scholarly journals nPhase: an accurate and contiguous phasing method for polyploids

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Omar Abou Saada ◽  
Andreas Tsouris ◽  
Chris Eberlein ◽  
Anne Friedrich ◽  
Joseph Schacherer
Keyword(s):  
Genome Sequencing ◽  
Population Genomics ◽  
Short Reads ◽  
Link Type ◽  
Long Reads

AbstractWhile genome sequencing and assembly are now routine, we do not have a full, precise picture of polyploid genomes. No existing polyploid phasing method provides accurate and contiguous haplotype predictions. We developed nPhase, a ploidy agnostic tool that leverages long reads and accurate short reads to solve alignment-based phasing for samples of unspecified ploidy (https://github.com/OmarOakheart/nPhase). nPhase is validated by tests on simulated and real polyploids. nPhase obtains on average over 95% accuracy and a contiguous 1.25 haplotigs per haplotype to cover more than 90% of each chromosome (heterozygosity rate ≥ 0.5%). nPhase allows population genomics and hybrid studies of polyploids.

scholarly journals nPhase: An accurate and contiguous phasing method for polyploids

2020 ◽  
Author(s):  
Omar Abou Saada ◽  
Andreas Tsouris ◽  
Anne Friedrich ◽  
Joseph Schacherer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genome Sequencing ◽  
Population Genomics ◽  
Genomic Data ◽  
Reference Alignment ◽  
Sequencing Data ◽  
Model Species ◽  
Short Reads ◽  
Link Type ◽  
Long Reads

AbstractWhile genome sequencing and assembly are now routine, we still do not have a full and precise picture of polyploid genomes. Phasing these genomes, i.e. deducing haplotypes from genomic data, remains a challenge. Despite numerous attempts, no existing polyploid phasing method provides accurate and contiguous haplotype predictions. To address this need, we developed nPhase, a ploidy agnostic pipeline and algorithm that leverage the accuracy of short reads and the length of long reads to solve reference alignment-based phasing for samples of unspecified ploidy (https://github.com/nPhasePipeline/nPhase). nPhase was validated on virtually constructed polyploid genomes of the model species Saccharomyces cerevisiae, generated by combining sequencing data of homozygous isolates. nPhase obtained on average >95% accuracy and a contiguous 1.25 haplotigs per haplotype to cover >90% of each chromosome (heterozygosity rate ≥0.5%). This new phasing method opens the door to explore polyploid genomes through applications such as population genomics and hybrid studies.

scholarly journals Long read metagenomics, the next step?

2020 ◽  
Author(s):  
Jose M. Haro-Moreno ◽  
Mario López-Pérez ◽  
Francisco Rodríguez-Valera
Keyword(s):  
Error Rate ◽  
Population Genomics ◽  
Short Read ◽  
Short Reads ◽  
Third Generation Sequencing ◽  
Long Reads ◽  
Oxford Nanopore ◽  
Flexible Genome ◽  
Long Read ◽  
Generation Sequencing

ABSTRACTBackgroundThird-generation sequencing has penetrated little in metagenomics due to the high error rate and dependence for assembly on short-read designed bioinformatics. However, 2nd generation sequencing metagenomics (mostly Illumina) suffers from limitations, particularly in allowing assembly of microbes with high microdiversity or retrieving the flexible (adaptive) compartment of prokaryotic genomes.ResultsHere we have used different 3rd generation techniques to study the metagenome of a well-known marine sample from the mixed epipelagic water column of the winter Mediterranean. We have compared Oxford Nanopore and PacBio last generation technologies with the classical approach using Illumina short reads followed by assembly. PacBio Sequel II CCS appears particularly suitable for cellular metagenomics due to its low error rate. Long reads allow efficient direct retrieval of complete genes (473M/Tb) and operons before assembly, facilitating annotation and compensates the limitations of short reads or short-read assemblies. MetaSPAdes was the most appropriate assembly program when used in combination with short reads. The assemblies of the long reads allow also the reconstruction of much more complete metagenome-assembled genomes, even from microbes with high microdiversity. The flexible genome of reconstructed MAGs is much more complete and allows rescuing more adaptive genes.ConclusionsFor most applications of metagenomics, from community structure analysis to ecosystem functioning, long-reads should be applied whenever possible. Particularly for in-silico screening of biotechnologically useful genes, or population genomics, long-read metagenomics appears presently as a very fruitful approach and can be used from raw reads, before a computing-demanding (and potentially artefactual) assembly step.

scholarly journals Draft genome sequencing of the sugarcane hybrid SP80-3280

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 861 ◽  
Author(s):  
Diego Mauricio Riaño-Pachón ◽  
Lucia Mattiello
Keyword(s):  
Genome Sequencing ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Commercial Cultivar ◽  
Link Type ◽  
Long Reads ◽  
Genomic Analyses ◽  
Draft Genome Sequencing

Sugarcane commercial cultivar SP80-3280 has been used as a model for genomic analyses in Brazil. Here we present a draft genome sequence employing Illumina TruSeq Synthetic Long reads. The dataset is available from NCBI BioProject with accession PRJNA272769.

scholarly journals Whole-genome sequencing with long reads reveals complex structure and origin of structural variation in human genetic variations and somatic mutations in cancer

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Akihiro Fujimoto ◽  
Jing Hao Wong ◽  
Yukiko Yoshii ◽  
Shintaro Akiyama ◽  
Azusa Tanaka ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Somatic Mutations ◽  
Complex Structure ◽  
Whole Genome ◽  
Structural Variations ◽  
Link Type ◽  
Long Reads ◽  
Liver Cancers ◽  
Long Read

AbstractBackgroundIdentification of germline variation and somatic mutations is a major issue in human genetics. However, due to the limitations of DNA sequencing technologies and computational algorithms, our understanding of genetic variation and somatic mutations is far from complete.MethodsIn the present study, we performed whole-genome sequencing using long-read sequencing technology (Oxford Nanopore) for 11 Japanese liver cancers and matched normal samples which were previously sequenced for the International Cancer Genome Consortium (ICGC). We constructed an analysis pipeline for the long-read data and identified germline and somatic structural variations (SVs).ResultsIn polymorphic germline SVs, our analysis identified 8004 insertions, 6389 deletions, 27 inversions, and 32 intra-chromosomal translocations. By comparing to the chimpanzee genome, we correctly inferred events that caused insertions and deletions and found that most insertions were caused by transposons andAluis the most predominant source, while other types of insertions, such as tandem duplications and processed pseudogenes, are rare. We inferred mechanisms of deletion generations and found that most non-allelic homolog recombination (NAHR) events were caused by recombination errors in SINEs. Analysis of somatic mutations in liver cancers showed that long reads could detect larger numbers of SVs than a previous short-read study and that mechanisms of cancer SV generation were different from that of germline deletions.ConclusionsOur analysis provides a comprehensive catalog of polymorphic and somatic SVs, as well as their possible causes. Our software are available athttps://github.com/afujimoto/CAMPHORandhttps://github.com/afujimoto/CAMPHORsomatic.

scholarly journals Draft genome sequencing of the sugarcane hybrid SP80-3280

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 861 ◽  
Author(s):  
Diego Mauricio Riaño-Pachón ◽  
Lucia Mattiello
Keyword(s):  
Genome Sequencing ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Commercial Cultivar ◽  
Link Type ◽  
Long Reads ◽  
Genomic Analyses ◽  
Draft Genome Sequencing

Sugarcane commercial cultivar SP80-3280 has been used as a model for genomic analyses in Brazil. Here we present a draft genome sequence employing Illumina TruSeq Synthetic Long reads. The dataset is available from NCBI BioProject with accession PRJNA272769.

scholarly journals Evaluating the accuracy of Listeria monocytogenes assemblies from quasimetagenomic samples using long and short reads

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Seth Commichaux ◽  
Kiran Javkar ◽  
Padmini Ramachandran ◽  
Niranjan Nagarajan ◽  
Denis Bertrand ◽  
...  
Keyword(s):  
Public Health ◽  
Public Health Response ◽  
High Quality ◽  
Short Read ◽  
Short Reads ◽  
The Core ◽  
Long Reads ◽  
Health Response ◽  
Long Read ◽  
Core Genes

Abstract Background Whole genome sequencing of cultured pathogens is the state of the art public health response for the bioinformatic source tracking of illness outbreaks. Quasimetagenomics can substantially reduce the amount of culturing needed before a high quality genome can be recovered. Highly accurate short read data is analyzed for single nucleotide polymorphisms and multi-locus sequence types to differentiate strains but cannot span many genomic repeats, resulting in highly fragmented assemblies. Long reads can span repeats, resulting in much more contiguous assemblies, but have lower accuracy than short reads. Results We evaluated the accuracy of Listeria monocytogenes assemblies from enrichments (quasimetagenomes) of naturally-contaminated ice cream using long read (Oxford Nanopore) and short read (Illumina) sequencing data. Accuracy of ten assembly approaches, over a range of sequencing depths, was evaluated by comparing sequence similarity of genes in assemblies to a complete reference genome. Long read assemblies reconstructed a circularized genome as well as a 71 kbp plasmid after 24 h of enrichment; however, high error rates prevented high fidelity gene assembly, even at 150X depth of coverage. Short read assemblies accurately reconstructed the core genes after 28 h of enrichment but produced highly fragmented genomes. Hybrid approaches demonstrated promising results but had biases based upon the initial assembly strategy. Short read assemblies scaffolded with long reads accurately assembled the core genes after just 24 h of enrichment, but were highly fragmented. Long read assemblies polished with short reads reconstructed a circularized genome and plasmid and assembled all the genes after 24 h enrichment but with less fidelity for the core genes than the short read assemblies. Conclusion The integration of long and short read sequencing of quasimetagenomes expedited the reconstruction of a high quality pathogen genome compared to either platform alone. A new and more complete level of information about genome structure, gene order and mobile elements can be added to the public health response by incorporating long read analyses with the standard short read WGS outbreak response.

scholarly journals Short and long-read genome sequencing methodologies for somatic variant detection; genomic analysis of a patient with diffuse large B-cell lymphoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hannah E. Roberts ◽  
Maria Lopopolo ◽  
Alistair T. Pagnamenta ◽  
Eshita Sharma ◽  
Duncan Parkes ◽  
...  
Keyword(s):  
B Cell ◽  
Genome Sequencing ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Somatic Variation ◽  
Single Nucleotide Variants ◽  
Germline Variants ◽  
Specificity And Sensitivity ◽  
Long Reads ◽  
Long Read

AbstractRecent advances in throughput and accuracy mean that the Oxford Nanopore Technologies PromethION platform is a now a viable solution for genome sequencing. Much of the validation of bioinformatic tools for this long-read data has focussed on calling germline variants (including structural variants). Somatic variants are outnumbered many-fold by germline variants and their detection is further complicated by the effects of tumour purity/subclonality. Here, we evaluate the extent to which Nanopore sequencing enables detection and analysis of somatic variation. We do this through sequencing tumour and germline genomes for a patient with diffuse B-cell lymphoma and comparing results with 150 bp short-read sequencing of the same samples. Calling germline single nucleotide variants (SNVs) from specific chromosomes of the long-read data achieved good specificity and sensitivity. However, results of somatic SNV calling highlight the need for the development of specialised joint calling algorithms. We find the comparative genome-wide performance of different tools varies significantly between structural variant types, and suggest long reads are especially advantageous for calling large somatic deletions and duplications. Finally, we highlight the utility of long reads for phasing clinically relevant variants, confirming that a somatic 1.6 Mb deletion and a p.(Arg249Met) mutation involving TP53 are oriented in trans.

scholarly journals PaperBLAST: Text-mining papers for information about homologs

2017 ◽  
Author(s):  
Morgan N. Price ◽  
Adam P. Arkin
Keyword(s):  
Text Mining ◽  
Genome Sequencing ◽  
Full Text ◽  
Large Scale ◽  
Scientific Literature ◽  
Protein Sequences ◽  
Protein Coding ◽  
Link Protein ◽  
Protein Coding Genes ◽  
Link Type

AbstractLarge-scale genome sequencing has identified millions of protein-coding genes whose function is unknown. Many of these proteins are similar to characterized proteins from other organisms, but much of this information is missing from annotation databases and is hidden in the scientific literature. To make this information accessible, PaperBLAST uses EuropePMC to search the full text of scientific articles for references to genes. PaperBLAST also takes advantage of curated resources that link protein sequences to scientific articles (Swiss-Prot, GeneRIF, and EcoCyc). PaperBLAST’s database includes over 700,000 scientific articles that mention over 400,000 different proteins. Given a protein of interest, PaperBLAST quickly finds similar proteins that are discussed in the literature and presents snippets of text from relevant articles or from the curators. PaperBLAST is available at http://papers.genomics.lbl.gov/.

scholarly journals Complete Genome Sequences of 12 Quinolone-Resistant Escherichia coli Strains Containing qnrS1 Based on Hybrid Assemblies

2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Håkon Kaspersen ◽  
Thomas H. A. Haverkamp ◽  
Hanna Karin Ilag ◽  
Øivind Øines ◽  
Camilla Sekse ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Complete Genome ◽  
Flow Cell ◽  
Hybrid Assembly ◽  
Genome Sequences ◽  
Content Type ◽  
Short Reads ◽  
Long Reads ◽  
Long Read ◽  
Hybrid Assemblies

ABSTRACT In total, 12 quinolone-resistant Escherichia coli (QREC) strains containing qnrS1 were submitted to long-read sequencing using a FLO-MIN106 flow cell on a MinION device. The long reads were assembled with short reads (Illumina) and analyzed using the MOB-suite pipeline. Six of these QREC genome sequences were closed after hybrid assembly.

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