scholarly journals Comprehensive comparison of Pacific Biosciences and Oxford Nanopore Technologies and their applications to transcriptome analysis

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 100 ◽  
Author(s):  
Jason L Weirather ◽  
Mariateresa de Cesare ◽  
Yunhao Wang ◽  
Paolo Piazza ◽  
Vittorio Sebastiano ◽  
...  

Background: Given the demonstrated utility of Third Generation Sequencing [Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT)] long reads in many studies, a comprehensive analysis and comparison of their data quality and applications is in high demand. Methods: Based on the transcriptome sequencing data from human embryonic stem cells, we analyzed multiple data features of PacBio and ONT, including error pattern, length, mappability and technical improvements over previous platforms. We also evaluated their application to transcriptome analyses, such as isoform identification and quantification and characterization of transcriptome complexity, by comparing the performance of PacBio, ONT and their corresponding Hybrid-Seq strategies (PacBio+Illumina and ONT+Illumina). Results: PacBio shows overall better data quality, while ONT provides a higher yield. As with data quality, PacBio performs marginally better than ONT in most aspects for both long reads only and Hybrid-Seq strategies in transcriptome analysis. In addition, Hybrid-Seq shows superior performance over long reads only in most transcriptome analyses. Conclusions: Both PacBio and ONT sequencing are suitable for full-length single-molecule transcriptome analysis. As this first use of ONT reads in a Hybrid-Seq analysis has shown, both PacBio and ONT can benefit from a combined Illumina strategy. The tools and analytical methods developed here provide a resource for future applications and evaluations of these rapidly-changing technologies.

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 100 ◽  
Author(s):  
Jason L Weirather ◽  
Mariateresa de Cesare ◽  
Yunhao Wang ◽  
Paolo Piazza ◽  
Vittorio Sebastiano ◽  
...  

Background: Given the demonstrated utility of Third Generation Sequencing [Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT)] long reads in many studies, a comprehensive analysis and comparison of their data quality and applications is in high demand. Methods: Based on the transcriptome sequencing data from human embryonic stem cells, we analyzed multiple data features of PacBio and ONT, including error pattern, length, mappability and technical improvements over previous platforms. We also evaluated their application to transcriptome analyses, such as isoform identification and quantification and characterization of transcriptome complexity, by comparing the performance of size-selected PacBio, non-size-selected ONT and their corresponding Hybrid-Seq strategies (PacBio+Illumina and ONT+Illumina). Results: PacBio shows overall better data quality, while ONT provides a higher yield. As with data quality, PacBio performs marginally better than ONT in most aspects for both long reads only and Hybrid-Seq strategies in transcriptome analysis. In addition, Hybrid-Seq shows superior performance over long reads only in most transcriptome analyses. Conclusions: Both PacBio and ONT sequencing are suitable for full-length single-molecule transcriptome analysis. As this first use of ONT reads in a Hybrid-Seq analysis has shown, both PacBio and ONT can benefit from a combined Illumina strategy. The tools and analytical methods developed here provide a resource for future applications and evaluations of these rapidly-changing technologies.


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Junwei Luo ◽  
Mengna Lyu ◽  
Ranran Chen ◽  
Xiaohong Zhang ◽  
Huimin Luo ◽  
...  

Abstract Background Scaffolding is an important step in genome assembly that orders and orients the contigs produced by assemblers. However, repetitive regions in contigs usually prevent scaffolding from producing accurate results. How to solve the problem of repetitive regions has received a great deal of attention. In the past few years, long reads sequenced by third-generation sequencing technologies (Pacific Biosciences and Oxford Nanopore) have been demonstrated to be useful for sequencing repetitive regions in genomes. Although some stand-alone scaffolding algorithms based on long reads have been presented, scaffolding still requires a new strategy to take full advantage of the characteristics of long reads. Results Here, we present a new scaffolding algorithm based on long reads and contig classification (SLR). Through the alignment information of long reads and contigs, SLR classifies the contigs into unique contigs and ambiguous contigs for addressing the problem of repetitive regions. Next, SLR uses only unique contigs to produce draft scaffolds. Then, SLR inserts the ambiguous contigs into the draft scaffolds and produces the final scaffolds. We compare SLR to three popular scaffolding tools by using long read datasets sequenced with Pacific Biosciences and Oxford Nanopore technologies. The experimental results show that SLR can produce better results in terms of accuracy and completeness. The open-source code of SLR is available at https://github.com/luojunwei/SLR. Conclusion In this paper, we describes SLR, which is designed to scaffold contigs using long reads. We conclude that SLR can improve the completeness of genome assembly.


2019 ◽  
Author(s):  
Josip Marić ◽  
Ivan Sović ◽  
Krešimir Križanović ◽  
Niranjan Nagarajan ◽  
Mile Šikić

AbstractIn this paper we present Graphmap2, a splice-aware mapper built on our previously developed DNA mapper Graphmap. Graphmap2 is tailored for long reads produced by Pacific Biosciences and Oxford Nanopore devices. It uses several newly developed algorithms which enable higher precision and recall of correctly detected transcripts and exon boundaries. We compared its performance with the state-of-the-art tools Minimap2 and Gmap. On both simulated and real datasets Graphmap2 achieves higher mappability and more correctly recognized exons and their ends. In addition we present an analysis of potential of splice aware mappers and long reads for the identification of previously unknown isoforms and even genes. The Graphmap2 tool is publicly available at https://github.com/lbcb-sci/graphmap2.


2020 ◽  
Author(s):  
Stefano M. Marino

ABSTRACTThe investigation of microbial communities through nucleotide sequencing has become an essential asset in environmental science, not only for research oriented activities but also for on-site monitoring; one technology, in particular, holds great promises for its application directly in the field: the Oxford Nanopore Technologies (ONT) MinION sequencer is a portable and affordable device, that produces long reads, with a remarkable sequencing output (in terms of bases/hour). One of the most common approaches in microbiological investigations through sequencing is the analysis of the 16S rRNA gene, known as 16S metabarcoding. Only recently the application of MinION has extended to 16S metabarcoding; to date, a limitation is still represented by the available computational protocols: due to the intrinsic, unique features of the technology ONT long reads cannot be adequately analyzed with tools developed for previous technologies (e.g. for Illumina). In this work a computational pipeline, specifically tailored to the usage of ONT reads in 16S metabarcoding, is developed, tested and discussed. This study is particularly addressed to on site evaluations, for environmental investigations or monitoring, where running time, costs and overall efficient usage of resources are particularly important.


2018 ◽  
Author(s):  
Haig Djambazian ◽  
Anthony Bayega ◽  
Konstantina T. Tsoumani ◽  
Efthimia Sagri ◽  
Maria-Eleni Gregoriou ◽  
...  

AbstractLong-read sequencing has greatly contributed to the generation of high quality assemblies, albeit at a high cost. It is also not always clear how to combine sequencing platforms. We sequenced the genome of the olive fruit fly (Bactrocera oleae), the most important pest in the olive fruits agribusiness industry, using Illumina short-reads, mate-pairs, 10x Genomics linked-reads, Pacific Biosciences (PacBio), and Oxford Nanopore Technologies (ONT). The 10x linked-reads assembly gave the most contiguous assembly with an N50 of 2.16 Mb. Scaffolding the linked-reads assembly using long-reads from ONT gave a more contiguous assembly with scaffold N50 of 4.59 Mb. We also present the most extensive transcriptome datasets of the olive fly derived from different tissues and stages of development. Finally, we used the Chromosome Quotient method to identify Y-chromosome scaffolds and show that the long-reads based assembly generates very highly contiguous Y-chromosome assembly.JR is a member of the MinION Access Program (MAP) and has received free-of-charge flow cells and sequencing kits from Oxford Nanopore Technologies for other projects. JR has had no other financial support from ONT.AB has received re-imbursement for travel costs associated with attending Nanopore Community meeting 2018, a meeting organized my Oxford Nanopore Technologies.


2019 ◽  
Vol 85 (21) ◽  
Author(s):  
Kaire Loit ◽  
Kalev Adamson ◽  
Mohammad Bahram ◽  
Rasmus Puusepp ◽  
Sten Anslan ◽  
...  

ABSTRACT Culture-based molecular identification methods have revolutionized detection of pathogens, yet these methods are slow and may yield inconclusive results from environmental materials. The second-generation sequencing tools have much-improved precision and sensitivity of detection, but these analyses are costly and may take several days to months. Of the third-generation sequencing techniques, the portable MinION device (Oxford Nanopore Technologies) has received much attention because of its small size and possibility of rapid analysis at reasonable cost. Here, we compare the relative performances of two third-generation sequencing instruments, MinION and Sequel (Pacific Biosciences), in identification and diagnostics of fungal and oomycete pathogens from conifer (Pinaceae) needles and potato (Solanum tuberosum) leaves and tubers. We demonstrate that the Sequel instrument is efficient for metabarcoding of complex samples, whereas MinION is not suited for this purpose due to a high error rate and multiple biases. However, we find that MinION can be utilized for rapid and accurate identification of dominant pathogenic organisms and other associated organisms from plant tissues following both amplicon-based and PCR-free metagenomics approaches. Using the metagenomics approach with shortened DNA extraction and incubation times, we performed the entire MinION workflow, from sample preparation through DNA extraction, sequencing, bioinformatics, and interpretation, in 2.5 h. We advocate the use of MinION for rapid diagnostics of pathogens and potentially other organisms, but care needs to be taken to control or account for multiple potential technical biases. IMPORTANCE Microbial pathogens cause enormous losses to agriculture and forestry, but current combined culturing- and molecular identification-based detection methods are too slow for rapid identification and application of countermeasures. Here, we develop new and rapid protocols for Oxford Nanopore MinION-based third-generation diagnostics of plant pathogens that greatly improve the speed of diagnostics. However, due to high error rate and technical biases in MinION, the Pacific BioSciences Sequel platform is more useful for in-depth amplicon-based biodiversity monitoring (metabarcoding) from complex environmental samples.


2018 ◽  
Author(s):  
Kristoffer Sahlin ◽  
Paul Medvedev

AbstractLong-read sequencing of transcripts with PacBio Iso-Seq and Oxford Nanopore Technologies has proven to be central to the study of complex isoform landscapes in many organisms. However, current de novo transcript reconstruction algorithms from long-read data are limited, leaving the potential of these technologies unfulfilled. A common bottleneck is the dearth of scalable and accurate algorithms for clustering long reads according to their gene family of origin. To address this challenge, we develop isONclust, a clustering algorithm that is greedy (in order to scale) and makes use of quality values (in order to handle variable error rates). We test isONclust on three simulated and five biological datasets, across a breadth of organisms, technologies, and read depths. Our results demonstrate that isONclust is a substantial improvement over previous approaches, both in terms of overall accuracy and/or scalability to large datasets. Our tool is available at https://github.com/ksahlin/isONclust.


2019 ◽  
Author(s):  
Beatriz Delgado ◽  
Magdalena Serrano ◽  
Carmen González ◽  
Alex Bach ◽  
Oscar González-Recio

AbstractIn the era of bioinformatics and metagenomics, the study of the ruminal microbiome has gained considerable relevance in the field of animal breeding, since the composition of the rumen microbiota significantly impacts production and the environment. Illumina sequencing is considered the gold standard for the analysis of microbiomes, but it is limited by obtaining only short DNA sequences to analyze. As an alternative, Oxford Nanopore Technologies (ONT) has developed a new sequencing technique based on nanopores that can be carried out in the MinION, a portable device with a low initial cost which long DNA readings can be obtained with. The aim of this study was to compare the performance of both types of sequencing applied to samples of ruminal content using a similar pipeline. The ONT sequencing provided similar results to the Illumina sequencing, although it was able to classify a greater number of readings at the species level, possibly due to the increase in the read size. The results also suggest that, due to the size of the reads, it would be possible to obtain the same amount of information in a smaller number of hours. However, detection of archaeal and eukaryotic species is still difficult to accomplish due to their low abundance in the rumen compared to bacteria, suggesting different pipelines and strategies are needed to obtain a whole representation of the less abundant species in the rumen microbiota.


2021 ◽  
Vol 12 ◽  
Author(s):  
McKenna Hicks ◽  
Thuy-Khanh Tran-Dao ◽  
Logan Mulroney ◽  
David L. Bernick

The Limnospira genus is a recently established clade that is economically important due to its worldwide use in biotechnology and agriculture. This genus includes organisms that were reclassified from Arthrospira, which are commercially marketed as “Spirulina.” Limnospira are photoautotrophic organisms that are widely used for research in nutrition, medicine, bioremediation, and biomanufacturing. Despite its widespread use, there is no closed genome for the Limnospira genus, and no reference genome for the type strain, Limnospira fusiformis. In this work, the L. fusiformis genome was sequenced using Oxford Nanopore Technologies MinION and assembled using only ultra-long reads (>35 kb). This assembly was polished with Illumina MiSeq reads sourced from an axenic L. fusiformis culture; axenicity was verified via microscopy and rDNA analysis. Ultra-long read sequencing resulted in a 6.42 Mb closed genome assembled as a single contig with no plasmid. Phylogenetic analysis placed L. fusiformis in the Limnospira clade; some Arthrospira were also placed in this clade, suggesting a misclassification of these strains. This work provides a fully closed and accurate reference genome for the economically important type strain, L. fusiformis. We also present a rapid axenicity method to isolate L. fusiformis. These contributions enable future biotechnological development of L. fusiformis by way of genetic engineering.


2017 ◽  
Author(s):  
Pierre Morisse ◽  
Thierry Lecroq ◽  
Arnaud Lefebvre

AbstractMotivationThe recent rise of long read sequencing technologies such as Pacific Biosciences and Oxford Nanopore allows to solve assembly problems for larger and more complex genomes than what allowed short reads technologies. However, these long reads are very noisy, reaching an error rate of around 10 to 15% for Pacific Biosciences, and up to 30% for Oxford Nanopore. The error correction problem has been tackled by either self-correcting the long reads, or using complementary short reads in a hybrid approach, but most methods only focus on Pacific Biosciences data, and do not apply to Oxford Nanopore reads. Moreover, even though recent chemistries from Oxford Nanopore promise to lower the error rate below 15%, it is still higher in practice, and correcting such noisy long reads remains an issue.ResultsWe present HG-CoLoR, a hybrid error correction method that focuses on a seed-and-extend approach based on the alignment of the short reads to the long reads, followed by the traversal of a variable-order de Bruijn graph, built from the short reads. Our experiments show that HG-CoLoR manages to efficiently correct Oxford Nanopore long reads that display an error rate as high as 44%. When compared to other state-of-the-art long read error correction methods able to deal with Oxford Nanopore data, our experiments also show that HG-CoLoR provides the best trade-off between runtime and quality of the results, and is the only method able to efficiently scale to eukaryotic genomes.Availability and implementationHG-CoLoR is implemented is C++, supported on Linux platforms and freely available at https://github.com/morispi/HG-CoLoRContact: [email protected] informationSupplementary data are available at Bioinformatics online.


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