. Finally, the operational taxonomic unit (OUT) amount, rarefaction curve, microbial number and species were compared through data analysis. It was found that at the same amount of DNA template, the proportion of the community composition was not the best with more numbers of PCR cycle, although the species number was much more. In all, when the PCR cycle number is 25, the number of species and proportion of the community composition were the most optimal both in soil or chyme samples.

Identification of novel BRCA founder mutations in Middle Eastern breast cancer patients using capture and Sanger sequencing analysis.

Science.gov (United States)

Bu, Rong; Siraj, Abdul K; Al-Obaisi, Khadija A S; Beg, Shaham; Al Hazmi, Mohsen; Ajarim, Dahish; Tulbah, Asma; Al-Dayel, Fouad; Al-Kuraya, Khawla S

2016-09-01

Ethnic differences of breast cancer genomics have prompted us to investigate the spectra of BRCA1 and BRCA2 mutations in different populations. The prevalence and effect of BRCA 1 and BRCA 2 mutations in Middle Eastern population is not fully explored. To characterize the prevalence of BRCA mutations in Middle Eastern breast cancer patients, BRCA mutation screening was performed in 818 unselected breast cancer patients using Capture and/or Sanger sequencing. 19 short tandem repeat (STR) markers were used for founder mutation analysis. In our study, nine different types of deleterious mutation were identified in 28 (3.4%) cases, 25 (89.3%) cases in BRCA 1 and 3 (10.7%) cases in BRCA 2. Seven recurrent mutations identified accounted for 92.9% (26/28) of all the mutant cases. Haplotype analysis was performed to confirm c.1140 dupG and c.4136_4137delCT mutations as novel putative founder mutation, accounting for 46.4% (13/28) of all BRCA mutant cases and 1.6% (13/818) of all the breast cancer cases, respectively. Moreover, BRCA 1 mutation was significantly associated with BRCA 1 protein expression loss (p = 0.0005). Our finding revealed that a substantial number of BRCA mutations were identified in clinically high risk breast cancer from Middle East region. Identification of the mutation spectrum, prevalence and founder effect in Middle Eastern population facilitates genetic counseling, risk assessment and development of cost-effective screening strategy. © 2016 UICC.

A thaumatin-like genomic sequence identification in Vitis vinifera l., stormy wines and musts based on direct pcr

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Jana Žiarovská

2018-03-01

Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 Direct polymerase chain reaction method was use to amplify a thaumatin-like sequence of Vitis vinifera L. in grapes as well as in stormy wines and musts. Thaumatin-like proteins (TLPs of Vitis vinifera possess beside its function in abiotic and biotic stress response another one - they are able to cause protein haze in wine unless removed prior to bottling. Direct PCR is an approach where omission of DNA extraction is typical prior the amplification of the target site of plant genome. Crude extract or small pieces of plant tissues are used in the analysis directly without steps of extraction and purification of gDNA. The biological material that was used in analysis was collected during August - October 2017 in local stores and winery Sabo and comprises from cultivars Iršai, Muškát, Savignon Blanc, Svätovavrinecké, Dornfelder and Pálava. Direct PCR was performed by a cutted piece of grape tissue and a dilution buffer was use in 1:2 for stormy wine or must, respectively. Direct amplification of thaumatin-like protein sequence of Vitis vinifera was performed along with the control reactions with the primers for conserved region of plant chloroplast. Possitive amplification of thaumatin-like allergen sequence resulted in 570 bp amplicon. The most abundant amplicons were amplified in stormy wines, followed by musts and the amplicons from grapes were weaker when comparing them to others. The amplicon specificity checking of obtained PCR product of thaumatin-like allergen was performed by restriction cleavage by Psi I and resulted in restriction amplicons of the 80 bp, 81 bp, 94 bp and 315 bp in length. Confirmation of the amplicon specificity by restriction cleavage support the potential of direct PCR to become a reproducible method that will be fully applicable in routine analysis of not only plant genomes in the future, but it was demonstrated, that it works in liquids, too.  

Development of a multiplex Q-PCR to detect Trichoderma harzianum Rifai strain T22 in plant roots.

Science.gov (United States)

Horn, Ivo R; van Rijn, Menno; Zwetsloot, Tom J J; Basmagi, Said; Dirks-Mulder, Anita; van Leeuwen, Willem B; Ravensberg, Willem J; Gravendeel, Barbara

2016-02-01

The fungal species Trichoderma harzianum is widely used as a biological agent in crop protection. To verify the continued presence of this fungus on plant roots manually inoculated with T. harzianum strain T22, a Q-PCR was designed using specific probes for this particular strain. To develop these molecular diagnostic tools, genome mining was first carried out to retrieve putative new regions by which different strains of T. harzianum could be distinguished. Subsequently, Sanger sequencing of the L-aminoacid oxidase gene (aox1) in T. harzianum was applied to determine the mutations differing between various strains isolated from the Trichoderma collection of Koppert Biological Systems. Based on the sequence information obtained, a set of hydrolysis probes was subsequently developed which discriminated T. harzianum T22 strains varying in only a single nucleotide. Probes designed for two strains uniquely recognized the respective strains in Q-PCR with a detection limit of 12,5ng DNA. Titration assays in which T. harzianum DNA from distinct strains was varied further underscored the specificity of the probes. Lastly, fungal DNA extracted from roots of greenhouse cultured tomato plants was analyzed using the probe-based assay. DNA from T. harzianum strain T22 could readily be identified on roots of greenhouse reared tomato plants inoculated with varying concentrations up to one week after treatment with a detection limit of 3e6 colony forming units of T. harzianum T22. We conclude that the Q-PCR method is a reliable and robust method for assessing the presence and quantity of T. harzianum strain T22 in manually inoculated plant material. Our method provides scope for the development of DNA based strain specific identification of additional strains of Trichoderma and other fungal biological control agents. Copyright © 2015 Elsevier B.V. All rights reserved.

Experience of targeted Usher exome sequencing as a clinical test

Science.gov (United States)

Besnard, Thomas; García-García, Gema; Baux, David; Vaché, Christel; Faugère, Valérie; Larrieu, Lise; Léonard, Susana; Millan, Jose M; Malcolm, Sue; Claustres, Mireille; Roux, Anne-Françoise

2014-01-01

We show that massively parallel targeted sequencing of 19 genes provides a new and reliable strategy for molecular diagnosis of Usher syndrome (USH) and nonsyndromic deafness, particularly appropriate for these disorders characterized by a high clinical and genetic heterogeneity and a complex structure of several of the genes involved. A series of 71 patients including Usher patients previously screened by Sanger sequencing plus newly referred patients was studied. Ninety-eight percent of the variants previously identified by Sanger sequencing were found by next-generation sequencing (NGS). NGS proved to be efficient as it offers analysis of all relevant genes which is laborious to reach with Sanger sequencing. Among the 13 newly referred Usher patients, both mutations in the same gene were identified in 77% of cases (10 patients) and one candidate pathogenic variant in two additional patients. This work can be considered as pilot for implementing NGS for genetically heterogeneous diseases in clinical service. PMID:24498627

Molecular genetics of the Usher syndrome in Lebanon: identification of 11 novel protein truncating mutations by whole exome sequencing.

Science.gov (United States)

Reddy, Ramesh; Fahiminiya, Somayyeh; El Zir, Elie; Mansour, Ahmad; Megarbane, Andre; Majewski, Jacek; Slim, Rima

2014-01-01

Usher syndrome (USH) is a genetically heterogeneous condition with ten disease-causing genes. The spectrum of genes and mutations causing USH in the Lebanese and Middle Eastern populations has not been described. Consequently, diagnostic approaches designed to screen for previously reported mutations were unlikely to identify the mutations in 11 unrelated families, eight of Lebanese and three of Middle Eastern origins. In addition, six of the ten USH genes consist of more than 20 exons, each, which made mutational analysis by Sanger sequencing of PCR-amplified exons from genomic DNA tedious and costly. The study was aimed at the identification of USH causing genes and mutations in 11 unrelated families with USH type I or II. Whole exome sequencing followed by expanded familial validation by Sanger sequencing. We identified disease-causing mutations in all the analyzed patients in four USH genes, MYO7A, USH2A, GPR98 and CDH23. Eleven of the mutations were novel and protein truncating, including a complex rearrangement in GPR98. Our data highlight the genetic diversity of Usher syndrome in the Lebanese population and the time and cost-effectiveness of whole exome sequencing approach for mutation analysis of genetically heterogeneous conditions caused by large genes.

Molecular genetics of the Usher syndrome in Lebanon: identification of 11 novel protein truncating mutations by whole exome sequencing.

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Ramesh Reddy

Full Text Available Usher syndrome (USH is a genetically heterogeneous condition with ten disease-causing genes. The spectrum of genes and mutations causing USH in the Lebanese and Middle Eastern populations has not been described. Consequently, diagnostic approaches designed to screen for previously reported mutations were unlikely to identify the mutations in 11 unrelated families, eight of Lebanese and three of Middle Eastern origins. In addition, six of the ten USH genes consist of more than 20 exons, each, which made mutational analysis by Sanger sequencing of PCR-amplified exons from genomic DNA tedious and costly. The study was aimed at the identification of USH causing genes and mutations in 11 unrelated families with USH type I or II.Whole exome sequencing followed by expanded familial validation by Sanger sequencing.We identified disease-causing mutations in all the analyzed patients in four USH genes, MYO7A, USH2A, GPR98 and CDH23. Eleven of the mutations were novel and protein truncating, including a complex rearrangement in GPR98.Our data highlight the genetic diversity of Usher syndrome in the Lebanese population and the time and cost-effectiveness of whole exome sequencing approach for mutation analysis of genetically heterogeneous conditions caused by large genes.

Molecular Genetics of the Usher Syndrome in Lebanon: Identification of 11 Novel Protein Truncating Mutations by Whole Exome Sequencing

Science.gov (United States)

Reddy, Ramesh; Fahiminiya, Somayyeh; El Zir, Elie; Mansour, Ahmad; Megarbane, Andre; Majewski, Jacek; Slim, Rima

2014-01-01

Background Usher syndrome (USH) is a genetically heterogeneous condition with ten disease-causing genes. The spectrum of genes and mutations causing USH in the Lebanese and Middle Eastern populations has not been described. Consequently, diagnostic approaches designed to screen for previously reported mutations were unlikely to identify the mutations in 11 unrelated families, eight of Lebanese and three of Middle Eastern origins. In addition, six of the ten USH genes consist of more than 20 exons, each, which made mutational analysis by Sanger sequencing of PCR-amplified exons from genomic DNA tedious and costly. The study was aimed at the identification of USH causing genes and mutations in 11 unrelated families with USH type I or II. Methods Whole exome sequencing followed by expanded familial validation by Sanger sequencing. Results We identified disease-causing mutations in all the analyzed patients in four USH genes, MYO7A, USH2A, GPR98 and CDH23. Eleven of the mutations were novel and protein truncating, including a complex rearrangement in GPR98. Conclusion Our data highlight the genetic diversity of Usher syndrome in the Lebanese population and the time and cost-effectiveness of whole exome sequencing approach for mutation analysis of genetically heterogeneous conditions caused by large genes. PMID:25211151

Discovery of novel MHC-class I alleles and haplotypes in Filipino cynomolgus macaques (Macaca fascicularis) by pyrosequencing and Sanger sequencing: Mafa-class I polymorphism.

Science.gov (United States)

Shiina, Takashi; Yamada, Yukiho; Aarnink, Alice; Suzuki, Shingo; Masuya, Anri; Ito, Sayaka; Ido, Daisuke; Yamanaka, Hisashi; Iwatani, Chizuru; Tsuchiya, Hideaki; Ishigaki, Hirohito; Itoh, Yasushi; Ogasawara, Kazumasa; Kulski, Jerzy K; Blancher, Antoine

2015-10-01

Although the low polymorphism of the major histocompatibility complex (MHC) transplantation genes in the Filipino cynomolgus macaque (Macaca fascicularis) is expected to have important implications in the selection and breeding of animals for medical research, detailed polymorphism information is still lacking for many of the duplicated class I genes. To better elucidate the degree and types of MHC polymorphisms and haplotypes in the Filipino macaque population, we genotyped 127 unrelated animals by the Sanger sequencing method and high-resolution pyrosequencing and identified 112 different alleles, 28 at cynomolgus macaque MHC (Mafa)-A, 54 at Mafa-B, 12 at Mafa-I, 11 at Mafa-E, and seven at Mafa-F alleles, of which 56 were newly described. Of them, the newly discovered Mafa-A8*01:01 lineage allele had low nucleotide similarities (Filipino macaque population would identify these and other high-frequency Mafa-class I haplotypes that could be used as MHC control animals for the benefit of biomedical research.

Mung bean nuclease treatment increases capture specificity of microdroplet-PCR based targeted DNA enrichment.

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Zhenming Yu

Full Text Available Targeted DNA enrichment coupled with next generation sequencing has been increasingly used for interrogation of select sub-genomic regions at high depth of coverage in a cost effective manner. Specificity measured by on-target efficiency is a key performance metric for target enrichment. Non-specific capture leads to off-target reads, resulting in waste of sequencing throughput on irrelevant regions. Microdroplet-PCR allows simultaneous amplification of up to thousands of regions in the genome and is among the most commonly used strategies for target enrichment. Here we show that carryover of single-stranded template genomic DNA from microdroplet-PCR constitutes a major contributing factor for off-target reads in the resultant libraries. Moreover, treatment of microdroplet-PCR enrichment products with a nuclease specific to single-stranded DNA alleviates off-target load and improves enrichment specificity. We propose that nuclease treatment of enrichment products should be incorporated in the workflow of targeted sequencing using microdroplet-PCR for target capture. These findings may have a broad impact on other PCR based applications for which removal of template DNA is beneficial.

"First generation" automated DNA sequencing technology.

Science.gov (United States)

Slatko, Barton E; Kieleczawa, Jan; Ju, Jingyue; Gardner, Andrew F; Hendrickson, Cynthia L; Ausubel, Frederick M

2011-10-01

Beginning in the 1980s, automation of DNA sequencing has greatly increased throughput, reduced costs, and enabled large projects to be completed more easily. The development of automation technology paralleled the development of other aspects of DNA sequencing: better enzymes and chemistry, separation and imaging technology, sequencing protocols, robotics, and computational advancements (including base-calling algorithms with quality scores, database developments, and sequence analysis programs). Despite the emergence of high-throughput sequencing platforms, automated Sanger sequencing technology remains useful for many applications. This unit provides background and a description of the "First-Generation" automated DNA sequencing technology. It also includes protocols for using the current Applied Biosystems (ABI) automated DNA sequencing machines. © 2011 by John Wiley & Sons, Inc.

Artemis and ACT: viewing, annotating and comparing sequences stored in a relational database.

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Carver, Tim; Berriman, Matthew; Tivey, Adrian; Patel, Chinmay; Böhme, Ulrike; Barrell, Barclay G; Parkhill, Julian; Rajandream, Marie-Adèle

2008-12-01

Artemis and Artemis Comparison Tool (ACT) have become mainstream tools for viewing and annotating sequence data, particularly for microbial genomes. Since its first release, Artemis has been continuously developed and supported with additional functionality for editing and analysing sequences based on feedback from an active user community of laboratory biologists and professional annotators. Nevertheless, its utility has been somewhat restricted by its limitation to reading and writing from flat files. Therefore, a new version of Artemis has been developed, which reads from and writes to a relational database schema, and allows users to annotate more complex, often large and fragmented, genome sequences. Artemis and ACT have now been extended to read and write directly to the Generic Model Organism Database (GMOD, http://www.gmod.org) Chado relational database schema. In addition, a Gene Builder tool has been developed to provide structured forms and tables to edit coordinates of gene models and edit functional annotation, based on standard ontologies, controlled vocabularies and free text. Artemis and ACT are freely available (under a GPL licence) for download (for MacOSX, UNIX and Windows) at the Wellcome Trust Sanger Institute web sites: http://www.sanger.ac.uk/Software/Artemis/ http://www.sanger.ac.uk/Software/ACT/

Transcriptome Sequencing of Dianthus spiculifolius and Analysis of the Genes Involved in Responses to Combined Cold and Drought Stress.

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Zhou, Aimin; Ma, Hongping; Liu, Enhui; Jiang, Tongtong; Feng, Shuang; Gong, Shufang; Wang, Jingang

2017-04-17

Dianthus spiculifolius , a perennial herbaceous flower and a member of the Caryophyllaceae family, has strong resistance to cold and drought stresses. To explore the transcriptional responses of D. spiculifolius to individual and combined stresses, we performed transcriptome sequencing of seedlings under normal conditions or subjected to cold treatment (CT), simulated drought treatment (DT), or their combination (CTDT). After de novo assembly of the obtained reads, 112,015 unigenes were generated. Analysis of differentially expressed genes (DEGs) showed that 2026, 940, and 2346 genes were up-regulated and 1468, 707, and 1759 were down-regulated in CT, DT, and CTDT samples, respectively. Among all the DEGs, 182 up-regulated and 116 down-regulated genes were identified in all the treatment groups. Analysis of metabolic pathways and regulatory networks associated with the DEGs revealed overlaps and cross-talk between cold and drought stress response pathways. The expression profiles of the selected DEGs in CT, DT, and CTDT samples were characterized and confirmed by quantitative RT-PCR. These DEGs and metabolic pathways may play important roles in the response of D. spiculifolius to the combined stress. Functional characterization of these genes and pathways will provide new targets for enhancement of plant stress tolerance through genetic manipulation.

DNA microarray-based PCR ribotyping of Clostridium difficile.

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Schneeberg, Alexander; Ehricht, Ralf; Slickers, Peter; Baier, Vico; Neubauer, Heinrich; Zimmermann, Stefan; Rabold, Denise; Lübke-Becker, Antina; Seyboldt, Christian

2015-02-01

This study presents a DNA microarray-based assay for fast and simple PCR ribotyping of Clostridium difficile strains. Hybridization probes were designed to query the modularly structured intergenic spacer region (ISR), which is also the template for conventional and PCR ribotyping with subsequent capillary gel electrophoresis (seq-PCR) ribotyping. The probes were derived from sequences available in GenBank as well as from theoretical ISR module combinations. A database of reference hybridization patterns was set up from a collection of 142 well-characterized C. difficile isolates representing 48 seq-PCR ribotypes. The reference hybridization patterns calculated by the arithmetic mean were compared using a similarity matrix analysis. The 48 investigated seq-PCR ribotypes revealed 27 array profiles that were clearly distinguishable. The most frequent human-pathogenic ribotypes 001, 014/020, 027, and 078/126 were discriminated by the microarray. C. difficile strains related to 078/126 (033, 045/FLI01, 078, 126, 126/FLI01, 413, 413/FLI01, 598, 620, 652, and 660) and 014/020 (014, 020, and 449) showed similar hybridization patterns, confirming their genetic relatedness, which was previously reported. A panel of 50 C. difficile field isolates was tested by seq-PCR ribotyping and the DNA microarray-based assay in parallel. Taking into account that the current version of the microarray does not discriminate some closely related seq-PCR ribotypes, all isolates were typed correctly. Moreover, seq-PCR ribotypes without reference profiles available in the database (ribotype 009 and 5 new types) were correctly recognized as new ribotypes, confirming the performance and expansion potential of the microarray. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Comprehensive transcriptome assembly of Chickpea (Cicer arietinum L. using sanger and next generation sequencing platforms: development and applications.

Directory of Open Access Journals (Sweden)

Himabindu Kudapa

Full Text Available A comprehensive transcriptome assembly of chickpea has been developed using 134.95 million Illumina single-end reads, 7.12 million single-end FLX/454 reads and 139,214 Sanger expressed sequence tags (ESTs from >17 genotypes. This hybrid transcriptome assembly, referred to as Cicer arietinumTranscriptome Assembly version 2 (CaTA v2, available at http://data.comparative-legumes.org/transcriptomes/cicar/lista_cicar-201201, comprising 46,369 transcript assembly contigs (TACs has an N50 length of 1,726 bp and a maximum contig size of 15,644 bp. Putative functions were determined for 32,869 (70.8% of the TACs and gene ontology assignments were determined for 21,471 (46.3%. The new transcriptome assembly was compared with the previously available chickpea transcriptome assemblies as well as to the chickpea genome. Comparative analysis of CaTA v2 against transcriptomes of three legumes - Medicago, soybean and common bean, resulted in 27,771 TACs common to all three legumes indicating strong conservation of genes across legumes. CaTA v2 was also used for identification of simple sequence repeats (SSRs and intron spanning regions (ISRs for developing molecular markers. ISRs were identified by aligning TACs to the Medicago genome, and their putative mapping positions at chromosomal level were identified using transcript map of chickpea. Primer pairs were designed for 4,990 ISRs, each representing a single contig for which predicted positions are inferred and distributed across eight linkage groups. A subset of randomly selected ISRs representing all eight chickpea linkage groups were validated on five chickpea genotypes and showed 20% polymorphism with average polymorphic information content (PIC of 0.27. In summary, the hybrid transcriptome assembly developed and novel markers identified can be used for a variety of applications such as gene discovery, marker-trait association, diversity analysis etc., to advance genetics research and breeding

Identification of Bacillus Probiotics Isolated from Soil Rhizosphere Using 16S rRNA, recA, rpoB Gene Sequencing and RAPD-PCR.

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Mohkam, Milad; Nezafat, Navid; Berenjian, Aydin; Mobasher, Mohammad Ali; Ghasemi, Younes

2016-03-01

Some Bacillus species, especially Bacillus subtilis and Bacillus pumilus groups, have highly similar 16S rRNA gene sequences, which are hard to identify based on 16S rDNA sequence analysis. To conquer this drawback, rpoB, recA sequence analysis along with randomly amplified polymorphic (RAPD) fingerprinting was examined as an alternative method for differentiating Bacillus species. The 16S rRNA, rpoB and recA genes were amplified via a polymerase chain reaction using their specific primers. The resulted PCR amplicons were sequenced, and phylogenetic analysis was employed by MEGA 6 software. Identification based on 16S rRNA gene sequencing was underpinned by rpoB and recA gene sequencing as well as RAPD-PCR technique. Subsequently, concatenation and phylogenetic analysis showed that extent of diversity and similarity were better obtained by rpoB and recA primers, which are also reinforced by RAPD-PCR methods. However, in one case, these approaches failed to identify one isolate, which in combination with the phenotypical method offsets this issue. Overall, RAPD fingerprinting, rpoB and recA along with concatenated genes sequence analysis discriminated closely related Bacillus species, which highlights the significance of the multigenic method in more precisely distinguishing Bacillus strains. This research emphasizes the benefit of RAPD fingerprinting, rpoB and recA sequence analysis superior to 16S rRNA gene sequence analysis for suitable and effective identification of Bacillus species as recommended for probiotic products.

Ras mutations are rare in solitary cold and toxic thyroid nodules.

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Krohn, K; Reske, A; Ackermann, F; Müller, A; Paschke, R

2001-08-01

Activation of ras proto-oncogenes as a result of point mutations is detectable in a significant percentage of most types of tumour. Similar to neoplasms of other organs, mutations of all three ras genes can be found in thyroid tumours. H-, K- and N-ras mutations have been detected in up to 20% of follicular adenomas and adenomatous nodules which were not functionally characterized. This raises the question as to whether ras mutations are specific for hypofunctional nodules and TSH receptor mutations for hyperfunctioning nodules. To investigate ras and TSH receptor mutations with respect to functional differentiation we studied 41 scintigraphically cold nodules and 47 toxic thyroid nodules. To address the likelihood of a somatic mutation we also studied the clonal origin of these tumours. Genomic DNA was extracted from nodular and surrounding tissue. Mutational hot spots in exons 1 and 2 of the H- and K-ras gene were PCR amplified and sequenced using big dye terminator chemistry. Denaturing gradient gel electrophoresis (DGGE) was used to verify sequencing results for the H-ras gene and to analyse the N-ras gene because its greater sensitivity in detecting somatic mutations. Clonality of nodular thyroid tissue was evaluated using X-Chromosome inactivation based on PCR amplification of the human androgen receptor locus. Monoclonal origin was detectable in 14 of 23 informative samples from cold thyroid nodules. In toxic thyroid nodules the frequency of clonal tissue was 20 in 30 informative cases. Only one point mutation could be found in the N-ras gene codon 61 (Gly to Arg) in a cold adenomatous nodule which was monoclonal. In toxic thyroid nodules no ras mutation was detectable. Our study suggests that ras mutations are rare in solitary cold and toxic thyroid nodules and that the frequent monoclonal origin of these tumours implies somatic mutations in genes other than H-, K- and N-ras.

A sweetpotato gene index established by de novo assembly of pyrosequencing and Sanger sequences and mining for gene-based microsatellite markers

Directory of Open Access Journals (Sweden)

Solis Julio

2010-10-01

Full Text Available Abstract Background Sweetpotato (Ipomoea batatas (L. Lam., a hexaploid outcrossing crop, is an important staple and food security crop in developing countries in Africa and Asia. The availability of genomic resources for sweetpotato is in striking contrast to its importance for human nutrition. Previously existing sequence data were restricted to around 22,000 expressed sequence tag (EST sequences and ~ 1,500 GenBank sequences. We have used 454 pyrosequencing to augment the available gene sequence information to enhance functional genomics and marker design for this plant species. Results Two quarter 454 pyrosequencing runs used two normalized cDNA collections from stems and leaves from drought-stressed sweetpotato clone Tanzania and yielded 524,209 reads, which were assembled together with 22,094 publically available expressed sequence tags into 31,685 sets of overlapping DNA segments and 34,733 unassembled sequences. Blastx comparisons with the UniRef100 database allowed annotation of 23,957 contigs and 15,342 singletons resulting in 24,657 putatively unique genes. Further, 27,119 sequences had no match to protein sequences of UniRef100database. On the basis of this gene index, we have identified 1,661 gene-based microsatellite sequences, of which 223 were selected for testing and 195 were successfully amplified in a test panel of 6 hexaploid (I. batatas and 2 diploid (I. trifida accessions. Conclusions The sweetpotato gene index is a useful source for functionally annotated sweetpotato gene sequences that contains three times more gene sequence information for sweetpotato than previous EST assemblies. A searchable version of the gene index, including a blastn function, is available at http://www.cipotato.org/sweetpotato_gene_index.

Yeast identification by sequencing, biochemical kits, MALDI-TOF MS and rep-PCR DNA fingerprinting.

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Zhao, Ying; Tsang, Chi-Ching; Xiao, Meng; Chan, Jasper F W; Lau, Susanna K P; Kong, Fanrong; Xu, Yingchun; Woo, Patrick C Y

2017-12-08

No study has comprehensively evaluated the performance of 28S nrDNA and ITS sequencing, commercial biochemical test kits, MALDI-TOF MS platforms, and the emerging rep-PCR DNA fingerprinting technology using a cohort of yeast strains collected from a clinical microbiology laboratory. In this study, using 71 clinically important yeast isolates (excluding Candida albicans) collected from a single centre, we determined the concordance of 28S nrDNA and ITS sequencing and evaluated the performance of two commercial test kits, two MALDI-TOF MS platforms, and rep-PCR DNA fingerprinting. 28S nrDNA and ITS sequencing showed complete agreement on the identities of the 71 isolates. Using sequencing results as the standard, 78.9% and 71.8% isolates were correctly identified using the API 20C AUX and Vitek 2 YST ID Card systems, respectively; and 90.1% and 80.3% isolates were correctly identified using the Bruker and Vitek MALDI-TOF MS platforms, respectively. Of the 18 strains belonging to the Candida parapsilosis species complex tested by DiversiLab automated rep-PCR DNA fingerprinting, all were identified only as Candida parapsilosis with similarities ≥93.2%, indicating the misidentification of Candida metapsilosis and Candida orthopsilosis. However, hierarchical cluster analysis of the rep-PCR DNA fingerprints of these three species within this species complex formed three different discrete clusters, indicating that this technology can potentially differentiate the three species. To achieve higher accuracies of identification, the databases of commercial biochemical test kits, MALDI-TOF MS platforms, and DiversiLab automated rep-PCR DNA fingerprinting needs further enrichment, particularly for uncommonly encountered yeast species. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

International Interlaboratory Digital PCR Study Demonstrating High Reproducibility for the Measurement of a Rare Sequence Variant.

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Whale, Alexandra S; Devonshire, Alison S; Karlin-Neumann, George; Regan, Jack; Javier, Leanne; Cowen, Simon; Fernandez-Gonzalez, Ana; Jones, Gerwyn M; Redshaw, Nicholas; Beck, Julia; Berger, Andreas W; Combaret, Valérie; Dahl Kjersgaard, Nina; Davis, Lisa; Fina, Frederic; Forshew, Tim; Fredslund Andersen, Rikke; Galbiati, Silvia; González Hernández, Álvaro; Haynes, Charles A; Janku, Filip; Lacave, Roger; Lee, Justin; Mistry, Vilas; Pender, Alexandra; Pradines, Anne; Proudhon, Charlotte; Saal, Lao H; Stieglitz, Elliot; Ulrich, Bryan; Foy, Carole A; Parkes, Helen; Tzonev, Svilen; Huggett, Jim F

2017-02-07

This study tested the claim that digital PCR (dPCR) can offer highly reproducible quantitative measurements in disparate laboratories. Twenty-one laboratories measured four blinded samples containing different quantities of a KRAS fragment encoding G12D, an important genetic marker for guiding therapy of certain cancers. This marker is challenging to quantify reproducibly using quantitative PCR (qPCR) or next generation sequencing (NGS) due to the presence of competing wild type sequences and the need for calibration. Using dPCR, 18 laboratories were able to quantify the G12D marker within 12% of each other in all samples. Three laboratories appeared to measure consistently outlying results; however, proper application of a follow-up analysis recommendation rectified their data. Our findings show that dPCR has demonstrable reproducibility across a large number of laboratories without calibration. This could enable the reproducible application of molecular stratification to guide therapy and, potentially, for molecular diagnostics.

Implementation of Cloud based next generation sequencing data analysis in a clinical laboratory.

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Onsongo, Getiria; Erdmann, Jesse; Spears, Michael D; Chilton, John; Beckman, Kenneth B; Hauge, Adam; Yohe, Sophia; Schomaker, Matthew; Bower, Matthew; Silverstein, Kevin A T; Thyagarajan, Bharat

2014-05-23

The introduction of next generation sequencing (NGS) has revolutionized molecular diagnostics, though several challenges remain limiting the widespread adoption of NGS testing into clinical practice. One such difficulty includes the development of a robust bioinformatics pipeline that can handle the volume of data generated by high-throughput sequencing in a cost-effective manner. Analysis of sequencing data typically requires a substantial level of computing power that is often cost-prohibitive to most clinical diagnostics laboratories. To address this challenge, our institution has developed a Galaxy-based data analysis pipeline which relies on a web-based, cloud-computing infrastructure to process NGS data and identify genetic variants. It provides additional flexibility, needed to control storage costs, resulting in a pipeline that is cost-effective on a per-sample basis. It does not require the usage of EBS disk to run a sample. We demonstrate the validation and feasibility of implementing this bioinformatics pipeline in a molecular diagnostics laboratory. Four samples were analyzed in duplicate pairs and showed 100% concordance in mutations identified. This pipeline is currently being used in the clinic and all identified pathogenic variants confirmed using Sanger sequencing further validating the software.

Sequence characterized amplified region (SCAR) markers-based ...

African Journals Online (AJOL)

ajl yemi

2011-12-19

Dec 19, 2011 ... reverse transcription polymerase chain reaction (RT-PCR), differential-display .... were synthesized by Sangon Biological Engineering Technology and. Services ..... to cold tolerance to scar markers in common carp. J. Dalian.

A Case Study into Microbial Genome Assembly Gap Sequences and Finishing Strategies.

Science.gov (United States)

Utturkar, Sagar M; Klingeman, Dawn M; Hurt, Richard A; Brown, Steven D

2017-01-01

This study characterized regions of DNA which remained unassembled by either PacBio and Illumina sequencing technologies for seven bacterial genomes. Two genomes were manually finished using bioinformatics and PCR/Sanger sequencing approaches and regions not assembled by automated software were analyzed. Gaps present within Illumina assemblies mostly correspond to repetitive DNA regions such as multiple rRNA operon sequences. PacBio gap sequences were evaluated for several properties such as GC content, read coverage, gap length, ability to form strong secondary structures, and corresponding annotations. Our hypothesis that strong secondary DNA structures blocked DNA polymerases and contributed to gap sequences was not accepted. PacBio assemblies had few limitations overall and gaps were explained as cumulative effect of lower than average sequence coverage and repetitive sequences at contig termini. An important aspect of the present study is the compilation of biological features that interfered with assembly and included active transposons, multiple plasmid sequences, phage DNA integration, and large sequence duplication. Our targeted genome finishing approach and systematic evaluation of the unassembled DNA will be useful for others looking to close, finish, and polish microbial genome sequences.

Advantages and Limitations of Ribosomal RNA PCR and DNA Sequencing for Identification of Bacteria in Cardiac Valves of Danish Patients

DEFF Research Database (Denmark)

Kemp, Michael; Bangsborg, Jette; Kjerulf, Anne

2013-01-01

of direct molecular identification should also address weaknesses, their relevance in the given setting, and possible improvements. In this study cardiac valves from 56 Danish patients referred for surgery for infective endocarditis were analysed by microscopy and culture as well as by PCR targeting part...... of the bacterial 16S rRNA gene followed by DNA sequencing of the PCR product. PCR and DNA sequencing identified significant bacteria in 49 samples from 43 patients, including five out of 13 culture-negative cases. No rare, exotic, or intracellular bacteria were identified. There was a general agreement between...... bacterial identity obtained by ribosomal PCR and DNA sequencing from the valves and bacterial isolates from blood culture. However, DNA sequencing of the 16S rRNA gene did not discriminate well among non-haemolytic streptococci, especially within the Streptococcus mitis group. Ribosomal PCR with subsequent...

Development and evaluation of a novel fast broad-range 16S ribosomal DNA PCR and sequencing assay for diagnosis of bacterial infective endocarditis: multi-year experience in a large Canadian healthcare zone and a literature review.

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Miller, Robert J H; Chow, Barbara; Pillai, Dylan; Church, Deirdre

2016-04-12

The study aimed to explore the sensitivity and specificity of a novel fast 16S rDNA PCR and sequencing assay for the improved diagnosis of infective endocarditis (IE) in patients with suspected native or prosthetic heart valve (HV) infection over a multi-year period at our cardiovascular center. Sixty-eight patients were prospectively enrolled who underwent HV replacement for suspected or confirmed IE between February 1, 2009 and September 1, 2014. Patient demographics, medical co-morbidities, Duke's criteria, culture results, and antibiotic therapy were collected by detailed chart reviews. Dual-priming oligonucleotide primers targeted to 500 bps of the V1-V3 region of the 16S rRNA gene were used to perform fast broad-range 16S rDNA PCR and Sanger sequencing on ribosomal DNA extracted from HV tissues. The performance/diagnostic efficiency of the molecular test was evaluated against blood cultures and Gram stain and culture of HV tissue in patients' with definite IE according to Duke's criteria. Fifty patients (73.5%) had definite IE and another 8 (11.8%) had possible IE according to Duke's criteria. Cardiac surgery was delayed an average of 15.4 days from the time of the patient's last positive blood culture, and appropriate antibiotic therapy was given in the pre-operative period. While 44/50 (88%) patients had a positive blood culture, HV tissue culture was only positive in 23 (46%) of them. Molecular testing of all HV tissues had sensitivity, specificity, NPV and PPV of 92, 77.8, 77.8 and 92% compared to 44, 100, 39.1 and 100% respectively for culture for diagnosis of definite IE. For prosthetic HV tissue, 16S rDNA PCR had sensitivity of 93% and specificity of 83% compared to 35 and 100% respectively for culture. A literature review showed that the diagnostic accuracy of our novel fast broad-range 16S rDNA PCR assay was similar or better than that of previously published studies. This novel fast broad-range 16S rDNA PCR/sequencing test had superior sensitivity

A safe an easy method for building consensus HIV sequences from 454 massively parallel sequencing data.

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Fernández-Caballero Rico, Jose Ángel; Chueca Porcuna, Natalia; Álvarez Estévez, Marta; Mosquera Gutiérrez, María Del Mar; Marcos Maeso, María Ángeles; García, Federico

2018-02-01

To show how to generate a consensus sequence from the information of massive parallel sequences data obtained from routine HIV anti-retroviral resistance studies, and that may be suitable for molecular epidemiology studies. Paired Sanger (Trugene-Siemens) and next-generation sequencing (NGS) (454 GSJunior-Roche) HIV RT and protease sequences from 62 patients were studied. NGS consensus sequences were generated using Mesquite, using 10%, 15%, and 20% thresholds. Molecular evolutionary genetics analysis (MEGA) was used for phylogenetic studies. At a 10% threshold, NGS-Sanger sequences from 17/62 patients were phylogenetically related, with a median bootstrap-value of 88% (IQR83.5-95.5). Association increased to 36/62 sequences, median bootstrap 94% (IQR85.5-98)], using a 15% threshold. Maximum association was at the 20% threshold, with 61/62 sequences associated, and a median bootstrap value of 99% (IQR98-100). A safe method is presented to generate consensus sequences from HIV-NGS data at 20% threshold, which will prove useful for molecular epidemiological studies. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Mixed Sequence Reader: A Program for Analyzing DNA Sequences with Heterozygous Base Calling

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Chang, Chun-Tien; Tsai, Chi-Neu; Tang, Chuan Yi; Chen, Chun-Houh; Lian, Jang-Hau; Hu, Chi-Yu; Tsai, Chia-Lung; Chao, Angel; Lai, Chyong-Huey; Wang, Tzu-Hao; Lee, Yun-Shien

2012-01-01

The direct sequencing of PCR products generates heterozygous base-calling fluorescence chromatograms that are useful for identifying single-nucleotide polymorphisms (SNPs), insertion-deletions (indels), short tandem repeats (STRs), and paralogous genes. Indels and STRs can be easily detected using the currently available Indelligent or ShiftDetector programs, which do not search reference sequences. However, the detection of other genomic variants remains a challenge due to the lack of appropriate tools for heterozygous base-calling fluorescence chromatogram data analysis. In this study, we developed a free web-based program, Mixed Sequence Reader (MSR), which can directly analyze heterozygous base-calling fluorescence chromatogram data in .abi file format using comparisons with reference sequences. The heterozygous sequences are identified as two distinct sequences and aligned with reference sequences. Our results showed that MSR may be used to (i) physically locate indel and STR sequences and determine STR copy number by searching NCBI reference sequences; (ii) predict combinations of microsatellite patterns using the Federal Bureau of Investigation Combined DNA Index System (CODIS); (iii) determine human papilloma virus (HPV) genotypes by searching current viral databases in cases of double infections; (iv) estimate the copy number of paralogous genes, such as β-defensin 4 (DEFB4) and its paralog HSPDP3. PMID:22778697

Flanking sequence determination and specific PCR identification of transgenic wheat B102-1-2.

Science.gov (United States)

Cao, Jijuan; Xu, Junyi; Zhao, Tongtong; Cao, Dongmei; Huang, Xin; Zhang, Piqiao; Luan, Fengxia

2014-01-01

The exogenous fragment sequence and flanking sequence between the exogenous fragment and recombinant chromosome of transgenic wheat B102-1-2 were successfully acquired using genome walking technology. The newly acquired exogenous fragment encoded the full-length sequence of transformed genes with transformed plasmid and corresponding functional genes including ubi, vector pBANF-bar, vector pUbiGUSPlus, vector HSP, reporter vector pUbiGUSPlus, promoter ubiquitin, and coli DH1. A specific polymerase chain reaction (PCR) identification method for transgenic wheat B102-1-2 was established on the basis of designed primers according to flanking sequence. This established specific PCR strategy was validated by using transgenic wheat, transgenic corn, transgenic soybean, transgenic rice, and non-transgenic wheat. A specifically amplified target band was observed only in transgenic wheat B102-1-2. Therefore, this method is characterized by high specificity, high reproducibility, rapid identification, and excellent accuracy for the identification of transgenic wheat B102-1-2.

A seminested PCR assay for detection and typing of human papillomavirus based on E1 gene sequences.

Science.gov (United States)

Cavalcante, Gustavo Henrique O; de Araújo, Josélio M G; Fernandes, José Veríssimo; Lanza, Daniel C F

2018-05-01

HPV infection is considered one of the leading causes of cervical cancer in the world. To date, more than 180 types of HPV have been described and viral typing is critical for defining the prognosis of cancer. In this work, a seminested PCR which allow fast and inexpensively detection and typing of HPV is presented. The system is based on the amplification of a variable length region within the viral gene E1, using three primers that potentially anneal in all HPV genomes. The amplicons produced in the first step can be identified by high resolution electrophoresis or direct sequencing. The seminested step includes nine specific primers which can be used in multiplex or individual reactions to discriminate the main types of HPV by amplicon size differentiation using agarose electrophoresis, reducing the time spent and cost per analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthetic internal control sequences to increase negative call veracity in multiplexed, quantitative PCR assays for Phakopsora pachyrhizi

Science.gov (United States)

Quantitative PCR (Q-PCR) utilizing specific primer sequences and a fluorogenic, 5’-exonuclease linear hydrolysis probe is well established as a detection and identification method for Phakopsora pachyrhizi, the soybean rust pathogen. Because of the extreme sensitivity of Q-PCR, the DNA of a single u...

IS1111 insertion sequences of Coxiella burnetii: characterization and use for repetitive element PCR-based differentiation of Coxiella burnetii isolates

Directory of Open Access Journals (Sweden)

Massung Robert F

2007-10-01

Full Text Available Abstract Background Coxiella burnetii contains the IS1111 transposase which is present 20 times in the Nine Mile phase I (9Mi/I genome. A single PCR primer that binds to each IS element, and primers specific to a region ~500-bp upstream of each of the 20 IS1111 elements were designed. The amplified products were characterized and used to develop a repetitive element PCR genotyping method. Results Isolates Nine Mile phase II, Nine Mile RSA 514, Nine Mile Baca, Scottish, Ohio, Australian QD, Henzerling phase I, Henzerling phase II, M44, KAV, PAV, Q238, Q195 and WAV were tested by PCR and compared to 9Mi/I. Sequencing was used to determine the exact differences in isolates which lacked specific IS elements or produced PCR products of differing size. From this data, an algorithm was created utilizing four primer pairs that allows for differentiation of unknown isolates into five genomic groups. Additional isolates (Priscilla Q177, Idaho Q, Qiyi, Poker Cat, Q229 and Q172 and nine veterinary samples were characterized using the algorithm which resulted in their placement into three distinct genomic groups. Conclusion Through this study significant differences, including missing elements and sequence alterations within and near IS element coding regions, were found between the isolates tested. Further, a method for differentiation of C. burnetii isolates into one of five genomic groups was created. This algorithm may ultimately help to determine the relatedness between known and unknown isolates of C. burnetii.

A novel PCR-based system for the detection of four species of human malaria parasites and Plasmodium knowlesi

Science.gov (United States)

Komaki-Yasuda, Kanako; Vincent, Jeanne Perpétue; Nakatsu, Masami; Kato, Yasuyuki; Ohmagari, Norio

2018-01-01

A microscopy-based diagnosis is the gold standard for the detection and identification of malaria parasites in a patient’s blood. However, the detection of cases involving a low number of parasites and the differentiation of species sometimes requires a skilled microscopist. Although PCR-based diagnostic methods are already known to be very powerful tools, the time required to apply such methods is still much longer in comparison to traditional microscopic observation. Thus, improvements to PCR systems are sought to facilitate the more rapid and accurate detection of human malaria parasites Plasmodium falciparum, P. vivax, P. ovale, and P. malariae, as well as P. knowlesi, which is a simian malaria parasite that is currently widely distributed in Southeast Asia. A nested PCR that targets the small subunit ribosomal RNA genes of malaria parasites was performed using a “fast PCR enzyme”. In the first PCR, universal primers for all parasite species were used. In the second PCR, inner-specific primers, which targeted sequences from P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi, were used. The PCR reaction time was reduced with the use of the “fast PCR enzyme”, with only 65 minutes required to perform the first and second PCRs. The specific primers only reacted with the sequences of their targeted parasite species and never cross-reacted with sequences from other species under the defined PCR conditions. The diagnoses of 36 clinical samples that were obtained using this new PCR system were highly consistent with the microscopic diagnoses. PMID:29370297

A novel PCR-based system for the detection of four species of human malaria parasites and Plasmodium knowlesi.

Directory of Open Access Journals (Sweden)

Kanako Komaki-Yasuda

Full Text Available A microscopy-based diagnosis is the gold standard for the detection and identification of malaria parasites in a patient's blood. However, the detection of cases involving a low number of parasites and the differentiation of species sometimes requires a skilled microscopist. Although PCR-based diagnostic methods are already known to be very powerful tools, the time required to apply such methods is still much longer in comparison to traditional microscopic observation. Thus, improvements to PCR systems are sought to facilitate the more rapid and accurate detection of human malaria parasites Plasmodium falciparum, P. vivax, P. ovale, and P. malariae, as well as P. knowlesi, which is a simian malaria parasite that is currently widely distributed in Southeast Asia. A nested PCR that targets the small subunit ribosomal RNA genes of malaria parasites was performed using a "fast PCR enzyme". In the first PCR, universal primers for all parasite species were used. In the second PCR, inner-specific primers, which targeted sequences from P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi, were used. The PCR reaction time was reduced with the use of the "fast PCR enzyme", with only 65 minutes required to perform the first and second PCRs. The specific primers only reacted with the sequences of their targeted parasite species and never cross-reacted with sequences from other species under the defined PCR conditions. The diagnoses of 36 clinical samples that were obtained using this new PCR system were highly consistent with the microscopic diagnoses.

Next-generation sequencing for genetic testing of familial colorectal cancer syndromes.

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Simbolo, Michele; Mafficini, Andrea; Agostini, Marco; Pedrazzani, Corrado; Bedin, Chiara; Urso, Emanuele D; Nitti, Donato; Turri, Giona; Scardoni, Maria; Fassan, Matteo; Scarpa, Aldo

2015-01-01

Genetic screening in families with high risk to develop colorectal cancer (CRC) prevents incurable disease and permits personalized therapeutic and follow-up strategies. The advancement of next-generation sequencing (NGS) technologies has revolutionized the throughput of DNA sequencing. A series of 16 probands for either familial adenomatous polyposis (FAP; 8 cases) or hereditary nonpolyposis colorectal cancer (HNPCC; 8 cases) were investigated for intragenic mutations in five CRC familial syndromes-associated genes (APC, MUTYH, MLH1, MSH2, MSH6) applying both a custom multigene Ion AmpliSeq NGS panel and conventional Sanger sequencing. Fourteen pathogenic variants were detected in 13/16 FAP/HNPCC probands (81.3 %); one FAP proband presented two co-existing pathogenic variants, one in APC and one in MUTYH. Thirteen of these 14 pathogenic variants were detected by both NGS and Sanger, while one MSH2 mutation (L280FfsX3) was identified only by Sanger sequencing. This is due to a limitation of the NGS approach in resolving sequences close or within homopolymeric stretches of DNA. To evaluate the performance of our NGS custom panel we assessed its capability to resolve the DNA sequences corresponding to 2225 pathogenic variants reported in the COSMIC database for APC, MUTYH, MLH1, MSH2, MSH6. Our NGS custom panel resolves the sequences where 2108 (94.7 %) of these variants occur. The remaining 117 mutations reside inside or in close proximity to homopolymer stretches; of these 27 (1.2 %) are imprecisely identified by the software but can be resolved by visual inspection of the region, while the remaining 90 variants (4.0 %) are blind spots. In summary, our custom panel would miss 4 % (90/2225) of pathogenic variants that would need a small set of Sanger sequencing reactions to be solved. The multiplex NGS approach has the advantage of analyzing multiple genes in multiple samples simultaneously, requiring only a reduced number of Sanger sequences to resolve

A novel PCR-based marker for identifying Ns chromosomes in wheat-Psathyrostachys huashanica Keng derivative lines

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J. Wang

2013-10-01

Full Text Available Psathyrostachys huashanica Keng is an endangered species that is endemic to China, which provides an important gene pool for wheat improvement. We developed a quick and reliable PCR-based diagnostic assay to accurately and efficiently detect P. huashanica DNA sequences from introgression lines, which was based on a species-specific marker derived from genomic DNA. The 900-bp PCR-amplified band used as a P. huashanica-specific RAPD marker was tested with 21 different plant species and was converted into a sequence-characterized amplified region (SCAR marker by cloning and sequencing the selected fragments (pHs11. This SCAR marker, which was designated as RHS23, could clearly distinguish the presence of P. huashanica DNA repetitive sequences in wheat-P. huashanica derivative lines. The specificity of the marker was validated using 21 different plant species and a complete set of wheat-P. huashanica disomic addition lines (1Ns–7Ns, 2n=44=22II. This specific sequence targeted the Ns genome of P. huashanica and it was present in all the seven P. huashanica chromosomes. Therefore, this SCAR marker is specific for P. huashanica chromosomes and may be used in the identification of alien repetitive sequences in large gene pools. This diagnostic PCR assay for screening the target genetic material may play a key role in marker-assisted selective breeding programs.

The analysis of novel microRNA mimic sequences in cancer cells reveals lack of specificity in stem-loop RT-qPCR-based microRNA detection.

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Winata, Patrick; Williams, Marissa; McGowan, Eileen; Nassif, Najah; van Zandwijk, Nico; Reid, Glen

2017-11-17

MicroRNAs are frequently downregulated in cancer, and restoring expression has tumour suppressive activity in tumour cells. Our recent phase I clinical trial investigated microRNA-based therapy in patients with malignant pleural mesothelioma. Treatment with TargomiRs, microRNA mimics with novel sequence packaged in EGFR antibody-targeted bacterial minicells, revealed clear signs of clinical activity. In order to detect delivery of microRNA mimics to tumour cells in future clinical trials, we tested hydrolysis probe-based assays specific for the sequence of the novel mimics in transfected mesothelioma cell lines using RT-qPCR. The custom assays efficiently and specifically amplified the consensus mimics. However, we found that these assays gave a signal when total RNA from untransfected and control mimic-transfected cells were used as templates. Further investigation revealed that the reverse transcription step using stem-loop primers appeared to introduce substantial non-specific amplification with either total RNA or synthetic RNA templates. This suggests that reverse transcription using stem-loop primers suffers from an intrinsic lack of specificity for the detection of highly similar microRNAs in the same family, especially when analysing total RNA. These results suggest that RT-qPCR is unlikely to be an effective means to detect delivery of microRNA mimic-based drugs to tumour cells in patients.

A TaqMan real-time PCR-based assay for the identification of Fasciola spp.

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Alasaad, Samer; Soriguer, Ramón C; Abu-Madi, Marawan; El Behairy, Ahmed; Jowers, Michael J; Baños, Pablo Díez; Píriz, Ana; Fickel, Joerns; Zhu, Xing-Quan

2011-06-30

Real time quantitative PCR (qPCR) is one of the key technologies of the post-genome era, with clear advantages compared to normal end-point PCR. In this paper, we report the first qPCR-based assay for the identification of Fasciola spp. Based on sequences of the second internal transcribed spacers (ITS-2) of the ribosomal rRNA gene, we used a set of genus-specific primers for Fasciola ITS-2 amplification, and we designed species-specific internal TaqMan probes to identify F. hepatica and F. gigantica, as well as the hybrid 'intermediate'Fasciola. These primers and probes were used for the highly specific, sensitive, and simple identification of Fasciola species collected from different animal host from China, Spain, Niger and Egypt. The novel qPCR-based technique for the identification of Fasciola spp. may provide a useful tool for the epidemiological investigation of Fasciola infection, including their intermediate snail hosts. Copyright © 2011 Elsevier B.V. All rights reserved.

De novo transcriptome sequencing of Isaria cateniannulata and comparative analysis of gene expression in response to heat and cold stresses.

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Dingfeng Wang

Full Text Available Isaria cateniannulata is a very important and virulent entomopathogenic fungus that infects many insect pest species. Although I. cateniannulata is commonly exposed to extreme environmental temperature conditions, little is known about its molecular response mechanism to temperature stress. Here, we sequenced and de novo assembled the transcriptome of I. cateniannulata in response to high and low temperature stresses using Illumina RNA-Seq technology. Our assembly encompassed 17,514 unigenes (mean length = 1,197 bp, in which 11,445 unigenes (65.34% showed significant similarities to known sequences in NCBI non-redundant protein sequences (Nr database. Using digital gene expression analysis, 4,483 differentially expressed genes (DEGs were identified after heat treatment, including 2,905 up-regulated genes and 1,578 down-regulated genes. Under cold stress, 1,927 DEGs were identified, including 1,245 up-regulated genes and 682 down-regulated genes. The expression patterns of 18 randomly selected candidate DEGs resulting from quantitative real-time PCR (qRT-PCR were consistent with their transcriptome analysis results. Although DEGs were involved in many pathways, we focused on the genes that were involved in endocytosis: In heat stress, the pathway of clathrin-dependent endocytosis (CDE was active; however at low temperature stresses, the pathway of clathrin-independent endocytosis (CIE was active. Besides, four categories of DEGs acting as temperature sensors were observed, including cell-wall-major-components-metabolism-related (CWMCMR genes, heat shock protein (Hsp genes, intracellular-compatible-solutes-metabolism-related (ICSMR genes and glutathione S-transferase (GST. These results enhance our understanding of the molecular mechanisms of I. cateniannulata in response to temperature stresses and provide a valuable resource for the future investigations.

Identification of two novel pathogenic compound heterozygous MYO7A mutations in Usher syndrome by whole exome sequencing.

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Jia, Ying; Li, Xiaoge; Yang, Dong; Xu, Yi; Guo, Ying; Li, Xin

2018-01-01

The current study aims to identify the pathogenic sites in a core pedigree of Usher syndrome (USH). A core pedigree of USH was analyzed by whole exome sequencing (WES). Mutations were verified by polymerase chain reaction (PCR) amplification and Sanger sequencing. Two pathogenic variations (c.849+2T>C and c.5994G>A) in MYO7A were successfully identified and individually separated from parents. One variant (c.849+2T>C) was nonsense mutation, causing the protein terminated in advance, and the other one (c.5994G>A) located near the boundary of exon could cause aberrant splicing. This study provides a meaningful exploration for identification of clinical core genetic pedigrees. Copyright © 2017 Elsevier B.V. All rights reserved.

External and semi-internal controls for PCR amplification of homologous sequences in mixed templates

DEFF Research Database (Denmark)

Kalle, Elena; Gulevich, Alexander; Rensing, Christopher Günther T

2013-01-01

as an acceptable alternative. In order to evaluate the effects of inhibitors, a model multi-template mix was amplified in a mixture with DNAse-treated sample. Semi-internal control allowed establishment of intervals for robust PCR performance for different samples, thus enabling correct comparison of the samples......In a mixed template, the presence of homologous target DNA sequences creates environments that almost inevitably give rise to artifacts and biases during PCR. Heteroduplexes, chimeras, and skewed template-to-product ratios are the exclusive attributes of mixed template PCR and never occur....... This study demonstrated the efficiency of a model mixed template as an adequate external amplification control for a particular PCR application. The conditions of multi-template PCR do not allow implementation of a classic internal control; therefore we developed a convenient semi-internal control...

Lactobacillus strain diversity based on partial hsp60 gene sequences and design of PCR-restriction fragment length polymorphism assays for species identification and differentiation.

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Blaiotta, Giuseppe; Fusco, Vincenzina; Ercolini, Danilo; Aponte, Maria; Pepe, Olimpia; Villani, Francesco

2008-01-01

A phylogenetic tree showing diversities among 116 partial (499-bp) Lactobacillus hsp60 (groEL, encoding a 60-kDa heat shock protein) nucleotide sequences was obtained and compared to those previously described for 16S rRNA and tuf gene sequences. The topology of the tree produced in this study showed a Lactobacillus species distribution similar, but not identical, to those previously reported. However, according to the most recent systematic studies, a clear differentiation of 43 single-species clusters was detected/identified among the sequences analyzed. The slightly higher variability of the hsp60 nucleotide sequences than of the 16S rRNA sequences offers better opportunities to design or develop molecular assays allowing identification and differentiation of either distant or very closely related Lactobacillus species. Therefore, our results suggest that hsp60 can be considered an excellent molecular marker for inferring the taxonomy and phylogeny of members of the genus Lactobacillus and that the chosen primers can be used in a simple PCR procedure allowing the direct sequencing of the hsp60 fragments. Moreover, in this study we performed a computer-aided restriction endonuclease analysis of all 499-bp hsp60 partial sequences and we showed that the PCR-restriction fragment length polymorphism (RFLP) patterns obtainable by using both endonucleases AluI and TacI (in separate reactions) can allow identification and differentiation of all 43 Lactobacillus species considered, with the exception of the pair L. plantarum/L. pentosus. However, the latter species can be differentiated by further analysis with Sau3AI or MseI. The hsp60 PCR-RFLP approach was efficiently applied to identify and to differentiate a total of 110 wild Lactobacillus strains (including closely related species, such as L. casei and L. rhamnosus or L. plantarum and L. pentosus) isolated from cheese and dry-fermented sausages.

Nested PCR Biases in Interpreting Microbial Community Structure in 16S rRNA Gene Sequence Datasets.

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Yu, Guoqin; Fadrosh, Doug; Goedert, James J; Ravel, Jacques; Goldstein, Alisa M

2015-01-01

Sequencing of the PCR-amplified 16S rRNA gene has become a common approach to microbial community investigations in the fields of human health and environmental sciences. This approach, however, is difficult when the amount of DNA is too low to be amplified by standard PCR. Nested PCR can be employed as it can amplify samples with DNA concentration several-fold lower than standard PCR. However, potential biases with nested PCRs that could affect measurement of community structure have received little attention. In this study, we used 17 DNAs extracted from vaginal swabs and 12 DNAs extracted from stool samples to study the influence of nested PCR amplification of the 16S rRNA gene on the estimation of microbial community structure using Illumina MiSeq sequencing. Nested and standard PCR methods were compared on alpha- and beta-diversity metrics and relative abundances of bacterial genera. The effects of number of cycles in the first round of PCR (10 vs. 20) and microbial diversity (relatively low in vagina vs. high in stool) were also investigated. Vaginal swab samples showed no significant difference in alpha diversity or community structure between nested PCR and standard PCR (one round of 40 cycles). Stool samples showed significant differences in alpha diversity (except Shannon's index) and relative abundance of 13 genera between nested PCR with 20 cycles in the first round and standard PCR (Pnested PCR with 10 cycles in the first round and standard PCR. Operational taxonomic units (OTUs) that had low relative abundance (sum of relative abundance 27% of total OTUs in stool). Nested PCR introduced bias in estimated diversity and community structure. The bias was more significant for communities with relatively higher diversity and when more cycles were applied in the first round of PCR. We conclude that nested PCR could be used when standard PCR does not work. However, rare taxa detected by nested PCR should be validated by other technologies.

Sequence polymorphism can produce serious artefacts in real-time PCR assays: hard lessons from Pacific oysters

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Camara Mark D

2008-05-01

Full Text Available Abstract Background Since it was first described in the mid-1990s, quantitative real time PCR (Q-PCR has been widely used in many fields of biomedical research and molecular diagnostics. This method is routinely used to validate whole transcriptome analyses such as DNA microarrays, suppressive subtractive hybridization (SSH or differential display techniques such as cDNA-AFLP (Amplification Fragment Length Polymorphism. Despite efforts to optimize the methodology, misleading results are still possible, even when standard optimization approaches are followed. Results As part of a larger project aimed at elucidating transcriptome-level responses of Pacific oysters (Crassostrea gigas to various environmental stressors, we used microarrays and cDNA-AFLP to identify Expressed Sequence Tag (EST fragments that are differentially expressed in response to bacterial challenge in two heat shock tolerant and two heat shock sensitive full-sib oyster families. We then designed primers for these differentially expressed ESTs in order to validate the results using Q-PCR. For two of these ESTs we tested fourteen primer pairs each and using standard optimization methods (i.e. melt-curve analysis to ensure amplification of a single product, determined that of the fourteen primer pairs tested, six and nine pairs respectively amplified a single product and were thus acceptable for further testing. However, when we used these primers, we obtained different statistical outcomes among primer pairs, raising unexpected but serious questions about their reliability. We hypothesize that as a consequence of high levels of sequence polymorphism in Pacific oysters, Q-PCR amplification is sub-optimal in some individuals because sequence variants in priming sites results in poor primer binding and amplification in some individuals. This issue is similar to the high frequency of null alleles observed for microsatellite markers in Pacific oysters. Conclusion This study highlights

Use of PCR with Sequence-specific Primers for High-Resolution Human Leukocyte Antigen Typing of Patients with Narcolepsy

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Woo, Hye In; Joo, Eun Yeon; Lee, Kyung Wha

2012-01-01

Background Narcolepsy is a neurologic disorder characterized by excessive daytime sleepiness, symptoms of abnormal rapid eye movement (REM) sleep, and a strong association with HLA-DRB1*1501, -DQA1*0102, and -DQB1*0602. Here, we investigated the clinico-physical characteristics of Korean patients with narcolepsy, their HLA types, and the clinical utility of high-resolution PCR with sequence-specific primers (PCR-SSP) as a simple typing method for identifying DRB1*15/16, DQA1, and DQB1 alleles. Methods The study population consisted of 67 consecutively enrolled patients having unexplained daytime sleepiness and diagnosed narcolepsy based on clinical and neurological findings. Clinical data and the results of the multiple sleep latency test and polysomnography were reviewed, and HLA typing was performed using both high-resolution PCR-SSP and sequence-based typing (SBT). Results The 44 narcolepsy patients with cataplexy displayed significantly higher frequencies of DRB1*1501 (Pc= 0.003), DQA1*0102 (Pc=0.001), and DQB1*0602 (Pc=0.014) than the patients without cataplexy. Among patients carrying DRB1*1501-DQB1*0602 or DQA1*0102, the frequencies of a mean REM sleep latency of less than 20 min in nocturnal polysomnography and clinical findings, including sleep paralysis and hypnagogic hallucination were significantly higher. SBT and PCR-SSP showed 100% concordance for high-resolution typing of DRB1*15/16 alleles and DQA1 and DQB1 loci. Conclusions The clinical characteristics and somnographic findings of narcolepsy patients were associated with specific HLA alleles, including DRB1*1501, DQA1*0102, and DQB1*0602. Application of high-resolution PCR-SSP, a reliable and simple method, for both allele- and locus-specific HLA typing of DRB1*15/16, DQA1, and DQB1 would be useful for characterizing clinical status among subjects with narcolepsy. PMID:22259780

The effects of alignment quality, distance calculation method, sequence filtering, and region on the analysis of 16S rRNA gene-based studies.

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Patrick D Schloss

Full Text Available Pyrosequencing of PCR-amplified fragments that target variable regions within the 16S rRNA gene has quickly become a powerful method for analyzing the membership and structure of microbial communities. This approach has revealed and introduced questions that were not fully appreciated by those carrying out traditional Sanger sequencing-based methods. These include the effects of alignment quality, the best method of calculating pairwise genetic distances for 16S rRNA genes, whether it is appropriate to filter variable regions, and how the choice of variable region relates to the genetic diversity observed in full-length sequences. I used a diverse collection of 13,501 high-quality full-length sequences to assess each of these questions. First, alignment quality had a significant impact on distance values and downstream analyses. Specifically, the greengenes alignment, which does a poor job of aligning variable regions, predicted higher genetic diversity, richness, and phylogenetic diversity than the SILVA and RDP-based alignments. Second, the effect of different gap treatments in determining pairwise genetic distances was strongly affected by the variation in sequence length for a region; however, the effect of different calculation methods was subtle when determining the sample's richness or phylogenetic diversity for a region. Third, applying a sequence mask to remove variable positions had a profound impact on genetic distances by muting the observed richness and phylogenetic diversity. Finally, the genetic distances calculated for each of the variable regions did a poor job of correlating with the full-length gene. Thus, while it is tempting to apply traditional cutoff levels derived for full-length sequences to these shorter sequences, it is not advisable. Analysis of beta-diversity metrics showed that each of these factors can have a significant impact on the comparison of community membership and structure. Taken together, these results

A one-step, real-time PCR assay for rapid detection of rhinovirus.

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Do, Duc H; Laus, Stella; Leber, Amy; Marcon, Mario J; Jordan, Jeanne A; Martin, Judith M; Wadowsky, Robert M

2010-01-01

One-step, real-time PCR assays for rhinovirus have been developed for a limited number of PCR amplification platforms and chemistries, and some exhibit cross-reactivity with genetically similar enteroviruses. We developed a one-step, real-time PCR assay for rhinovirus by using a sequence detection system (Applied Biosystems; Foster City, CA). The primers were designed to amplify a 120-base target in the noncoding region of picornavirus RNA, and a TaqMan (Applied Biosystems) degenerate probe was designed for the specific detection of rhinovirus amplicons. The PCR assay had no cross-reactivity with a panel of 76 nontarget nucleic acids, which included RNAs from 43 enterovirus strains. Excellent lower limits of detection relative to viral culture were observed for the PCR assay by using 38 of 40 rhinovirus reference strains representing different serotypes, which could reproducibly detect rhinovirus serotype 2 in viral transport medium containing 10 to 10,000 TCID(50) (50% tissue culture infectious dose endpoint) units/ml of the virus. However, for rhinovirus serotypes 59 and 69, the PCR assay was less sensitive than culture. Testing of 48 clinical specimens from children with cold-like illnesses for rhinovirus by the PCR and culture assays yielded detection rates of 16.7% and 6.3%, respectively. For a batch of 10 specimens, the entire assay was completed in 4.5 hours. This real-time PCR assay enables detection of many rhinovirus serotypes with the Applied Biosystems reagent-instrument platform.

High-Throughput Next-Generation Sequencing of Polioviruses

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Montmayeur, Anna M.; Schmidt, Alexander; Zhao, Kun; Magaña, Laura; Iber, Jane; Castro, Christina J.; Chen, Qi; Henderson, Elizabeth; Ramos, Edward; Shaw, Jing; Tatusov, Roman L.; Dybdahl-Sissoko, Naomi; Endegue-Zanga, Marie Claire; Adeniji, Johnson A.; Oberste, M. Steven; Burns, Cara C.

2016-01-01

ABSTRACT The poliovirus (PV) is currently targeted for worldwide eradication and containment. Sanger-based sequencing of the viral protein 1 (VP1) capsid region is currently the standard method for PV surveillance. However, the whole-genome sequence is sometimes needed for higher resolution global surveillance. In this study, we optimized whole-genome sequencing protocols for poliovirus isolates and FTA cards using next-generation sequencing (NGS), aiming for high sequence coverage, efficiency, and throughput. We found that DNase treatment of poliovirus RNA followed by random reverse transcription (RT), amplification, and the use of the Nextera XT DNA library preparation kit produced significantly better results than other preparations. The average viral reads per total reads, a measurement of efficiency, was as high as 84.2% ± 15.6%. PV genomes covering >99 to 100% of the reference length were obtained and validated with Sanger sequencing. A total of 52 PV genomes were generated, multiplexing as many as 64 samples in a single Illumina MiSeq run. This high-throughput, sequence-independent NGS approach facilitated the detection of a diverse range of PVs, especially for those in vaccine-derived polioviruses (VDPV), circulating VDPV, or immunodeficiency-related VDPV. In contrast to results from previous studies on other viruses, our results showed that filtration and nuclease treatment did not discernibly increase the sequencing efficiency of PV isolates. However, DNase treatment after nucleic acid extraction to remove host DNA significantly improved the sequencing results. This NGS method has been successfully implemented to generate PV genomes for molecular epidemiology of the most recent PV isolates. Additionally, the ability to obtain full PV genomes from FTA cards will aid in facilitating global poliovirus surveillance. PMID:27927929

Targeted next-generation sequencing makes new molecular diagnoses and expands genotype-phenotype relationship in Ehlers-Danlos syndrome.

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Weerakkody, Ruwan A; Vandrovcova, Jana; Kanonidou, Christina; Mueller, Michael; Gampawar, Piyush; Ibrahim, Yousef; Norsworthy, Penny; Biggs, Jennifer; Abdullah, Abdulshakur; Ross, David; Black, Holly A; Ferguson, David; Cheshire, Nicholas J; Kazkaz, Hanadi; Grahame, Rodney; Ghali, Neeti; Vandersteen, Anthony; Pope, F Michael; Aitman, Timothy J

2016-11-01

Ehlers-Danlos syndrome (EDS) comprises a group of overlapping hereditary disorders of connective tissue with significant morbidity and mortality, including major vascular complications. We sought to identify the diagnostic utility of a next-generation sequencing (NGS) panel in a mixed EDS cohort. We developed and applied PCR-based NGS assays for targeted, unbiased sequencing of 12 collagen and aortopathy genes to a cohort of 177 unrelated EDS patients. Variants were scored blind to previous genetic testing and then compared with results of previous Sanger sequencing. Twenty-eight pathogenic variants in COL5A1/2, COL3A1, FBN1, and COL1A1 and four likely pathogenic variants in COL1A1, TGFBR1/2, and SMAD3 were identified by the NGS assays. These included all previously detected single-nucleotide and other short pathogenic variants in these genes, and seven newly detected pathogenic or likely pathogenic variants leading to clinically significant diagnostic revisions. Twenty-two variants of uncertain significance were identified, seven of which were in aortopathy genes and required clinical follow-up. Unbiased NGS-based sequencing made new molecular diagnoses outside the expected EDS genotype-phenotype relationship and identified previously undetected clinically actionable variants in aortopathy susceptibility genes. These data may be of value in guiding future clinical pathways for genetic diagnosis in EDS.Genet Med 18 11, 1119-1127.

A DEL phenotype attributed to RHD Exon 9 sequence deletion: slipped-strand mispairing and blood group polymorphisms.

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Lopez, Genghis H; Turner, Robyn M; McGowan, Eunike C; Schoeman, Elizna M; Scott, Stacy A; O'Brien, Helen; Millard, Glenda M; Roulis, Eileen V; Allen, Amanda J; Liew, Yew-Wah; Flower, Robert L; Hyland, Catherine A

2018-03-01

The RhD blood group antigen is extremely polymorphic and the DEL phenotype represents one such class of polymorphisms. The DEL phenotype prevalent in East Asian populations arises from a synonymous substitution defined as RHD*1227A. However, initially, based on genomic and cDNA studies, the genetic basis for a DEL phenotype in Taiwan was attributed to a deletion of RHD Exon 9 that was never verified at the genomic level by any other independent group. Here we investigate the genetic basis for a Caucasian donor with a DEL partial D phenotype and compare the genomic findings to those initial molecular studies. The 3'-region of the RHD gene was amplified by long-range polymerase chain reaction (PCR) for massively parallel sequencing. Primers were designed to encompass a deletion, flanking Exon 9, by standard PCR for Sanger sequencing. Targeted sequencing of exons and flanking introns was also performed. Genomic DNA exhibited a 1012-bp deletion spanning from Intron 8, across Exon 9 into Intron 9. The deletion breakpoints occurred between two 25-bp repeat motifs flanking Exon 9 such that one repeat sequence remained. Deletion mutations bordered by repeat sequences are a hallmark of slipped-strand mispairing (SSM) event. We propose this genetic mechanism generated the germline deletion in the Caucasian donor. Extensive studies show that the RHD*1227A is the most prevalent DEL allele in East Asian populations and may have confounded the initial molecular studies. Review of the literature revealed that the SSM model explains some of the extreme polymorphisms observed in the clinically significant RhD blood group antigen. © 2017 AABB.

PCR amplification of repetitive sequences as a possible approach in relative species quantification

DEFF Research Database (Denmark)

Ballin, Nicolai Zederkopff; Vogensen, Finn Kvist; Karlsson, Anders H

2012-01-01

Abstract Both relative and absolute quantifications are possible in species quantification when single copy genomic DNA is used. However, amplification of single copy genomic DNA does not allow a limit of detection as low as one obtained from amplification of repetitive sequences. Amplification...... of repetitive sequences is therefore frequently used in absolute quantification but problems occur in relative quantification as the number of repetitive sequences is unknown. A promising approach was developed where data from amplification of repetitive sequences were used in relative quantification of species...... to relatively quantify the amount of chicken DNA in a binary mixture of chicken DNA and pig DNA. However, the designed PCR primers lack the specificity required for regulatory species control....

Spectrum of benzo[a]pyrene-induced mutations in the Pig-a gene of L5178YTk+/- cells identified with next generation sequencing.

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Revollo, Javier; Wang, Yiying; McKinzie, Page; Dad, Azra; Pearce, Mason; Heflich, Robert H; Dobrovolsky, Vasily N

2017-12-01

We used Sanger sequencing and next generation sequencing (NGS) for analysis of mutations in the endogenous X-linked Pig-a gene of clonally expanded L5178YTk +/- cells. The clones developed from single cells that were sorted on a flow cytometer based upon the expression pattern of the GPI-anchored marker, CD90, on their surface. CD90-deficient and CD90-proficient cells were sorted from untreated cultures and CD90-deficient cells were sorted from cultures treated with benzo[a]pyrene (B[a]P). Pig-a mutations were identified in all clones developed from CD90-deficient cells; no Pig-a mutations were found in clones of CD90-proficient cells. The spectrum of B[a]P-induced Pig-a mutations was dominated by basepair substitutions, small insertions and deletions at G:C, or at sequences rich in G:C content. We observed high concordance between Pig-a mutations determined by Sanger sequencing and by NGS, but NGS was able to identify mutations in samples that were difficult to analyze by Sanger sequencing (e.g., mixtures of two mutant clones). Overall, the NGS method is a cost and labor efficient high throughput approach for analysis of a large number of mutant clones. Published by Elsevier B.V.

PCR-based methods for the detection of L1014 kdr mutation in Anopheles culicifacies sensu lato

Science.gov (United States)

Singh, Om P; Bali, Prerna; Hemingway, Janet; Subbarao, Sarala K; Dash, Aditya P; Adak, Tridibes

2009-01-01

Background Anopheles culicifacies s.l., a major malaria vector in India, has developed widespread resistance to DDT and is becoming resistant to pyrethroids–the only insecticide class recommended for the impregnation of bed nets. Knock-down resistance due to a point mutation in the voltage gated sodium channel at L1014 residue (kdr) is a common mechanism of resistance to DDT and pyrethroids. The selection of this resistance may pose a serious threat to the success of the pyrethroid-impregnated bed net programme. This study reports the presence of kdr mutation (L1014F) in a field population of An. culicifacies s.l. and three new PCR-based methods for kdr genotyping. Methods The IIS4-IIS5 linker to IIS6 segments of the para type voltage gated sodium channel gene of DDT and pyrethroid resistant An. culicifacies s.l. population from the Surat district of India was sequenced. This revealed the presence of an A-to-T substitution at position 1014 leading to a leucine-phenylalanine mutation (L1014F) in a few individuals. Three molecular methods viz. Allele Specific PCR (AS-PCR), an Amplification Refractory Mutation System (ARMS) and Primer Introduced Restriction Analysis-PCR (PIRA-PCR) were developed and tested for kdr genotyping. The specificity of the three assays was validated following DNA sequencing of the samples genotyped. Results The genotyping of this An. culicifacies s.l. population by the three PCR based assays provided consistent result and were in agreement with DNA sequencing result. A low frequency of the kdr allele mostly in heterozygous condition was observed in the resistant population. Frequencies of the different genotypes were in Hardy-Weinberg equilibrium. Conclusion The Leu-Phe mutation, which generates the kdr phenotype in many insects, was detected in a pyrethroid and DDT resistant An. culicifacies s.l. population. Three PCR-based methods were developed for kdr genotyping. All the three assays were specific. The ARMS method was refractory to non

PCR-based methods for the detection of L1014 kdr mutation in Anopheles culicifacies sensu lato

Directory of Open Access Journals (Sweden)

Dash Aditya P

2009-07-01

Full Text Available Abstract Background Anopheles culicifacies s.l., a major malaria vector in India, has developed widespread resistance to DDT and is becoming resistant to pyrethroids–the only insecticide class recommended for the impregnation of bed nets. Knock-down resistance due to a point mutation in the voltage gated sodium channel at L1014 residue (kdr is a common mechanism of resistance to DDT and pyrethroids. The selection of this resistance may pose a serious threat to the success of the pyrethroid-impregnated bed net programme. This study reports the presence of kdr mutation (L1014F in a field population of An. culicifacies s.l. and three new PCR-based methods for kdr genotyping. Methods The IIS4-IIS5 linker to IIS6 segments of the para type voltage gated sodium channel gene of DDT and pyrethroid resistant An. culicifacies s.l. population from the Surat district of India was sequenced. This revealed the presence of an A-to-T substitution at position 1014 leading to a leucine-phenylalanine mutation (L1014F in a few individuals. Three molecular methods viz. Allele Specific PCR (AS-PCR, an Amplification Refractory Mutation System (ARMS and Primer Introduced Restriction Analysis-PCR (PIRA-PCR were developed and tested for kdr genotyping. The specificity of the three assays was validated following DNA sequencing of the samples genotyped. Results The genotyping of this An. culicifacies s.l. population by the three PCR based assays provided consistent result and were in agreement with DNA sequencing result. A low frequency of the kdr allele mostly in heterozygous condition was observed in the resistant population. Frequencies of the different genotypes were in Hardy-Weinberg equilibrium. Conclusion The Leu-Phe mutation, which generates the kdr phenotype in many insects, was detected in a pyrethroid and DDT resistant An. culicifacies s.l. population. Three PCR-based methods were developed for kdr genotyping. All the three assays were specific. The ARMS method

Species-Level Phylogeny and Polyploid Relationships in Hordeum (Poaceae) Inferred by Next-Generation Sequencing and In Silico Cloning of Multiple Nuclear Loci.

Science.gov (United States)

Brassac, Jonathan; Blattner, Frank R

2015-09-01

Polyploidization is an important speciation mechanism in the barley genus Hordeum. To analyze evolutionary changes after allopolyploidization, knowledge of parental relationships is essential. One chloroplast and 12 nuclear single-copy loci were amplified by polymerase chain reaction (PCR) in all Hordeum plus six out-group species. Amplicons from each of 96 individuals were pooled, sheared, labeled with individual-specific barcodes and sequenced in a single run on a 454 platform. Reference sequences were obtained by cloning and Sanger sequencing of all loci for nine supplementary individuals. The 454 reads were assembled into contigs representing the 13 loci and, for polyploids, also homoeologues. Phylogenetic analyses were conducted for all loci separately and for a concatenated data matrix of all loci. For diploid taxa, a Bayesian concordance analysis and a coalescent-based dated species tree was inferred from all gene trees. Chloroplast matK was used to determine the maternal parent in allopolyploid taxa. The relative performance of different multilocus analyses in the presence of incomplete lineage sorting and hybridization was also assessed. The resulting multilocus phylogeny reveals for the first time species phylogeny and progenitor-derivative relationships of all di- and polyploid Hordeum taxa within a single analysis. Our study proves that it is possible to obtain a multilocus species-level phylogeny for di- and polyploid taxa by combining PCR with next-generation sequencing, without cloning and without creating a heavy load of sequence data. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

The utility of Next Generation Sequencing for molecular diagnostics in Rett syndrome.

Science.gov (United States)

Vidal, Silvia; Brandi, Núria; Pacheco, Paola; Gerotina, Edgar; Blasco, Laura; Trotta, Jean-Rémi; Derdak, Sophia; Del Mar O'Callaghan, Maria; Garcia-Cazorla, Àngels; Pineda, Mercè; Armstrong, Judith

2017-09-25

Rett syndrome (RTT) is an early-onset neurodevelopmental disorder that almost exclusively affects girls and is totally disabling. Three genes have been identified that cause RTT: MECP2, CDKL5 and FOXG1. However, the etiology of some of RTT patients still remains unknown. Recently, next generation sequencing (NGS) has promoted genetic diagnoses because of the quickness and affordability of the method. To evaluate the usefulness of NGS in genetic diagnosis, we present the genetic study of RTT-like patients using different techniques based on this technology. We studied 1577 patients with RTT-like clinical diagnoses and reviewed patients who were previously studied and thought to have RTT genes by Sanger sequencing. Genetically, 477 of 1577 patients with a RTT-like suspicion have been diagnosed. Positive results were found in 30% by Sanger sequencing, 23% with a custom panel, 24% with a commercial panel and 32% with whole exome sequencing. A genetic study using NGS allows the study of a larger number of genes associated with RTT-like symptoms simultaneously, providing genetic study of a wider group of patients as well as significantly reducing the response time and cost of the study.

Implementation of Targeted Next Generation Sequencing in Clinical Diagnostics

DEFF Research Database (Denmark)

Larsen, Martin Jakob; Burton, Mark; Thomassen, Mads

Accurate mutation detection is essential in clinical genetic diagnostics of monogenic hereditary diseases. Targeted next generation sequencing (NGS) provides a promising and cost-effective alternative to Sanger sequencing and MLPA analysis currently used in most diagnostic laboratories. One...... of mutation positive controls previously characterized by Sanger/MLPA analysis. Agilent SureSelect Target-Enrichment kits were used for capturing a set of genes associated with hereditary breast and ovarian cancer syndrome and a compilation of genes involved in multiple rare single gene disorders......, respectively. For diagnostics, the sequencing coverage is essential, wherefore a minimum coverage of 30x per nucleotide in the coding regions was used as our primary quality criterion. For the majority of the included genes, we obtained adequate gene coverage, in which we were able to detect 100% of the known...

Exponential Megapriming PCR (EMP) Cloning—Seamless DNA Insertion into Any Target Plasmid without Sequence Constraints

Science.gov (United States)

Ulrich, Alexander; Andersen, Kasper R.; Schwartz, Thomas U.

2012-01-01

We present a fast, reliable and inexpensive restriction-free cloning method for seamless DNA insertion into any plasmid without sequence limitation. Exponential megapriming PCR (EMP) cloning requires two consecutive PCR steps and can be carried out in one day. We show that EMP cloning has a higher efficiency than restriction-free (RF) cloning, especially for long inserts above 2.5 kb. EMP further enables simultaneous cloning of multiple inserts. PMID:23300917

Detection and Resolution of Cryptosporidium Species and Species Mixtures by Genus-Specific Nested PCR-Restriction Fragment Length Polymorphism Analysis, Direct Sequencing, and Cloning ▿

Science.gov (United States)

Ruecker, Norma J.; Hoffman, Rebecca M.; Chalmers, Rachel M.; Neumann, Norman F.

2011-01-01

Molecular methods incorporating nested PCR-restriction fragment length polymorphism (RFLP) analysis of the 18S rRNA gene of Cryptosporidium species were validated to assess performance based on limit of detection (LoD) and for detecting and resolving mixtures of species and genotypes within a single sample. The 95% LoD was determined for seven species (Cryptosporidium hominis, C. parvum, C. felis, C. meleagridis, C. ubiquitum, C. muris, and C. andersoni) and ranged from 7 to 11 plasmid template copies with overlapping 95% confidence limits. The LoD values for genomic DNA from oocysts on microscope slides were 7 and 10 template copies for C. andersoni and C. parvum, respectively. The repetitive nested PCR-RFLP slide protocol had an LoD of 4 oocysts per slide. When templates of two species were mixed in equal ratios in the nested PCR-RFLP reaction mixture, there was no amplification bias toward one species over another. At high ratios of template mixtures (>1:10), there was a reduction or loss of detection of the less abundant species by RFLP analysis, most likely due to heteroduplex formation in the later cycles of the PCR. Replicate nested PCR was successful at resolving many mixtures of Cryptosporidium at template concentrations near or below the LoD. The cloning of nested PCR products resulted in 17% of the cloned sequences being recombinants of the two original templates. Limiting-dilution nested PCR followed by the sequencing of PCR products resulted in no sequence anomalies, suggesting that this method is an effective and accurate way to study the species diversity of Cryptosporidium, particularly for environmental water samples, in which mixtures of parasites are common. PMID:21498746

Can abundance of protists be inferred from sequence data: a case study of foraminifera.

Directory of Open Access Journals (Sweden)

Alexandra A-T Weber

Full Text Available Protists are key players in microbial communities, yet our understanding of their role in ecosystem functioning is seriously impeded by difficulties in identification of protistan species and their quantification. Current microscopy-based methods used for determining the abundance of protists are tedious and often show a low taxonomic resolution. Recent development of next-generation sequencing technologies offered a very powerful tool for studying the richness of protistan communities. Still, the relationship between abundance of species and number of sequences remains subjected to various technical and biological biases. Here, we test the impact of some of these biological biases on sequence abundance of SSU rRNA gene in foraminifera. First, we quantified the rDNA copy number and rRNA expression level of three species of foraminifera by qPCR. Then, we prepared five mock communities with these species, two in equal proportions and three with one species ten times more abundant. The libraries of rDNA and cDNA of the mock communities were constructed, Sanger sequenced and the sequence abundance was calculated. The initial species proportions were compared to the raw sequence proportions as well as to the sequence abundance normalized by rDNA copy number and rRNA expression level per species. Our results showed that without normalization, all sequence data differed significantly from the initial proportions. After normalization, the congruence between the number of sequences and number of specimens was much better. We conclude that without normalization, species abundance determination based on sequence data was not possible because of the effect of biological biases. Nevertheless, by taking into account the variation of rDNA copy number and rRNA expression level we were able to infer species abundance, suggesting that our approach can be successful in controlled conditions.

Ion torrent personal genome machine sequencing for genomic typing of Neisseria meningitidis for rapid determination of multiple layers of typing information.

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Vogel, Ulrich; Szczepanowski, Rafael; Claus, Heike; Jünemann, Sebastian; Prior, Karola; Harmsen, Dag

2012-06-01

Neisseria meningitidis causes invasive meningococcal disease in infants, toddlers, and adolescents worldwide. DNA sequence-based typing, including multilocus sequence typing, analysis of genetic determinants of antibiotic resistance, and sequence typing of vaccine antigens, has become the standard for molecular epidemiology of the organism. However, PCR of multiple targets and consecutive Sanger sequencing provide logistic constraints to reference laboratories. Taking advantage of the recent development of benchtop next-generation sequencers (NGSs) and of BIGSdb, a database accommodating and analyzing genome sequence data, we therefore explored the feasibility and accuracy of Ion Torrent Personal Genome Machine (PGM) sequencing for genomic typing of meningococci. Three strains from a previous meningococcus serogroup B community outbreak were selected to compare conventional typing results with data generated by semiconductor chip-based sequencing. In addition, sequencing of the meningococcal type strain MC58 provided information about the general performance of the technology. The PGM technology generated sequence information for all target genes addressed. The results were 100% concordant with conventional typing results, with no further editing being necessary. In addition, the amount of typing information, i.e., nucleotides and target genes analyzed, could be substantially increased by the combined use of genome sequencing and BIGSdb compared to conventional methods. In the near future, affordable and fast benchtop NGS machines like the PGM might enable reference laboratories to switch to genomic typing on a routine basis. This will reduce workloads and rapidly provide information for laboratory surveillance, outbreak investigation, assessment of vaccine preventability, and antibiotic resistance gene monitoring.

Generic detection of poleroviruses using an RT-PCR assay targeting the RdRp coding sequence.

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Lotos, Leonidas; Efthimiou, Konstantinos; Maliogka, Varvara I; Katis, Nikolaos I

2014-03-01

In this study a two-step RT-PCR assay was developed for the generic detection of poleroviruses. The RdRp coding region was selected as the primers' target, since it differs significantly from that of other members in the family Luteoviridae and its sequence can be more informative than other regions in the viral genome. Species specific RT-PCR assays targeting the same region were also developed for the detection of the six most widespread poleroviral species (Beet mild yellowing virus, Beet western yellows virus, Cucurbit aphid-borne virus, Carrot red leaf virus, Potato leafroll virus and Turnip yellows virus) in Greece and the collection of isolates. These isolates along with other characterized ones were used for the evaluation of the generic PCR's detection range. The developed assay efficiently amplified a 593bp RdRp fragment from 46 isolates of 10 different Polerovirus species. Phylogenetic analysis using the generic PCR's amplicon sequence showed that although it cannot accurately infer evolutionary relationships within the genus it can differentiate poleroviruses at the species level. Overall, the described generic assay could be applied for the reliable detection of Polerovirus infections and, in combination with the specific PCRs, for the identification of new and uncharacterized species in the genus. Copyright © 2013 Elsevier B.V. All rights reserved.

Allocation and sequencing in 1-out-of-N heterogeneous cold-standby systems: Multi-objective harmony search with dynamic parameters tuning

International Nuclear Information System (INIS)

Valaei, M.R.; Behnamian, J.

2017-01-01

A redundancy allocation is a famous problem in reliability sciences. A lot of researcher investigated about this problem, but a few of them focus on heterogeneous 1-out-of-N: G cold-standby redundancy in each subsystem. This paper considers a redundancy allocation problem (RAP) and standby element sequencing problem (SESP) for 1-out-of-N: G heterogeneous cold-standby system, simultaneously. Moreover, here, maximizing reliability of cold-standby allocation and minimizing cost of buying and time-independent elements are considered as two conflict objectives. This problem is NP-Hard and consequently, devizing a metaheuristic to solve this problem, especially for large-sized instances, is highly desirable. In this paper, we propose a multi-objective harmony search. Based on Taguchi experimental design, we, also, present a new parameters tuning method to improve the proposed algorithm. - Graphical abstract: Example of solution encoding. - Highlights: • This paper considers a redundancy allocation and standby element sequencing problem. • To solve this problem, a multi-objective harmony search algorithm is proposed. • Dynamic parameters tuning method is applied to improved the algorithm. • With this method, sensitivity of the algorithm to initial parameters is reduced.

Introduction on Using the FastPCR Software and the Related Java Web Tools for PCR and Oligonucleotide Assembly and Analysis.

Science.gov (United States)

Kalendar, Ruslan; Tselykh, Timofey V; Khassenov, Bekbolat; Ramanculov, Erlan M

2017-01-01

This chapter introduces the FastPCR software as an integrated tool environment for PCR primer and probe design, which predicts properties of oligonucleotides based on experimental studies of the PCR efficiency. The software provides comprehensive facilities for designing primers for most PCR applications and their combinations. These include the standard PCR as well as the multiplex, long-distance, inverse, real-time, group-specific, unique, overlap extension PCR for multi-fragments assembling cloning and loop-mediated isothermal amplification (LAMP). It also contains a built-in program to design oligonucleotide sets both for long sequence assembly by ligase chain reaction and for design of amplicons that tile across a region(s) of interest. The software calculates the melting temperature for the standard and degenerate oligonucleotides including locked nucleic acid (LNA) and other modifications. It also provides analyses for a set of primers with the prediction of oligonucleotide properties, dimer and G/C-quadruplex detection, linguistic complexity as well as a primer dilution and resuspension calculator. The program consists of various bioinformatical tools for analysis of sequences with the GC or AT skew, CG% and GA% content, and the purine-pyrimidine skew. It also analyzes the linguistic sequence complexity and performs generation of random DNA sequence as well as restriction endonucleases analysis. The program allows to find or create restriction enzyme recognition sites for coding sequences and supports the clustering of sequences. It performs efficient and complete detection of various repeat types with visual display. The FastPCR software allows the sequence file batch processing that is essential for automation. The program is available for download at http://primerdigital.com/fastpcr.html , and its online version is located at http://primerdigital.com/tools/pcr.html .

Exponential megapriming PCR (EMP cloning--seamless DNA insertion into any target plasmid without sequence constraints.

Directory of Open Access Journals (Sweden)

Alexander Ulrich

Full Text Available We present a fast, reliable and inexpensive restriction-free cloning method for seamless DNA insertion into any plasmid without sequence limitation. Exponential megapriming PCR (EMP cloning requires two consecutive PCR steps and can be carried out in one day. We show that EMP cloning has a higher efficiency than restriction-free (RF cloning, especially for long inserts above 2.5 kb. EMP further enables simultaneous cloning of multiple inserts.

International interlaboratory study comparing single organism 16S rRNA gene sequencing data: Beyond consensus sequence comparisons

Science.gov (United States)

Olson, Nathan D.; Lund, Steven P.; Zook, Justin M.; Rojas-Cornejo, Fabiola; Beck, Brian; Foy, Carole; Huggett, Jim; Whale, Alexandra S.; Sui, Zhiwei; Baoutina, Anna; Dobeson, Michael; Partis, Lina; Morrow, Jayne B.

2015-01-01

This study presents the results from an interlaboratory sequencing study for which we developed a novel high-resolution method for comparing data from different sequencing platforms for a multi-copy, paralogous gene. The combination of PCR amplification and 16S ribosomal RNA gene (16S rRNA) sequencing has revolutionized bacteriology by enabling rapid identification, frequently without the need for culture. To assess variability between laboratories in sequencing 16S rRNA, six laboratories sequenced the gene encoding the 16S rRNA from Escherichia coli O157:H7 strain EDL933 and Listeria monocytogenes serovar 4b strain NCTC11994. Participants performed sequencing methods and protocols available in their laboratories: Sanger sequencing, Roche 454 pyrosequencing®, or Ion Torrent PGM®. The sequencing data were evaluated on three levels: (1) identity of biologically conserved position, (2) ratio of 16S rRNA gene copies featuring identified variants, and (3) the collection of variant combinations in a set of 16S rRNA gene copies. The same set of biologically conserved positions was identified for each sequencing method. Analytical methods using Bayesian and maximum likelihood statistics were developed to estimate variant copy ratios, which describe the ratio of nucleotides at each identified biologically variable position, as well as the likely set of variant combinations present in 16S rRNA gene copies. Our results indicate that estimated variant copy ratios at biologically variable positions were only reproducible for high throughput sequencing methods. Furthermore, the likely variant combination set was only reproducible with increased sequencing depth and longer read lengths. We also demonstrate novel methods for evaluating variable positions when comparing multi-copy gene sequence data from multiple laboratories generated using multiple sequencing technologies. PMID:27077030

International interlaboratory study comparing single organism 16S rRNA gene sequencing data: Beyond consensus sequence comparisons

Directory of Open Access Journals (Sweden)

Nathan D. Olson

2015-03-01

Full Text Available This study presents the results from an interlaboratory sequencing study for which we developed a novel high-resolution method for comparing data from different sequencing platforms for a multi-copy, paralogous gene. The combination of PCR amplification and 16S ribosomal RNA gene (16S rRNA sequencing has revolutionized bacteriology by enabling rapid identification, frequently without the need for culture. To assess variability between laboratories in sequencing 16S rRNA, six laboratories sequenced the gene encoding the 16S rRNA from Escherichia coli O157:H7 strain EDL933 and Listeria monocytogenes serovar 4b strain NCTC11994. Participants performed sequencing methods and protocols available in their laboratories: Sanger sequencing, Roche 454 pyrosequencing®, or Ion Torrent PGM®. The sequencing data were evaluated on three levels: (1 identity of biologically conserved position, (2 ratio of 16S rRNA gene copies featuring identified variants, and (3 the collection of variant combinations in a set of 16S rRNA gene copies. The same set of biologically conserved positions was identified for each sequencing method. Analytical methods using Bayesian and maximum likelihood statistics were developed to estimate variant copy ratios, which describe the ratio of nucleotides at each identified biologically variable position, as well as the likely set of variant combinations present in 16S rRNA gene copies. Our results indicate that estimated variant copy ratios at biologically variable positions were only reproducible for high throughput sequencing methods. Furthermore, the likely variant combination set was only reproducible with increased sequencing depth and longer read lengths. We also demonstrate novel methods for evaluating variable positions when comparing multi-copy gene sequence data from multiple laboratories generated using multiple sequencing technologies.

Diagnosis of clinical samples spotted on FTA cards using PCR-based methods.

Science.gov (United States)

Jamjoom, Manal; Sultan, Amal H

2009-04-01

The broad clinical presentation of Leishmaniasis makes the diagnosis of current and past cases of this disease rather difficult. Differential diagnosis is important because diseases caused by other aetiologies and a clinical spectrum similar to that of leishmaniasis (e.g. leprosy, skin cancers and tuberculosis for CL; malaria and schistosomiasis for VL) are often present in endemic areas of endemicity. Presently, a variety of methods have been developed and tested to aid the identification and diagnosis of Leishmania. The advent of the PCR technology has opened new channels for the diagnosis of leishmaniasis in a variety of clinical materials. PCR is a simple, rapid procedure that has been adapted for diagnosis of leishmaniasis. A range of tools is currently available for the diagnosis and identification of leishmaniasis and Leishmania species, respectively. However, none of these diagnostic tools are examined and tested using samples spotted on FTA cards. Three different PCR-based approaches were examined including: kDNA minicircle, Leishmania 18S rRNA gene and PCR-RFLP of Intergenic region of ribosomal protein. PCR primers were designed that sit within the coding sequences of genes (relatively well conserved) but which amplify across the intervening intergenic sequence (relatively variable). These were used in PCR-RFLP on reference isolates of 10 of the most important Leishmania species: L. donovani, L. infantum, L. major & L. tropica. Digestion of PCR products with restriction enzymes produced species-specific restriction patterns allowed discrimination of reference isolates. The kDNA minicircle primers are highly sensitive in diagnosis of both bone marrow and skin smears from FTA cards. Leishmania 18S rRNA gene conserved region is sensitive in identification of bone marrow smear but less sensitive in diagnosing skin smears. The intergenic nested PCR-RFLP using P5 & P6 as well as P1 & P2 newly designed primers showed high level of reproducibility and sensitivity

PCR amplification and sequences of cDNA clones for the small and large subunits of ADP-glucose pyrophosphorylase from barley tissues.

Science.gov (United States)

Villand, P; Aalen, R; Olsen, O A; Lüthi, E; Lönneborg, A; Kleczkowski, L A

1992-06-01

Several cDNAs encoding the small and large subunit of ADP-glucose pyrophosphorylase (AGP) were isolated from total RNA of the starchy endosperm, roots and leaves of barley by polymerase chain reaction (PCR). Sets of degenerate oligonucleotide primers, based on previously published conserved amino acid sequences of plant AGP, were used for synthesis and amplification of the cDNAs. For either the endosperm, roots and leaves, the restriction analysis of PCR products (ca. 550 nucleotides each) has revealed heterogeneity, suggesting presence of three transcripts for AGP in the endosperm and roots, and up to two AGP transcripts in the leaf tissue. Based on the derived amino acid sequences, two clones from the endosperm, beps and bepl, were identified as coding for the small and large subunit of AGP, respectively, while a leaf transcript (blpl) encoded the putative large subunit of AGP. There was about 50% identity between the endosperm clones, and both of them were about 60% identical to the leaf cDNA. Northern blot analysis has indicated that beps and bepl are expressed in both the endosperm and roots, while blpl is detectable only in leaves. Application of the PCR technique in studies on gene structure and gene expression of plant AGP is discussed.

Combining real-time PCR and next-generation DNA sequencing to provide quantitative comparisons of fungal aerosol populations

Science.gov (United States)

Dannemiller, Karen C.; Lang-Yona, Naama; Yamamoto, Naomichi; Rudich, Yinon; Peccia, Jordan

2014-02-01

We examined fungal communities associated with the PM10 mass of Rehovot, Israel outdoor air samples collected in the spring and fall seasons. Fungal communities were described by 454 pyrosequencing of the internal transcribed spacer (ITS) region of the fungal ribosomal RNA encoding gene. To allow for a more quantitative comparison of fungal exposure in humans, the relative abundance values of specific taxa were transformed to absolute concentrations through multiplying these values by the sample's total fungal spore concentration (derived from universal fungal qPCR). Next, the sequencing-based absolute concentrations for Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, and Penicillium/Aspergillus spp. were compared to taxon-specific qPCR concentrations for A. alternata, C. cladosporioides, E. nigrum, and Penicillium/Aspergillus spp. derived from the same spring and fall aerosol samples. Results of these comparisons showed that the absolute concentration values generated from pyrosequencing were strongly associated with the concentration values derived from taxon-specific qPCR (for all four species, p 0.70). The correlation coefficients were greater for species present in higher concentrations. Our microbial aerosol population analyses demonstrated that fungal diversity (number of fungal operational taxonomic units) was higher in the spring compared to the fall (p = 0.02), and principal coordinate analysis showed distinct seasonal differences in taxa distribution (ANOSIM p = 0.004). Among genera containing allergenic and/or pathogenic species, the absolute concentrations of Alternaria, Aspergillus, Fusarium, and Cladosporium were greater in the fall, while Cryptococcus, Penicillium, and Ulocladium concentrations were greater in the spring. The transformation of pyrosequencing fungal population relative abundance data to absolute concentrations can improve next-generation DNA sequencing-based quantitative aerosol exposure assessment.

Accelerator-based pulsed cold neutron source

International Nuclear Information System (INIS)

Inoue, Kazuhiko; Iwasa, Hirokatsu; Kiyanagi, Yoshiaki

1979-01-01

An accelerator-based pulsed cold neutron source was constructed. The accelerator is a 35 MeV electron linear accelerator with 1 kW average beam power. The cold neutron beam intensity at a specimen is equivalent to that of a research reactor of 10 14 n/cm 2 .s thermal flux in the case of the quasi-elastic neutron scattering measurements. In spite of some limitations to the universal uses, it has been demonstrated by this facility that the modest capacity accelerator-based pulsed cold neutron source is a highly efficient cold neutron source with low capital investment. Design philosophy, construction details, performance and some operational experiences are described. (author)

Application of High-Throughput Next-Generation Sequencing for HLA Typing on Buccal Extracted DNA: Results from over 10,000 Donor Recruitment Samples.

Science.gov (United States)

Yin, Yuxin; Lan, James H; Nguyen, David; Valenzuela, Nicole; Takemura, Ping; Bolon, Yung-Tsi; Springer, Brianna; Saito, Katsuyuki; Zheng, Ying; Hague, Tim; Pasztor, Agnes; Horvath, Gyorgy; Rigo, Krisztina; Reed, Elaine F; Zhang, Qiuheng

2016-01-01

Unambiguous HLA typing is important in hematopoietic stem cell transplantation (HSCT), HLA disease association studies, and solid organ transplantation. However, current molecular typing methods only interrogate the antigen recognition site (ARS) of HLA genes, resulting in many cis-trans ambiguities that require additional typing methods to resolve. Here we report high-resolution HLA typing of 10,063 National Marrow Donor Program (NMDP) registry donors using long-range PCR by next generation sequencing (NGS) approach on buccal swab DNA. Multiplex long-range PCR primers amplified the full-length of HLA class I genes (A, B, C) from promotor to 3' UTR. Class II genes (DRB1, DQB1) were amplified from exon 2 through part of exon 4. PCR amplicons were pooled and sheared using Covaris fragmentation. Library preparation was performed using the Illumina TruSeq Nano kit on the Beckman FX automated platform. Each sample was tagged with a unique barcode, followed by 2×250 bp paired-end sequencing on the Illumina MiSeq. HLA typing was assigned using Omixon Twin software that combines two independent computational algorithms to ensure high confidence in allele calling. Consensus sequence and typing results were reported in Histoimmunogenetics Markup Language (HML) format. All homozygous alleles were confirmed by Luminex SSO typing and exon novelties were confirmed by Sanger sequencing. Using this automated workflow, over 10,063 NMDP registry donors were successfully typed under high-resolution by NGS. Despite known challenges of nucleic acid degradation and low DNA concentration commonly associated with buccal-based specimens, 97.8% of samples were successfully amplified using long-range PCR. Among these, 98.2% were successfully reported by NGS, with an accuracy rate of 99.84% in an independent blind Quality Control audit performed by the NDMP. In this study, NGS-HLA typing identified 23 null alleles (0.023%), 92 rare alleles (0.091%) and 42 exon novelties (0.042%). Long

Application of High-Throughput Next-Generation Sequencing for HLA Typing on Buccal Extracted DNA: Results from over 10,000 Donor Recruitment Samples.

Directory of Open Access Journals (Sweden)

Yuxin Yin

Full Text Available Unambiguous HLA typing is important in hematopoietic stem cell transplantation (HSCT, HLA disease association studies, and solid organ transplantation. However, current molecular typing methods only interrogate the antigen recognition site (ARS of HLA genes, resulting in many cis-trans ambiguities that require additional typing methods to resolve. Here we report high-resolution HLA typing of 10,063 National Marrow Donor Program (NMDP registry donors using long-range PCR by next generation sequencing (NGS approach on buccal swab DNA.Multiplex long-range PCR primers amplified the full-length of HLA class I genes (A, B, C from promotor to 3' UTR. Class II genes (DRB1, DQB1 were amplified from exon 2 through part of exon 4. PCR amplicons were pooled and sheared using Covaris fragmentation. Library preparation was performed using the Illumina TruSeq Nano kit on the Beckman FX automated platform. Each sample was tagged with a unique barcode, followed by 2×250 bp paired-end sequencing on the Illumina MiSeq. HLA typing was assigned using Omixon Twin software that combines two independent computational algorithms to ensure high confidence in allele calling. Consensus sequence and typing results were reported in Histoimmunogenetics Markup Language (HML format. All homozygous alleles were confirmed by Luminex SSO typing and exon novelties were confirmed by Sanger sequencing.Using this automated workflow, over 10,063 NMDP registry donors were successfully typed under high-resolution by NGS. Despite known challenges of nucleic acid degradation and low DNA concentration commonly associated with buccal-based specimens, 97.8% of samples were successfully amplified using long-range PCR. Among these, 98.2% were successfully reported by NGS, with an accuracy rate of 99.84% in an independent blind Quality Control audit performed by the NDMP. In this study, NGS-HLA typing identified 23 null alleles (0.023%, 92 rare alleles (0.091% and 42 exon novelties (0.042%.Long

Optimization of analytical parameters for inferring relationships among Escherichia coli isolates from repetitive-element PCR by maximizing correspondence with multilocus sequence typing data.

Science.gov (United States)

Goldberg, Tony L; Gillespie, Thomas R; Singer, Randall S

2006-09-01

Repetitive-element PCR (rep-PCR) is a method for genotyping bacteria based on the selective amplification of repetitive genetic elements dispersed throughout bacterial chromosomes. The method has great potential for large-scale epidemiological studies because of its speed and simplicity; however, objective guidelines for inferring relationships among bacterial isolates from rep-PCR data are lacking. We used multilocus sequence typing (MLST) as a "gold standard" to optimize the analytical parameters for inferring relationships among Escherichia coli isolates from rep-PCR data. We chose 12 isolates from a large database to represent a wide range of pairwise genetic distances, based on the initial evaluation of their rep-PCR fingerprints. We conducted MLST with these same isolates and systematically varied the analytical parameters to maximize the correspondence between the relationships inferred from rep-PCR and those inferred from MLST. Methods that compared the shapes of densitometric profiles ("curve-based" methods) yielded consistently higher correspondence values between data types than did methods that calculated indices of similarity based on shared and different bands (maximum correspondences of 84.5% and 80.3%, respectively). Curve-based methods were also markedly more robust in accommodating variations in user-specified analytical parameter values than were "band-sharing coefficient" methods, and they enhanced the reproducibility of rep-PCR. Phylogenetic analyses of rep-PCR data yielded trees with high topological correspondence to trees based on MLST and high statistical support for major clades. These results indicate that rep-PCR yields accurate information for inferring relationships among E. coli isolates and that accuracy can be enhanced with the use of analytical methods that consider the shapes of densitometric profiles.

Revealing the microbiota of marketed edible insects through PCR-DGGE, metagenomic sequencing and real-time PCR.

Science.gov (United States)

Osimani, Andrea; Milanović, Vesna; Garofalo, Cristiana; Cardinali, Federica; Roncolini, Andrea; Sabbatini, Riccardo; De Filippis, Francesca; Ercolini, Danilo; Gabucci, Claudia; Petruzzelli, Annalisa; Tonucci, Franco; Clementi, Francesca; Aquilanti, Lucia

2018-07-02

The present study aimed to identify the microbiota present in six species of processed edible insects produced in Thailand and marketed worldwide via the internet, namely, giant water bugs (Belostoma lutarium), black ants (Polyrhachis), winged termites (alates, Termitoidae), rhino beetles (Hyboschema contractum), mole crickets (Gryllotalpidae), and silkworm pupae (Bombyx mori). For each species, two samples of boiled, dried and salted insects were purchased. The microbial DNA was extracted from the insect samples and subjected to polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), high-throughput sequencing and qualitative real-time PCR assays. The microbiota of the analyzed samples were widely characterized by the presence of spore-forming bacteria mainly represented by the genera Bacillus and Clostridium. Moreover, the genera Anaerobacillus, Paenibacillus, Geobacillus, Pseudomonas, Stenotrophomonas, Massilia, Delftia, Lactobacillus, Staphylococcus, Streptococcus, Vagococcus, and Vibrio were also detected. Real-time PCR allowed for ascertainment of the absence of Coxiella burnetii, Shiga toxin-producing E. coli (STEC), and Pseudomonas aeruginosa in all samples. The results of this study confirm the importance of combining different molecular techniques to characterize the biodiversity of complex ecosystems such as edible insects. The presence of potential human pathogens suggests the need for a careful application of good manufacturing practices during insect processing. This study provides further data that will be useful in risk analyses of edible insects as a novel food source. Copyright © 2018 Elsevier B.V. All rights reserved.

Transcriptome Profiling of the Pineapple under Low Temperature to Facilitate Its Breeding for Cold Tolerance

Science.gov (United States)

Chen, Chengjie; Zhang, Yafeng; Xu, Zhiqiang; Luan, Aiping; Mao, Qi; Feng, Junting; Xie, Tao; Gong, Xue; Wang, Xiaoshuang; Chen, Hao; He, Yehua

2016-01-01

The pineapple (Ananas comosus) is cold sensitive. Most cultivars are injured during winter periods, especially in sub-tropical regions. There is a lack of molecular information on the pineapple’s response to cold stress. In this study, high-throughput transcriptome sequencing and gene expression analysis were performed on plantlets of a cold-tolerant genotype of the pineapple cultivar ‘Shenwan’ before and after cold treatment. A total of 1,186 candidate cold responsive genes were identified, and their credibility was confirmed by RT-qPCR. Gene set functional enrichment analysis indicated that genes related to cell wall properties, stomatal closure and ABA and ROS signal transduction play important roles in pineapple cold tolerance. In addition, a protein association network of CORs (cold responsive genes) was predicted, which could serve as an entry point to dissect the complex cold response network. Our study found a series of candidate genes and their association network, which will be helpful to cold stress response studies and pineapple breeding for cold tolerance. PMID:27656892

Novel ZEB2-BCL11B Fusion Gene Identified by RNA-Sequencing in Acute Myeloid Leukemia with t(2;14(q22;q32.

Directory of Open Access Journals (Sweden)

Synne Torkildsen

Full Text Available RNA-sequencing of a case of acute myeloid leukemia with the bone marrow karyotype 46,XY,t(2;14(q22;q32[5]/47,XY,idem,+?4,del(6(q13q21[cp6]/46,XY[4] showed that the t(2;14 generated a ZEB2-BCL11B chimera in which exon 2 of ZEB2 (nucleotide 595 in the sequence with accession number NM_014795.3 was fused to exon 2 of BCL11B (nucleotide 554 in the sequence with accession number NM_022898.2. RT-PCR together with Sanger sequencing verified the presence of the above-mentioned fusion transcript. All functional domains of BCL11B are retained in the chimeric protein. Abnormal expression of BCL11B coding regions subjected to control by the ZEB2 promoter seems to be the leukemogenic mechanism behind the translocation.

Extreme assay sensitivity in molecular diagnostics further unveils intratumour heterogeneity in metastatic colorectal cancer as well as artifactual low-frequency mutations in the KRAS gene.

Science.gov (United States)

Mariani, Sara; Bertero, Luca; Osella-Abate, Simona; Di Bello, Cristiana; Francia di Celle, Paola; Coppola, Vittoria; Sapino, Anna; Cassoni, Paola; Marchiò, Caterina

2017-07-25

Gene mutations in the RAS family rule out metastatic colorectal carcinomas (mCRCs) from anti-EGFR therapies. We report a retrospective analysis by Sequenom Massarray and fast COLD-PCR followed by Sanger sequencing on 240 mCRCs. By Sequenom, KRAS and NRAS exons 2-3-4 were mutated in 52.9% (127/240) of tumours, while BRAF codon 600 mutations reached 5% (12/240). Fast COLD-PCR found extra mutations at KRAS exon 2 in 15/166 (9%) of samples, previously diagnosed by Sequenom as wild-type or mutated at RAS (exons 3-4) or BRAF genes. After UDG digestion results were reproduced in 2/12 analysable subclonally mutated samples leading to a frequency of true subclonal KRAS mutations of 1.2% (2.1% of the previous Sequenom wild-type subgroup). In 10 out of 12 samples, the subclonal KRAS mutations disappeared (9 out of 12) or turned to a different sequence variant (1 out of 12). mCRC can harbour coexisting multiple gene mutations. High sensitivity assays allow the detection of a small subset of patients harbouring true subclonal KRAS mutations. However, DNA changes with mutant allele frequencies <3% detected in formalin-fixed paraffin-embedded samples may be artifactual in a non-negligible fraction of cases. UDG pre-treatment of DNA is mandatory to identify true DNA changes in archival samples and avoid misinterpretation due to artifacts.

An integrated PCR colony hybridization approach to screen cDNA libraries for full-length coding sequences.

Science.gov (United States)

Pollier, Jacob; González-Guzmán, Miguel; Ardiles-Diaz, Wilson; Geelen, Danny; Goossens, Alain

2011-01-01

cDNA-Amplified Fragment Length Polymorphism (cDNA-AFLP) is a commonly used technique for genome-wide expression analysis that does not require prior sequence knowledge. Typically, quantitative expression data and sequence information are obtained for a large number of differentially expressed gene tags. However, most of the gene tags do not correspond to full-length (FL) coding sequences, which is a prerequisite for subsequent functional analysis. A medium-throughput screening strategy, based on integration of polymerase chain reaction (PCR) and colony hybridization, was developed that allows in parallel screening of a cDNA library for FL clones corresponding to incomplete cDNAs. The method was applied to screen for the FL open reading frames of a selection of 163 cDNA-AFLP tags from three different medicinal plants, leading to the identification of 109 (67%) FL clones. Furthermore, the protocol allows for the use of multiple probes in a single hybridization event, thus significantly increasing the throughput when screening for rare transcripts. The presented strategy offers an efficient method for the conversion of incomplete expressed sequence tags (ESTs), such as cDNA-AFLP tags, to FL-coding sequences.

Comparative study of different methodologies to detect the JAK2 V617F mutation in chronic BCR-ABL1 negative myeloproliferative neoplasms

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Alline Didone

2016-04-01

Full Text Available Objectives: A mutation in the JAK2 gene, V617F, has been identified in several BCR-ABL1 negative myeloproliferative neoplasms (MPN: polycythemia vera (PV, essential thrombocythemia (ET, and primary myelofibrosis (PMF. Defining the presence or absence of this mutation is an essential part of clinical diagnostic algorithms and patient management. Here, we aimed to evaluate the performance of three PCR-based assays: Amplification Refractory Mutation System (ARMS, High-Resolution Melting analysis (HRM, and Sanger direct sequencing, and compare their results with those obtained by a PCR restriction fragment polymorphism assay (PCR-RFLP. Design and methods: We used blood samples from 136 patients (PV=20; PMF=20; ET=28, and other MPN suspected cases=68. Results: Comparable results were observed among the four assays in patients with PV, PMF, and MPN suspected cases. In patients with a diagnosis of ET, the JAK2 V617F mutation was detected in 67.8% of them by the PCR-ARMS and PCR-HRM assay and in 64% of them by the conventional Sanger sequence approach. The PCR-ARMS and PCR-HRM assays were 100% concordant. With these tests, only one of the 20 patients with ET and one of the three patients with clinically suspected MPN gave different results compared with those obtained by the PCR-RFLP. Conclusions: Our results have demonstrated that the PCR-ARMS and PCR-HRM assays could detect the JAK2 V617F mutation effectively in MPN patients, but PCR-HRM assays are rapid and the most cost-effective procedures. Keywords: Myeloproliferative, JAK2 V617F, Mutation, Wild type, Screening

Contiguous 22.1-kb deletion embracing AVPR2 and ARHGAP4 genes at novel breakpoints leads to nephrogenic diabetes insipidus in a Chinese pedigree.

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Bai, Ying; Chen, Yibing; Kong, Xiangdong

2018-02-02

It has been reported that mutations in arginine vasopressin type 2 receptor (AVPR2) cause congenital X-linked nephrogenic diabetes insipidus (NDI). However, only a few cases of AVPR2 deletion have been documented in China. An NDI pedigree was included in this study, including the proband and his mother. All NDI patients had polyuria, polydipsia, and growth retardation. PCR mapping, long range PCR and sanger sequencing were used to identify genetic causes of NDI. A novel 22,110 bp deletion comprising AVPR2 and ARH4GAP4 genes was identified by PCR mapping, long range PCR and sanger sequencing. The deletion happened perhaps due to the 4-bp homologous sequence (TTTT) at the junctions of both 5' and 3' breakpoints. The gross deletion co-segregates with NDI. After analyzing available data of putative clinical signs of AVPR2 and ARH4GAP4 deletion, we reconsider the potential role of AVPR2 deletion in short stature. We identified a novel 22.1-kb deletion leading to X-linked NDI in a Chinese pedigree, which would increase the current knowledge in AVPR2 mutation.

Cloning of the koi herpesvirus (KHV gene encoding thymidine kinase and its use for a highly sensitive PCR based diagnosis

Directory of Open Access Journals (Sweden)

Gilad Oren

2005-03-01

Full Text Available Abstract Background Outbreaks with mass mortality among common carp Cyprinus carpio carpio and koi Cyprinus carpio koi have occurred worldwide since 1998. The herpes-like virus isolated from diseased fish is different from Herpesvirus cyprini and channel catfish virus and was accordingly designated koi herpesvirus (KHV. Diagnosis of KHV infection based on viral isolation and current PCR assays has a limited sensitivity and therefore new tools for the diagnosis of KHV infections are necessary. Results A robust and sensitive PCR assay based on a defined gene sequence of KHV was developed to improve the diagnosis of KHV infection. From a KHV genomic library, a hypothetical thymidine kinase gene (TK was identified, subcloned and expressed as a recombinant protein. Preliminary characterization of the recombinant TK showed that it has a kinase activity using dTTP but not dCTP as a substrate. A PCR assay based on primers selected from the defined DNA sequence of the TK gene was developed and resulted in a 409 bp amplified fragment. The TK based PCR assay did not amplify the DNAs of other fish herpesviruses such as Herpesvirus cyprini (CHV and the channel catfish virus (CCV. The TK based PCR assay was specific for the detection of KHV and was able to detect as little as 10 fentograms of KHV DNA corresponding to 30 virions. The TK based PCR was compared to previously described PCR assays and to viral culture in diseased fish and was shown to be the most sensitive method of diagnosis of KHV infection. Conclusion The TK based PCR assay developed in this work was shown to be specific for the detection of KHV. The TK based PCR assay was more sensitive for the detection of KHV than previously described PCR assays; it was as sensitive as virus isolation which is the golden standard method for KHV diagnosis and was able to detect as little as 10 fentograms of KHV DNA corresponding to 30 virions.

Sequence diversity in haloalkane dehalogenases, as revealed by PCR using family-specific primers

Czech Academy of Sciences Publication Activity Database

Kotík, Michael; Faměrová, Veronika

2012-01-01

Roč. 88, č. 2 (2012), s. 212-217 ISSN 0167-7012 R&D Projects: GA ČR GAP504/10/0137; GA ČR GAP207/10/0135 Institutional research plan: CEZ:AV0Z50200510 Keywords : Dehalogenation * Consensus sequence * Degenerate PCR primer Subject RIV: EE - Microbiology, Virology Impact factor: 2.161, year: 2012

Charcot-Marie-Tooth disease: The development of a diagnostic platform using next generation sequencing

DEFF Research Database (Denmark)

Christensen, Rikke; Væth, Signe; Thorsen, Kasper

, Sanger sequencing of 4 genes have led to a diagnosis in approximately 30% of the patients. Aims: 1) Development of a targeted NGS platform containing 63 genes that currently are found to be associated with CMT. 2) Analysis of the increased diagnostic yield using this platform to analyze 200 CMT samples...... previously analyzed using Sanger sequencing without identification of a disease causing mutation. Materials and Methods: Libraries for 200 patient samples obtained for CMT diagnostics were prepared using Illumina Truseq and target enrichment using SeqCap EZ Choise Library (Nimblegen). The libraries were...

Clinical metagenomic analysis of bacterial communities in breast abscesses of granulomatous mastitis.

Science.gov (United States)

Yu, Hai-Jing; Deng, Hua; Ma, Jian; Huang, Shu-Jun; Yang, Jian-Min; Huang, Yan-Fen; Mu, Xiao-Ping; Zhang, Liang; Wang, Qi

2016-12-01

Granulomatous mastitis (GM) is a chronic inflammatory breast lesion. Its etiology remains incompletely defined. Although mounting evidence suggests the involvement of Corynebacterium in GM, there has been no systematic study of GM bacteriology using -omics technology. The bacterial diversity and relative abundances in breast abscesses from 19 women with GM were investigated using 16S rDNA metagenomic sequencing and Sanger sequencing. A quantitative PCR (qPCR) assay was also developed to identify Corynebacterium kroppenstedtii. A bioinformatic analysis revealed that Corynebacterium was present in the 19 GM patients, with abundances ranging from 1.1% to 58.9%. Of note, Corynebacterium was the most abundant taxon in seven patients (more than a third of the subjects). The predominance of Corynebacterium kroppenstedtii infection (11 of 19 patients, 57.9%) was confirmed with Sanger sequencing and the qPCR assay. This study profiled the microbiota of patients with GM and indicated an important role for Corynebacterium, and in particular C. kroppenstedtii, in the pathogenesis of this disease. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Quality Control of the Traditional Patent Medicine Yimu Wan Based on SMRT Sequencing and DNA Barcoding

Science.gov (United States)

Jia, Jing; Xu, Zhichao; Xin, Tianyi; Shi, Linchun; Song, Jingyuan

2017-01-01

Substandard traditional patent medicines may lead to global safety-related issues. Protecting consumers from the health risks associated with the integrity and authenticity of herbal preparations is of great concern. Of particular concern is quality control for traditional patent medicines. Here, we establish an effective approach for verifying the biological composition of traditional patent medicines based on single-molecule real-time (SMRT) sequencing and DNA barcoding. Yimu Wan (YMW), a classical herbal prescription recorded in the Chinese Pharmacopoeia, was chosen to test the method. Two reference YMW samples were used to establish a standard method for analysis, which was then applied to three different batches of commercial YMW samples. A total of 3703 and 4810 circular-consensus sequencing (CCS) reads from two reference and three commercial YMW samples were mapped to the ITS2 and psbA-trnH regions, respectively. Moreover, comparison of intraspecific genetic distances based on SMRT sequencing data with reference data from Sanger sequencing revealed an ITS2 and psbA-trnH intergenic spacer that exhibited high intraspecific divergence, with the sites of variation showing significant differences within species. Using the CCS strategy for SMRT sequencing analysis was adequate to guarantee the accuracy of identification. This study demonstrates the application of SMRT sequencing to detect the biological ingredients of herbal preparations. SMRT sequencing provides an affordable way to monitor the legality and safety of traditional patent medicines. PMID:28620408

A Simple Method for the Extraction, PCR-amplification, Cloning, and Sequencing of Pasteuria 16S rDNA from Small Numbers of Endospores.

Science.gov (United States)

Atibalentja, N; Noel, G R; Ciancio, A

2004-03-01

For many years the taxonomy of the genus Pasteuria has been marred with confusion because the bacterium could not be cultured in vitro and, therefore, descriptions were based solely on morphological, developmental, and pathological characteristics. The current study sought to devise a simple method for PCR-amplification, cloning, and sequencing of Pasteuria 16S rDNA from small numbers of endospores, with no need for prior DNA purification. Results show that DNA extracts from plain glass bead-beating of crude suspensions containing 10,000 endospores at 0.2 x 10 endospores ml(-1) were sufficient for PCR-amplification of Pasteuria 16S rDNA, when used in conjunction with specific primers. These results imply that for P. penetrans and P. nishizawae only one parasitized female of Meloidogyne spp. and Heterodera glycines, respectively, should be sufficient, and as few as eight cadavers of Belonolaimus longicaudatus with an average number of 1,250 endospores of "Candidatus Pasteuria usgae" are needed for PCR-amplification of Pasteuria 16S rDNA. The method described in this paper should facilitate the sequencing of the 16S rDNA of the many Pasteuria isolates that have been reported on nematodes and, consequently, expedite the classification of those isolates through comparative sequence analysis.

Accurate typing of short tandem repeats from genome-wide sequencing data and its applications.

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Fungtammasan, Arkarachai; Ananda, Guruprasad; Hile, Suzanne E; Su, Marcia Shu-Wei; Sun, Chen; Harris, Robert; Medvedev, Paul; Eckert, Kristin; Makova, Kateryna D

2015-05-01

Short tandem repeats (STRs) are implicated in dozens of human genetic diseases and contribute significantly to genome variation and instability. Yet profiling STRs from short-read sequencing data is challenging because of their high sequencing error rates. Here, we developed STR-FM, short tandem repeat profiling using flank-based mapping, a computational pipeline that can detect the full spectrum of STR alleles from short-read data, can adapt to emerging read-mapping algorithms, and can be applied to heterogeneous genetic samples (e.g., tumors, viruses, and genomes of organelles). We used STR-FM to study STR error rates and patterns in publicly available human and in-house generated ultradeep plasmid sequencing data sets. We discovered that STRs sequenced with a PCR-free protocol have up to ninefold fewer errors than those sequenced with a PCR-containing protocol. We constructed an error correction model for genotyping STRs that can distinguish heterozygous alleles containing STRs with consecutive repeat numbers. Applying our model and pipeline to Illumina sequencing data with 100-bp reads, we could confidently genotype several disease-related long trinucleotide STRs. Utilizing this pipeline, for the first time we determined the genome-wide STR germline mutation rate from a deeply sequenced human pedigree. Additionally, we built a tool that recommends minimal sequencing depth for accurate STR genotyping, depending on repeat length and sequencing read length. The required read depth increases with STR length and is lower for a PCR-free protocol. This suite of tools addresses the pressing challenges surrounding STR genotyping, and thus is of wide interest to researchers investigating disease-related STRs and STR evolution. © 2015 Fungtammasan et al.; Published by Cold Spring Harbor Laboratory Press.

External and semi-internal controls for PCR amplification of homologous sequences in mixed templates.

Science.gov (United States)

Kalle, Elena; Gulevich, Alexander; Rensing, Christopher

2013-11-01

In a mixed template, the presence of homologous target DNA sequences creates environments that almost inevitably give rise to artifacts and biases during PCR. Heteroduplexes, chimeras, and skewed template-to-product ratios are the exclusive attributes of mixed template PCR and never occur in a single template assay. Yet, multi-template PCR has been used without appropriate attention to quality control and assay validation, in spite of the fact that such practice diminishes the reliability of results. External and internal amplification controls became obligatory elements of good laboratory practice in different PCR assays. We propose the inclusion of an analogous approach as a quality control system for multi-template PCR applications. The amplification controls must take into account the characteristics of multi-template PCR and be able to effectively monitor particular assay performance. This study demonstrated the efficiency of a model mixed template as an adequate external amplification control for a particular PCR application. The conditions of multi-template PCR do not allow implementation of a classic internal control; therefore we developed a convenient semi-internal control as an acceptable alternative. In order to evaluate the effects of inhibitors, a model multi-template mix was amplified in a mixture with DNAse-treated sample. Semi-internal control allowed establishment of intervals for robust PCR performance for different samples, thus enabling correct comparison of the samples. The complexity of the external and semi-internal amplification controls must be comparable with the assumed complexity of the samples. We also emphasize that amplification controls should be applied in multi-template PCR regardless of the post-assay method used to analyze products. © 2013 Elsevier B.V. All rights reserved.

Cold inducible promoter driven Cre-lox system proved to be highly efficient for marker gene excision in transgenic barley.

Science.gov (United States)

Éva, Csaba; Téglás, Flóra; Zelenyánszki, Helga; Tamás, Cecília; Juhász, Angéla; Mészáros, Klára; Tamás, László

2018-01-10

A Cre-lox based auto-excision strategy has been adapted for barley, capable of cre and selectable marker gene (SMG) removal. The cold inducible wheat promoter called wcs120 was utilised for driving Cre expression. The binary vector was carrying the transgene (uidA) and a so called 'recombination cassette' flanked by the lox sequences. This part included both the recombinase gene and the SMG (bar) under the control of a constitutive promoter. T 0 , T 1 and T 2 transgenic plants were subjected to low temperature (at 4°C, 10°C and 12°C) at different developmental stages to induce recombination. The presence of uidA, cre, and bar genes and recombination footprints were studied by PCR and DNA sequencing, while cre transcription was followed by qRT-PCR. These analyses indicated that, cold treatment of the germinating seeds (4°C for 3days) followed by plant growing at higher temperature (24°C) has been the most efficient (90-100%), and this treatment lead to heritable changes in the genome. Thermal separation of Cre accumulation (at low temperature) from Cre enzyme activity (at higher temperature) could have prevented the premature excision of its own encoding gene, and lead to high expression level thereby increasing recombination frequency. Copyright © 2017 Elsevier B.V. All rights reserved.

Two unusual hepatitis C virus subtypes, 2j and 2q, in Spain: Identification by nested-PCR and sequencing of a NS5B region.

Science.gov (United States)

Margall, N; March, F; Español, M; Torras, X; Gallego, A; Coll, P

2015-10-01

Many studies have reported the use of the NS5B gene to subtype hepatitis C virus (HCV). Other HCV genes, such as HCV-5' UTR, Core (C) and E1, have also been used. In some studies, NS5B have been used together with 5'-UTR or C genes to improve genotyping results obtained using commercial procedures. Only two studies in Spain have compared molecular techniques versus commercial procedures regarding the efficacy of HCV subtyping. The aim of this study was to determine whether nested PCR and sequencing of a NS5B region was more reliable than commercial procedures to subtype HCV. We analyzed the results of HCV genotyping in [726] serum specimens collected from 2001 to 2013. From 2001 to 2011, we used PCR and INNO-LiPA hybridization or its new version Versant HCV Genotype 2.0 assay (471 samples). From 2012 to 2013, we used nested PCR and sequencing of a NS5B region (255 cases). This method used two pairs of primers to amplify the RNA of the sample converted to DNA by retrotranscription. The amplification product of 270 base pairs was further sequenced. To identify the subtype, the sequences obtained were compared to those in the international database: http://hcv.lanl.gov./content/sequence/, HCV/ToolsOutline.html and Geno2pheno[hcv] http://hcv.bioinf.mpi-inf.mpg.de/index.php. Nested PCR of a NS5B region and sequencing identified all but one subtype (0.4%, 1/255), differentiated all 1a subtypes from 1b subtypes, and characterized all HCV 2-4 subtypes. This approach also distinguished two subtypes, 2j and 2q, that had rarely been detected previously in Spain. However, commercial procedures failed to subtype 12.7% (60/471) of samples and to genotype 0.6% of specimens (3/471). Nested PCR and sequencing of a NS5B region improved the subtyping of HCV in comparison with classical procedures and identified two rare subtypes in Spain: 2j and 2q. However, full length genome sequencing is recommended to confirm HCV 2j and 2q subtypes. Copyright © 2015. Published by Elsevier B.V.

Statistical method to compare massive parallel sequencing pipelines.

Science.gov (United States)

Elsensohn, M H; Leblay, N; Dimassi, S; Campan-Fournier, A; Labalme, A; Roucher-Boulez, F; Sanlaville, D; Lesca, G; Bardel, C; Roy, P

2017-03-01

Today, sequencing is frequently carried out by Massive Parallel Sequencing (MPS) that cuts drastically sequencing time and expenses. Nevertheless, Sanger sequencing remains the main validation method to confirm the presence of variants. The analysis of MPS data involves the development of several bioinformatic tools, academic or commercial. We present here a statistical method to compare MPS pipelines and test it in a comparison between an academic (BWA-GATK) and a commercial pipeline (TMAP-NextGENe®), with and without reference to a gold standard (here, Sanger sequencing), on a panel of 41 genes in 43 epileptic patients. This method used the number of variants to fit log-linear models for pairwise agreements between pipelines. To assess the heterogeneity of the margins and the odds ratios of agreement, four log-linear models were used: a full model, a homogeneous-margin model, a model with single odds ratio for all patients, and a model with single intercept. Then a log-linear mixed model was fitted considering the biological variability as a random effect. Among the 390,339 base-pairs sequenced, TMAP-NextGENe® and BWA-GATK found, on average, 2253.49 and 1857.14 variants (single nucleotide variants and indels), respectively. Against the gold standard, the pipelines had similar sensitivities (63.47% vs. 63.42%) and close but significantly different specificities (99.57% vs. 99.65%; p < 0.001). Same-trend results were obtained when only single nucleotide variants were considered (99.98% specificity and 76.81% sensitivity for both pipelines). The method allows thus pipeline comparison and selection. It is generalizable to all types of MPS data and all pipelines.

Special Issue: Next Generation DNA Sequencing

Directory of Open Access Journals (Sweden)

Paul Richardson

2010-10-01

Full Text Available Next Generation Sequencing (NGS refers to technologies that do not rely on traditional dideoxy-nucleotide (Sanger sequencing where labeled DNA fragments are physically resolved by electrophoresis. These new technologies rely on different strategies, but essentially all of them make use of real-time data collection of a base level incorporation event across a massive number of reactions (on the order of millions versus 96 for capillary electrophoresis for instance. The major commercial NGS platforms available to researchers are the 454 Genome Sequencer (Roche, Illumina (formerly Solexa Genome analyzer, the SOLiD system (Applied Biosystems/Life Technologies and the Heliscope (Helicos Corporation. The techniques and different strategies utilized by these platforms are reviewed in a number of the papers in this special issue. These technologies are enabling new applications that take advantage of the massive data produced by this next generation of sequencing instruments. [...

Differentiation of Toxocara canis and Toxocara cati based on PCR-RFLP analyses of rDNA-ITS and mitochondrial cox1 and nad1 regions.

Science.gov (United States)

Mikaeili, Fattaneh; Mathis, Alexander; Deplazes, Peter; Mirhendi, Hossein; Barazesh, Afshin; Ebrahimi, Sepideh; Kia, Eshrat Beigom

2017-09-26

The definitive genetic identification of Toxocara species is currently based on PCR/sequencing. The objectives of the present study were to design and conduct an in silico polymerase chain reaction-restriction fragment length polymorphism method for identification of Toxocara species. In silico analyses using the DNASIS and NEBcutter softwares were performed with rDNA internal transcribed spacers, and mitochondrial cox1 and nad1 sequences obtained in our previous studies along with relevant sequences deposited in GenBank. Consequently, RFLP profiles were designed and all isolates of T. canis and T. cati collected from dogs and cats in different geographical areas of Iran were investigated with the RFLP method using some of the identified suitable enzymes. The findings of in silico analyses predicted that on the cox1 gene only the MboII enzyme is appropriate for PCR-RFLP to reliably distinguish the two species. No suitable enzyme for PCR-RFLP on the nad1 gene was identified that yields the same pattern for all isolates of a species. DNASIS software showed that there are 241 suitable restriction enzymes for the differentiation of T. canis from T. cati based on ITS sequences. RsaI, MvaI and SalI enzymes were selected to evaluate the reliability of the in silico PCR-RFLP. The sizes of restriction fragments obtained by PCR-RFLP of all samples consistently matched the expected RFLP patterns. The ITS sequences are usually conserved and the PCR-RFLP approach targeting the ITS sequence is recommended for the molecular differentiation of Toxocara species and can provide a reliable tool for identification purposes particularly at the larval and egg stages.

Genomic Variability of Haemophilus influenzae Isolated from Mexican Children Determined by Using Enterobacterial Repetitive Intergenic Consensus Sequences and PCR

OpenAIRE

Gomez-De-Leon, Patricia; Santos, Jose I.; Caballero, Javier; Gomez, Demostenes; Espinosa, Luz E.; Moreno, Isabel; Piñero, Daniel; Cravioto, Alejandro

2000-01-01

Genomic fingerprints from 92 capsulated and noncapsulated strains of Haemophilus influenzae from Mexican children with different diseases and healthy carriers were generated by PCR using the enterobacterial repetitive intergenic consensus (ERIC) sequences. A cluster analysis by the unweighted pair-group method with arithmetic averages based on the overall similarity as estimated from the characteristics of the genomic fingerprints, was conducted to group the strains. A total of 69 fingerprint...

Complete chloroplast genome sequence of a major economic species, Ziziphus jujuba (Rhamnaceae).

Science.gov (United States)

Ma, Qiuyue; Li, Shuxian; Bi, Changwei; Hao, Zhaodong; Sun, Congrui; Ye, Ning

2017-02-01

Ziziphus jujuba is an important woody plant with high economic and medicinal value. Here, we analyzed and characterized the complete chloroplast (cp) genome of Z. jujuba, the first member of the Rhamnaceae family for which the chloroplast genome sequence has been reported. We also built a web browser for navigating the cp genome of Z. jujuba ( http://bio.njfu.edu.cn/gb2/gbrowse/Ziziphus_jujuba_cp/ ). Sequence analysis showed that this cp genome is 161,466 bp long and has a typical quadripartite structure of large (LSC, 89,120 bp) and small (SSC, 19,348 bp) single-copy regions separated by a pair of inverted repeats (IRs, 26,499 bp). The sequence contained 112 unique genes, including 78 protein-coding genes, 30 transfer RNAs, and four ribosomal RNAs. The genome structure, gene order, GC content, and codon usage are similar to other typical angiosperm cp genomes. A total of 38 tandem repeats, two forward repeats, and three palindromic repeats were detected in the Z. jujuba cp genome. Simple sequence repeat (SSR) analysis revealed that most SSRs were AT-rich. The homopolymer regions in the cp genome of Z. jujuba were verified and manually corrected by Sanger sequencing. One-third of mononucleotide repeats were found to be erroneously sequenced by the 454 pyrosequencing, which resulted in sequences of 1-4 bases shorter than that by the Sanger sequencing. Analyzing the cp genome of Z. jujuba revealed that the IR contraction and expansion events resulted in ycf1 and rps19 pseudogenes. A phylogenetic analysis based on 64 protein-coding genes showed that Z. jujuba was closely related to members of the Elaeagnaceae family, which will be helpful for phylogenetic studies of other Rosales species. The complete cp genome sequence of Z. jujuba will facilitate population, phylogenetic, and cp genetic engineering studies of this economic plant.

The role of the physician: Eugene Sanger and a standard of care at the Elmira prison camp.

Science.gov (United States)

Waggoner, Jesse

2008-01-01

The conduct of American military physicians in prisoner of war (POW) camps has been called into question by the abuse scandals at Abu Ghraib and Guantánamo Bay. This essay explores the experiences of the first U.S. military physicians to confront POW patients in large numbers-events that occurred during the American Civil War. While POWs received sub-standard care in camps north and south, the war also saw the issuance of the first document to outline the rights of POWs. This ambivalence toward the proper care and treatment of the POW is evident in the career of Dr. Eugene Sanger, the first Union surgeon at the prison camp in Elmira, New York. Sanger demonstrated both concern about the sanitary condition of the camp and pride in the deaths of POWs as furthering the overall war aims. His cruelty attracted some censure, but Sanger never faced disciplinary action. He was honorably discharged and went on to become the Surgeon General of his home state. This article places his actions at Elmira in the context of medical ethics, Army orders, and Northern opinion in 1864, and it will argue that the lack of Federal response to Eugene Sanger's poor record while serving at the prison set a precedent for inferior medical care of POWs by American military physicians.

Ion Torrent sequencing as a tool for mutation discovery in the flax (Linum usitatissimum L.) genome.

Science.gov (United States)

Galindo-González, Leonardo; Pinzón-Latorre, David; Bergen, Erik A; Jensen, Dustin C; Deyholos, Michael K

2015-01-01

Detection of induced mutations is valuable for inferring gene function and for developing novel germplasm for crop improvement. Many reverse genetics approaches have been developed to identify mutations in genes of interest within a mutagenized population, including some approaches that rely on next-generation sequencing (e.g. exome capture, whole genome resequencing). As an alternative to these genome or exome-scale methods, we sought to develop a scalable and efficient method for detection of induced mutations that could be applied to a small number of target genes, using Ion Torrent technology. We developed this method in flax (Linum usitatissimum), to demonstrate its utility in a crop species. We used an amplicon-based approach in which DNA samples from an ethyl methanesulfonate (EMS)-mutagenized population were pooled and used as template in PCR reactions to amplify a region of each gene of interest. Barcodes were incorporated during PCR, and the pooled amplicons were sequenced using an Ion Torrent PGM. A pilot experiment with known SNPs showed that they could be detected at a frequency > 0.3% within the pools. We then selected eight genes for which we wanted to discover novel mutations, and applied our approach to screen 768 individuals from the EMS population, using either the Ion 314 or Ion 316 chips. Out of 29 potential mutations identified after processing the NGS reads, 16 mutations were confirmed using Sanger sequencing. The methodology presented here demonstrates the utility of Ion Torrent technology in detecting mutation variants in specific genome regions for large populations of a species such as flax. The methodology could be scaled-up to test >100 genes using the higher capacity chips now available from Ion Torrent.

Refining the Results of a Classical SELEX Experiment by Expanding the Sequence Data Set of an Aptamer Pool Selected for Protein A

OpenAIRE

Regina Stoltenburg; Beate Strehlitz

2018-01-01

New, as yet undiscovered aptamers for Protein A were identified by applying next generation sequencing (NGS) to a previously selected aptamer pool. This pool was obtained in a classical SELEX (Systematic Evolution of Ligands by EXponential enrichment) experiment using the FluMag-SELEX procedure followed by cloning and Sanger sequencing. PA#2/8 was identified as the only Protein A-binding aptamer from the Sanger sequence pool, and was shown to be able to bind intact cells of Staphylococcus aur...

Advantages and limitations of quantitative PCR (Q-PCR)-based approaches in microbial ecology.

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Smith, Cindy J; Osborn, A Mark

2009-01-01

Quantitative PCR (Q-PCR or real-time PCR) approaches are now widely applied in microbial ecology to quantify the abundance and expression of taxonomic and functional gene markers within the environment. Q-PCR-based analyses combine 'traditional' end-point detection PCR with fluorescent detection technologies to record the accumulation of amplicons in 'real time' during each cycle of the PCR amplification. By detection of amplicons during the early exponential phase of the PCR, this enables the quantification of gene (or transcript) numbers when these are proportional to the starting template concentration. When Q-PCR is coupled with a preceding reverse transcription reaction, it can be used to quantify gene expression (RT-Q-PCR). This review firstly addresses the theoretical and practical implementation of Q-PCR and RT-Q-PCR protocols in microbial ecology, highlighting key experimental considerations. Secondly, we review the applications of (RT)-Q-PCR analyses in environmental microbiology and evaluate the contribution and advances gained from such approaches. Finally, we conclude by offering future perspectives on the application of (RT)-Q-PCR in furthering understanding in microbial ecology, in particular, when coupled with other molecular approaches and more traditional investigations of environmental systems.

Analyzing Plasmodium falciparum erythrocyte membrane protein 1 gene expression by a next generation sequencing based method

DEFF Research Database (Denmark)

Jespersen, Jakob S.; Petersen, Bent; Seguin-Orlando, Andaine

2013-01-01

at identifying PfEMP1 features associated with high virulence. Here we present the first effective method for sequence analysis of var genes expressed in field samples: a sequential PCR and next generation sequencing based technique applied on expressed var sequence tags and subsequently on long range PCR......, encoded by ~60 highly variable 'var' genes per haploid genome. PfEMP1 is exported to the surface of infected erythrocytes and is thought to be fundamental to immune evasion by adhesion to host and parasite factors. The highly variable nature has constituted a roadblock in var expression studies aimed...

Discrepancy between Hepatitis C Virus Genotypes and NS4-Based Serotypes: Association with Their Subgenomic Sequences

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Nan Nwe Win

2017-01-01

Full Text Available Determination of hepatitis C virus (HCV genotypes plays an important role in the direct-acting agent era. Discrepancies between HCV genotyping and serotyping assays are occasionally observed. Eighteen samples with discrepant results between genotyping and serotyping methods were analyzed. HCV serotyping and genotyping were based on the HCV nonstructural 4 (NS4 region and 5′-untranslated region (5′-UTR, respectively. HCV core and NS4 regions were chosen to be sequenced and were compared with the genotyping and serotyping results. Deep sequencing was also performed for the corresponding HCV NS4 regions. Seventeen out of 18 discrepant samples could be sequenced by the Sanger method. Both HCV core and NS4 sequences were concordant with that of genotyping in the 5′-UTR in all 17 samples. In cloning analysis of the HCV NS4 region, there were several amino acid variations, but each sequence was much closer to the peptide with the same genotype. Deep sequencing revealed that minor clones with different subgenotypes existed in two of the 17 samples. Genotyping by genome amplification showed high consistency, while several false reactions were detected by serotyping. The deep sequencing method also provides accurate genotyping results and may be useful for analyzing discrepant cases. HCV genotyping should be correctly determined before antiviral treatment.

PCR-Based EST Mapping in Wheat (Triticum aestivum L.

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J. PERRY GUSTAFSON

2009-04-01

Full Text Available Mapping expressed sequence tags (ESTs to hexaploid wheat is aimed to reveal the structure and function of the hexaploid wheat genome. Sixty eight ESTs representing 26 genes were mapped into all seven homologous chromosome groups of wheat (Triticum aestivum L using a polymerase chain reaction technique. The majority of the ESTs were mapped to homologous chromosome group 2, and the least were mapped to homologous chromosome group 6. Comparative analysis between the EST map from this study and the EST map based on RFLPs showed 14 genes that have been mapped by both approaches were mapped to the same arm of the same homologous chromosome, which indicated that using PCR-based ESTs was a reliable approach in mapping ESTs in hexaploid wheat.

De Novo Assembly and Transcriptome Analysis of Bulb Onion (Allium cepa L.) during Cold Acclimation Using Contrasting Genotypes.

Science.gov (United States)

Han, Jeongsukhyeon; Thamilarasan, Senthil Kumar; Natarajan, Sathishkumar; Park, Jong-In; Chung, Mi-Young; Nou, Ill-Sup

2016-01-01

Bulb onion (Allium cepa) is the second most widely cultivated and consumed vegetable crop in the world. During winter, cold injury can limit the production of bulb onion. Genomic resources available for bulb onion are still very limited. To date, no studies on heritably durable cold and freezing tolerance have been carried out in bulb onion genotypes. We applied high-throughput sequencing technology to cold (2°C), freezing (-5 and -15°C), and control (25°C)-treated samples of cold tolerant (CT) and cold susceptible (CS) genotypes of A. cepa lines. A total of 452 million paired-end reads were de novo assembled into 54,047 genes with an average length of 1,331 bp. Based on similarity searches, these genes were aligned with entries in the public non-redundant (nr) database, as well as KEGG and COG database. Differentially expressed genes (DEGs) were identified using log10 values with the FPKM method. Among 5,167DEGs, 491 genes were differentially expressed at freezing temperature compared to the control temperature in both CT and CS libraries. The DEG results were validated with qRT-PCR. We performed GO and KEGG pathway enrichment analyses of all DEGs and iPath interactive analysis found 31 pathways including those related to metabolism of carbohydrate, nucleotide, energy, cofactors and vitamins, other amino acids and xenobiotics biodegradation. Furthermore, a large number of molecular markers were identified from the assembled genes, including simple sequence repeats (SSRs) 4,437 and SNP substitutions of transition and transversion types of CT and CS. Our study is the first to provide a transcriptome sequence resource for Allium spp. with regard to cold and freezing stress. We identified a large set of genes and determined their DEG profiles under cold and freezing conditions using two different genotypes. These data represent a valuable resource for genetic and genomic studies of Allium spp.

De Novo Assembly and Transcriptome Analysis of Bulb Onion (Allium cepa L. during Cold Acclimation Using Contrasting Genotypes.

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Jeongsukhyeon Han

Full Text Available Bulb onion (Allium cepa is the second most widely cultivated and consumed vegetable crop in the world. During winter, cold injury can limit the production of bulb onion. Genomic resources available for bulb onion are still very limited. To date, no studies on heritably durable cold and freezing tolerance have been carried out in bulb onion genotypes. We applied high-throughput sequencing technology to cold (2°C, freezing (-5 and -15°C, and control (25°C-treated samples of cold tolerant (CT and cold susceptible (CS genotypes of A. cepa lines. A total of 452 million paired-end reads were de novo assembled into 54,047 genes with an average length of 1,331 bp. Based on similarity searches, these genes were aligned with entries in the public non-redundant (nr database, as well as KEGG and COG database. Differentially expressed genes (DEGs were identified using log10 values with the FPKM method. Among 5,167DEGs, 491 genes were differentially expressed at freezing temperature compared to the control temperature in both CT and CS libraries. The DEG results were validated with qRT-PCR. We performed GO and KEGG pathway enrichment analyses of all DEGs and iPath interactive analysis found 31 pathways including those related to metabolism of carbohydrate, nucleotide, energy, cofactors and vitamins, other amino acids and xenobiotics biodegradation. Furthermore, a large number of molecular markers were identified from the assembled genes, including simple sequence repeats (SSRs 4,437 and SNP substitutions of transition and transversion types of CT and CS. Our study is the first to provide a transcriptome sequence resource for Allium spp. with regard to cold and freezing stress. We identified a large set of genes and determined their DEG profiles under cold and freezing conditions using two different genotypes. These data represent a valuable resource for genetic and genomic studies of Allium spp.

Virus surveys of Capsicum spp. in the Republic of Benin reveal the prevalence of pepper vein yellows virus and the identification of a previously uncharacterised polerovirus species.

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Afouda, Leonard; Kone, Daouda; Zinsou, Valerien; Dossou, Laurence; Kenyon, Lawrence; Winter, Stephan; Knierim, Dennis

2017-06-01

Surveys were conducted in 2014 and 2015 in Southern and Northern Benin, respectively, to identify the viruses infecting peppers (Capsicum spp.). The samples were screened by ELISA for cucumber mosaic virus (CMV), pepper veinal mottle virus (PVMV), potato virus Y (PVY) and tomato yellow leaf curl virus (TYLCV). A generic reverse transcription PCR (RT-PCR) was used to test for the presence of poleroviruses. ELISA tests confirmed the prevalence of all viruses, while the RT-PCR detected pepper vein yellows virus (PeVYV) which is reported for the first time in Benin. A further, divergent polerovirus isolate was detected from a single pepper sample originating from southern Benin. Screening of samples collected from solanaceous plants during virus surveys in Mali (conducted in 2009) also detected this divergent polerovirus isolate in two samples from African eggplants. The complete genome sequence was obtained from the Mali isolate using transcriptome sequencing and by conventional Sanger sequencing of overlapping RT-PCR products. Based on the sequence characteristics of this isolate we propose a new polerovirus species, African eggplant yellowing virus (AeYV).

Illumina MiSeq Sequencing for Preliminary Analysis of Microbiome Causing Primary Endodontic Infections in Egypt

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Sally Ali Tawfik

2018-01-01

Full Text Available The use of high throughput next generation technologies has allowed more comprehensive analysis than traditional Sanger sequencing. The specific aim of this study was to investigate the microbial diversity of primary endodontic infections using Illumina MiSeq sequencing platform in Egyptian patients. Samples were collected from 19 patients in Suez Canal University Hospital (Endodontic Department using sterile # 15K file and paper points. DNA was extracted using Mo Bio power soil DNA isolation extraction kit followed by PCR amplification and agarose gel electrophoresis. The microbiome was characterized on the basis of the V3 and V4 hypervariable region of the 16S rRNA gene by using paired-end sequencing on Illumina MiSeq device. MOTHUR software was used in sequence filtration and analysis of sequenced data. A total of 1858 operational taxonomic units at 97% similarity were assigned to 26 phyla, 245 families, and 705 genera. Four main phyla Firmicutes, Bacteroidetes, Proteobacteria, and Synergistetes were predominant in all samples. At genus level, Prevotella, Bacillus, Porphyromonas, Streptococcus, and Bacteroides were the most abundant. Illumina MiSeq platform sequencing can be used to investigate oral microbiome composition of endodontic infections. Elucidating the ecology of endodontic infections is a necessary step in developing effective intracanal antimicrobials.

An improved PCR method for direct identification of Porphyra (Bangiales, Rhodophyta) using conchocelis based on a RUBISCO intergenic spacer

Science.gov (United States)

Wang, Chao; Dong, Dong; Wang, Guangce; Zhang, Baoyu; Peng, Guang; Xu, Pu; Tang, Xiaorong

2009-09-01

An improved method of PCR in which the small segment of conchocelis is amplified directly without DNA extraction was used to amplify a RUBISCO intergenic spacer DNA fragment from nine species of red algal genus Porphyra (Bangiales, Rhodophyta), including Porphyra yezoensis (Jiangsu, China), P. haitanensis (Fujian, China), P. oligospermatangia (Qingdao, China), P. katadai (Qingdao, China), P. tenera (Qingdao, China), P. suborboculata (Fujian, China), P. pseudolinearis (Kogendo, Korea), P. linearis (Devon, England), and P. fallax (Seattle, USA). Standard PCR and the method developed here were both conducted using primers specific for the RUBISCO spacer region, after which the two PCR products were sequenced. The sequencing data of the amplicons obtained using both methods were identical, suggesting that the improved PCR method was functional. These findings indicate that the method developed here may be useful for the rapid identification of species of Porphyra in a germplasm bank. In addition, a phylogenetic tree was constructed using the RUBISCO spacer and partial rbcS sequence, and the results were in concordant with possible alternative phylogenies based on traditional morphological taxonomic characteristics, indicating that the RUBISCO spacer is a useful region for phylogenetic studies.

Comparison of PCR-RFLP pattern with sequencing analysis of the ITS region of Hyrcanain\\'s Tilia

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Hamed Yousefzadeh

2014-01-01

T. hyrcana and T. rubra from Hyrcanian's origin, but it could not separate T. begonifloia from the other hyrcanian species. In this respect, derived results were similar to sequencing one. In conclusion, with regard to less expensive and less time consuming PCR-RFLP technique and high similarity between its result with sequencing, we recommend this method as a simple and economical method with relatively high efficiency studding plant phylogeny.

Exploiting transcriptome data for the development and characterization of gene-based SSR markers related to cold tolerance in oil palm (Elaeis guineensis).

Science.gov (United States)

Xiao, Yong; Zhou, Lixia; Xia, Wei; Mason, Annaliese S; Yang, Yaodong; Ma, Zilong; Peng, Ming

2014-12-19

The oil palm (Elaeis guineensis, 2n = 32) has the highest oil yield of any crop species, as well as comprising the richest dietary source of provitamin A. For the tropical species, the best mean growth temperature is about 27°C, with a minimal growth temperature of 15°C. Hence, the plantation area is limited into the geographical ranges of 10°N to 10°S. Enhancing cold tolerance capability will increase the total cultivation area and subsequently oil productivity of this tropical species. Developing molecular markers related to cold tolerance would be helpful for molecular breeding of cold tolerant Elaeis guineensis. In total, 5791 gene-based SSRs were identified in 51,452 expressed sequences from Elaeis guineensis transcriptome data: approximately one SSR was detected per 10 expressed sequences. Of these 5791 gene-based SSRs, 916 were derived from expressed sequences up- or down-regulated at least two-fold in response to cold stress. A total of 182 polymorphic markers were developed and characterized from 442 primer pairs flanking these cold-responsive SSR repeats. The polymorphic information content (PIC) of these polymorphic SSR markers across 24 lines of Elaeis guineensis varied from 0.08 to 0.65 (mean = 0.31 ± 0.12). Using in-silico mapping, 137 (75.3%) of the 182 polymorphic SSR markers were located onto the 16 Elaeis guineensis chromosomes. Total coverage of 473 Mbp was achieved, with an average physical distance of 3.4 Mbp between adjacent markers (range 96 bp - 20.8 Mbp). Meanwhile, Comparative analysis of transcriptome under cold stress revealed that one ICE1 putative ortholog, five CBF putative orthologs, 19 NAC transcription factors and four cold-induced orhologs were up-regulated at least two fold in response to cold stress. Interestingly, 5' untranslated region of both Unigene21287 (ICE1) and CL2628.Contig1 (NAC) both contained an SSR markers. In the present study, a series of SSR markers were developed based on sequences

Differentiation of sheep pox and goat poxviruses by sequence analysis and PCR-RFLP of P32 gene.

Science.gov (United States)

Hosamani, Madhusudan; Mondal, Bimalendu; Tembhurne, Prabhakar A; Bandyopadhyay, Santanu Kumar; Singh, Raj Kumar; Rasool, Thaha Jamal

2004-08-01

Sheep pox and Goat pox are highly contagious viral diseases of small ruminants. These diseases were earlier thought to be caused by a single species of virus, as they are serologically indistinguishable. P32, one of the major immunogenic genes of Capripoxvirus, was isolated and Sequenced from two Indian isolates of goat poxvirus (GPV) and a vaccine strain of sheep poxvirus (SPV). The sequences were compared with other P32 sequences of capripoxviruses available in the database. Sequence analysis revealed that sheep pox and goat poxviruses share 97.5 and 94.7% homology at nucleotide and amino acid level, respectively. A major difference between them is the presence of an additional aspartic acid at 55th position of P32 of sheep poxvirus that is absent in both goat poxvirus and lumpy skin disease virus. Further, six unique neutral nucleotide substitutions were observed at positions 77, 275, 403, 552, 867 and 964 in the sequence of goat poxvirus, which can be taken as GPV signature residues. Similar unique nucleotide signatures could be identified in SPV and LSDV sequences also. Phylogenetic analysis showed that members of the Capripoxvirus could be delineated into three distinct clusters of GPV, SPV and LSDV based on the P32 genomic sequence. Using this information, a PCR-RFLP method has been developed for unequivocal genomic differentiation of SPV and GPV.

Genomic Characterization of Flavobacterium psychrophilum Serotypes and Development of a Multiplex PCR-Based Serotyping Scheme

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Tatiana Rochat

2017-09-01

Full Text Available Flavobacterium psychrophilum is a devastating bacterial pathogen of salmonids reared in freshwater worldwide. So far, serological diversity between isolates has been described but the underlying molecular factors remain unknown. By combining complete genome sequence analysis and the serotyping method proposed by Lorenzen and Olesen (1997 for a set of 34 strains, we identified key molecular determinants of the serotypes. This knowledge allowed us to develop a robust multiplex PCR-based serotyping scheme, which was applied to 244 bacterial isolates. The results revealed a striking association between PCR-serotype and fish host species and illustrate the use of this approach as a simple and cost-effective method for the determination of F. psychrophilum serogroups. PCR-based serotyping could be a useful tool in a range of applications such as disease surveillance, selection of salmonids for bacterial coldwater disease resistance and future vaccine formulation.

A complete mitochondrial genome sequence from a mesolithic wild aurochs (Bos primigenius.

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Ceiridwen J Edwards

Full Text Available BACKGROUND: The derivation of domestic cattle from the extinct wild aurochs (Bos primigenius has been well-documented by archaeological and genetic studies. Genetic studies point towards the Neolithic Near East as the centre of origin for Bos taurus, with some lines of evidence suggesting possible, albeit rare, genetic contributions from locally domesticated wild aurochsen across Eurasia. Inferences from these investigations have been based largely on the analysis of partial mitochondrial DNA sequences generated from modern animals, with limited sequence data from ancient aurochsen samples. Recent developments in DNA sequencing technologies, however, are affording new opportunities for the examination of genetic material retrieved from extinct species, providing new insight into their evolutionary history. Here we present DNA sequence analysis of the first complete mitochondrial genome (16,338 base pairs from an archaeologically-verified and exceptionally-well preserved aurochs bone sample. METHODOLOGY: DNA extracts were generated from an aurochs humerus bone sample recovered from a cave site located in Derbyshire, England and radiocarbon-dated to 6,738+/-68 calibrated years before present. These extracts were prepared for both Sanger and next generation DNA sequencing technologies (Illumina Genome Analyzer. In total, 289.9 megabases (22.48% of the post-filtered DNA sequences generated using the Illumina Genome Analyzer from this sample mapped with confidence to the bovine genome. A consensus B. primigenius mitochondrial genome sequence was constructed and was analysed alongside all available complete bovine mitochondrial genome sequences. CONCLUSIONS: For all nucleotide positions where both Sanger and Illumina Genome Analyzer sequencing methods gave high-confidence calls, no discrepancies were observed. Sequence analysis reveals evidence of heteroplasmy in this sample and places this mitochondrial genome sequence securely within a previously

A complete mitochondrial genome sequence from a mesolithic wild aurochs (Bos primigenius).

LENUS (Irish Health Repository)

Edwards, Ceiridwen J

2010-01-01

BACKGROUND: The derivation of domestic cattle from the extinct wild aurochs (Bos primigenius) has been well-documented by archaeological and genetic studies. Genetic studies point towards the Neolithic Near East as the centre of origin for Bos taurus, with some lines of evidence suggesting possible, albeit rare, genetic contributions from locally domesticated wild aurochsen across Eurasia. Inferences from these investigations have been based largely on the analysis of partial mitochondrial DNA sequences generated from modern animals, with limited sequence data from ancient aurochsen samples. Recent developments in DNA sequencing technologies, however, are affording new opportunities for the examination of genetic material retrieved from extinct species, providing new insight into their evolutionary history. Here we present DNA sequence analysis of the first complete mitochondrial genome (16,338 base pairs) from an archaeologically-verified and exceptionally-well preserved aurochs bone sample. METHODOLOGY: DNA extracts were generated from an aurochs humerus bone sample recovered from a cave site located in Derbyshire, England and radiocarbon-dated to 6,738+\\/-68 calibrated years before present. These extracts were prepared for both Sanger and next generation DNA sequencing technologies (Illumina Genome Analyzer). In total, 289.9 megabases (22.48%) of the post-filtered DNA sequences generated using the Illumina Genome Analyzer from this sample mapped with confidence to the bovine genome. A consensus B. primigenius mitochondrial genome sequence was constructed and was analysed alongside all available complete bovine mitochondrial genome sequences. CONCLUSIONS: For all nucleotide positions where both Sanger and Illumina Genome Analyzer sequencing methods gave high-confidence calls, no discrepancies were observed. Sequence analysis reveals evidence of heteroplasmy in this sample and places this mitochondrial genome sequence securely within a previously identified

SNP discovery in the transcriptome of white Pacific shrimp Litopenaeus vannamei by next generation sequencing.

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Yang Yu

Full Text Available The application of next generation sequencing technology has greatly facilitated high throughput single nucleotide polymorphism (SNP discovery and genotyping in genetic research. In the present study, SNPs were discovered based on two transcriptomes of Litopenaeus vannamei (L. vannamei generated from Illumina sequencing platform HiSeq 2000. One transcriptome of L. vannamei was obtained through sequencing on the RNA from larvae at mysis stage and its reference sequence was de novo assembled. The data from another transcriptome were downloaded from NCBI and the reads of the two transcriptomes were mapped separately to the assembled reference by BWA. SNP calling was performed using SAMtools. A total of 58,717 and 36,277 SNPs with high quality were predicted from the two transcriptomes, respectively. SNP calling was also performed using the reads of two transcriptomes together, and a total of 96,040 SNPs with high quality were predicted. Among these 96,040 SNPs, 5,242 and 29,129 were predicted as non-synonymous and synonymous SNPs respectively. Characterization analysis of the predicted SNPs in L. vannamei showed that the estimated SNP frequency was 0.21% (one SNP per 476 bp and the estimated ratio for transition to transversion was 2.0. Fifty SNPs were randomly selected for validation by Sanger sequencing after PCR amplification and 76% of SNPs were confirmed, which indicated that the SNPs predicted in this study were reliable. These SNPs will be very useful for genetic study in L. vannamei, especially for the high density linkage map construction and genome-wide association studies.

A PCR-based epidemiological survey of Hepatozoon canis in dogs in Nigeria.

Science.gov (United States)

Sasaki, Mizuki; Omobowale, Olutayo; Ohta, Kaisaku; Tozuka, Morito; Matsuu, Aya; Hirata, Haruyuki; Nottidge, Helen Oyebukola; Ikadai, Hiromi; Oyamada, Takashi

2008-07-01

The prevalence of Hepatozoon canis infections in dogs in Nigeria was surveyed using molecular methods. DNA was extracted from blood samples obtained from 400 dogs. A primer set that amplified the Babesia canis 18S rRNA gene, which has high similarity to the H. canis 18S rRNA gene, was used for the PCR. As a result, samples from 81 dogs (20.3%) produced 757 bp bands, which differed from the 698 bp band that corresponded to B. canis infection. The sequence of the PCR products of 10 samples were determined, all of which corresponded with the H. canis sequence.

Conventional Morphology Versus PCR Sequencing, rep-PCR, and MALDI-TOF-MS for Identification of Clinical Aspergillus Isolates Collected Over a 2-Year Period in a University Hospital at Kayseri, Turkey.

Science.gov (United States)

Atalay, Altay; Koc, Ayse Nedret; Suel, Ahmet; Sav, Hafize; Demir, Gonca; Elmali, Ferhan; Cakir, Nuri; Seyedmousavi, Seyedmojtaba

2016-09-01

Aspergillus species cause a wide range of diseases in humans, including allergies, localized infections, or fatal disseminated diseases. Rapid detection and identification of Aspergillus spp. facilitate effective patient management. In the current study we compared conventional morphological methods with PCR sequencing, rep-PCR, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for the identification of Aspergillus strains. A total of 24 consecutive clinical isolates of Aspergillus were collected during 2012-2014. Conventional morphology and rep-PCR were performed in our Mycology Laboratory. The identification, evaluation, and reporting of strains using MALDI-TOF-MS were performed by BioMérieux Diagnostic, Inc. in Istanbul. DNA sequence analysis of the clinical isolates was performed by the BMLabosis laboratory in Ankara. Samples consisted of 18 (75%) lower respiratory tract specimens, 3 otomycosis (12.5%) ear tissues, 1 sample from keratitis, and 1 sample from a cutaneous wound. According to DNA sequence analysis, 12 (50%) specimens were identified as A. fumigatus, 8 (33.3%) as A. flavus, 3 (12.5%) as A. niger, and 1 (4.2%) as A. terreus. Statistically, there was good agreement between the conventional morphology and rep-PCR and MALDI-TOF methods; kappa values were κ = 0.869, 0.871, and 0.916, respectively (P < 0.001). The good level of agreement between the methods included in the present study and sequence method could be due to the identification of Aspergillus strains that were commonly encountered. Therefore, it was concluded that studies conducted with a higher number of isolates, which include other Aspergillus strains, are required. © 2016 Wiley Periodicals, Inc.

[Complete genome sequencing and sequence analysis of BCG Tice].

Science.gov (United States)

Wang, Zhiming; Pan, Yuanlong; Wu, Jun; Zhu, Baoli

2012-10-04

The objective of this study is to obtain the complete genome sequence of Bacillus Calmette-Guerin Tice (BCG Tice), in order to provide more information about the molecular biology of BCG Tice and design more reasonable vaccines to prevent tuberculosis. We assembled the data from high-throughput sequencing with SOAPdenovo software, with many contigs and scaffolds obtained. There are many sequence gaps and physical gaps remained as a result of regional low coverage and low quality. We designed primers at the end of contigs and performed PCR amplification in order to link these contigs and scaffolds. With various enzymes to perform PCR amplification, adjustment of PCR reaction conditions, and combined with clone construction to sequence, all the gaps were finished. We obtained the complete genome sequence of BCG Tice and submitted it to GenBank of National Center for Biotechnology Information (NCBI). The genome of BCG Tice is 4334064 base pairs in length, with GC content 65.65%. The problems and strategies during the finishing step of BCG Tice sequencing are illuminated here, with the hope of affording some experience to those who are involved in the finishing step of genome sequencing. The microarray data were verified by our results.

IDENTIFIKASI TIPE HLA KELAS II DENGAN TEKNIK PCR

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Ervi Salwati

2012-09-01

Full Text Available HLA (Human Leukocyte Antigen contains a set of genes located together on the short arm of chromosome 6. These genes control immune responses, graft acceptance or rejection and tumor surveillance. These abilities have close relationship with genetic variation (occur in "many forms" or alleles that bind and present antigens to T lymphocytes. Using advanced technology and molecular biology approaches (PCR technique detection of genetic variation in the HLA region (or HLA typing has been performed based on DNA.. PCR is an in vitro technique to amplify the DNA sequence enzymatically. "Sequence Specific Primers" (SSP are designed for this PCR to obtain amplification of specific alleles or groups of alleles. The PCR products are visualized through agarose gel electrophoresis stained with ethidium bromide. The PCR technique requires small amount of whole blood (0.5 - 1 ml, gives rapid, accurate and complete result. This paper discuss identification of HLA class II typing using PCR-SSP technique and show the examples of the results.   Key words: HLA (Human Leukocyte Antigen class II, PCR (Polymerase Chain Reaction

Discrimination of gastrointestinal nematode eggs from crude fecal egg preparations by inhibitor-resistant conventional and real-time PCR.

Science.gov (United States)

Demeler, Janina; Ramünke, Sabrina; Wolken, Sonja; Ianiello, Davide; Rinaldi, Laura; Gahutu, Jean Bosco; Cringoli, Giuseppe; von Samson-Himmelstjerna, Georg; Krücken, Jürgen

2013-01-01

be used such as RFLP, reverse-line-blot, Sanger sequencing and HRM.

Discrimination of gastrointestinal nematode eggs from crude fecal egg preparations by inhibitor-resistant conventional and real-time PCR.

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Janina Demeler

different post PCR methods can be used such as RFLP, reverse-line-blot, Sanger sequencing and HRM.

Simultaneous discrimination of species and strains in Lactobacillus rhamnosus using species-specific PCR combined with multiplex mini-sequencing technology.

Science.gov (United States)

Huang, Chien-Hsun; Chang, Mu-Tzu; Huang, Lina; Chu, Wen-Shen

2015-12-01

This study described the use of species-specific PCR in combination with SNaPshot mini-sequencing to achieve species identification and strain differentiation in Lactobacillus rhamnosus. To develop species-specific PCR and strain subtyping primers, the dnaJ gene was used as a target, and its corresponding sequences were analyzed both in Lb. rhamnosus and in a subset of its phylogenetically closest species. The results indicated that the species-specific primer pair was indeed specific for Lb. rhamnosus, and the mini-sequencing assay was able to unambiguously distinguish Lb. rhamnosus strains into different haplotypes. In conclusion, we have successfully developed a rapid, accurate and cost-effective assay for inter- and intraspecies discrimination of Lb. rhamnosus, which can be applied to achieve efficient quality control of probiotic products. Copyright © 2015 Elsevier Ltd. All rights reserved.

Multiplex PCR identification of Taenia spp. in rodents and carnivores.

Science.gov (United States)

Al-Sabi, Mohammad N S; Kapel, Christian M O

2011-11-01

The genus Taenia includes several species of veterinary and public health importance, but diagnosis of the etiological agent in definitive and intermediate hosts often relies on labor intensive and few specific morphometric criteria, especially in immature worms and underdeveloped metacestodes. In the present study, a multiplex PCR, based on five primers targeting the 18S rDNA and ITS2 sequences, produced a species-specific banding patterns for a range of Taenia spp. Species typing by the multiplex PCR was compared to morphological identification and sequencing of cox1 and/or 12S rDNA genes. As compared to sequencing, the multiplex PCR identified 31 of 32 Taenia metacestodes from rodents, whereas only 14 cysts were specifically identified by morphology. Likewise, the multiplex PCR identified 108 of 130 adult worms, while only 57 were identified to species by morphology. The tested multiplex PCR system may potentially be used for studies of Taenia spp. transmitted between rodents and carnivores.

Characterisation of Toxoplasma gondii isolates using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) of the non-coding Toxoplasma gondii (TGR)-gene sequences

DEFF Research Database (Denmark)

Høgdall, Estrid; Vuust, Jens; Lind, Peter

2000-01-01

of using TGR gene variants as markers to distinguish among T. gondii isolates from different animals and different geographical sources. Based on the band patterns obtained by restriction fragment length polymorphism (RFLP) analysis of the polymerase chain reaction (PCR) amplified TGR sequences, the T...

Authentication of Herbal Supplements Using Next-Generation Sequencing.

Directory of Open Access Journals (Sweden)

Natalia V Ivanova

Full Text Available DNA-based testing has been gaining acceptance as a tool for authentication of a wide range of food products; however, its applicability for testing of herbal supplements remains contentious.We utilized Sanger and Next-Generation Sequencing (NGS for taxonomic authentication of fifteen herbal supplements representing three different producers from five medicinal plants: Echinacea purpurea, Valeriana officinalis, Ginkgo biloba, Hypericum perforatum and Trigonella foenum-graecum. Experimental design included three modifications of DNA extraction, two lysate dilutions, Internal Amplification Control, and multiple negative controls to exclude background contamination. Ginkgo supplements were also analyzed using HPLC-MS for the presence of active medicinal components.All supplements yielded DNA from multiple species, rendering Sanger sequencing results for rbcL and ITS2 regions either uninterpretable or non-reproducible between the experimental replicates. Overall, DNA from the manufacturer-listed medicinal plants was successfully detected in seven out of eight dry herb form supplements; however, low or poor DNA recovery due to degradation was observed in most plant extracts (none detected by Sanger; three out of seven-by NGS. NGS also revealed a diverse community of fungi, known to be associated with live plant material and/or the fermentation process used in the production of plant extracts. HPLC-MS testing demonstrated that Ginkgo supplements with degraded DNA contained ten key medicinal components.Quality control of herbal supplements should utilize a synergetic approach targeting both DNA and bioactive components, especially for standardized extracts with degraded DNA. The NGS workflow developed in this study enables reliable detection of plant and fungal DNA and can be utilized by manufacturers for quality assurance of raw plant materials, contamination control during the production process, and the final product. Interpretation of results should

Authentication of Herbal Supplements Using Next-Generation Sequencing.

Science.gov (United States)

Ivanova, Natalia V; Kuzmina, Maria L; Braukmann, Thomas W A; Borisenko, Alex V; Zakharov, Evgeny V

2016-01-01

DNA-based testing has been gaining acceptance as a tool for authentication of a wide range of food products; however, its applicability for testing of herbal supplements remains contentious. We utilized Sanger and Next-Generation Sequencing (NGS) for taxonomic authentication of fifteen herbal supplements representing three different producers from five medicinal plants: Echinacea purpurea, Valeriana officinalis, Ginkgo biloba, Hypericum perforatum and Trigonella foenum-graecum. Experimental design included three modifications of DNA extraction, two lysate dilutions, Internal Amplification Control, and multiple negative controls to exclude background contamination. Ginkgo supplements were also analyzed using HPLC-MS for the presence of active medicinal components. All supplements yielded DNA from multiple species, rendering Sanger sequencing results for rbcL and ITS2 regions either uninterpretable or non-reproducible between the experimental replicates. Overall, DNA from the manufacturer-listed medicinal plants was successfully detected in seven out of eight dry herb form supplements; however, low or poor DNA recovery due to degradation was observed in most plant extracts (none detected by Sanger; three out of seven-by NGS). NGS also revealed a diverse community of fungi, known to be associated with live plant material and/or the fermentation process used in the production of plant extracts. HPLC-MS testing demonstrated that Ginkgo supplements with degraded DNA contained ten key medicinal components. Quality control of herbal supplements should utilize a synergetic approach targeting both DNA and bioactive components, especially for standardized extracts with degraded DNA. The NGS workflow developed in this study enables reliable detection of plant and fungal DNA and can be utilized by manufacturers for quality assurance of raw plant materials, contamination control during the production process, and the final product. Interpretation of results should involve an

Genome-wide linkage, exome sequencing and functional analyses identify ABCB6 as the pathogenic gene of dyschromatosis universalis hereditaria.

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Hong Liu

Full Text Available As a genetic disorder of abnormal pigmentation, the molecular basis of dyschromatosis universalis hereditaria (DUH had remained unclear until recently when ABCB6 was reported as a causative gene of DUH.We performed genome-wide linkage scan using Illumina Human 660W-Quad BeadChip and exome sequencing analyses using Agilent SureSelect Human All Exon Kits in a multiplex Chinese DUH family to identify the pathogenic mutations and verified the candidate mutations using Sanger sequencing. Quantitative RT-PCR and Immunohistochemistry was performed to verify the expression of the pathogenic gene, Zebrafish was also used to confirm the functional role of ABCB6 in melanocytes and pigmentation.Genome-wide linkage (assuming autosomal dominant inheritance mode and exome sequencing analyses identified ABCB6 as the disease candidate gene by discovering a coding mutation (c.1358C>T; p.Ala453Val that co-segregates with the disease phenotype. Further mutation analysis of ABCB6 in four other DUH families and two sporadic cases by Sanger sequencing confirmed the mutation (c.1358C>T; p.Ala453Val and discovered a second, co-segregating coding mutation (c.964A>C; p.Ser322Lys in one of the four families. Both mutations were heterozygous in DUH patients and not present in the 1000 Genome Project and dbSNP database as well as 1,516 unrelated Chinese healthy controls. Expression analysis in human skin and mutagenesis interrogation in zebrafish confirmed the functional role of ABCB6 in melanocytes and pigmentation. Given the involvement of ABCB6 mutations in coloboma, we performed ophthalmological examination of the DUH carriers of ABCB6 mutations and found ocular abnormalities in them.Our study has advanced our understanding of DUH pathogenesis and revealed the shared pathological mechanism between pigmentary DUH and ocular coloboma.

A high-throughput splinkerette-PCR method for the isolation and sequencing of retroviral insertion sites

DEFF Research Database (Denmark)

Uren, Anthony G; Mikkers, Harald; Kool, Jaap

2009-01-01

sites has been a major limitation to performing screens on this scale. Here we present a method for the high-throughput isolation of insertion sites using a highly efficient splinkerette-PCR method coupled with capillary or 454 sequencing. This protocol includes a description of the procedure for DNA......Insertional mutagens such as viruses and transposons are a useful tool for performing forward genetic screens in mice to discover cancer genes. These screens are most effective when performed using hundreds of mice; however, until recently, the cost-effective isolation and sequencing of insertion...

A ribosomal RNA gene intergenic spacer based PCR and DGGE fingerprinting method for the analysis of specific rhizobial communities in soil

NARCIS (Netherlands)

de Oliveira, VM; Manfio, GP; Coutinho, HLD; Keijzer-Wolters, AC; van Elsas, JD

A direct molecular method for assessing the diversity of specific populations of rhizobia in soil, based on nested PCR amplification of 16S-23S ribosomal RNA gene (rDNA) intergenic spacer (IGS) sequences, was developed. Initial generic amplification of bacterial rDNA IGS sequences from soil DNA was

A ribosomal RNA gene intergenic spacer based PCR and DGGE fingerprinting method for the analysis of specific rhizobial communities in soil

NARCIS (Netherlands)

Oliveira, de V.M.; Manfio, G.P.; Coutinho, H.L.D.; Keijzer-Wolters, A.C.; Elsas, van J.D.

2006-01-01

A direct molecular method for assessing the diversity of specific populations of rhizobia in soil, based on nested PCR amplification of 16S-23S ribosomal RNA gene (rDNA) intergenic spacer (IGS) sequences, was developed. Initial generic amplification of bacterial rDNA IGS sequences from soil DNA was

Bioinformatic tools for PCR Primer design

African Journals Online (AJOL)

ES

reaction (PCR), oligo hybridization and DNA sequencing. Proper primer design is actually one of the most important factors/steps in successful DNA sequencing. Various bioinformatics programs are available for selection of primer pairs from a template sequence. The plethora programs for PCR primer design reflects the.

Eliminating PCR contamination

International Nuclear Information System (INIS)

Fox, J.C.; Ait-Khaled, Mounir; Webster, Alison; Emery, V.C.

1991-01-01

The sensitivity of polymerase chain reaction (PCR) can mean that even very low levels of contamination with the target DNA will result in a positive signal. At present this aspect is a major limitation in the use of PCR as a routine diagnostic method. By exposing PCR reagents to UV light, contaminating DNA can be inactivated, thus providing an opportunity to eradicate false positive reactions. UV irradiation was applied to PCR systems used for detection of human cytomegalovirus CMV and human immunodeficiency virus (HIV) and shown to be effective in eradicating both laboratory encountered contamination and plasmid DNA (below 100 pg) added to PCR systems prior to UV exposure. Sensitivity of a PCR system to amplify the long terminal repeat (LTR) sequence of HIV-1 was not affected by the irradiation procedure; however, ultimate sensitivity of a PCR system for the amplification of an early gene pro-motor sequence of the CMV genome was reduced 1000-fold. UV irradiation did not affect the size of the PCR product as determined by strand separating polyacrylamide gel electrophoresis of a 32 P-labelled amplimer. Thus, a simple pre-exposure to UV light would seem a worth-wile step to incorporate into PCR protocols provided that the effects on sensitivity have been determined empirically for each PCR system. (author). 11 refs.; 3 figs

Pseudogene of dihydrolipoyl succinyltransferase (E2k) found by PCR amplification and direct sequencing of rodent-human cell hybrid DNAs

Energy Technology Data Exchange (ETDEWEB)

Cai, X.; Ali, G.; Blass, J.P. [Cornell Univ. Medical College, White Plains, NY (United States); Szabo, P. [Cornell Univ. Medical College, New York, NY (United States); Tanzi, R.E. [Massachusetts General Hospital, Boston, MA (United States)

1994-07-01

Previous studies have indicated that the cDNA for the E2k component of the human {alpha}-ketoglutarate dehydrogenase complex (KGDHC) hybridized not only to a major locus on chromosome 14q24.3 in a region associated with familial Alzheimer`s disease and with Joseph-Machado disease, but also to another locus on chromosome 1p31. The authors now report that PCR of genomic DNA and direct sequencing indicated that the chromosome 1 locus is an intronless pseudogene. PCR of genomic DNA amplified E2k fragments from mouse-human cell hybrids containing human chromosome 1 DNA but not from hybrids containing human chromosome 14 DNA. The resulting amplicons were of comparable sizes to those when the cDNA was used to template. The direct sequencing of these amplicons confirmed the lack of introns and indicated a frame shift, which led to the presence of four termination codons early in the coding region. PCR followed by direct sequencing of the amplicons appears to be a convenient method for identifying intronless pseudogenes.

PCR-based isolation and identification of full-length low-molecular-weight glutenin subunit genes in bread wheat (Triticum aestivum L.).

Science.gov (United States)

Zhang, Xiaofei; Liu, Dongcheng; Jiang, Wei; Guo, Xiaoli; Yang, Wenlong; Sun, Jiazhu; Ling, Hongqing; Zhang, Aimin

2011-12-01

Low-molecular-weight glutenin subunits (LMW-GSs) are encoded by a multi-gene family and are essential for determining the quality of wheat flour products, such as bread and noodles. However, the exact role or contribution of individual LMW-GS genes to wheat quality remains unclear. This is, at least in part, due to the difficulty in characterizing complete sequences of all LMW-GS gene family members in bread wheat. To identify full-length LMW-GS genes, a polymerase chain reaction (PCR)-based method was established, consisting of newly designed conserved primers and the previously developed LMW-GS gene molecular marker system. Using the PCR-based method, 17 LMW-GS genes were identified and characterized in Xiaoyan 54, of which 12 contained full-length sequences. Sequence alignments showed that 13 LMW-GS genes were identical to those found in Xiaoyan 54 using the genomic DNA library screening, and the other four full-length LMW-GS genes were first isolated from Xiaoyan 54. In Chinese Spring, 16 unique LMW-GS genes were isolated, and 13 of them contained full-length coding sequences. Additionally, 16 and 17 LMW-GS genes in Dongnong 101 and Lvhan 328 (chosen from the micro-core collections of Chinese germplasm), respectively, were also identified. Sequence alignments revealed that at least 15 LMW-GS genes were common in the four wheat varieties, and allelic variants of each gene shared high sequence identities (>95%) but exhibited length polymorphism in repetitive regions. This study provides a PCR-based method for efficiently identifying LMW-GS genes in bread wheat, which will improve the characterization of complex members of the LMW-GS gene family and facilitate the understanding of their contributions to wheat quality.

The Quest for Rare Variants: Pooled Multiplexed Next Generation Sequencing in Plants

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Fabio eMarroni

2012-06-01

Full Text Available Next generation sequencing (NGS instruments produce an unprecedented amount of sequence data at contained costs. This gives researchers the possibility of designing studies with adequate power to identify rare variants at a fraction of the economic and labor resources required by individual Sanger sequencing. As of today, only three research groups working in plant sciences have exploited this potentiality. They showed that pooled NGS can provide results in excellent agreement with those obtained by individual Sanger sequencing. Aim of this review is to convey to the reader the general ideas underlying the use of pooled NGS for the identification of rare variants. To facilitate a thorough understanding of the possibilities of the method we will explain in detail the variations in study design and discuss their advantages and disadvantages. We will show that information on allele frequency obtained by pooled next generation sequencing can be used to accurately compute basic population genetics indexes such as allele frequency, nucleotide diversity and Tajima’s D. Finally we will discuss applications and future perspectives of the multiplexed NGS approach.

Simultaneous digital quantification and fluorescence-based size characterization of massively parallel sequencing libraries.

Science.gov (United States)

Laurie, Matthew T; Bertout, Jessica A; Taylor, Sean D; Burton, Joshua N; Shendure, Jay A; Bielas, Jason H

2013-08-01

Due to the high cost of failed runs and suboptimal data yields, quantification and determination of fragment size range are crucial steps in the library preparation process for massively parallel sequencing (or next-generation sequencing). Current library quality control methods commonly involve quantification using real-time quantitative PCR and size determination using gel or capillary electrophoresis. These methods are laborious and subject to a number of significant limitations that can make library calibration unreliable. Herein, we propose and test an alternative method for quality control of sequencing libraries using droplet digital PCR (ddPCR). By exploiting a correlation we have discovered between droplet fluorescence and amplicon size, we achieve the joint quantification and size determination of target DNA with a single ddPCR assay. We demonstrate the accuracy and precision of applying this method to the preparation of sequencing libraries.

Rapid and Accurate Sequencing of Enterovirus Genomes Using MinION Nanopore Sequencer.

Science.gov (United States)

Wang, Ji; Ke, Yue Hua; Zhang, Yong; Huang, Ke Qiang; Wang, Lei; Shen, Xin Xin; Dong, Xiao Ping; Xu, Wen Bo; Ma, Xue Jun

2017-10-01

Knowledge of an enterovirus genome sequence is very important in epidemiological investigation to identify transmission patterns and ascertain the extent of an outbreak. The MinION sequencer is increasingly used to sequence various viral pathogens in many clinical situations because of its long reads, portability, real-time accessibility of sequenced data, and very low initial costs. However, information is lacking on MinION sequencing of enterovirus genomes. In this proof-of-concept study using Enterovirus 71 (EV71) and Coxsackievirus A16 (CA16) strains as examples, we established an amplicon-based whole genome sequencing method using MinION. We explored the accuracy, minimum sequencing time, discrimination and high-throughput sequencing ability of MinION, and compared its performance with Sanger sequencing. Within the first minute (min) of sequencing, the accuracy of MinION was 98.5% for the single EV71 strain and 94.12%-97.33% for 10 genetically-related CA16 strains. In as little as 14 min, 99% identity was reached for the single EV71 strain, and in 17 min (on average), 99% identity was achieved for 10 CA16 strains in a single run. MinION is suitable for whole genome sequencing of enteroviruses with sufficient accuracy and fine discrimination and has the potential as a fast, reliable and convenient method for routine use. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Next-Generation Sequencing Platforms

Science.gov (United States)

Mardis, Elaine R.

2013-06-01

Automated DNA sequencing instruments embody an elegant interplay among chemistry, engineering, software, and molecular biology and have built upon Sanger's founding discovery of dideoxynucleotide sequencing to perform once-unfathomable tasks. Combined with innovative physical mapping approaches that helped to establish long-range relationships between cloned stretches of genomic DNA, fluorescent DNA sequencers produced reference genome sequences for model organisms and for the reference human genome. New types of sequencing instruments that permit amazing acceleration of data-collection rates for DNA sequencing have been developed. The ability to generate genome-scale data sets is now transforming the nature of biological inquiry. Here, I provide an historical perspective of the field, focusing on the fundamental developments that predated the advent of next-generation sequencing instruments and providing information about how these instruments work, their application to biological research, and the newest types of sequencers that can extract data from single DNA molecules.

UGT1A1 (TA)n genotyping in sickle-cell disease: high resolution melting (HRM) curve analysis or direct sequencing, what is the best way?

Science.gov (United States)

Thomas, Vincent; Mazard, Blandine; Garcia, Caroline; Lacan, Philippe; Gagnieu, Marie-Claude; Joly, Philippe

2013-09-23

Minucci et al. have proposed in 2010 a rapid, simple and cost-effective HRM method on the LightCycler 480® apparatus (Roche) for the determination of the 6/6, 6/7 and 7/7 genotypes of the (TA)n UGT1A1 promoter polymorphism. However, they have not studied the n=5 and n=8 alleles which can be quite frequent in sickle-cell disease patients. The aim of our study was to test this HRM protocol to all the 10 possible (TA)n UGT1A1 genotypes (i.e. 5/5, 5/6, 5/7, 5/8, 6/6, 6/7, 6/8, 7/7, 7/8 and 8/8) by using our SCD cohort of patients. All genotypes could be unambiguously identified except 6/7 and 6/8 which give a similar HRM profile. For those two genotypes, the differentiation necessitates either a direct Sanger sequencing or a second PCR protocol followed by a 3% agarose gel migration. For the (TA)n UGT1A1 promoter genotyping of African patients, each lab has to wonder what is the best way between (i) direct Sanger sequencing of all patients and (ii) HRM protocol for all patients followed by a complementary analysis to differentiate the 6/7 and 6/8 genotypes. © 2013. Published by Elsevier B.V. All rights reserved.

Use of next generation sequencing data to develop a qPCR method for specific detection of EU-unauthorized genetically modified Bacillus subtilis overproducing riboflavin.

Science.gov (United States)

Barbau-Piednoir, Elodie; De Keersmaecker, Sigrid C J; Delvoye, Maud; Gau, Céline; Philipp, Patrick; Roosens, Nancy H

2015-11-11

Recently, the presence of an unauthorized genetically modified (GM) Bacillus subtilis bacterium overproducing vitamin B2 in a feed additive was notified by the Rapid Alert System for Food and Feed (RASFF). This has demonstrated that a contamination by a GM micro-organism (GMM) may occur in feed additives and has confronted for the first time,the enforcement laboratories with this type of RASFF. As no sequence information of this GMM nor any specific detection or identification method was available, Next GenerationSequencing (NGS) was used to generate sequence information. However, NGS data analysis often requires appropriate tools, involving bioinformatics expertise which is not alwayspresent in the average enforcement laboratory. This hampers the use of this technology to rapidly obtain critical sequence information in order to be able to develop a specific qPCRdetection method. Data generated by NGS were exploited using a simple BLAST approach. A TaqMan® qPCR method was developed and tested on isolated bacterial strains and on the feed additive directly. In this study, a very simple strategy based on the common BLAST tools that can be used by any enforcement lab without profound bioinformatics expertise, was successfully used toanalyse the B. subtilis data generated by NGS. The results were used to design and assess a new TaqMan® qPCR method, specifically detecting this GM vitamin B2 overproducing bacterium. The method complies with EU critical performance parameters for specificity, sensitivity, PCR efficiency and repeatability. The VitB2-UGM method also could detect the B. subtilis strain in genomic DNA extracted from the feed additive, without prior culturing step. The proposed method, provides a crucial tool for specifically and rapidly identifying this unauthorized GM bacterium in food and feed additives by enforcement laboratories. Moreover, this work can be seen as a case study to substantiate how the use of NGS data can offer an added value to easily

Statistical framework for detection of genetically modified organisms based on Next Generation Sequencing.

Science.gov (United States)

Willems, Sander; Fraiture, Marie-Alice; Deforce, Dieter; De Keersmaecker, Sigrid C J; De Loose, Marc; Ruttink, Tom; Herman, Philippe; Van Nieuwerburgh, Filip; Roosens, Nancy

2016-02-01

Because the number and diversity of genetically modified (GM) crops has significantly increased, their analysis based on real-time PCR (qPCR) methods is becoming increasingly complex and laborious. While several pioneers already investigated Next Generation Sequencing (NGS) as an alternative to qPCR, its practical use has not been assessed for routine analysis. In this study a statistical framework was developed to predict the number of NGS reads needed to detect transgene sequences, to prove their integration into the host genome and to identify the specific transgene event in a sample with known composition. This framework was validated by applying it to experimental data from food matrices composed of pure GM rice, processed GM rice (noodles) or a 10% GM/non-GM rice mixture, revealing some influential factors. Finally, feasibility of NGS for routine analysis of GM crops was investigated by applying the framework to samples commonly encountered in routine analysis of GM crops. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Yellowstone Lake Nanoarchaeota

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Scott eClingenpeel

2013-09-01

Full Text Available Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park, where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1,349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels. However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (70 pyrosequencing reads was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

Comparative analysis of minor histocompatibility antigens genotyping methods

Directory of Open Access Journals (Sweden)

A. S. Vdovin

2016-01-01

Full Text Available The wide range of techniques could be employed to find mismatches in minor histocompatibility antigens between transplant recipients and their donors. In the current study we compared three genotyping methods based on polymerase chain reaction (PCR for four minor antigens. Three of the tested methods: allele-specific PCR, restriction fragment length polymorphism and real-time PCR with TaqMan probes demonstrated 100% reliability when compared to Sanger sequencing for all of the studied polymorphisms. High resolution melting analysis was unsuitable for genotyping of one of the tested minor antigens (HA-1 as it has linked synonymous polymorphism. Obtained data could be used to select the strategy for large-scale clinical genotyping.

Cold stress alters transcription in meiotic anthers of cold tolerant chickpea (Cicer arietinum L.).

Science.gov (United States)

Sharma, Kamal Dev; Nayyar, Harsh

2014-10-11

Cold stress at reproductive phase in susceptible chickpea (Cicer arietinum L.) leads to pollen sterility induced flower abortion. The tolerant genotypes, on the other hand, produce viable pollen and set seed under cold stress. Genomic information on pollen development in cold-tolerant chickpea under cold stress is currently unavailable. DDRT-PCR analysis was carried out to identify anther genes involved in cold tolerance in chickpea genotype ICC16349 (cold-tolerant). A total of 9205 EST bands were analyzed. Cold stress altered expression of 127 ESTs (90 up-regulated, 37 down-regulated) in anthers, more than two third (92) of which were novel with unknown protein identity and function. Remaining about one third (35) belonged to several functional categories such as pollen development, signal transduction, ion transport, transcription, carbohydrate metabolism, translation, energy and cell division. The categories with more number of transcripts were carbohydrate/triacylglycerol metabolism, signal transduction, pollen development and transport. All but two transcripts in these categories were up-regulated under cold stress. To identify time of regulation after stress and organ specificity, expression levels of 25 differentially regulated transcripts were also studied in anthers at six time points and in four organs (anthers, gynoecium, leaves and roots) at four time points. Limited number of genes were involved in regulating cold tolerance in chickpea anthers. Moreover, the cold tolerance was manifested by up-regulation of majority of the differentially expressed transcripts. The anthers appeared to employ dual cold tolerance mechanism based on their protection from cold by enhancing triacylglycerol and carbohydrate metabolism; and maintenance of normal pollen development by regulating pollen development genes. Functional characterization of about two third of the novel genes is needed to have precise understanding of the cold tolerance mechanisms in chickpea anthers.

A Bac Library and Paired-PCR Approach to Mapping and Completing the Genome Sequence of Sulfolobus Solfataricus P2

DEFF Research Database (Denmark)

She, Qunxin; Confalonieri, F.; Zivanovic, Y.

2000-01-01

The original strategy used in the Sulfolobus solfatnricus genome project was to sequence non overlapping, or minimally overlapping, cosmid or lambda inserts without constructing a physical map. However, after only about two thirds of the genome sequence was completed, this approach became counter......-productive because there was a high sequence bias in the cosmid and lambda libraries. Therefore, a new approach was devised for linking the sequenced regions which may be generally applicable. BAC libraries were constructed and terminal sequences of the clones were determined and used for both end mapping and PCR...

A ribosomal RNA gene intergenic spacer based PCR and DGGE fingerprinting method for the analysis of specific rhizobial communities in soil.

Science.gov (United States)

de Oliveira, Valéria Maia; Manfio, Gilson Paulo; da Costa Coutinho, Heitor Luiz; Keijzer-Wolters, Anneke Christina; van Elsas, Jan Dirk

2006-03-01

A direct molecular method for assessing the diversity of specific populations of rhizobia in soil, based on nested PCR amplification of 16S-23S ribosomal RNA gene (rDNA) intergenic spacer (IGS) sequences, was developed. Initial generic amplification of bacterial rDNA IGS sequences from soil DNA was followed by specific amplification of (1) sequences affiliated with Rhizobium leguminosarum "sensu lato" and (2) R. tropici. Using analysis of the amplified sequences in clone libraries obtained on the basis of soil DNA, this two-sided method was shown to be very specific for rhizobial subpopulations in soil. It was then further validated as a direct fingerprinting tool of the target rhizobia based on denaturing gradient gel electrophoresis (DGGE). The PCR-DGGE approach was applied to soils from fields in Brazil cultivated with common bean (Phaseolus vulgaris) under conventional or no-tillage practices. The community fingerprints obtained allowed the direct analysis of the respective rhizobial community structures in soil samples from the two contrasting agricultural practices. Data obtained with both primer sets revealed clustering of the community structures of the target rhizobial types along treatment. Moreover, the DGGE profiles obtained with the R. tropici primer set indicated that the abundance and diversity of these organisms were favoured under NT practices. These results suggest that the R. leguminosarum-as well as R. tropici-targeted IGS-based nested PCR and DGGE are useful tools for monitoring the effect of agricultural practices on these and related rhizobial subpopulations in soils.

Molecular diagnostics for congenital hearing loss including 15 deafness genes using a next generation sequencing platform

Directory of Open Access Journals (Sweden)

De Keulenaer Sarah

2012-05-01

Full Text Available Abstract Background Hereditary hearing loss (HL can originate from mutations in one of many genes involved in the complex process of hearing. Identification of the genetic defects in patients is currently labor intensive and expensive. While screening with Sanger sequencing for GJB2 mutations is common, this is not the case for the other known deafness genes (> 60. Next generation sequencing technology (NGS has the potential to be much more cost efficient. Published methods mainly use hybridization based target enrichment procedures that are time saving and efficient, but lead to loss in sensitivity. In this study we used a semi-automated PCR amplification and NGS in order to combine high sensitivity, speed and cost efficiency. Results In this proof of concept study, we screened 15 autosomal recessive deafness genes in 5 patients with congenital genetic deafness. 646 specific primer pairs for all exons and most of the UTR of the 15 selected genes were designed using primerXL. Using patient specific identifiers, all amplicons were pooled and analyzed using the Roche 454 NGS technology. Three of these patients are members of families in which a region of interest has previously been characterized by linkage studies. In these, we were able to identify two new mutations in CDH23 and OTOF. For another patient, the etiology of deafness was unclear, and no causal mutation was found. In a fifth patient, included as a positive control, we could confirm a known mutation in TMC1. Conclusions We have developed an assay that holds great promise as a tool for screening patients with familial autosomal recessive nonsyndromal hearing loss (ARNSHL. For the first time, an efficient, reliable and cost effective genetic test, based on PCR enrichment, for newborns with undiagnosed deafness is available.

Barcoding the food chain: from Sanger to high-throughput sequencing.

Science.gov (United States)

Littlefair, Joanne E; Clare, Elizabeth L

2016-11-01

Society faces the complex challenge of supporting biodiversity and ecosystem functioning, while ensuring food security by providing safe traceable food through an ever-more-complex global food chain. The increase in human mobility brings the added threat of pests, parasites, and invaders that further complicate our agro-industrial efforts. DNA barcoding technologies allow researchers to identify both individual species, and, when combined with universal primers and high-throughput sequencing techniques, the diversity within mixed samples (metabarcoding). These tools are already being employed to detect market substitutions, trace pests through the forensic evaluation of trace "environmental DNA", and to track parasitic infections in livestock. The potential of DNA barcoding to contribute to increased security of the food chain is clear, but challenges remain in regulation and the need for validation of experimental analysis. Here, we present an overview of the current uses and challenges of applied DNA barcoding in agriculture, from agro-ecosystems within farmland to the kitchen table.

Gold nanoparticle-based RT-PCR and real-time quantitative RT-PCR assays for detection of Japanese encephalitis virus

International Nuclear Information System (INIS)

Huang, S-H; Tsai, M-H; Lin, C-W; Yang, T-C; Chuang, P-H; Tsai, I-S; Lu, H-C; Wan Lei; Lin, Y-J; Lai, C-H

2008-01-01

Virus isolation and antibody detection are routinely used for diagnosis of Japanese encephalitis virus (JEV) infection, but the low level of transient viremia in some JE patients makes JEV isolation from clinical and surveillance samples very difficult. We describe the use of gold nanoparticle-based RT-PCR and real-time quantitative RT-PCR assays for detection of JEV from its RNA genome. We tested the effect of gold nanoparticles on four different PCR systems, including conventional PCR, reverse-transcription PCR (RT-PCR), and SYBR green real-time PCR and RT-PCR assays for diagnosis in the acute phase of JEV infection. Gold nanoparticles increased the amplification yield of the PCR product and shortened the PCR time compared to the conventional reaction. In addition, nanogold-based real-time RT-PCR showed a linear relationship between Ct and template amount using ten-fold dilutions of JEV. The nanogold-based RT-PCR and real-time quantitative RT-PCR assays were able to detect low levels (1-10 000 copies) of the JEV RNA genomes extracted from culture medium or whole blood, providing early diagnostic tools for the detection of low-level viremia in the acute-phase infection. The assays described here were simple, sensitive, and rapid approaches for detection and quantitation of JEV in tissue cultured samples as well as clinical samples

Complete nucleotide sequence of a novel Hibiscus-infecting Cilevirus from Florida and its relationship with closely associated Cileviruses

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The complete nucleotide sequence of a recently discovered Florida (FL) isolate of Hibiscus infecting Cilevirus (HiCV) was determined by Sanger sequencing. The movement- and coat- protein gene sequences of the HiCV-FL isolate are more divergent than other genes of the previously sequenced HiCV-HA (Ha...

ABO Blood Group Genotyping by Real-time PCR in Kazakh Population

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Pavel Tarlykov

2014-12-01

Full Text Available Introduction. ABO blood group genotyping is a new technology in hematology that helps prevent adverse transfusion reactions in patients. Identification of antigens on the surface of red blood cells is based on serology; however, genotyping employs a different strategy and is aimed directly at genes that determine the surface proteins. ABO blood group genotyping by real-time PCR has several crucial advantages over other PCR-based techniques, such as high rapidity and reliability of analysis. The purpose of this study was to examine nucleotide substitutions differences by blood types using a PCR-based method on Kazakh blood donors.Methods. The study was approved by the Ethics Committee of the National Center for Biotechnology. Venous blood samples from 369 healthy Kazakh blood donors, whose blood types had been determined by serological methods, were collected after obtaining informed consent. The phenotypes of the samples included blood group A (n = 99, B (n = 93, O (n = 132, and AB (n = 45. Genomic DNA was extracted using a salting-out method. PCR products of ABO gene were sequenced on an ABI 3730xl DNA analyzer (Applied Biosystems. The resulting nucleotide sequences were compared and aligned against reference sequence NM_020469.2. Real-time PCR analysis was performed on CFX96 Touch™ Real-Time PCR Detection System (BioRad.Results. Direct sequencing of ABO gene in 369 samples revealed that the vast majority of nucleotide substitutions that change the ABO phenotype were limited to exons 6 and 7 of the ABO gene at positions 261, 467, 657, 796, 803, 930 and 1,060. However, genotyping of only three of them (261, 796 and 803 resulted in identification of major ABO genotypes in the Kazakh population. As a result, TaqMan probe based real-time PCR assay for the specific detection of genotypes 261, 796 and 803 was developed. The assay did not take into account several other mutations that may affect the determination of blood group, because they have a

Interlaboratory diagnostic accuracy of a Salmonella specific PCR-based method

DEFF Research Database (Denmark)

Malorny, B.; Hoorfar, Jeffrey; Hugas, M.

2003-01-01

A collaborative study involving four European laboratories was conducted to investigate the diagnostic accuracy of a Salmonella specific PCR-based method, which was evaluated within the European FOOD-PCR project (http://www.pcr.dk). Each laboratory analysed by the PCR a set of independent obtained...... presumably naturally contaminated samples and compared the results with the microbiological culture method. The PCR-based method comprised a preenrichment step in buffered peptone water followed by a thermal cell lysis using a closed tube resin-based method. Artificially contaminated minced beef and whole......-based diagnostic methods and is currently proposed as international standard document....

PCR-based approach to SINE isolation: simple and complex SINEs.

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Borodulina, Olga R; Kramerov, Dmitri A

2005-04-11

Highly repeated copies of short interspersed elements (SINEs) occur in eukaryotic genomes. The distribution of each SINE family is usually restricted to some genera, families, or orders. SINEs have an RNA polymerase III internal promoter, which is composed of boxes A and B. Here we propose a method for isolation of novel SINE families based on genomic DNA PCR with oligonucleotide identical to box A as a primer. Cloning of the size-heterogeneous PCR-products and sequencing of their terminal regions allow determination of SINE structure. Using this approach, two novel SINE families, Rhin-1 and Das-1, from the genomes of great horseshoe bat (Rhinolophus ferrumequinum) and nine-banded armadillo (Dasypus novemcinctus), respectively, were isolated and studied. The distribution of Rhin-1 is restricted to two of six bat families tested. Copies of this SINE are characterized by frequent internal insertions and significant length (200-270 bp). Das-1 being only 90 bp in length is one of the shortest SINEs known. Most of Das-1 nucleotide sequences demonstrate significant similarity to alanine tRNA which appears to be an evolutionary progenitor of this SINE. Together with three other known SINEs (ID, Vic-1, and CYN), Das-1 constitutes a group of simple SINEs. Interestingly, three SINE families of this group are alanine tRNA-derived. Most probably, this tRNA gave rise to short and simple but successful SINEs several times during mammalian evolution.

Software for optimization of SNP and PCR-RFLP genotyping to discriminate many genomes with the fewest assays

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Wagner Mark C

2005-05-01

Full Text Available Abstract Background Microbial forensics is important in tracking the source of a pathogen, whether the disease is a naturally occurring outbreak or part of a criminal investigation. Results A method and SPR Opt (SNP and PCR-RFLP Optimization software to perform a comprehensive, whole-genome analysis to forensically discriminate multiple sequences is presented. Tools for the optimization of forensic typing using Single Nucleotide Polymorphism (SNP and PCR-Restriction Fragment Length Polymorphism (PCR-RFLP analyses across multiple isolate sequences of a species are described. The PCR-RFLP analysis includes prediction and selection of optimal primers and restriction enzymes to enable maximum isolate discrimination based on sequence information. SPR Opt calculates all SNP or PCR-RFLP variations present in the sequences, groups them into haplotypes according to their co-segregation across those sequences, and performs combinatoric analyses to determine which sets of haplotypes provide maximal discrimination among all the input sequences. Those set combinations requiring that membership in the fewest haplotypes be queried (i.e. the fewest assays be performed are found. These analyses highlight variable regions based on existing sequence data. These markers may be heterogeneous among unsequenced isolates as well, and thus may be useful for characterizing the relationships among unsequenced as well as sequenced isolates. The predictions are multi-locus. Analyses of mumps and SARS viruses are summarized. Phylogenetic trees created based on SNPs, PCR-RFLPs, and full genomes are compared for SARS virus, illustrating that purported phylogenies based only on SNP or PCR-RFLP variations do not match those based on multiple sequence alignment of the full genomes. Conclusion This is the first software to optimize the selection of forensic markers to maximize information gained from the fewest assays, accepting whole or partial genome sequence data as input. As

Identification of a novel Plasmopara halstedii elicitor protein combining de novo peptide sequencing algorithms and RACE-PCR

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Madlung Johannes

2010-05-01

Full Text Available Abstract Background Often high-quality MS/MS spectra of tryptic peptides do not match to any database entry because of only partially sequenced genomes and therefore, protein identification requires de novo peptide sequencing. To achieve protein identification of the economically important but still unsequenced plant pathogenic oomycete Plasmopara halstedii, we first evaluated the performance of three different de novo peptide sequencing algorithms applied to a protein digests of standard proteins using a quadrupole TOF (QStar Pulsar i. Results The performance order of the algorithms was PEAKS online > PepNovo > CompNovo. In summary, PEAKS online correctly predicted 45% of measured peptides for a protein test data set. All three de novo peptide sequencing algorithms were used to identify MS/MS spectra of tryptic peptides of an unknown 57 kDa protein of P. halstedii. We found ten de novo sequenced peptides that showed homology to a Phytophthora infestans protein, a closely related organism of P. halstedii. Employing a second complementary approach, verification of peptide prediction and protein identification was performed by creation of degenerate primers for RACE-PCR and led to an ORF of 1,589 bp for a hypothetical phosphoenolpyruvate carboxykinase. Conclusions Our study demonstrated that identification of proteins within minute amounts of sample material improved significantly by combining sensitive LC-MS methods with different de novo peptide sequencing algorithms. In addition, this is the first study that verified protein prediction from MS data by also employing a second complementary approach, in which RACE-PCR led to identification of a novel elicitor protein in P. halstedii.

Heterologous microarray experiments allow the identification of the early events associated with potato tuber cold sweetening

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Vitulli Federico

2008-04-01

Full Text Available Abstract Background Since its discovery more than 100 years ago, potato (Solanum tuberosum tuber cold-induced sweetening (CIS has been extensively investigated. Several carbohydrate-associated genes would seem to be involved in the process. However, many uncertainties still exist, as the relative contribution of each gene to the process is often unclear, possibly as the consequence of the heterogeneity of experimental systems. Some enzymes associated with CIS, such as β-amylases and invertases, have still to be identified at a sequence level. In addition, little is known about the early events that trigger CIS and on the involvement/association with CIS of genes different from carbohydrate-associated genes. Many of these uncertainties could be resolved by profiling experiments, but no GeneChip is available for the potato, and the production of the potato cDNA spotted array (TIGR has recently been discontinued. In order to obtain an overall picture of early transcriptional events associated with CIS, we investigated whether the commercially-available tomato Affymetrix GeneChip could be used to identify which potato cold-responsive gene family members should be further studied in detail by Real-Time (RT-PCR (qPCR. Results A tomato-potato Global Match File was generated for the interpretation of various aspects of the heterologous dataset, including the retrieval of best matching potato counterparts and annotation, and the establishment of a core set of highly homologous genes. Several cold-responsive genes were identified, and their expression pattern was studied in detail by qPCR over 26 days. We detected biphasic behaviour of mRNA accumulation for carbohydrate-associated genes and our combined GeneChip-qPCR data identified, at a sequence level, enzymatic activities such as β-amylases and invertases previously reported as being involved in CIS. The GeneChip data also unveiled important processes accompanying CIS, such as the induction of redox

Analysis of Litopenaeus vannamei transcriptome using the next-generation DNA sequencing technique.

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Chaozheng Li

Full Text Available BACKGROUND: Pacific white shrimp (Litopenaeus vannamei, the major species of farmed shrimps in the world, has been attracting extensive studies, which require more and more genome background knowledge. The now available transcriptome data of L. vannamei are insufficient for research requirements, and have not been adequately assembled and annotated. METHODOLOGY/PRINCIPAL FINDINGS: This is the first study that used a next-generation high-throughput DNA sequencing technique, the Solexa/Illumina GA II method, to analyze the transcriptome from whole bodies of L. vannamei larvae. More than 2.4 Gb of raw data were generated, and 109,169 unigenes with a mean length of 396 bp were assembled using the SOAP denovo software. 73,505 unigenes (>200 bp with good quality sequences were selected and subjected to annotation analysis, among which 37.80% can be matched in NCBI Nr database, 37.3% matched in Swissprot, and 44.1% matched in TrEMBL. Using BLAST and BLAST2Go softwares, 11,153 unigenes were classified into 25 Clusters of Orthologous Groups of proteins (COG categories, 8171 unigenes were assigned into 51 Gene ontology (GO functional groups, and 18,154 unigenes were divided into 220 Kyoto Encyclopedia of Genes and Genomes (KEGG pathways. To primarily verify part of the results of assembly and annotations, 12 assembled unigenes that are homologous to many embryo development-related genes were chosen and subjected to RT-PCR for electrophoresis and Sanger sequencing analyses, and to real-time PCR for expression profile analyses during embryo development. CONCLUSIONS/SIGNIFICANCE: The L. vannamei transcriptome analyzed using the next-generation sequencing technique enriches the information of L. vannamei genes, which will facilitate our understanding of the genome background of crustaceans, and promote the studies on L. vannamei.

Analytic performance studies and clinical reproducibility of a real-time PCR assay for the detection of epidermal growth factor receptor gene mutations in formalin-fixed paraffin-embedded tissue specimens of non-small cell lung cancer

International Nuclear Information System (INIS)

O’Donnell, Patrick; Shieh, Felice; Wei, Wen; Lawrence, H Jeffrey; Wu, Lin; Schilling, Robert; Bloom, Kenneth; Maltzman, Warren; Anderson, Steven; Soviero, Stephen; Ferguson, Jane; Shyu, Johnny; Current, Robert; Rehage, Taraneh; Tsai, Julie; Christensen, Mari; Tran, Ha Bich; Chien, Sean Shih-Chang

2013-01-01

Epidermal growth factor receptor (EGFR) gene mutations identify patients with non-small cell lung cancer (NSCLC) who have a high likelihood of benefiting from treatment with anti-EGFR tyrosine kinase inhibitors. Sanger sequencing is widely used for mutation detection but can be technically challenging, resulting in longer turn-around-time, with limited sensitivity for low levels of mutations. This manuscript details the technical performance verification studies and external clinical reproducibility studies of the cobas EGFR Mutation Test, a rapid multiplex real-time PCR assay designed to detect 41 mutations in exons 18, 19, 20 and 21. The assay’s limit of detection was determined using 25 formalin-fixed paraffin-embedded tissue (FFPET)-derived and plasmid DNA blends. Assay performance for a panel of 201 specimens was compared against Sanger sequencing with resolution of discordant specimens by quantitative massively parallel pyrosequencing (MPP). Internal and external reproducibility was assessed using specimens tested in duplicate by different operators, using different reagent lots, instruments and at different sites. The effects on the performance of the cobas EGFR test of endogenous substances and nine therapeutic drugs were evaluated in ten FFPET specimens. Other tests included an evaluation of the effects of necrosis, micro-organisms and homologous DNA sequences on assay performance, and the inclusivity of the assay for less frequent mutations. A >95% hit rate was obtained in blends with >5% mutant alleles, as determined by MPP analysis, at a total DNA input of 150 ng. The overall percent agreement between Sanger sequencing and the cobas test was 96.7% (negative percent agreement 97.5%; positive percent agreement 95.8%). Assay repeatability was 98% when tested with two operators, instruments, and reagent lots. In the external reproducibility study, the agreement was > 99% across all sites, all operators and all reagent lots for 11/12 tumors tested. Test

Molecular diagnosis of Usher syndrome: application of two different next generation sequencing-based procedures.

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Danilo Licastro

Full Text Available Usher syndrome (USH is a clinically and genetically heterogeneous disorder characterized by visual and hearing impairments. Clinically, it is subdivided into three subclasses with nine genes identified so far. In the present study, we investigated whether the currently available Next Generation Sequencing (NGS technologies are already suitable for molecular diagnostics of USH. We analyzed a total of 12 patients, most of which were negative for previously described mutations in known USH genes upon primer extension-based microarray genotyping. We enriched the NGS template either by whole exome capture or by Long-PCR of the known USH genes. The main NGS sequencing platforms were used: SOLiD for whole exome sequencing, Illumina (Genome Analyzer II and Roche 454 (GS FLX for the Long-PCR sequencing. Long-PCR targeting was more efficient with up to 94% of USH gene regions displaying an overall coverage higher than 25×, whereas whole exome sequencing yielded a similar coverage for only 50% of those regions. Overall this integrated analysis led to the identification of 11 novel sequence variations in USH genes (2 homozygous and 9 heterozygous out of 18 detected. However, at least two cases were not genetically solved. Our result highlights the current limitations in the diagnostic use of NGS for USH patients. The limit for whole exome sequencing is linked to the need of a strong coverage and to the correct interpretation of sequence variations with a non obvious, pathogenic role, whereas the targeted approach suffers from the high genetic heterogeneity of USH that may be also caused by the presence of additional causative genes yet to be identified.

Molecular Diagnosis of Usher Syndrome: Application of Two Different Next Generation Sequencing-Based Procedures

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Licastro, Danilo; Mutarelli, Margherita; Peluso, Ivana; Neveling, Kornelia; Wieskamp, Nienke; Rispoli, Rossella; Vozzi, Diego; Athanasakis, Emmanouil; D'Eustacchio, Angela; Pizzo, Mariateresa; D'Amico, Francesca; Ziviello, Carmela; Simonelli, Francesca; Fabretto, Antonella; Scheffer, Hans; Gasparini, Paolo; Banfi, Sandro; Nigro, Vincenzo

2012-01-01

Usher syndrome (USH) is a clinically and genetically heterogeneous disorder characterized by visual and hearing impairments. Clinically, it is subdivided into three subclasses with nine genes identified so far. In the present study, we investigated whether the currently available Next Generation Sequencing (NGS) technologies are already suitable for molecular diagnostics of USH. We analyzed a total of 12 patients, most of which were negative for previously described mutations in known USH genes upon primer extension-based microarray genotyping. We enriched the NGS template either by whole exome capture or by Long-PCR of the known USH genes. The main NGS sequencing platforms were used: SOLiD for whole exome sequencing, Illumina (Genome Analyzer II) and Roche 454 (GS FLX) for the Long-PCR sequencing. Long-PCR targeting was more efficient with up to 94% of USH gene regions displaying an overall coverage higher than 25×, whereas whole exome sequencing yielded a similar coverage for only 50% of those regions. Overall this integrated analysis led to the identification of 11 novel sequence variations in USH genes (2 homozygous and 9 heterozygous) out of 18 detected. However, at least two cases were not genetically solved. Our result highlights the current limitations in the diagnostic use of NGS for USH patients. The limit for whole exome sequencing is linked to the need of a strong coverage and to the correct interpretation of sequence variations with a non obvious, pathogenic role, whereas the targeted approach suffers from the high genetic heterogeneity of USH that may be also caused by the presence of additional causative genes yet to be identified. PMID:22952768

A real-time PCR assay with improved specificity for detection and discrimination of all clinically relevant Bordetella species by the presence and distribution of three Insertion Sequence elements

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Ossewaarde Jacobus M

2011-01-01

Full Text Available Abstract Background In Dutch laboratories molecular detection of B. pertussis and B. parapertussis is commonly based on insertion sequences IS481 and IS1001, respectively. Both IS elements are more widely spread among Bordetella species. Both Bordetella holmesii, and B. bronchiseptica can harbour IS481. Also, IS1001 is found among B. bronchiseptica. IS481, and IS1001 based PCR thus lacks specificity when used for detection of specific Bordetella spp. Findings We designed a PCR based on IS1002, another IS element that is present among Bordetella species, and exploited it as a template in combination with PCR for IS481, and IS1001. In combining the PCRs for IS481, IS1001, and IS1002, and including an inhibition control, we were able to detect and discriminate all clinically relevant Bordetella species. Conclusions We developed an improved PCR method for specific detection of B. pertussis, B. parapertussis, B. holmesii, and B. bronchiseptica.

Endophytic bacterial diversity in grapevine (Vitis vinifera L.) leaves described by 16S rRNA gene sequence analysis and length heterogeneity-PCR.

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Bulgari, Daniela; Casati, Paola; Brusetti, Lorenzo; Quaglino, Fabio; Brasca, Milena; Daffonchio, Daniele; Bianco, Piero Attilio

2009-08-01

Diversity of bacterial endophytes associated with grapevine leaf tissues was analyzed by cultivation and cultivation-independent methods. In order to identify bacterial endophytes directly from metagenome, a protocol for bacteria enrichment and DNA extraction was optimized. Sequence analysis of 16S rRNA gene libraries underscored five diverse Operational Taxonomic Units (OTUs), showing best sequence matches with gamma-Proteobacteria, family Enterobacteriaceae, with a dominance of the genus Pantoea. Bacteria isolation through cultivation revealed the presence of six OTUs, showing best sequence matches with Actinobacteria, genus Curtobacterium, and with Firmicutes genera Bacillus and Enterococcus. Length Heterogeneity-PCR (LH-PCR) electrophoretic peaks from single bacterial clones were used to setup a database representing the bacterial endophytes identified in association with grapevine tissues. Analysis of healthy and phytoplasma-infected grapevine plants showed that LH-PCR could be a useful complementary tool for examining the diversity of bacterial endophytes especially for diversity survey on a large number of samples.

Legionella confirmation in cooling tower water. Comparison of culture, real-time PCR and next generation sequencing.

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Farhat, Maha; Shaheed, Raja A; Al-Ali, Haider H; Al-Ghamdi, Abdullah S; Al-Hamaqi, Ghadeer M; Maan, Hawraa S; Al-Mahfoodh, Zainab A; Al-Seba, Hussain Z

2018-02-01

To investigate the presence of Legionella spp in cooling tower water. Legionella proliferation in cooling tower water has serious public health implications as it can be transmitted to humans via aerosols and cause Legionnaires' disease. Samples of cooling tower water were collected from King Fahd Hospital of the University (KFHU) (Imam Abdulrahman Bin Faisal University, 2015/2016). The water samples were analyzed by a standard Legionella culture method, real-time polymerase chain reaction (RT-PCR), and 16S rRNA next-generation sequencing. In addition, the bacterial community composition was evaluated. All samples were negative by conventional Legionella culture. In contrast, all water samples yielded positive results by real-time PCR (105 to 106 GU/L). The results of 16S rRNA next generation sequencing showed high similarity and reproducibility among the water samples. The majority of sequences were Alpha-, Beta-, and Gamma-proteobacteria, and Legionella was the predominant genus. The hydrogen-oxidizing gram-negative bacterium Hydrogenophaga was present at high abundance, indicating high metabolic activity. Sphingopyxis, which is known for its resistance to antimicrobials and as a pioneer in biofilm formation, was also detected. Our findings indicate that monitoring of Legionella in cooling tower water would be enhanced by use of both conventional culturing and molecular methods.

Development and application of a universal Hemoplasma screening assay based on the SYBR green PCR principle.

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Willi, Barbara; Meli, Marina L; Lüthy, Ruedi; Honegger, Hanspeter; Wengi, Nicole; Hoelzle, Ludwig E; Reusch, Claudia E; Lutz, Hans; Hofmann-Lehmann, Regina

2009-12-01

Hemotropic mycoplasmas (hemoplasmas) are the causative agents of infectious anemia in several mammalian species. Their zoonotic potential has recently been substantiated by the identification of a feline hemoplasma isolate in an immunocompromised human patient. Although species-specific diagnostic molecular methods have been developed, their application as screening tools is limited due to the species diversity of hemoplasmas. The goals of this study were to develop a universal hemoplasma screening assay with broad specificity based on the SYBR green PCR principle, to compare the assay with hemoplasma-specific TaqMan PCR, and to analyze potential tick vectors and human blood samples to address the zoonotic potential. The newly developed PCR assay based on the 16S rRNA gene amplified feline, canine, bovine, porcine, camelid, and murine hemoplasmas, as well as Mycoplasma penetrans and Mycoplasma pneumoniae. The lower detection limit for feline and canine hemoplasmas was 1 to 10 copies/PCR. The assay exhibited 98.2% diagnostic sensitivity and 92.1% diagnostic specificity for feline hemoplasmas. All 1,950 Ixodes ticks were PCR negative, suggesting that Ixodes ticks are not relevant vectors for the above-mentioned hemoplasma species in Switzerland. None of the 414 blood samples derived from anemic or immunocompromised human patients revealed a clear positive result. The SYBR green PCR assay described here is a suitable tool to screen for known and so-far-undiscovered hemoplasma species. Positive results should be confirmed by specific TaqMan PCR or sequencing.

The quest for rare variants: pooled multiplexed next generation sequencing in plants.

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Marroni, Fabio; Pinosio, Sara; Morgante, Michele

2012-01-01

Next generation sequencing (NGS) instruments produce an unprecedented amount of sequence data at contained costs. This gives researchers the possibility of designing studies with adequate power to identify rare variants at a fraction of the economic and labor resources required by individual Sanger sequencing. As of today, few research groups working in plant sciences have exploited this potentiality, showing that pooled NGS provides results in excellent agreement with those obtained by individual Sanger sequencing. The aim of this review is to convey to the reader the general ideas underlying the use of pooled NGS for the identification of rare variants. To facilitate a thorough understanding of the possibilities of the method, we will explain in detail the possible experimental and analytical approaches and discuss their advantages and disadvantages. We will show that information on allele frequency obtained by pooled NGS can be used to accurately compute basic population genetics indexes such as allele frequency, nucleotide diversity, and Tajima's D. Finally, we will discuss applications and future perspectives of the multiplexed NGS approach.

Real-time DNA barcoding in a rainforest using nanopore sequencing: opportunities for rapid biodiversity assessments and local capacity building.

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Pomerantz, Aaron; Peñafiel, Nicolás; Arteaga, Alejandro; Bustamante, Lucas; Pichardo, Frank; Coloma, Luis A; Barrio-Amorós, César L; Salazar-Valenzuela, David; Prost, Stefan

2018-04-01

Advancements in portable scientific instruments provide promising avenues to expedite field work in order to understand the diverse array of organisms that inhabit our planet. Here, we tested the feasibility for in situ molecular analyses of endemic fauna using a portable laboratory fitting within a single backpack in one of the world's most imperiled biodiversity hotspots, the Ecuadorian Chocó rainforest. We used portable equipment, including the MinION nanopore sequencer (Oxford Nanopore Technologies) and the miniPCR (miniPCR), to perform DNA extraction, polymerase chain reaction amplification, and real-time DNA barcoding of reptile specimens in the field. We demonstrate that nanopore sequencing can be implemented in a remote tropical forest to quickly and accurately identify species using DNA barcoding, as we generated consensus sequences for species resolution with an accuracy of >99% in less than 24 hours after collecting specimens. The flexibility of our mobile laboratory further allowed us to generate sequence information at the Universidad Tecnológica Indoamérica in Quito for rare, endangered, and undescribed species. This includes the recently rediscovered Jambato toad, which was thought to be extinct for 28 years. Sequences generated on the MinION required as few as 30 reads to achieve high accuracy relative to Sanger sequencing, and with further multiplexing of samples, nanopore sequencing can become a cost-effective approach for rapid and portable DNA barcoding. Overall, we establish how mobile laboratories and nanopore sequencing can help to accelerate species identification in remote areas to aid in conservation efforts and be applied to research facilities in developing countries. This opens up possibilities for biodiversity studies by promoting local research capacity building, teaching nonspecialists and students about the environment, tackling wildlife crime, and promoting conservation via research-focused ecotourism.

Characterization of a novel HLA-B*39:01:01-related allele, HLA-B*39:130, by cloning and phasing.

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Li, L X; Tian, W; Zhu, F M; Wang, W Y; Cai, J H

2017-12-01

A novel HLA-B*39:01:01-related variant, HLA-B*39:130, has been identified in a normal individual of Han ethnicity in Hunan province, southern China. Following Sanger polymerase chain reaction-sequence-based typing (PCR-SBT), this new allele was further confirmed by cloning, phasing and sequencing. Aligned with HLA-B*39:01:01, HLA-B*39:130 has a nonsynonymous thymine substitution at nucleotide position 94 in exon 4, resulting in amino acid change from threonine to isoleucine at codon 214 (ACA→ATA) of the mature HLA-BmRNA molecule. © 2017 John Wiley & Sons Ltd.

PCR Based Microbial Monitor for Analysis of Recycled Water Aboard the ISSA: Issues and Prospects

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Cassell, Gail H.; Lefkowitz, Elliot J.; Glass, John I.

1995-01-01

added to a PCR assay; There are not likely to be contaminants in ISSA recycled water that would inhibit PCR resulting in false-negative results; The TaqMan PCR product detection system is the most promising method for developing a rapid, highly automated gene-based microbial monitoring system. The method is inherently quantitative. NASA and other government agencies have invested in other technologies that, although potentially could lead to revolutionary advances, are not likely to mature in the next 5 years into working systems; PCR-based methods cannot distinguish between DNA or RNA of a viable microorganism and that of a non-viable organism. This may or may not be an important issue with reclaimed water on the ISSA. The recycling system probably damages the capacity of the genetic material of any bacteria or viruses killed during processing to serve as a template in a PCR desinged to amplify a large segment of DNA (less than 650 base pairs). If necessary, vital dye staining could be used in addition to PCR, to enumerate the viable cells in a water sample; The quality control methods have been developed to insure that PCR's are working properly, and that reactions are not contaminated with PCR carryover products which could lead to the generation of false-positive results; and The sequences of the small rRNA subunit gene for a large number of microorganisms are known, and they consititue the best database for rational development of the oligonucleotide reagents that give PCR its great specificity. From those gene sequences, sets of oligonucleotide primers for PCR and Taqman detection that could be used in a NASA microbial monitor were constructed using computer based methods. In addition to space utilization, a microbial monitior will have tremendous terrestrial applications. Analysis of patient samples for microbial pathogens, testing industrial effluent for biofouling bacteria, and detection biological warfare agents on the battlefield are but a few of the diverse

Draft genome sequences of two protease-producing strains of Arsukibacterium, isolated from two cold and alkaline environments

DEFF Research Database (Denmark)

Lylloff, Jeanette Eva; Hansen, Lea Benedicte Skov; Jepsen, Morten

2015-01-01

Arsukibacterium ikkense GCM72(T) and a close relative, Arsukibacterium sp. MJ3, were isolated from two cold and alkaline environments as producers of extracellular proteolytic enzymes active at high pH and low temperature. This report describes the two draft genome sequences, which may serve...

Combining Maize Base Germplasm for Cold Tolerance Breeding

OpenAIRE

Rodríguez Graña, Víctor Manuel; Butrón Gómez, Ana María; Sandoya Miranda, Germán; Ordás Pérez, Amando; Revilla Temiño, Pedro

2007-01-01

Early planting can contribute to increased grain yield of maize (Zea mays L.), but it requires cold tolerance. A limited number of cold-tolerant maize genotypes have been reported. The objectives of this study were to test a new strategy to improve cold tolerance in maize searching for broad x narrow genetic combinations that may be useful as base populations for breeding programs, to compare genotype performance under cold-controlled and field conditions, and to establish the major genetic e...

A genomic library-based amplification approach (GL-PCR) for the mapping of multiple IS6110 insertion sites and strain differentiation of Mycobacterium tuberculosis.

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Namouchi, Amine; Mardassi, Helmi

2006-11-01

Evidence suggests that insertion of the IS6110 element is not without consequence to the biology of Mycobacterium tuberculosis complex strains. Thus, mapping of multiple IS6110 insertion sites in the genome of biomedically relevant clinical isolates would result in a better understanding of the role of this mobile element, particularly with regard to transmission, adaptability and virulence. In the present paper, we describe a versatile strategy, referred to as GL-PCR, that amplifies IS6110-flanking sequences based on the construction of a genomic library. M. tuberculosis chromosomal DNA is fully digested with HincII and then ligated into a plasmid vector between T7 and T3 promoter sequences. The ligation reaction product is transformed into Escherichia coli and selective PCR amplification targeting both 5' and 3' IS6110-flanking sequences are performed on the plasmid library DNA. For this purpose, four separate PCR reactions are performed, each combining an outward primer specific for one IS6110 end with either T7 or T3 primer. Determination of the nucleotide sequence of the PCR products generated from a single ligation reaction allowed mapping of 21 out of the 24 IS6110 copies of two 12 banded M. tuberculosis strains, yielding an overall sensitivity of 87,5%. Furthermore, by simply comparing the migration pattern of GL-PCR-generated products, the strategy proved to be as valuable as IS6110 RFLP for molecular typing of M. tuberculosis complex strains. Importantly, GL-PCR was able to discriminate between strains differing by a single IS6110 band.

Multiplex enrichment quantitative PCR (ME-qPCR): a high-throughput, highly sensitive detection method for GMO identification.

Science.gov (United States)

Fu, Wei; Zhu, Pengyu; Wei, Shuang; Zhixin, Du; Wang, Chenguang; Wu, Xiyang; Li, Feiwu; Zhu, Shuifang

2017-04-01

Among all of the high-throughput detection methods, PCR-based methodologies are regarded as the most cost-efficient and feasible methodologies compared with the next-generation sequencing or ChIP-based methods. However, the PCR-based methods can only achieve multiplex detection up to 15-plex due to limitations imposed by the multiplex primer interactions. The detection throughput cannot meet the demands of high-throughput detection, such as SNP or gene expression analysis. Therefore, in our study, we have developed a new high-throughput PCR-based detection method, multiplex enrichment quantitative PCR (ME-qPCR), which is a combination of qPCR and nested PCR. The GMO content detection results in our study showed that ME-qPCR could achieve high-throughput detection up to 26-plex. Compared to the original qPCR, the Ct values of ME-qPCR were lower for the same group, which showed that ME-qPCR sensitivity is higher than the original qPCR. The absolute limit of detection for ME-qPCR could achieve levels as low as a single copy of the plant genome. Moreover, the specificity results showed that no cross-amplification occurred for irrelevant GMO events. After evaluation of all of the parameters, a practical evaluation was performed with different foods. The more stable amplification results, compared to qPCR, showed that ME-qPCR was suitable for GMO detection in foods. In conclusion, ME-qPCR achieved sensitive, high-throughput GMO detection in complex substrates, such as crops or food samples. In the future, ME-qPCR-based GMO content identification may positively impact SNP analysis or multiplex gene expression of food or agricultural samples. Graphical abstract For the first-step amplification, four primers (A, B, C, and D) have been added into the reaction volume. In this manner, four kinds of amplicons have been generated. All of these four amplicons could be regarded as the target of second-step PCR. For the second-step amplification, three parallels have been taken for

BRAF mutation testing in solid tumors: a methodological comparison.

Science.gov (United States)

Weyant, Grace W; Wisotzkey, Jeffrey D; Benko, Floyd A; Donaldson, Keri J

2014-09-01

Solid tumor genotyping has become standard of care for the characterization of proto-oncogene mutational status, which has traditionally been accomplished with Sanger sequencing. However, companion diagnostic assays and comparable laboratory-developed tests are becoming increasingly popular, such as the cobas 4800 BRAF V600 Mutation Test and the INFINITI KRAS-BRAF assay, respectively. This study evaluates and validates the analytical performance of the INFINITI KRAS-BRAF assay and compares concordance of BRAF status with two reference assays, the cobas test and Sanger sequencing. DNA extraction from FFPE tissue specimens was performed followed by multiplex PCR amplification and fluorescent label incorporation using allele-specific primer extension. Hybridization to a microarray, signal detection, and analysis were then performed. The limits of detection were determined by testing dilutions of mutant BRAF alleles within wild-type background DNA, and accuracy was calculated based on these results. The INFINITI KRAS-BRAF assay produced 100% concordance with the cobas test and Sanger sequencing and had sensitivity equivalent to the cobas assay. The INFINITI assay is repeatable with at least 95% accuracy in the detection of mutant and wild-type BRAF alleles. These results confirm that the INFINITI KRAS-BRAF assay is comparable to traditional sequencing and the Food and Drug Administration-approved companion diagnostic assay for the detection of BRAF mutations. Copyright © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Human papillomavirus detection and typing using a nested-PCR-RFLP assay.

Science.gov (United States)

Coser, Janaina; Boeira, Thaís da Rocha; Fonseca, André Salvador Kazantzi; Ikuta, Nilo; Lunge, Vagner Ricardo

2011-01-01

It is clinically important to detect and type human papillomavirus (HPV) in a sensitive and specific manner. Development of a nested-polymerase chain reaction-restriction fragment length polymorphism (nested-PCR-RFLP) assay to detect and type HPV based on the analysis of L1 gene. Analysis of published DNA sequence of mucosal HPV types to select sequences of new primers. Design of an original nested-PCR assay using the new primers pair selected and classical MY09/11 primers. HPV detection and typing in cervical samples using the nested-PCR-RFLP assay. The nested-PCR-RFLP assay detected and typed HPV in cervical samples. Of the total of 128 clinical samples submitted to simple PCR and nested-PCR for detection of HPV, 37 (28.9%) were positive for the virus by both methods and 25 samples were positive only by nested-PCR (67.5% increase in detection rate compared with single PCR). All HPV positive samples were effectively typed by RFLP assay. The method of nested-PCR proved to be an effective diagnostic tool for HPV detection and typing.

Strand specific RNA-sequencing and membrane lipid profiling reveals growth phase-dependent cold stress response mechanisms in Listeria monocytogenes

Science.gov (United States)

Hingston, Patricia; Chen, Jessica; Allen, Kevin; Truelstrup Hansen, Lisbeth

2017-01-01

The human pathogen Listeria monocytogenes continues to pose a challenge in the food industry, where it is known to contaminate ready-to-eat foods and grow during refrigerated storage. Increased knowledge of the cold-stress response of this pathogen will enhance the ability to control it in the food-supply-chain. This study utilized strand-specific RNA sequencing and whole cell fatty acid (FA) profiling to characterize the bacterium’s cold stress response. RNA and FAs were extracted from a cold-tolerant strain at five time points between early lag phase and late stationary-phase, both at 4°C and 20°C. Overall, more genes (1.3×) were suppressed than induced at 4°C. Late stationary-phase cells exhibited the greatest number (n = 1,431) and magnitude (>1,000-fold) of differentially expressed genes (>2-fold, pmonocytogenes, the growth-phase dependency of its cold-stress regulon, and the active roles of antisense transcripts in regulating its cold stress response. PMID:28662112

Genomic Aberrations in Crizotinib Resistant Lung Adenocarcinoma Samples Identified by Transcriptome Sequencing.

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Ali Saber

Full Text Available ALK-break positive non-small cell lung cancer (NSCLC patients initially respond to crizotinib, but resistance occurs inevitably. In this study we aimed to identify fusion genes in crizotinib resistant tumor samples. Re-biopsies of three patients were subjected to paired-end RNA sequencing to identify fusion genes using deFuse and EricScript. The IGV browser was used to determine presence of known resistance-associated mutations. Sanger sequencing was used to validate fusion genes and digital droplet PCR to validate mutations. ALK fusion genes were detected in all three patients with EML4 being the fusion partner. One patient had no additional fusion genes. Another patient had one additional fusion gene, but without a predicted open reading frame (ORF. The third patient had three additional fusion genes, of which two were derived from the same chromosomal region as the EML4-ALK. A predicted ORF was identified only in the CLIP4-VSNL1 fusion product. The fusion genes validated in the post-treatment sample were also present in the biopsy before crizotinib. ALK mutations (p.C1156Y and p.G1269A detected in the re-biopsies of two patients, were not detected in pre-treatment biopsies. In conclusion, fusion genes identified in our study are unlikely to be involved in crizotinib resistance based on presence in pre-treatment biopsies. The detection of ALK mutations in post-treatment tumor samples of two patients underlines their role in crizotinib resistance.

Detection of a divergent variant of grapevine virus F by next-generation sequencing.

Science.gov (United States)

Molenaar, Nicholas; Burger, Johan T; Maree, Hans J

2015-08-01

The complete genome sequence of a South African isolate of grapevine virus F (GVF) is presented. It was first detected by metagenomic next-generation sequencing of field samples and validated through direct Sanger sequencing. The genome sequence of GVF isolate V5 consists of 7539 nucleotides and contains a poly(A) tail. It has a typical vitivirus genome arrangement that comprises five open reading frames (ORFs), which share only 88.96 % nucleotide sequence identity with the existing complete GVF genome sequence (JX105428).

Sequence recombination and conservation of Varroa destructor virus-1 and deformed wing virus in field collected honey bees (Apis mellifera.

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Hui Wang

Full Text Available We sequenced small (s RNAs from field collected honeybees (Apis mellifera and bumblebees (Bombuspascuorum using the Illumina technology. The sRNA reads were assembled and resulting contigs were used to search for virus homologues in GenBank. Matches with Varroadestructor virus-1 (VDV1 and Deformed wing virus (DWV genomic sequences were obtained for A. mellifera but not B. pascuorum. Further analyses suggested that the prevalent virus population was composed of VDV-1 and a chimera of 5'-DWV-VDV1-DWV-3'. The recombination junctions in the chimera genomes were confirmed by using RT-PCR, cDNA cloning and Sanger sequencing. We then focused on conserved short fragments (CSF, size > 25 nt in the virus genomes by using GenBank sequences and the deep sequencing data obtained in this study. The majority of CSF sites confirmed conservation at both between-species (GenBank sequences and within-population (dataset of this study levels. However, conserved nucleotide positions in the GenBank sequences might be variable at the within-population level. High mutation rates (Pi>10% were observed at a number of sites using the deep sequencing data, suggesting that sequence conservation might not always be maintained at the population level. Virus-host interactions and strategies for developing RNAi treatments against VDV1/DWV infections are discussed.

Single tube genotyping of sickle cell anaemia using PCR-based SNP analysis.

Science.gov (United States)

Waterfall, C M; Cobb, B D

2001-12-01

Allele-specific amplification (ASA) is a generally applicable technique for the detection of known single nucleotide polymorphisms (SNPs), deletions, insertions and other sequence variations. Conventionally, two reactions are required to determine the zygosity of DNA in a two-allele system, along with significant upstream optimisation to define the specific test conditions. Here, we combine single tube bi-directional ASA with a 'matrix-based' optimisation strategy, speeding up the whole process in a reduced reaction set. We use sickle cell anaemia as our model SNP system, a genetic disease that is currently screened using ASA methods. Discriminatory conditions were rapidly optimised enabling the unambiguous identification of DNA from homozygous sickle cell patients (HbS/S), heterozygous carriers (HbA/S) or normal DNA in a single tube. Simple downstream mathematical analyses based on product yield across the optimisation set allow an insight into the important aspects of priming competition and component interactions in this competitive PCR. This strategy can be applied to any polymorphism, defining specific conditions using a multifactorial approach. The inherent simplicity and low cost of this PCR-based method validates bi-directional ASA as an effective tool in future clinical screening and pharmacogenomic research where more expensive fluorescence-based approaches may not be desirable.

Novel Tetra-Primer ARMS-PCR Assays for Thiopurine Intolerance Susceptibility Mutations NUDT15 c.415C>T and TPMT c.719A>G (TPMT*3C in East Asians

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Chi-Chun Ho

2017-10-01

Full Text Available Thiopurines are clinically useful in the management of diverse immunological and malignant conditions. Nevertheless, these purine analogues can cause lethal myelosuppression, which may be prevented by prospective testing for variants in the thiopurine S-methyltransferase (TPMT and, in East Asians, Nudix hydrolase 15 (NUDT15 genes. Two single-tube, tetra-primer amplification refractory mutation system polymerase chain reaction (ARMS-PCR assays were developed to genotype the common loss-of-function variants NUDT15 c.415C>T (rs116855232 and TPMT*3C c.719A>G (rs1142345. In a group of 60 unselected patients, one and seven were found to be homozygous and heterozygous, respectively, for NUDT15 c.415C>T; one was found to be heterozygous for TPMT*3C c.719A>G. There was no non-specific amplification, and the genotypes were 100% concordant with Sanger sequencing. Limit-of-detection for both assays was below 1 ng of heterozygous template per reaction. Time- and cost-effective ARMS-PCR assays, suitable for genotyping East-Asian patients for thiopurine intolerance, were successfully developed and validated.

Multiplexed microsatellite recovery using massively parallel sequencing

Science.gov (United States)

Jennings, T.N.; Knaus, B.J.; Mullins, T.D.; Haig, S.M.; Cronn, R.C.

2011-01-01

Conservation and management of natural populations requires accurate and inexpensive genotyping methods. Traditional microsatellite, or simple sequence repeat (SSR), marker analysis remains a popular genotyping method because of the comparatively low cost of marker development, ease of analysis and high power of genotype discrimination. With the availability of massively parallel sequencing (MPS), it is now possible to sequence microsatellite-enriched genomic libraries in multiplex pools. To test this approach, we prepared seven microsatellite-enriched, barcoded genomic libraries from diverse taxa (two conifer trees, five birds) and sequenced these on one lane of the Illumina Genome Analyzer using paired-end 80-bp reads. In this experiment, we screened 6.1 million sequences and identified 356958 unique microreads that contained di- or trinucleotide microsatellites. Examination of four species shows that our conversion rate from raw sequences to polymorphic markers compares favourably to Sanger- and 454-based methods. The advantage of multiplexed MPS is that the staggering capacity of modern microread sequencing is spread across many libraries; this reduces sample preparation and sequencing costs to less than $400 (USD) per species. This price is sufficiently low that microsatellite libraries could be prepared and sequenced for all 1373 organisms listed as 'threatened' and 'endangered' in the United States for under $0.5M (USD).

Comparison and evaluation of two exome capture kits and sequencing platforms for variant calling.

Science.gov (United States)

Zhang, Guoqiang; Wang, Jianfeng; Yang, Jin; Li, Wenjie; Deng, Yutian; Li, Jing; Huang, Jun; Hu, Songnian; Zhang, Bing

2015-08-05

To promote the clinical application of next-generation sequencing, it is important to obtain accurate and consistent variants of target genomic regions at low cost. Ion Proton, the latest updated semiconductor-based sequencing instrument from Life Technologies, is designed to provide investigators with an inexpensive platform for human whole exome sequencing that achieves a rapid turnaround time. However, few studies have comprehensively compared and evaluated the accuracy of variant calling between Ion Proton and Illumina sequencing platforms such as HiSeq 2000, which is the most popular sequencing platform for the human genome. The Ion Proton sequencer combined with the Ion TargetSeq Exome Enrichment Kit together make up TargetSeq-Proton, whereas SureSelect-Hiseq is based on the Agilent SureSelect Human All Exon v4 Kit and the HiSeq 2000 sequencer. Here, we sequenced exonic DNA from four human blood samples using both TargetSeq-Proton and SureSelect-HiSeq. We then called variants in the exonic regions that overlapped between the two exome capture kits (33.6 Mb). The rates of shared variant loci called by two sequencing platforms were from 68.0 to 75.3% in four samples, whereas the concordance of co-detected variant loci reached 99%. Sanger sequencing validation revealed that the validated rate of concordant single nucleotide polymorphisms (SNPs) (91.5%) was higher than the SNPs specific to TargetSeq-Proton (60.0%) or specific to SureSelect-HiSeq (88.3%). With regard to 1-bp small insertions and deletions (InDels), the Sanger sequencing validated rates of concordant variants (100.0%) and SureSelect-HiSeq-specific (89.6%) were higher than those of TargetSeq-Proton-specific (15.8%). In the sequencing of exonic regions, a combination of using of two sequencing strategies (SureSelect-HiSeq and TargetSeq-Proton) increased the variant calling specificity for concordant variant loci and the sensitivity for variant loci called by any one platform. However, for the

Second generation sequencing of the mesothelioma tumor genome.

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Raphael Bueno

2010-05-01

Full Text Available The current paradigm for elucidating the molecular etiology of cancers relies on the interrogation of small numbers of genes, which limits the scope of investigation. Emerging second-generation massively parallel DNA sequencing technologies have enabled more precise definition of the cancer genome on a global scale. We examined the genome of a human primary malignant pleural mesothelioma (MPM tumor and matched normal tissue by using a combination of sequencing-by-synthesis and pyrosequencing methodologies to a 9.6X depth of coverage. Read density analysis uncovered significant aneuploidy and numerous rearrangements. Method-dependent informatics rules, which combined the results of different sequencing platforms, were developed to identify and validate candidate mutations of multiple types. Many more tumor-specific rearrangements than point mutations were uncovered at this depth of sequencing, resulting in novel, large-scale, inter- and intra-chromosomal deletions, inversions, and translocations. Nearly all candidate point mutations appeared to be previously unknown SNPs. Thirty tumor-specific fusions/translocations were independently validated with PCR and Sanger sequencing. Of these, 15 represented disrupted gene-encoding regions, including kinases, transcription factors, and growth factors. One large deletion in DPP10 resulted in altered transcription and expression of DPP10 transcripts in a set of 53 additional MPM tumors correlated with survival. Additionally, three point mutations were observed in the coding regions of NKX6-2, a transcription regulator, and NFRKB, a DNA-binding protein involved in modulating NFKB1. Several regions containing genes such as PCBD2 and DHFR, which are involved in growth factor signaling and nucleotide synthesis, respectively, were selectively amplified in the tumor. Second-generation sequencing uncovered all types of mutations in this MPM tumor, with DNA rearrangements representing the dominant type.

Heat pipe based cold energy storage systems for datacenter energy conservation

International Nuclear Information System (INIS)

Singh, Randeep; Mochizuki, Masataka; Mashiko, Koichi; Nguyen, Thang

2011-01-01

In the present paper, design and economics of the novel type of thermal control system for datacenter using heat pipe based cold energy storage has been proposed and discussed. Two types of cold energy storage system namely: ice storage system and cold water storage system are explained and sized for datacenter with heat output capacity of 8800 kW. Basically, the cold energy storage will help to reduce the chiller running time that will save electricity related cost and decrease greenhouse gas emissions resulting from the electricity generation from non-renewable sources. The proposed cold energy storage system can be retrofit or connected in the existing datacenter facilities without major design changes. Out of the two proposed systems, ice based cold energy storage system is mainly recommended for datacenters which are located in very cold locations and therefore can offer long term seasonal storage of cold energy within reasonable cost. One of the potential application domains for ice based cold energy storage system using heat pipes is the emergency backup system for datacenter. Water based cold energy storage system provides more compact size with short term storage (hours to days) and is potential for datacenters located in areas with yearly average temperature below the permissible cooling water temperature (∼25 o C). The aforesaid cold energy storage systems were sized on the basis of metrological conditions in Poughkeepsie, New York. As an outcome of the thermal and cost analysis, water based cold energy storage system with cooling capability to handle 60% of datacenter yearly heat load will provide an optimum system size with minimum payback period of 3.5 years. Water based cold energy storage system using heat pipes can be essentially used as precooler for chiller. Preliminary results obtained from the experimental system to test the capability of heat pipe based cold energy storage system have provided satisfactory outcomes and validated the proposed

Cold cathodes on ultra-dispersed diamond base

International Nuclear Information System (INIS)

Alimova, A.N.; Zhirnov, V.V.; Chubun, N.N.; Belobrov, P.I.

1998-01-01

Prospects of application of nano diamond powders for fabrication of cold cathodes are discussed.Cold cathodes based on silicon pointed structures with nano diamond coatings were prepared.The deposition technique of diamond coating was dielectrophoresis from suspension of nano diamond powder in organic liquids.The cathodes were tested in sealed prototypes of vacuum electronic devices

Improved diagnostic PCR assay for Actinobacillus pleuropneumoniae based on the nucleotide sequence of an outer membrane lipoprotein

DEFF Research Database (Denmark)

Gram, Trine; Ahrens, Peter

1998-01-01

species related to A. pleuropneumoniae or isolated from pigs were assayed. They were all found negative in the PCR, as were tonsil cultures from 50 pigs of an A. pleuropneumoniae-negative herd. The sensitivity assessed by agarose gel analysis of the PCR product was 10(2) CFU/PCR test tube. The specificity...

Overexpression of a repressor MdMYB15L negatively regulates anthocyanin and cold tolerance in red-fleshed callus.

Science.gov (United States)

Xu, Haifeng; Yang, Guanxian; Zhang, Jing; Wang, Yicheng; Zhang, Tianliang; Wang, Nan; Jiang, Shenghui; Zhang, Zongying; Chen, Xuesen

2018-04-14

The cold-induced metabolic pathway and anthocyanin biosynthesis play important roles in plant growth. In this study, we identified a bHLH binding motif in the MdMYB15L protein using protein sequence analyses. Yeast two-hybrid and pull-down assays showed that MdMYB15L could interact with MdbHLH33. Overexpressing MdMYB15L in red-fleshed callus inhibited the expression of MdCBF2 and resulted in reduced cold tolerance but did not affect anthocyanin levels. Chip-PCR and EMSA analysis showed that MdMYB15L could bind the type II cis-acting element found in the MdCBF2 promoter. Overexpressing MdMYB15L in red-fleshed callus overexpressing MdbHLH33 also reduced cold tolerance and reduced MdbHLH33-induced anthocyanin biosynthesis. Knocking out the bHLH binding sequence of MdMYB15L (LBSMdMYB15L) prevented LBSMdMYB15L from interacting with MdbHLH33. Overexpressing LBSMdMYB15L in red-fleshed callus overexpressing MdbHLH33 also reduced cold tolerance and reduced MdbHLH33-induced anthocyanin biosynthesis. Together, these results suggested that an apple repressor MdMYB15L might play a key role in the cold signaling and anthocyanin metabolic pathways. Copyright © 2018 Elsevier Inc. All rights reserved.

Differentiation between spore-forming and asporogenic bacteria using a PCR and southern hybridization based method

Energy Technology Data Exchange (ETDEWEB)

Brill, J.A.; Wiegel, J. [Univ. of Georgia, Athens, GA (United States)

1997-12-31

A set of molecular probes was devised to develop a method for screening for the presence of sequences homologous to three representative genes exclusively involved in endosporulation. Based on known gene sequences, degenerate PCR primers were designed against spo0A and ssp. Experimental conditions were devised under which homologs of both genes were consistently detected in endospore-forming bacteria, but not in asporogenic bacteria. The PCR amplification products and dpaA/B from Bacillus subtilis were used as hybridization probes for Southern blots. Identical conditions were used with the genomic DNA from endospore-forming and asporogenic bacteria. We therefore concluded that the probes specifically detect the targeted sporulation genes and we obtained no indication that genes homologous to ssp, spo0A and dpaA/B are present in asporogenic bacteria. Thus, this assay can potentially be used to detect spore-forming bacteria in various kinds of samples and to distinguish between bacteria containing sporulation genes and those who do not regardless of whether sporulation is observed or not. 43 refs., 3 figs., 1 tab.

The Quest for Rare Variants: Pooled Multiplexed Next Generation Sequencing in Plants

OpenAIRE

Fabio eMarroni; Sara ePinosio; Sara ePinosio; Michele eMorgante

2012-01-01

Next generation sequencing (NGS) instruments produce an unprecedented amount of sequence data at contained costs. This gives researchers the possibility of designing studies with adequate power to identify rare variants at a fraction of the economic and labor resources required by individual Sanger sequencing. As of today, only three research groups working in plant sciences have exploited this potentiality. They showed that pooled NGS can provide results in excellent agreement with those obt...

The Quest for Rare Variants: Pooled Multiplexed Next Generation Sequencing in Plants

OpenAIRE

Marroni, Fabio; Pinosio, Sara; Morgante, Michele

2012-01-01

Next generation sequencing (NGS) instruments produce an unprecedented amount of sequence data at contained costs. This gives researchers the possibility of designing studies with adequate power to identify rare variants at a fraction of the economic and labor resources required by individual Sanger sequencing. As of today, few research groups working in plant sciences have exploited this potentiality, showing that pooled NGS provides results in excellent agreement with those obtained by indiv...

Real-Time PCR Typing of Escherichia coli Based on Multiple Single Nucleotide Polymorphisms--a Convenient and Rapid Method.

Science.gov (United States)

Lager, Malin; Mernelius, Sara; Löfgren, Sture; Söderman, Jan

2016-01-01

Healthcare-associated infections caused by Escherichia coli and antibiotic resistance due to extended-spectrum beta-lactamase (ESBL) production constitute a threat against patient safety. To identify, track, and control outbreaks and to detect emerging virulent clones, typing tools of sufficient discriminatory power that generate reproducible and unambiguous data are needed. A probe based real-time PCR method targeting multiple single nucleotide polymorphisms (SNP) was developed. The method was based on the multi locus sequence typing scheme of Institute Pasteur and by adaptation of previously described typing assays. An 8 SNP-panel that reached a Simpson's diversity index of 0.95 was established, based on analysis of sporadic E. coli cases (ESBL n = 27 and non-ESBL n = 53). This multi-SNP assay was used to identify the sequence type 131 (ST131) complex according to the Achtman's multi locus sequence typing scheme. However, it did not fully discriminate within the complex but provided a diagnostic signature that outperformed a previously described detection assay. Pulsed-field gel electrophoresis typing of isolates from a presumed outbreak (n = 22) identified two outbreaks (ST127 and ST131) and three different non-outbreak-related isolates. Multi-SNP typing generated congruent data except for one non-outbreak-related ST131 isolate. We consider multi-SNP real-time PCR typing an accessible primary generic E. coli typing tool for rapid and uniform type identification.

Comparison of multiple DNA dyes for real-time PCR: effects of dye concentration and sequence composition on DNA amplification and melting temperature

DEFF Research Database (Denmark)

Guðnason, Haukur; Dufva, Hans Martin; Bang, Dang Duong

2007-01-01

investigate 15 different intercalating DNA dyes for their inhibitory effects on PCR, effects on DNA melting temperature and possible preferential binding to GC-rich sequences. Our results demonstrated that in contrast to the results of SYBR Green I, two intercalating dyes SYTO-13 and SYTO-82 do not inhibit......The importance of real-time polymerase chain reaction (PCR) has increased steadily in clinical applications over the last decade. Many applications utilize SYBR Green I dye to follow the accumulation of amplicons in real time. SYBR Green I has, however, a number of limitations that include...... the inhibition of PCR, preferential binding to GC-rich sequences and effects on melting curve analysis. Although a few alternative dyes without some of these limitations have been recently proposed, no large-scale investigation into the properties of intercalating dyes has been performed. In this study, we...

Sequence analysis of the canine mitochondrial DNA control region from shed hair samples in criminal investigations.

Science.gov (United States)

Berger, C; Berger, B; Parson, W

2012-01-01

In recent years, evidence from domestic dogs has increasingly been analyzed by forensic DNA testing. Especially, canine hairs have proved most suitable and practical due to the high rate of hair transfer occurring between dogs and humans. Starting with the description of a contamination-free sample handling procedure, we give a detailed workflow for sequencing hypervariable segments (HVS) of the mtDNA control region from canine evidence. After the hair material is lysed and the DNA extracted by Phenol/Chloroform, the amplification and sequencing strategy comprises the HVS I and II of the canine control region and is optimized for DNA of medium-to-low quality and quantity. The sequencing procedure is based on the Sanger Big-dye deoxy-terminator method and the separation of the sequencing reaction products is performed on a conventional multicolor fluorescence detection capillary electrophoresis platform. Finally, software-aided base calling and sequence interpretation are addressed exemplarily.

Quantification of bacteria adherent to gastrointestinal mucosa by real-time PCR

NARCIS (Netherlands)

Huijsdens, Xander W.; Linskens, Ronald K.; Mak, Mariëtte; Meuwissen, Stephan G. M.; Vandenbroucke-Grauls, Christina M. J. E.; Savelkoul, Paul H. M.

2002-01-01

The use of real-time quantitative PCR (5' nuclease PCR assay) as a tool to study the gastrointestinal microflora that adheres to the colonic mucosa was evaluated. We developed primers and probes based on the 16S ribosomal DNA gene sequences for the detection of Escherichia coli and Bacteroides

PCR-based assays versus direct sequencing for evaluating the effect of KRAS status on anti-EGFR treatment response in colorectal cancer patients: a systematic review and meta-analysis.

Directory of Open Access Journals (Sweden)

Lianfeng Shan

Full Text Available The survival rate of colorectal cancer (CRC patients carrying wild-type KRAS is significantly increased by combining anti-EGFR monoclonal antibody (mAb with standard chemotherapy. However, conflicting data exist in both the wild-type KRAS and mutant KRAS groups, which strongly challenge CRC anti-EGFR treatment. Here we conducted a meta-analysis in an effort to provide more reliable information regarding anti-EGFR treatment in CRC patients.We searched full reports of randomized clinical trials using Medline, the American Society of Clinical Oncology (ASCO, and the European Society for Medical Oncology (ESMO. Two investigators independently screened the published literature according to our inclusive and exclusive criteria and the relative data were extracted. We used Review Manager 5.2 software to analyze the data.The addition of anti-EGFR mAb to standard chemotherapy significantly improved both progression-free survival (PFS and median overall survival (mOS in the wild-type KRAS group; hazard ratios (HRs for PFS and mOS were 0.70 [95% confidence interval (CI, 0.58-0.84] and 0.83 [95% CI, 0.75-0.91], respectively. In sub-analyses of the wild-type KRAS group, when PCR-based assays are employed, PFS and mOS notably increase: the HRs were 0.74 [95% CI, 0.62-0.88] and 0.87 [95% CI, 0.78-0.96], respectively. In sub-analyses of the mutant KRAS group, neither PCR-based assays nor direct sequencing enhance PFS or mOS.Our data suggest that PCR-based assays with high sensitivity and specificity allow accurate identification of patients with wild-type KRAS and thus increase PFS and mOS. Furthermore, such assays liberate patients with mutant KRAS from unnecessary drug side effects, and provide them an opportunity to receive appropriate treatment. Thus, establishing a precise standard reference test will substantially optimize CRC-targeted therapies.

Refining the Results of a Classical SELEX Experiment by Expanding the Sequence Data Set of an Aptamer Pool Selected for Protein A

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Regina Stoltenburg

2018-02-01

Full Text Available New, as yet undiscovered aptamers for Protein A were identified by applying next generation sequencing (NGS to a previously selected aptamer pool. This pool was obtained in a classical SELEX (Systematic Evolution of Ligands by EXponential enrichment experiment using the FluMag-SELEX procedure followed by cloning and Sanger sequencing. PA#2/8 was identified as the only Protein A-binding aptamer from the Sanger sequence pool, and was shown to be able to bind intact cells of Staphylococcus aureus. In this study, we show the extension of the SELEX results by re-sequencing of the same aptamer pool using a medium throughput NGS approach and data analysis. Both data pools were compared. They confirm the selection of a highly complex and heterogeneous oligonucleotide pool and show consistently a high content of orphans as well as a similar relative frequency of certain sequence groups. But in contrast to the Sanger data pool, the NGS pool was clearly dominated by one sequence group containing the known Protein A-binding aptamer PA#2/8 as the most frequent sequence in this group. In addition, we found two new sequence groups in the NGS pool represented by PA-C10 and PA-C8, respectively, which also have high specificity for Protein A. Comparative affinity studies reveal differences between the aptamers and confirm that PA#2/8 remains the most potent sequence within the selected aptamer pool reaching affinities in the low nanomolar range of KD = 20 ± 1 nM.

Refining the Results of a Classical SELEX Experiment by Expanding the Sequence Data Set of an Aptamer Pool Selected for Protein A.

Science.gov (United States)

Stoltenburg, Regina; Strehlitz, Beate

2018-02-24

New, as yet undiscovered aptamers for Protein A were identified by applying next generation sequencing (NGS) to a previously selected aptamer pool. This pool was obtained in a classical SELEX (Systematic Evolution of Ligands by EXponential enrichment) experiment using the FluMag-SELEX procedure followed by cloning and Sanger sequencing. PA#2/8 was identified as the only Protein A-binding aptamer from the Sanger sequence pool, and was shown to be able to bind intact cells of Staphylococcus aureus . In this study, we show the extension of the SELEX results by re-sequencing of the same aptamer pool using a medium throughput NGS approach and data analysis. Both data pools were compared. They confirm the selection of a highly complex and heterogeneous oligonucleotide pool and show consistently a high content of orphans as well as a similar relative frequency of certain sequence groups. But in contrast to the Sanger data pool, the NGS pool was clearly dominated by one sequence group containing the known Protein A-binding aptamer PA#2/8 as the most frequent sequence in this group. In addition, we found two new sequence groups in the NGS pool represented by PA-C10 and PA-C8, respectively, which also have high specificity for Protein A. Comparative affinity studies reveal differences between the aptamers and confirm that PA#2/8 remains the most potent sequence within the selected aptamer pool reaching affinities in the low nanomolar range of K D = 20 ± 1 nM.

Transcriptome sequencing of the blind subterranean mole rat, Spalax galili: Utility and potential for the discovery of novel evolutionary patterns

KAUST Repository

Malik, Assaf; Korol, Abraham; Hü bner, Sariel; Hernandez, Alvaro G.; Thimmapuram, Jyothi; Ali, Shahjahan; Glaser, Fabian; Paz, Arnon; Avivi, Aaron; Band, Mark

2011-01-01

sequencing of Spalax galili, a chromosomal type of S. ehrenbergi. cDNA pools from muscle and brain tissues isolated from animals exposed to hypoxic and normoxic conditions were sequenced using Sanger, GS FLX, and GS FLX Titanium technologies. Assembly

Development of a Web Tool for Escherichia coli Subtyping Based on fimH Alleles.

Science.gov (United States)

Roer, Louise; Tchesnokova, Veronika; Allesøe, Rosa; Muradova, Mariya; Chattopadhyay, Sujay; Ahrenfeldt, Johanne; Thomsen, Martin C F; Lund, Ole; Hansen, Frank; Hammerum, Anette M; Sokurenko, Evgeni; Hasman, Henrik

2017-08-01

The aim of this study was to construct a valid publicly available method for in silico fimH subtyping of Escherichia coli particularly suitable for differentiation of fine-resolution subgroups within clonal groups defined by standard multilocus sequence typing (MLST). FimTyper was constructed as a FASTA database containing all currently known fimH alleles. The software source code is publicly available at https://bitbucket.org/genomicepidemiology/fimtyper, the database is freely available at https://bitbucket.org/genomicepidemiology/fimtyper_db, and a service implementing the software is available at https://cge.cbs.dtu.dk/services/FimTyper FimTyper was validated on three data sets: one containing Sanger sequences of fimH alleles of 42 E. coli isolates generated prior to the current study (data set 1), one containing whole-genome sequence (WGS) data of 243 third-generation-cephalosporin-resistant E. coli isolates (data set 2), and one containing a randomly chosen subset of 40 E. coli isolates from data set 2 that were subjected to conventional fimH subtyping (data set 3). The combination of the three data sets enabled an evaluation and comparison of FimTyper on both Sanger sequences and WGS data. FimTyper correctly predicted all 42 fimH subtypes from the Sanger sequences from data set 1 and successfully analyzed all 243 draft genomes from data set 2. FimTyper subtyping of the Sanger sequences and WGS data from data set 3 were in complete agreement. Additionally, fimH subtyping was evaluated on a phylogenetic network of 122 sequence type 131 (ST131) E. coli isolates. There was perfect concordance between the typology and fimH -based subclones within ST131, with accurate identification of the pandemic multidrug-resistant clonal subgroup ST131- H 30. FimTyper provides a standardized tool, as a rapid alternative to conventional fimH subtyping, highly suitable for surveillance and outbreak detection. Copyright © 2017 American Society for Microbiology.

De novo transcriptome profiling of cold-stressed siliques during pod filling stages of Indian mustard (Brassica juncea L.

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Somya eSinha

2015-10-01

Full Text Available Low temperature is a major abiotic stress that impedes plant growth and development. Brassica juncea is an economically important oil seed crop and is sensitive to freezing stress during pod filling subsequently leading to abortion of seeds. To understand the cold stress mediated global perturbations in gene expression, whole transcriptome of B. juncea siliques that were exposed to sub-optimal temperature was sequenced. Manually self-pollinated siliques at different stages of development were subjected to either short (6 h or long (12 h durations of chilling stress followed by construction of RNA-seq libraries and deep sequencing using Illumina’s NGS platform. De-novo assembly of B. juncea transcriptome resulted in 133641 transcripts, whose combined length was 117 Mb and N50 value was 1428 bp. We identified 13342 differentially regulated transcripts by pair-wise comparison of 18 transcriptome libraries. Hierarchical clustering of these differentially expressed transcripts along with Spearman correlation analysis identified two major clusters representing early (5-15 DAP and late stages (20-30 DAP of silique development. Detailed analysis led to the discovery of two gene expression clusters whose transcripts were inducible at both durations of the cold stress irrespective of the developmental stages. We further explored the expression patterns of gene families encoding for transcription factors (TFs, transcription regulators (TRs and kinases, and found that cold stress induced protein kinases specifically during early silique development. We validated the digital gene expression profiles of selected transcripts by qPCR and found a high degree of concordance between the two analyses. To our knowledge this is the first report of transcriptome sequencing of cold-stressed B. juncea siliques. The data generated in this study would be a valuable resource for not only understanding the cold stress signaling pathway but also for introducing cold

DNA microarray-based solid-phase RT-PCR for rapid detection and identification of influenza virus type A and subtypes H5 and H7

DEFF Research Database (Denmark)

Yi, Sun; Dhumpa, Raghuram; Bang, Dang Duong

2011-01-01

of RNA extract in the liquid phase with sequence-specific nested PCR on the solid phase. A simple ultraviolet cross-linking method was used to immobilize the DNA probes over an unmodified glass surface, which makes solid-phase PCR a convenient possibility for AIV screening. The testing of 33 avian fecal....... In this article, a DNA microarray-based solid-phase polymerase chain reaction (PCR) approach has been developed for rapid detection of influenza virus type A and for simultaneous identification of pathogenic virus subtypes H5 and H7. This solid-phase RT-PCR method combined reverse-transcription amplification...

Novel Genetic Variants of Sporadic Atrial Septal Defect (ASD) in a Chinese Population Identified by Whole-Exome Sequencing (WES).

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Liu, Yong; Cao, Yu; Li, Yaxiong; Lei, Dongyun; Li, Lin; Hou, Zong Liu; Han, Shen; Meng, Mingyao; Shi, Jianlin; Zhang, Yayong; Wang, Yi; Niu, Zhaoyi; Xie, Yanhua; Xiao, Benshan; Wang, Yuanfei; Li, Xiao; Yang, Lirong; Wang, Wenju; Jiang, Lihong

2018-03-05

BACKGROUND Recently, mutations in several genes have been described to be associated with sporadic ASD, but some genetic variants remain to be identified. The aim of this study was to use whole-exome sequencing (WES) combined with bioinformatics analysis to identify novel genetic variants in cases of sporadic congenital ASD, followed by validation by Sanger sequencing. MATERIAL AND METHODS Five Han patients with secundum ASD were recruited, and their tissue samples were analyzed by WES, followed by verification by Sanger sequencing of tissue and blood samples. Further evaluation using blood samples included 452 additional patients with sporadic secundum ASD (212 male and 240 female patients) and 519 healthy subjects (252 male and 267 female subjects) for further verification by a multiplexed MassARRAY system. Bioinformatic analyses were performed to identify novel genetic variants associated with sporadic ASD. RESULTS From five patients with sporadic ASD, a total of 181,762 genomic variants in 33 exon loci, validated by Sanger sequencing, were selected and underwent MassARRAY analysis in 452 patients with ASD and 519 healthy subjects. Three loci with high mutation frequencies, the 138665410 FOXL2 gene variant, the 23862952 MYH6 gene variant, and the 71098693 HYDIN gene variant were found to be significantly associated with sporadic ASD (PASD (PASD, and supported the use of WES and bioinformatics analysis to identify disease-associated mutations.

Application of Whole Exome Sequencing in Six Families with an Initial Diagnosis of Autosomal Dominant Retinitis Pigmentosa: Lessons Learned

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Fernandez-San Jose, Patricia; Liu, Yichuan; March, Michael; Pellegrino, Renata; Golhar, Ryan; Corton, Marta; Blanco-Kelly, Fiona; López-Molina, Maria Isabel; García-Sandoval, Blanca; Guo, Yiran; Tian, Lifeng; Liu, Xuanzhu; Guan, Liping; Zhang, Jianguo; Keating, Brendan; Xu, Xun

2015-01-01

This study aimed to identify the genetics underlying dominant forms of inherited retinal dystrophies using whole exome sequencing (WES) in six families extensively screened for known mutations or genes. Thirty-eight individuals were subjected to WES. Causative variants were searched among single nucleotide variants (SNVs) and insertion/deletion variants (indels) and whenever no potential candidate emerged, copy number variant (CNV) analysis was performed. Variants or regions harboring a candidate variant were prioritized and segregation of the variant with the disease was further assessed using Sanger sequencing in case of SNVs and indels, and quantitative PCR (qPCR) for CNVs. SNV and indel analysis led to the identification of a previously reported mutation in PRPH2. Two additional mutations linked to different forms of retinal dystrophies were identified in two families: a known frameshift deletion in RPGR, a gene responsible for X-linked retinitis pigmentosa and p.Ser163Arg in C1QTNF5 associated with Late-Onset Retinal Degeneration. A novel heterozygous deletion spanning the entire region of PRPF31 was also identified in the affected members of a fourth family, which was confirmed with qPCR. This study allowed the identification of the genetic cause of the retinal dystrophy and the establishment of a correct diagnosis in four families, including a large heterozygous deletion in PRPF31, typically considered one of the pitfalls of this method. Since all findings in this study are restricted to known genes, we propose that targeted sequencing using gene-panel is an optimal first approach for the genetic screening and that once known genetic causes are ruled out, WES might be used to uncover new genes involved in inherited retinal dystrophies. PMID:26197217

PCR-Free Enrichment of Mitochondrial DNA from Human Blood and Cell Lines for High Quality Next-Generation DNA Sequencing.

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Meetha P Gould

Full Text Available Recent advances in sequencing technology allow for accurate detection of mitochondrial sequence variants, even those in low abundance at heteroplasmic sites. Considerable sequencing cost savings can be achieved by enriching samples for mitochondrial (relative to nuclear DNA. Reduction in nuclear DNA (nDNA content can also help to avoid false positive variants resulting from nuclear mitochondrial sequences (numts. We isolate intact mitochondrial organelles from both human cell lines and blood components using two separate methods: a magnetic bead binding protocol and differential centrifugation. DNA is extracted and further enriched for mitochondrial DNA (mtDNA by an enzyme digest. Only 1 ng of the purified DNA is necessary for library preparation and next generation sequence (NGS analysis. Enrichment methods are assessed and compared using mtDNA (versus nDNA content as a metric, measured by using real-time quantitative PCR and NGS read analysis. Among the various strategies examined, the optimal is differential centrifugation isolation followed by exonuclease digest. This strategy yields >35% mtDNA reads in blood and cell lines, which corresponds to hundreds-fold enrichment over baseline. The strategy also avoids false variant calls that, as we show, can be induced by the long-range PCR approaches that are the current standard in enrichment procedures. This optimization procedure allows mtDNA enrichment for efficient and accurate massively parallel sequencing, enabling NGS from samples with small amounts of starting material. This will decrease costs by increasing the number of samples that may be multiplexed, ultimately facilitating efforts to better understand mitochondria-related diseases.

The Sequence Characteristics and Expression Models Reveal Superoxide Dismutase Involved in Cold Response and Fruiting Body Development in Volvariella volvacea

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Jun-Jie Yan

2016-01-01

Full Text Available As the first defence for cells to counteract the toxicity of active oxygen, superoxide dismutase (SOD plays an important role in the response of living organisms to stress and cell differentiation. One extracellular Cu-ZnSOD (ecCu-ZnSOD, and two MnSODs, were identified based on the Volvariella volvacea genome sequence. All three genes have complicated alternative splicing modes during transcription; only when the fourth intron is retained can the Vv_Cu-Znsod1 gene be translated into a protein sequence with SOD functional domains. The expression levels of the three sod genes in the pilei are higher than in the stipe. The Vv_Cu-Znsod1 and the Vv_Mnsod2 are co-expressed in different developmental stages of the fruiting body, with the highest level of expression in the pilei of the egg stage, and they show a significant, positive correlation with the efficiency of karyogamy, indicating the potential role of these two genes during karyogamy. The expression of the ecCu-Znsod and two Vv_Mnsod genes showed a significant up-regulated when treated by cold stress for one hour; however, the lack of the intracellular Cu-ZnSOD encoding gene (icCu-Znsod and the special locus of the ecCu-Znsod gene initiation codon suggested a possible reason for the autolysis phenomenon of V. volvacea in cold conditions.

RNA-Seq and Mass-Spectrometry-Based Lipidomics Reveal Extensive Changes of Glycerolipid Pathways in Brown Adipose Tissue in Response to Cold

DEFF Research Database (Denmark)

Marcher, Ann-Britt; Loft, Anne; Nielsen, Ronni

2015-01-01

involved in glycerophospholipid synthesis and fatty acid elongation. This is accompanied by significant changes in the acyl chain composition of triacylglycerols (TAGs) as well as subspecies-selective changes of acyl chains in glycerophospholipids. These results indicate that cold adaptation of BAT......Cold exposure greatly alters brown adipose tissue (BAT) gene expression and metabolism to increase thermogenic capacity. Here, we used RNA sequencing and mass-spectrometry-based lipidomics to provide a comprehensive resource describing the molecular signature of cold adaptation at the level...... of the transcriptome and lipidome. We show that short-term (3-day) cold exposure leads to a robust increase in expression of several brown adipocyte genes related to thermogenesis as well as the gene encoding the hormone irisin. However, pathway analysis shows that the most significantly induced genes are those...

Cross-border outbreak of listeriosis caused by cold-smoked salmon, revealed by integrated surveillance and whole genome sequencing (WGS), Denmark and France, 2015 to 2017

DEFF Research Database (Denmark)

Schjorring, Susanne; Lassen, Sofie Gillesberg; Jensen, Tenna

2017-01-01

In August 2017, an outbreak of six listeriosis cases in Denmark was traced to cold-smoked salmon, using epidemiological investigations and whole-genome sequencing (WGS) analyses. Exchange of genome sequences allowed identification in France of a food isolate from a salmon-derived product and a hu......In August 2017, an outbreak of six listeriosis cases in Denmark was traced to cold-smoked salmon, using epidemiological investigations and whole-genome sequencing (WGS) analyses. Exchange of genome sequences allowed identification in France of a food isolate from a salmon-derived product...... and a human isolate from 2016 within the same cgMLST cluster as the Danish isolates (L2-SL8-ST8-CT771). The salmon product came from a third European Union country. WGS can rapidly link human cases and food isolates across Europe....

Comparison of DNA Microarray, Loop-Mediated Isothermal Amplification (LAMP) and Real-Time PCR with DNA Sequencing for Identification of Fusarium spp. Obtained from Patients with Hematologic Malignancies.

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de Souza, Marcela; Matsuzawa, Tetsuhiro; Sakai, Kanae; Muraosa, Yasunori; Lyra, Luzia; Busso-Lopes, Ariane Fidelis; Levin, Anna Sara Shafferman; Schreiber, Angélica Zaninelli; Mikami, Yuzuru; Gonoi, Tohoru; Kamei, Katsuhiko; Moretti, Maria Luiza; Trabasso, Plínio

2017-08-01

The performance of three molecular biology techniques, i.e., DNA microarray, loop-mediated isothermal amplification (LAMP), and real-time PCR were compared with DNA sequencing for properly identification of 20 isolates of Fusarium spp. obtained from blood stream as etiologic agent of invasive infections in patients with hematologic malignancies. DNA microarray, LAMP and real-time PCR identified 16 (80%) out of 20 samples as Fusarium solani species complex (FSSC) and four (20%) as Fusarium spp. The agreement among the techniques was 100%. LAMP exhibited 100% specificity, while DNA microarray, LAMP and real-time PCR showed 100% sensitivity. The three techniques had 100% agreement with DNA sequencing. Sixteen isolates were identified as FSSC by sequencing, being five Fusarium keratoplasticum, nine Fusarium petroliphilum and two Fusarium solani. On the other hand, sequencing identified four isolates as Fusarium non-solani species complex (FNSSC), being three isolates as Fusarium napiforme and one isolate as Fusarium oxysporum. Finally, LAMP proved to be faster and more accessible than DNA microarray and real-time PCR, since it does not require a thermocycler. Therefore, LAMP signalizes as emerging and promising methodology to be used in routine identification of Fusarium spp. among cases of invasive fungal infections.

Specific PCR-based detection of Alternaria helianthi

DEFF Research Database (Denmark)

Udayashankar, A.C.; Nayaka, S. Chandra; Archana, B.

2012-01-01

Alternaria helianthi is an important seed-borne pathogenic fungus responsible for blight disease in sunflower. The current detection methods, which are based on culture and morphological identification, are time-consuming, laborious and are not always reliable. A PCR-based diagnostic method...... tested. The detection limit of the PCR method was of 10 pg from template DNA. The primers could also detect the pathogen in infected sunflower seed. This species-specific PCR method provides a quick, simple, powerful and reliable alternative to conventional methods in the detection and identification...

Development of primers for sequencing the NSP1, NSP3, and VP6 genes of the group A porcine rotavirus

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Fernanda Dornelas Florentino Silva

2014-02-01

Full Text Available Rotavirus is the causative pathogen of diarrhea in humans and in several animal species. Eight pairs of primers were developed and used for Sanger sequencing of the coding region of the NSP1, NSP3, and VP6 genes based on the conserved regions of the genome of the group A porcine rotavirus. Three samples previously screened as positive for group A rotaviruses were subjected to gene amplification and sequencing to characterize the pathogen. The information generated from this study is crucial for the understanding of the epidemiology of the disease.

DSAP: deep-sequencing small RNA analysis pipeline.

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Huang, Po-Jung; Liu, Yi-Chung; Lee, Chi-Ching; Lin, Wei-Chen; Gan, Richie Ruei-Chi; Lyu, Ping-Chiang; Tang, Petrus

2010-07-01

DSAP is an automated multiple-task web service designed to provide a total solution to analyzing deep-sequencing small RNA datasets generated by next-generation sequencing technology. DSAP uses a tab-delimited file as an input format, which holds the unique sequence reads (tags) and their corresponding number of copies generated by the Solexa sequencing platform. The input data will go through four analysis steps in DSAP: (i) cleanup: removal of adaptors and poly-A/T/C/G/N nucleotides; (ii) clustering: grouping of cleaned sequence tags into unique sequence clusters; (iii) non-coding RNA (ncRNA) matching: sequence homology mapping against a transcribed sequence library from the ncRNA database Rfam (http://rfam.sanger.ac.uk/); and (iv) known miRNA matching: detection of known miRNAs in miRBase (http://www.mirbase.org/) based on sequence homology. The expression levels corresponding to matched ncRNAs and miRNAs are summarized in multi-color clickable bar charts linked to external databases. DSAP is also capable of displaying miRNA expression levels from different jobs using a log(2)-scaled color matrix. Furthermore, a cross-species comparative function is also provided to show the distribution of identified miRNAs in different species as deposited in miRBase. DSAP is available at http://dsap.cgu.edu.tw.

Comparison of Four Human Papillomavirus Genotyping Methods: Next-generation Sequencing, INNO-LiPA, Electrochemical DNA Chip, and Nested-PCR.

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Nilyanimit, Pornjarim; Chansaenroj, Jira; Poomipak, Witthaya; Praianantathavorn, Kesmanee; Payungporn, Sunchai; Poovorawan, Yong

2018-03-01

Human papillomavirus (HPV) infection causes cervical cancer, thus necessitating early detection by screening. Rapid and accurate HPV genotyping is crucial both for the assessment of patients with HPV infection and for surveillance studies. Fifty-eight cervicovaginal samples were tested for HPV genotypes using four methods in parallel: nested-PCR followed by conventional sequencing, INNO-LiPA, electrochemical DNA chip, and next-generation sequencing (NGS). Seven HPV genotypes (16, 18, 31, 33, 45, 56, and 58) were identified by all four methods. Nineteen HPV genotypes were detected by NGS, but not by nested-PCR, INNO-LiPA, or electrochemical DNA chip. Although NGS is relatively expensive and complex, it may serve as a sensitive HPV genotyping method. Because of its highly sensitive detection of multiple HPV genotypes, NGS may serve as an alternative for diagnostic HPV genotyping in certain situations. © The Korean Society for Laboratory Medicine

Discrimination of the Lactobacillus acidophilus group using sequencing, species-specific PCR and SNaPshot mini-sequencing technology based on the recA gene.

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Huang, Chien-Hsun; Chang, Mu-Tzu; Huang, Mu-Chiou; Wang, Li-Tin; Huang, Lina; Lee, Fwu-Ling

2012-10-01

To clearly identify specific species and subspecies of the Lactobacillus acidophilus group using phenotypic and genotypic (16S rDNA sequence analysis) techniques alone is difficult. The aim of this study was to use the recA gene for species discrimination in the L. acidophilus group, as well as to develop a species-specific primer and single nucleotide polymorphism primer based on the recA gene sequence for species and subspecies identification. The average sequence similarity for the recA gene among type strains was 80.0%, and most members of the L. acidophilus group could be clearly distinguished. The species-specific primer was designed according to the recA gene sequencing, which was employed for polymerase chain reaction with the template DNA of Lactobacillus strains. A single 231-bp species-specific band was found only in L. delbrueckii. A SNaPshot mini-sequencing assay using recA as a target gene was also developed. The specificity of the mini-sequencing assay was evaluated using 31 strains of L. delbrueckii species and was able to unambiguously discriminate strains belonging to the subspecies L. delbrueckii subsp. bulgaricus. The phylogenetic relationships of most strains in the L. acidophilus group can be resolved using recA gene sequencing, and a novel method to identify the species and subspecies of the L. delbrueckii and L. delbrueckii subsp. bulgaricus was developed by species-specific polymerase chain reaction combined with SNaPshot mini-sequencing. Copyright © 2012 Society of Chemical Industry.

Cost-effective sequencing of full-length cDNA clones powered by a de novo-reference hybrid assembly.

Science.gov (United States)

Kuroshu, Reginaldo M; Watanabe, Junichi; Sugano, Sumio; Morishita, Shinichi; Suzuki, Yutaka; Kasahara, Masahiro

2010-05-07

Sequencing full-length cDNA clones is important to determine gene structures including alternative splice forms, and provides valuable resources for experimental analyses to reveal the biological functions of coded proteins. However, previous approaches for sequencing cDNA clones were expensive or time-consuming, and therefore, a fast and efficient sequencing approach was demanded. We developed a program, MuSICA 2, that assembles millions of short (36-nucleotide) reads collected from a single flow cell lane of Illumina Genome Analyzer to shotgun-sequence approximately 800 human full-length cDNA clones. MuSICA 2 performs a hybrid assembly in which an external de novo assembler is run first and the result is then improved by reference alignment of shotgun reads. We compared the MuSICA 2 assembly with 200 pooled full-length cDNA clones finished independently by the conventional primer-walking using Sanger sequencers. The exon-intron structure of the coding sequence was correct for more than 95% of the clones with coding sequence annotation when we excluded cDNA clones insufficiently represented in the shotgun library due to PCR failure (42 out of 200 clones excluded), and the nucleotide-level accuracy of coding sequences of those correct clones was over 99.99%. We also applied MuSICA 2 to full-length cDNA clones from Toxoplasma gondii, to confirm that its ability was competent even for non-human species. The entire sequencing and shotgun assembly takes less than 1 week and the consumables cost only approximately US$3 per clone, demonstrating a significant advantage over previous approaches.

Mycobacterial Interspersed Repetitive-Unit–Variable-Number Tandem-Repeat (MIRU-VNTR) Genotyping of Mycobacterium intracellulare for Strain Comparison with Establishment of a PCR-Based Database

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Iakhiaeva, Elena; McNulty, Steven; Brown Elliott, Barbara A.; Falkinham, Joseph O.; Williams, Myra D.; Vasireddy, Ravikiran; Wilson, Rebecca W.; Turenne, Christine

2013-01-01

Strain comparison is important to population genetics and to evaluate relapses in patients with Mycobacterium avium complex (MAC) lung disease, but the “gold standard” of pulsed-field gel electrophoresis (PFGE) is time-consuming and complex. We used variable-number tandem repeats (VNTR) for fingerprinting of respiratory isolates of M. intracellulare from patients with underlying bronchiectasis, to establish a nonsequence-based database for population analysis. Different genotypes identified by PFGE underwent species identification using a 16S rRNA gene multiplex PCR. Genotypes of M. intracellulare were confirmed by internal transcribed spacer 1 (ITS1) sequencing and characterized using seven VNTR primers. The pattern of VNTR amplicon sizes and repeat number defined each specific VNTR type. Forty-two VNTR types were identified among 84 genotypes. PFGE revealed most isolates with the same VNTR type to be clonal or exhibit similar grouping of bands. Repetitive sequence-based PCR (rep-PCR) showed minimal pattern diversity between VNTR types compared to PFGE. Fingerprinting of relapse isolates from 31 treated patients using VNTR combined with 16S multiplex PCR unambiguously and reliably distinguished different genotypes from the same patient, with results comparable to those of PFGE. VNTR for strain comparison is easier and faster than PFGE, is as accurate as PFGE, and does not require sequencing. Starting with a collection of 167 M. intracellulare isolates, VNTR distinguished M. intracellulare into 42 clonal groups. Comparison of isolates from different geographic areas, habitats, and clinical settings is now possible. PMID:23175249

Mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) genotyping of mycobacterium intracellulare for strain comparison with establishment of a PCR-based database.

Science.gov (United States)

Iakhiaeva, Elena; McNulty, Steven; Brown Elliott, Barbara A; Falkinham, Joseph O; Williams, Myra D; Vasireddy, Ravikiran; Wilson, Rebecca W; Turenne, Christine; Wallace, Richard J

2013-02-01

Strain comparison is important to population genetics and to evaluate relapses in patients with Mycobacterium avium complex (MAC) lung disease, but the "gold standard" of pulsed-field gel electrophoresis (PFGE) is time-consuming and complex. We used variable-number tandem repeats (VNTR) for fingerprinting of respiratory isolates of M. intracellulare from patients with underlying bronchiectasis, to establish a nonsequence-based database for population analysis. Different genotypes identified by PFGE underwent species identification using a 16S rRNA gene multiplex PCR. Genotypes of M. intracellulare were confirmed by internal transcribed spacer 1 (ITS1) sequencing and characterized using seven VNTR primers. The pattern of VNTR amplicon sizes and repeat number defined each specific VNTR type. Forty-two VNTR types were identified among 84 genotypes. PFGE revealed most isolates with the same VNTR type to be clonal or exhibit similar grouping of bands. Repetitive sequence-based PCR (rep-PCR) showed minimal pattern diversity between VNTR types compared to PFGE. Fingerprinting of relapse isolates from 31 treated patients using VNTR combined with 16S multiplex PCR unambiguously and reliably distinguished different genotypes from the same patient, with results comparable to those of PFGE. VNTR for strain comparison is easier and faster than PFGE, is as accurate as PFGE, and does not require sequencing. Starting with a collection of 167 M. intracellulare isolates, VNTR distinguished M. intracellulare into 42 clonal groups. Comparison of isolates from different geographic areas, habitats, and clinical settings is now possible.

Ultrasensitive quantitation of human papillomavirus type 16 E6 oncogene sequences by nested real time PCR

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López-Revilla Rubén

2010-05-01

Full Text Available Abstract Background We have developed an ultrasensitive method based on conventional PCR preamplification followed by nested amplification through real time PCR (qPCR in the presence of the DNA intercalating agent EvaGreen. Results Amplification mixtures calibrated with a known number of pHV101 copies carrying a 645 base pair (bp-long insert of the human papillomavirus type 16 (HPV16 E6 oncogene were used to generate the E6-1 amplicon of 645 bp by conventional PCR and then the E6-2 amplicon of 237 bp by nested qPCR. Direct and nested qPCR mixtures for E6-2 amplification corresponding to 2.5 × 102-2.5 × 106 initial pHV101 copies had threshold cycle (Ct values in the ranges of 18.7-29.0 and 10.0-25.0, respectively. The Ct of qPCR mixtures prepared with 1/50 volumes of preamplified mixtures containing 50 ng of DNA of the SiHa cell line (derived from an invasive cervical cancer with one HPV16 genome per cell was 19.9. Thermal fluorescence extinction profiles of E6-2 amplicons generated from pHV101 and SiHa DNA were identical, with a peak at 85.5°C. Conclusions Our method based on conventional preamplification for 15 cycles increased 10,750 times the sensitivity of nested qPCR for the quantitation of the E6 viral oncogene and confirmed that the SiHa cell line contains one E6-HPV16 copy per cell.

PCR-based verification of positive rapid diagnostic tests for intestinal protozoa infections with variable test band intensity.

Science.gov (United States)

Becker, Sören L; Müller, Ivan; Mertens, Pascal; Herrmann, Mathias; Zondie, Leyli; Beyleveld, Lindsey; Gerber, Markus; du Randt, Rosa; Pühse, Uwe; Walter, Cheryl; Utzinger, Jürg

2017-10-01

Stool-based rapid diagnostic tests (RDTs) for pathogenic intestinal protozoa (e.g. Cryptosporidium spp. and Giardia intestinalis) allow for prompt diagnosis and treatment in resource-constrained settings. Such RDTs can improve individual patient management and facilitate population-based screening programmes in areas without microbiological laboratories for confirmatory testing. However, RDTs are difficult to interpret in case of 'trace' results with faint test band intensities and little is known about whether such ambiguous results might indicate 'true' infections. In a longitudinal study conducted in poor neighbourhoods of Port Elizabeth, South Africa, a total of 1428 stool samples from two cohorts of schoolchildren were examined on the spot for Cryptosporidium spp. and G. intestinalis using an RDT (Crypto/Giardia DuoStrip; Coris BioConcept). Overall, 121 samples were positive for G. intestinalis and the RDT suggested presence of cryptosporidiosis in 22 samples. After a storage period of 9-10 months in cohort 1 and 2-3 months in cohort 2, samples were subjected to multiplex PCR (BD Max™ Enteric Parasite Panel, Becton Dickinson). Ninety-three percent (112/121) of RDT-positive samples for G. intestinalis were confirmed by PCR, with a correlation between RDT test band intensity and quantitative pathogen load present in the sample. For Cryptosporidium spp., all positive RDTs had faintly visible lines and these were negative on PCR. The performance of the BD Max™ PCR was nearly identical in both cohorts, despite the prolonged storage at disrupted cold chain conditions in cohort 1. The Crypto/Giardia DuoStrip warrants further validation in communities with a high incidence of diarrhoea. Copyright © 2017 Elsevier B.V. All rights reserved.

Targeted 'next-generation' sequencing in anophthalmia and microphthalmia patients confirms SOX2, OTX2 and FOXE3 mutations.

Science.gov (United States)

Jimenez, Nelson Lopez; Flannick, Jason; Yahyavi, Mani; Li, Jiang; Bardakjian, Tanya; Tonkin, Leath; Schneider, Adele; Sherr, Elliott H; Slavotinek, Anne M

2011-12-28

Anophthalmia/microphthalmia (A/M) is caused by mutations in several different transcription factors, but mutations in each causative gene are relatively rare, emphasizing the need for a testing approach that screens multiple genes simultaneously. We used next-generation sequencing to screen 15 A/M patients for mutations in 9 pathogenic genes to evaluate this technology for screening in A/M. We used a pooled sequencing design, together with custom single nucleotide polymorphism (SNP) calling software. We verified predicted sequence alterations using Sanger sequencing. We verified three mutations - c.542delC in SOX2, resulting in p.Pro181Argfs*22, p.Glu105X in OTX2 and p.Cys240X in FOXE3. We found several novel sequence alterations and SNPs that were likely to be non-pathogenic - p.Glu42Lys in CRYBA4, p.Val201Met in FOXE3 and p.Asp291Asn in VSX2. Our analysis methodology gave one false positive result comprising a mutation in PAX6 (c.1268A > T, predicting p.X423LeuextX*15) that was not verified by Sanger sequencing. We also failed to detect one 20 base pair (bp) deletion and one 3 bp duplication in SOX2. Our results demonstrated the power of next-generation sequencing with pooled sample groups for the rapid screening of candidate genes for A/M as we were correctly able to identify disease-causing mutations. However, next-generation sequencing was less useful for small, intragenic deletions and duplications. We did not find mutations in 10/15 patients and conclude that there is a need for further gene discovery in A/M.

Chromogenic in situ hybridisation (CISH) is a powerful method to detect ALK-positive non-small cell lung carcinomas.

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Wagner, F; Streubel, A; Roth, A; Stephan-Falkenau, S; Mairinger, T

2014-05-01

We assessed the potential of a chromogenic in situ hybridisation (CISH) assay in comparison with quantitative reverse transcription (RT)-PCR (qPCR) to detect anaplastic lymphoma kinase (ALK) break apart-positive lung carcinomas. Dual-colour CISH using a break apart probe for the ALK gene on 2p23 was performed with 181 formalin-fixed, paraffin-embedded tissue and agar block sections from 175 cases of non-small cell lung carcinomas (NSCLC). Stained slides were analysed with a standard bright-field microscope at 1000× magnification by counting signals from 60 non-overlapping nuclei from three different tumour areas. Samples with ≥15% of positive nuclei were judged as ALK break apart-positive. All samples were simultaneously analysed by qPCR for EML4-ALK to validate CISH results, and positive samples were subject to Sanger sequencing. CISH was successful with 173 of 181 hybridised samples (96%), and seven ALK break apart-positive cases were detected. CISH signals were specific and distinct for both colours. All positive cases were confirmed by qPCR and Sanger sequencing, and concordance between CISH and qPCR was 100%. Nearly all samples (9/10) which failed by qPCR were accessible to CISH analysis. CISH is a very reliable, convenient and inexpensive method to detect ALK-positive NSCLC. CISH success rate is comparably high as with qPCR, and it detects all ALK break apart events in a single assay. It is of special value when RNA quality is poor, or when small biopsies with a very limited amount of tumour cells have to be analysed.

Intraspecific variations in Cyt b and D-loop sequences of Testudine species, Lissemys punctata from south Karnataka

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R. Lalitha

2018-01-01

Full Text Available The freshwater Testudine species have gained importance in recent years, as most of their population is threatened due to exploitation for delicacy and pet trade. In this regard, Lissemys punctata, a freshwater terrapin, predominantly distributed in Asian countries has gained its significance for the study. A pilot study report on mitochondrial markers (Cyt b and D-loop conducted on L. punctata species from southern Karnataka, India was presented in this investigation. A complete region spanning 1.14 kb and ∼1 kb was amplified by HotStart PCR and sequenced by Sanger sequencing. The Cyt b sequence revealed 85 substitution sites, no indels and 17 parsimony informative sites, whereas D-loop showed 189 variable sites, 51 parsimony informative sites with 5′ functional domains TAS, CSB-F, CSBs (1, 2, 3 preceding tandem repeat at 3′ end. Current data highlights the intraspecific variations in these target regions and variations validated using suitable evolutionary models points out that the overall point mutations observed in the region are transitions leading to no structural and functional alterations. The mitochondrial data generated uncover the genetic diversity within species and conservationist can utilize the data to estimate the effective population size or for forensic identification of animal or its seizures during unlawful trade activities.

ITS-2 sequences-based identification of Trichogramma species in South America

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R. P. Almeida

Full Text Available Abstract ITS2 (Internal transcribed spacer 2 sequences have been used in systematic studies and proved to be useful in providing a reliable identification of Trichogramma species. DNAr sequences ranged in size from 379 to 632 bp. In eleven T. pretiosum lines Wolbachia-induced parthenogenesis was found for the first time. These thelytokous lines were collected in Peru (9, Colombia (1 and USA (1. A dichotomous key for species identification was built based on the size of the ITS2 PCR product and restriction analysis using three endonucleases (EcoRI, MseI and MaeI. This molecular technique was successfully used to distinguish among seventeen native/introduced Trichogramma species collected in South America.

Comparison of DNA Quantification Methods for Next Generation Sequencing.

Science.gov (United States)

Robin, Jérôme D; Ludlow, Andrew T; LaRanger, Ryan; Wright, Woodring E; Shay, Jerry W

2016-04-06

Next Generation Sequencing (NGS) is a powerful tool that depends on loading a precise amount of DNA onto a flowcell. NGS strategies have expanded our ability to investigate genomic phenomena by referencing mutations in cancer and diseases through large-scale genotyping, developing methods to map rare chromatin interactions (4C; 5C and Hi-C) and identifying chromatin features associated with regulatory elements (ChIP-seq, Bis-Seq, ChiA-PET). While many methods are available for DNA library quantification, there is no unambiguous gold standard. Most techniques use PCR to amplify DNA libraries to obtain sufficient quantities for optical density measurement. However, increased PCR cycles can distort the library's heterogeneity and prevent the detection of rare variants. In this analysis, we compared new digital PCR technologies (droplet digital PCR; ddPCR, ddPCR-Tail) with standard methods for the titration of NGS libraries. DdPCR-Tail is comparable to qPCR and fluorometry (QuBit) and allows sensitive quantification by analysis of barcode repartition after sequencing of multiplexed samples. This study provides a direct comparison between quantification methods throughout a complete sequencing experiment and provides the impetus to use ddPCR-based quantification for improvement of NGS quality.

A DNA mini-barcode for land plants.

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Little, Damon P

2014-05-01

Small portions of the barcode region - mini-barcodes - may be used in place of full-length barcodes to overcome DNA degradation for samples with poor DNA preservation. 591,491,286 rbcL mini-barcode primer combinations were electronically evaluated for PCR universality, and two novel highly universal sets of priming sites were identified. Novel and published rbcL mini-barcode primers were evaluated for PCR amplification [determined with a validated electronic simulation (n = 2765) and empirically (n = 188)], Sanger sequence quality [determined empirically (n = 188)], and taxonomic discrimination [determined empirically (n = 30,472)]. PCR amplification for all mini-barcodes, as estimated by validated electronic simulation, was successful for 90.2-99.8% of species. Overall Sanger sequence quality for mini-barcodes was very low - the best mini-barcode tested produced sequences of adequate quality (B20 ≥ 0.5) for 74.5% of samples. The majority of mini-barcodes provide correct identifications of families in excess of 70.1% of the time. Discriminatory power noticeably decreased at lower taxonomic levels. At the species level, the discriminatory power of the best mini-barcode was less than 38.2%. For samples believed to contain DNA from only one species, an investigator should attempt to sequence, in decreasing order of utility and probability of success, mini-barcodes F (rbcL1/rbcLB), D (F52/R193) and K (F517/R604). For samples believed to contain DNA from more than one species, an investigator should amplify and sequence mini-barcode D (F52/R193). © 2013 John Wiley & Sons Ltd.

Effects of cold-working on pinning behaviour and critical current densities in NbTi-based superconductors

International Nuclear Information System (INIS)

Yamada, Y.; Murase, S.; Wada, H.; Tachikawa, K.

1985-01-01

The effects of cold-working on high-field pinning behaviour at 1.8 K and 4.2 K have been studied for multifilamentary NbTi, NbTiHf and NbTiTa superconductors, which were subjected to cold-working, heat treatment and cold-working, in sequence. It is found that the cold-working, either before or after heat treatment, shifts the peak in pinning force density to a higher field, while the maximum pinning force value is first increased with increasing amount of cold-working, and then decreased. This result can not be predicted by existing pinning theories, and we conclude that for pinning behaviour induced by cold-working, not only the introduction of pinning centres but also their size and spacing must be taken into account. (author)

Decoding DNA labels by melting curve analysis using real-time PCR.

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Balog, József A; Fehér, Liliána Z; Puskás, László G

2017-12-01

Synthetic DNA has been used as an authentication code for a diverse number of applications. However, existing decoding approaches are based on either DNA sequencing or the determination of DNA length variations. Here, we present a simple alternative protocol for labeling different objects using a small number of short DNA sequences that differ in their melting points. Code amplification and decoding can be done in two steps using quantitative PCR (qPCR). To obtain a DNA barcode with high complexity, we defined 8 template groups, each having 4 different DNA templates, yielding 158 (>2.5 billion) combinations of different individual melting temperature (Tm) values and corresponding ID codes. The reproducibility and specificity of the decoding was confirmed by using the most complex template mixture, which had 32 different products in 8 groups with different Tm values. The industrial applicability of our protocol was also demonstrated by labeling a drone with an oil-based paint containing a predefined DNA code, which was then successfully decoded. The method presented here consists of a simple code system based on a small number of synthetic DNA sequences and a cost-effective, rapid decoding protocol using a few qPCR reactions, enabling a wide range of authentication applications.

Deep nirS amplicon sequencing of San Francisco Bay sediments enables prediction of geography and environmental conditions from denitrifying community composition.

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Lee, Jessica A; Francis, Christopher A

2017-12-01

Denitrification is a dominant nitrogen loss process in the sediments of San Francisco Bay. In this study, we sought to understand the ecology of denitrifying bacteria by using next-generation sequencing (NGS) to survey the diversity of a denitrification functional gene, nirS (encoding cytchrome-cd 1 nitrite reductase), along the salinity gradient of San Francisco Bay over the course of a year. We compared our dataset to a library of nirS sequences obtained previously from the same samples by standard PCR cloning and Sanger sequencing, and showed that both methods similarly demonstrated geography, salinity and, to a lesser extent, nitrogen, to be strong determinants of community composition. Furthermore, the depth afforded by NGS enabled novel techniques for measuring the association between environment and community composition. We used Random Forests modelling to demonstrate that the site and salinity of a sample could be predicted from its nirS sequences, and to identify indicator taxa associated with those environmental characteristics. This work contributes significantly to our understanding of the distribution and dynamics of denitrifying communities in San Francisco Bay, and provides valuable tools for the further study of this key N-cycling guild in all estuarine systems. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Deinococcus gobiensis cold shock protein improves salt stress tolerance of escherichia coli

International Nuclear Information System (INIS)

Jiang Shijie; Wang Jin; Yang Mingkun; Chen Ming; Zhang Wei; Luo Xuegang

2013-01-01

The Deinococcus gobiensis I-0, an extremely radiation-resistant bacterium, isolated from the Gobi, has superior resistance to abiotic stress (e.g radiation, oxidation, dehydration and so on). The two cold-shock proteins encoded by csp1 (Dgo_CA1136) and csp2 (Dgo_PA0041) were identified in the complete genome sequence of D. gobiensis. In this study, we showed that D. gobiensis Csp1 protected Escherichia coli cells against cold shock and other abiotic stresses such as salt and osmotic shocks. The quantitative real-time PCR assay shows that the expression of trehalose synthase (otsA, otsB) was up-regulated remarkably under salt stress in the csp1-expressing strain, while no difference in the expression of the genes involved in trehalose degradation (treB and treC). The results suggested that Csp1 caused the accumulation of the trehalose was a major feature for improving tolerance to salt stress in E. coli. (authors)

Complete mitochondrial genome of freshwater shark Wallago attu (Bloch & Schneider) from Indus River Sindh, Pakistan.

Science.gov (United States)

Laghari, Muhammad Younis; Lashari, Punhal; Xu, Peng; Zhao, Zixia; Jiang, Li; Narejo, Naeem Tariq; Xin, Baoping; Sun, Xiaowen; Zhang, Yan

2016-01-01

Complete mitochondrial genome of fresh water giant catfish, Wallago attu, was isolated by LA PCR (TakaRa LAtaq, Dalian, China); and sequenced by Sanger's method to obtain the complete mitochondrial genome. The complete mitogenome was 15,639 bp in length and contains 13 typical vertebrate protein-coding genes, 2 rRNA and 22 tRNA genes. The whole genome base composition was estimated to be 31.17% A, 28.15% C, 15.55% G and 25.12% T. The complete mitochondrial genome of catfish, W. attu, provides the fundamental tools for genetic breeding.

Applications of the rep-PCR DNA fingerprinting technique to study microbial diversity, ecology and evolution.

Science.gov (United States)

Ishii, Satoshi; Sadowsky, Michael J

2009-04-01

A large number of repetitive DNA sequences are found in multiple sites in the genomes of numerous bacteria, archaea and eukarya. While the functions of many of these repetitive sequence elements are unknown, they have proven to be useful as the basis of several powerful tools for use in molecular diagnostics, medical microbiology, epidemiological analyses and environmental microbiology. The repetitive sequence-based PCR or rep-PCR DNA fingerprint technique uses primers targeting several of these repetitive elements and PCR to generate unique DNA profiles or 'fingerprints' of individual microbial strains. Although this technique has been extensively used to examine diversity among variety of prokaryotic microorganisms, rep-PCR DNA fingerprinting can also be applied to microbial ecology and microbial evolution studies since it has the power to distinguish microbes at the strain or isolate level. Recent advancement in rep-PCR methodology has resulted in increased accuracy, reproducibility and throughput. In this minireview, we summarize recent improvements in rep-PCR DNA fingerprinting methodology, and discuss its applications to address fundamentally important questions in microbial ecology and evolution.

The Genome Sequence of the psychrophilic archaeon, Methanococcoides burtonii: the Role of Genome Evolution in Cold-adaptation

Energy Technology Data Exchange (ETDEWEB)

Allen, Michelle A.; Lauro, Federico M.; Williams, Timothy J.; Burg, Dominic; Siddiqui, Khawar S.; De Francisci, David; Chong, Kevin W.Y.; Pilak, Oliver; Chew, Hwee H.; De Maere, Matthew Z.; Ting, Lily; Katrib, Marilyn; Ng, Charmaine; Sowers, Kevin R.; Galperin, Michael Y.; Anderson, Iain J.; Ivanova, Natalia; Dalin, Eileen; Martinez, Michelle; Lapidus, Alla; Hauser, Loren; Land, Miriam; Thomas, Torsten; Cavicchioli, Ricardo

2009-04-01

Psychrophilic archaea are abundant and perform critical roles throughout the Earth's expansive cold biosphere. Here we report the first complete genome sequence for a psychrophilic methanogenic archaeon, Methanococcoides burtonii. The genome sequence was manually annotated including the use of a five tiered Evidence Rating system that ranked annotations from Evidence Rating (ER) 1 (gene product experimentally characterized from the parent organism) to ER5 (hypothetical gene product) to provide a rapid means of assessing the certainty of gene function predictions. The genome is characterized by a higher level of aberrant sequence composition (51%) than any other archaeon. In comparison to hyper/thermophilic archaea which are subject to selection of synonymous codon usage, M. burtonii has evolved cold adaptation through a genomic capacity to accommodate highly skewed amino acid content, while retaining codon usage in common with its mesophilic Methanosarcina cousins. Polysaccharide biosynthesis genes comprise at least 3.3% of protein coding genes in the genome, and Cell wall/membrane/envelope biogenesis COG genes are over-represented. Likewise, signal transduction (COG category T) genes are over-represented and M. burtonii has a high 'IQ' (a measure of adaptive potential) compared to many methanogens. Numerous genes in these two over-represented COG categories appear to have been acquired from {var_epsilon}- and {delta}-proteobacteria, as do specific genes involved in central metabolism such as a novel B form of aconitase. Transposases also distinguish M. burtonii from other archaea, and their genomic characteristics indicate they play an important role in evolving the M. burtonii genome. Our study reveals a capacity for this model psychrophile to evolve through genome plasticity (including nucleotide skew, horizontal gene transfer and transposase activity) that enables adaptation to the cold, and to the biological and physical changes that have

Multiplex PCR-based assay for detection of Bordetella pertussis in nasopharyngeal swab specimens.

Science.gov (United States)

Wadowsky, R M; Michaels, R H; Libert, T; Kingsley, L A; Ehrlich, G D

1996-11-01

A multiplex PCR-based assay was developed for the detection of Bordetella pertussis in nasopharyngeal swab specimens. The assay simultaneously amplified two separate DNA targets (153 and 203 bp) within a B. pertussis repetitive element and a 438-bp target within the beta-actin gene of human DNA (PCR amplification control). PCR products were detected by a sensitive and specific liquid hybridization gel retardation assay. A total of 496 paired nasopharyngeal swab specimens were tested by both the PCR-based assay and culture. Although 30 (6%) of the specimens inhibited the amplification of the beta-actin target, in all 29 specimens studied, the inhibition disappeared on repeat testing or was easily overcome with a 1:8 dilution or less of specimen digest. Of the 495 specimen pairs yielding a final evaluable result by the PCR-based assay, 19.0% were positive by the PCR-based assay, whereas 13.9% were positive by culture (P < 0.0001). After resolving the PCR-positive, culture-negative results by testing an additional aliquot from these specimens by the multiplex PCR-based assay, the PCR-based assay had a sensitivity and specificity of 98.9 and 99.7%, respectively, compared with values of 73.4 and 100%, respectively, for culture. In comparison with patients with culture-confirmed pertussis, those with PCR-positive, culture-negative results were older and more likely to have had prolonged cough, immunization with pertussis vaccine, or treatment with erythromycin. This multiplex PCR-based assay is substantially more sensitive than culture and identifies specimens that contain inhibitors of PCR.

DNA Polymerases Drive DNA Sequencing-by-Synthesis Technologies: Both Past and Present

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Cheng-Yao eChen

2014-06-01

Full Text Available Next-generation sequencing (NGS technologies have revolutionized modern biological and biomedical research. The engines responsible for this innovation are DNA polymerases; they catalyze the biochemical reaction for deriving template sequence information. In fact, DNA polymerase has been a cornerstone of DNA sequencing from the very beginning. E. coli DNA polymerase I proteolytic (Klenow fragment was originally utilized in Sanger's dideoxy chain terminating DNA sequencing chemistry. From these humble beginnings followed an explosion of organism-specific, genome sequence information accessible via public database. Family A/B DNA polymerases from mesophilic/thermophilic bacteria/archaea were modified and tested in today's standard capillary electrophoresis (CE and NGS sequencing platforms. These enzymes were selected for their efficient incorporation of bulky dye-terminator and reversible dye-terminator nucleotides respectively. Third generation, real-time single molecule sequencing platform requires slightly different enzyme properties. Enterobacterial phage ⱷ29 DNA polymerase copies long stretches of DNA and possesses a unique capability to efficiently incorporate terminal phosphate-labeled nucleoside polyphosphates. Furthermore, ⱷ29 enzyme has also been utilized in emerging DNA sequencing technologies including nanopore-, and protein-transistor-based sequencing. DNA polymerase is, and will continue to be, a crucial component of sequencing technologies.

Verification of Frequency in Species of Nontuberculous Mycobacteria in Kermanshah Drinking Water Supplies Using the PCR-Sequencing Method.

Science.gov (United States)

Mohajeri, Parviz; Yazdani, Laya; Shahraki, Abdolrazagh Hashemi; Alvandi, Amirhoshang; Atashi, Sara; Farahani, Abbas; Almasi, Ali; Rezaei, Mansour

2017-04-01

Nontuberculous mycobacteria are habitants of environment, especially in aquatic systems. Some of them cause problems in immunodeficient patients. Over the last decade, 16S rRNA gene sequencing was established in 45 novel species of nontuberculous mycobacteria. Experiences revealed that this method underestimates the diversity, but does not distinguish between some of mycobacterium subsp. To recognize emerging rapidly growing mycobacteria and identify their subsp, rpoB gene sequencing has been developed. To better understand the transmission of nontuberculous mycobacterial species from drinking water and preventing the spread of illness with these bacteria, the aim of this study was to detect the presence of bacteria by PCR-sequencing techniques. Drinking water samples were collected from different areas of Kermanshah city in west of IRAN. After decontamination with cetylpyridinium chloride, samples were filtered with 0.45-micron filters, the filter transferred directly on growth medium waiting to appear in colonies, then DNA extraction and PCR were performed, and products were sent to sequencing. We found 35/110 (32%) nontuberculous mycobacterial species in drinking water samples, isolates included Mycobacterium goodii, Mycobacterium aurum, and Mycobacterium gastri with the most abundance (11.5%), followed by Mycobacterium smegmatis, Mycobacterium porcinum, Mycobacterium peregrinum, Mycobacterium mucogenicum, and Mycobacterium chelonae (8%). In this study, we recognized the evidence of contamination by nontuberculous mycobacteria in corroded water pipes. As a result of the high prevalence of these bacteria in drinking water in Kermanshah, this is important evidence of transmission through drinking water. This finding can also help public health policy makers control these isolates in drinking water supplies in Kermanshah.

Capillary-based integrated digital PCR in picoliter droplets.

Science.gov (United States)

Chen, Jinyu; Luo, Zhaofeng; Li, Lin; He, Jinlong; Li, Luoquan; Zhu, Jianwei; Wu, Ping; He, Liqun

2018-01-30

The droplet digital polymerase chain reaction (ddPCR) is becoming more and more popular in diagnostic applications in academia and industry. In commercially available ddPCR systems, after they have been made by a generator, the droplets have to be transferred manually to modules for amplification and detection. In practice, some of the droplets (∼10%) are lost during manual transfer, leading to underestimation of the targets. In addition, the droplets are also at risk of cross-contamination during transfer. By contrast, in labs, some chip-based ddPCRs have been demonstrated where droplets always run in channels. However, the droplets easily coalesce to large ones in chips due to wall wetting as well as thermal oscillation. The loss of droplets becomes serious when such ddPCRs are applied to absolutely quantify rare mutations, such as in early diagnostics in clinical research or when measuring biological diversity at the cell level. Here, we propose a capillary-based integrated ddPCR system that is used for the first time to realize absolute quantification in this way. In this system, a HPLC T-junction is used to generate droplets and a long HPLC capillary connects the generator with both a capillary-based thermocycler and a capillary-based cytometer. The performance of the system is validated by absolute quantification of a gene specific to lung cancer (LunX). The results show that this system has very good linearity (0.9988) at concentrations ranging from NTC to 2.4 × 10 -4 copies per μL. As compared to qPCR, the all-in-one scheme is superior both in terms of the detection limit and the smaller fold changes measurement. The system of ddPCR might provide a powerful approach for clinical or academic applications where rare events are mostly considered.

Targeted next-generation sequencing analysis identifies novel mutations in families with severe familial exudative vitreoretinopathy

Science.gov (United States)

Huang, Xiao-Yan; Zhuang, Hong; Wu, Ji-Hong; Li, Jian-Kang; Hu, Fang-Yuan; Zheng, Yu; Tellier, Laurent Christian Asker M.; Zhang, Sheng-Hai; Gao, Feng-Juan; Zhang, Jian-Guo

2017-01-01

Purpose Familial exudative vitreoretinopathy (FEVR) is a genetically and clinically heterogeneous disease, characterized by failure of vascular development of the peripheral retina. The symptoms of FEVR vary widely among patients in the same family, and even between the two eyes of a given patient. This study was designed to identify the genetic defect in a patient cohort of ten Chinese families with a definitive diagnosis of FEVR. Methods To identify the causative gene, next-generation sequencing (NGS)-based target capture sequencing was performed. Segregation analysis of the candidate variant was performed in additional family members by using Sanger sequencing and quantitative real-time PCR (QPCR). Results Of the cohort of ten FEVR families, six pathogenic variants were identified, including four novel and two known heterozygous mutations. Of the variants identified, four were missense variants, and two were novel heterozygous deletion mutations [LRP5, c.4053 DelC (p.Ile1351IlefsX88); TSPAN12, EX8Del]. The two novel heterozygous deletion mutations were not observed in the control subjects and could give rise to a relatively severe FEVR phenotype, which could be explained by the protein function prediction. Conclusions We identified two novel heterozygous deletion mutations [LRP5, c.4053 DelC (p.Ile1351IlefsX88); TSPAN12, EX8Del] using targeted NGS as a causative mutation for FEVR. These genetic deletion variations exhibit a severe form of FEVR, with tractional retinal detachments compared with other known point mutations. The data further enrich the mutation spectrum of FEVR and enhance our understanding of genotype–phenotype correlations to provide useful information for disease diagnosis, prognosis, and effective genetic counseling. PMID:28867931

Improved Efficiency and Reliability of NGS Amplicon Sequencing Data Analysis for Genetic Diagnostic Procedures Using AGSA Software

Directory of Open Access Journals (Sweden)

Axel Poulet

2016-01-01

Full Text Available Screening for BRCA mutations in women with familial risk of breast or ovarian cancer is an ideal situation for high-throughput sequencing, providing large amounts of low cost data. However, 454, Roche, and Ion Torrent, Thermo Fisher, technologies produce homopolymer-associated indel errors, complicating their use in routine diagnostics. We developed software, named AGSA, which helps to detect false positive mutations in homopolymeric sequences. Seventy-two familial breast cancer cases were analysed in parallel by amplicon 454 pyrosequencing and Sanger dideoxy sequencing for genetic variations of the BRCA genes. All 565 variants detected by dideoxy sequencing were also detected by pyrosequencing. Furthermore, pyrosequencing detected 42 variants that were missed with Sanger technique. Six amplicons contained homopolymer tracts in the coding sequence that were systematically misread by the software supplied by Roche. Read data plotted as histograms by AGSA software aided the analysis considerably and allowed validation of the majority of homopolymers. As an optimisation, additional 250 patients were analysed using microfluidic amplification of regions of interest (Access Array Fluidigm of the BRCA genes, followed by 454 sequencing and AGSA analysis. AGSA complements a complete line of high-throughput diagnostic sequence analysis, reducing time and costs while increasing reliability, notably for homopolymer tracts.

Memory Efficient Sequence Analysis Using Compressed Data Structures (Metagenomics Informatics Challenges Workshop: 10K Genomes at a Time)

Energy Technology Data Exchange (ETDEWEB)

Simpson, Jared

2011-10-13

Wellcome Trust Sanger Institute's Jared Simpson on Memory efficient sequence analysis using compressed data structures at the Metagenomics Informatics Challenges Workshop held at the DOE JGI on October 12-13, 2011.

Novel N4 Bacteriophages Prevail in the Cold Biosphere.

Science.gov (United States)

Zhan, Yuanchao; Buchan, Alison; Chen, Feng

2015-08-01

Coliphage N4 is a lytic bacteriophage discovered nearly half a century ago, and it was considered to be a "genetic orphan" until very recently, when several additional N4-like phages were discovered to infect nonenteric bacterial hosts. Interest in this genus of phages is stimulated by their unique genetic features and propagation strategies. To better understand the ecology of N4-like phages, we investigated the diversity and geographic patterns of N4-like phages by examining 56 Chesapeake Bay viral communities, using a PCR-clone library approach targeting a diagnostic N4-like DNA polymerase gene. Many new lineages of N4-like phages were found in the bay, and their genotypes shift from the lower to the upper bay. Interestingly, signature sequences of N4-like phages were recovered only from winter month samples, when water temperatures were below 4°C. An analysis of existing metagenomic libraries from various aquatic environments supports the hypothesis that N4-like phages are most prolific in colder waters. In particular, a high number of N4-like phages were detected in Organic Lake, Antarctica, a cold and hypersaline system. The prevalence of N4-like phages in the cold biosphere suggests these viruses possess yet-to-be-determined mechanisms that facilitate lytic infections under cold conditions. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Toward an international standard for PCR-based detection of Escherichia coli O157 - Part 1. Assay development and multi-center validation

DEFF Research Database (Denmark)

Abdulmawjood, A.; Bulte, M.; Cook, N.

2003-01-01

As part of a major European research project, a diagnostic PCR assay, including an internal amplification control, was developed and validated in a collaborative trial for the detection of Escherichia coli O157. The assay is based on amplification of sequences of the rJbE O157 gene. The collabora...

Species Identification of Fox-, Mink-, Dog-, and Rabbit-Derived Ingredients by Multiplex PCR and Real-Time PCR Assay.

Science.gov (United States)

Wu, Qingqing; Xiang, Shengnan; Wang, Wenjun; Zhao, Jinyan; Xia, Jinhua; Zhen, Yueran; Liu, Bang

2018-05-01

Various detection methods have been developed to date for identification of animal species. New techniques based on PCR approach have raised the hope of developing better identification methods, which can overcome the limitations of the existing methods. PCR-based methods used the mitochondrial DNA (mtDNA) as well as nuclear DNA sequences. In this study, by targeting nuclear DNA, multiplex PCR and real-time PCR methods were developed to assist with qualitative and quantitative analysis. The multiplex PCR was found to simultaneously and effectively distinguish four species (fox, dog, mink, and rabbit) ingredients by the different sizes of electrophoretic bands: 480, 317, 220, and 209 bp. Real-time fluorescent PCR's amplification profiles and standard curves showed good quantitative measurement responses and linearity, as indicated by good repeatability and coefficient of determination R 2  > 0.99. The quantitative results of quaternary DNA mixtures including mink, fox, dog, and rabbit DNA are in line with our expectations: R.D. (relative deviation) varied between 1.98 and 12.23% and R.S.D. (relative standard deviation) varied between 3.06 and 11.51%, both of which are well within the acceptance criterion of ≤ 25%. Combining the two methods is suitable for the rapid identification and accurate quantification of fox-, dog-, mink-, and rabbit-derived ingredients in the animal products.

Molecular analysis of dolphin morbillivirus: A new sensitive detection method based on nested RT-PCR.

Science.gov (United States)

Centelleghe, Cinzia; Beffagna, Giorgia; Zanetti, Rossella; Zappulli, Valentina; Di Guardo, Giovanni; Mazzariol, Sandro

2016-09-01

Cetacean Morbillivirus (CeMV) has been identified as the most pathogenic virus for cetaceans. Over the past three decades, this RNA virus has caused several outbreaks of lethal disease in odontocetes and mysticetes worldwide. Isolation and identification of CeMV RNA is very challenging in whales because of the poor preservation status frequently shown by tissues from stranded animals. Nested reverse transcription polymerase chain reaction (nested RT-PCR) is used instead of conventional RT-PCR when it is necessary to increase the sensitivity and the specificity of the reaction. This study describes a new nested RT-PCR technique useful to amplify small amounts of the cDNA copy of Cetacean morbillivirus (CeMV) when it is present in scant quantity in whales' biological specimens. This technique was used to analyze different tissues (lung, brain, spleen and other lymphoid tissues) from one under human care seal and seven cetaceans stranded along the Italian coastline between October 2011 and September 2015. A well-characterized, 200 base pair (bp) fragment of the dolphin Morbillivirus (DMV) haemagglutinin (H) gene, obtained by nested RT-PCR, was sequenced and used to confirm DMV positivity in all the eight marine mammals under study. In conclusion, this nested RT-PCR protocol can represent a sensitive detection method to identify CeMV-positive, poorly preserved tissue samples. Furthermore, this is also a rather inexpensive molecular technique, relatively easy to apply. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular discrimination of Echinococcus granulosus and Echinococcus multilocularis by sequencing and a new PCR-RFLP method with the potential use for other Echinococcus species.

Science.gov (United States)

Şakalar, Çağrı; Kuk, Salih; Erensoy, Ahmet; Dağli, Adile Ferda; Özercan, İbrahim Hanifi; Çetınkaya, Ülfet; Yazar, Süleyman

2014-01-01

To develop a novel polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) protocol using a new genomic marker sequence and a novel set of restriction enzymes in order to detect and discriminate 2 Echinococcus species, E. granulosus and E. multilocularis, found in formalin-fixed paraffin-embedded (FFPE) human tissues. DNA was isolated from 11 FFPE human tissue samples positive for cystic echinococcosis or alveolar echinococcosis. A mitochondrial genomic marker region was amplified and sequenced using a novel primer pair and a new PCR-RFLP protocol was developed for the detection and discrimination of E. granulosus and E. multilocularis using a set of restriction enzymes including AccI, MboI, MboII, and TsoI. The selected marker region was amplified using DNA isolated from FFPE human tissue samples positive for cystic echinococcosis or alveolar echinococcosis and the discrimination of E. granulosus and E. multilocularis was accomplished by use of the novel PCR-RFLP method. In this PCR-RFLP protocol, use of any single restriction enzyme is enough for the discrimination of E. granulosus and E. multilocularis. The PCR-RFLP protocol can be potentially used for the discrimination of 5 other Echinococcus species: E. oligarthus, E. shiquicus, E. ortleppi, E. canadensis, and E. vogeli.

High-throughput sequencing and copy number variation detection using formalin fixed embedded tissue in metastatic gastric cancer.

Directory of Open Access Journals (Sweden)

Seokhwi Kim

Full Text Available In the era of targeted therapy, mutation profiling of cancer is a crucial aspect of making therapeutic decisions. To characterize cancer at a molecular level, the use of formalin-fixed paraffin-embedded tissue is important. We tested the Ion AmpliSeq Cancer Hotspot Panel v2 and nCounter Copy Number Variation Assay in 89 formalin-fixed paraffin-embedded gastric cancer samples to determine whether they are applicable in archival clinical samples for personalized targeted therapies. We validated the results with Sanger sequencing, real-time quantitative PCR, fluorescence in situ hybridization and immunohistochemistry. Frequently detected somatic mutations included TP53 (28.17%, APC (10.1%, PIK3CA (5.6%, KRAS (4.5%, SMO (3.4%, STK11 (3.4%, CDKN2A (3.4% and SMAD4 (3.4%. Amplifications of HER2, CCNE1, MYC, KRAS and EGFR genes were observed in 8 (8.9%, 4 (4.5%, 2 (2.2%, 1 (1.1% and 1 (1.1% cases, respectively. In the cases with amplification, fluorescence in situ hybridization for HER2 verified gene amplification and immunohistochemistry for HER2, EGFR and CCNE1 verified the overexpression of proteins in tumor cells. In conclusion, we successfully performed semiconductor-based sequencing and nCounter copy number variation analyses in formalin-fixed paraffin-embedded gastric cancer samples. High-throughput screening in archival clinical samples enables faster, more accurate and cost-effective detection of hotspot mutations or amplification in genes.

Exome sequencing identifies mutations in ABCD1 and DACH2 in two brothers with a distinct phenotype

OpenAIRE

Zhang, Yanliang; Liu, Yanhui; Li, Ya; Duan, Yong; Zhang, Keyun; Wang, Junwang; Dai, Yong

2014-01-01

Background We report on two brothers with a distinct syndromic phenotype and explore the potential pathogenic cause. Methods Cytogenetic tests and exome sequencing were performed on the two brothers and their parents. Variants detected by exome sequencing were validated by Sanger sequencing. Results The main phenotype of the two brothers included congenital language disorder, growth retardation, intellectual disability, difficulty in standing and walking, and urinary and fecal incontinence. T...

Detection of Fusarium verticillioides by PCR-ELISA based on FUM21 gene.

Science.gov (United States)

Omori, Aline Myuki; Ono, Elisabete Yurie Sataque; Bordini, Jaqueline Gozzi; Hirozawa, Melissa Tiemi; Fungaro, Maria Helena Pelegrinelli; Ono, Mario Augusto

2018-08-01

Fusarium verticillioides is a primary corn pathogen and fumonisin producer which is associated with toxic effects in humans and animals. The traditional methods for detection of fungal contamination based on morphological characteristics are time-consuming and show low sensitivity and specificity. Therefore, the objective of this study was to develop a PCR-ELISA based on the FUM21 gene for F. verticillioides detection. The DNA of the F. verticillioides, Fusarium sp., Aspergillus sp. and Penicillium sp. isolates was analyzed by conventional PCR and PCR-ELISA to determine the specificity. The PCR-ELISA was specific to F. verticillioides isolates, showed a 2.5 pg detection limit and was 100-fold more sensitive than conventional PCR. In corn samples inoculated with F. verticillioides conidia, the detection limit of the PCR-ELISA was 1 × 10 4 conidia/g and was also 100-fold more sensitive than conventional PCR. Naturally contaminated corn samples were analyzed by PCR-ELISA based on the FUM21 gene and PCR-ELISA absorbance values correlated positively (p PCR-ELISA developed in this study can be useful for F. verticillioides detection in corn samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Targeted 'Next-Generation' sequencing in anophthalmia and microphthalmia patients confirms SOX2, OTX2 and FOXE3 mutations

Directory of Open Access Journals (Sweden)

Lopez Jimenez Nelson

2011-12-01

Full Text Available Abstract Background Anophthalmia/microphthalmia (A/M is caused by mutations in several different transcription factors, but mutations in each causative gene are relatively rare, emphasizing the need for a testing approach that screens multiple genes simultaneously. We used next-generation sequencing to screen 15 A/M patients for mutations in 9 pathogenic genes to evaluate this technology for screening in A/M. Methods We used a pooled sequencing design, together with custom single nucleotide polymorphism (SNP calling software. We verified predicted sequence alterations using Sanger sequencing. Results We verified three mutations - c.542delC in SOX2, resulting in p.Pro181Argfs*22, p.Glu105X in OTX2 and p.Cys240X in FOXE3. We found several novel sequence alterations and SNPs that were likely to be non-pathogenic - p.Glu42Lys in CRYBA4, p.Val201Met in FOXE3 and p.Asp291Asn in VSX2. Our analysis methodology gave one false positive result comprising a mutation in PAX6 (c.1268A > T, predicting p.X423LeuextX*15 that was not verified by Sanger sequencing. We also failed to detect one 20 base pair (bp deletion and one 3 bp duplication in SOX2. Conclusions Our results demonstrated the power of next-generation sequencing with pooled sample groups for the rapid screening of candidate genes for A/M as we were correctly able to identify disease-causing mutations. However, next-generation sequencing was less useful for small, intragenic deletions and duplications. We did not find mutations in 10/15 patients and conclude that there is a need for further gene discovery in A/M.

Transgene detection by digital droplet PCR.

Directory of Open Access Journals (Sweden)

Dirk A Moser