Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Determining exon connectivity in complex mRNAs by nanopore sequencing.

ABSTRACT: Short-read high-throughput RNA sequencing, though powerful, is limited in its ability to directly measure exon connectivity in mRNAs that contain multiple alternative exons located farther apart than the maximum read length. Here, we use the Oxford Nanopore MinION sequencer to identify 7,899 'full-length' isoforms expressed from four Drosophila genes, Dscam1, MRP, Mhc, and Rdl. These results demonstrate that nanopore sequencing can be used to deconvolute individual isoforms and that it has the potential to be a powerful method for comprehensive transcriptome characterization.

SUBMITTER: Bolisetty MT

PROVIDER: S-EPMC4588896 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Determining exon connectivity in complex mRNAs by nanopore sequencing.

Bolisetty Mohan T MT Rajadinakaran Gopinath G Graveley Brenton R BR

Genome biology 20150930

Short-read high-throughput RNA sequencing, though powerful, is limited in its ability to directly measure exon connectivity in mRNAs that contain multiple alternative exons located farther apart than the maximum read length. Here, we use the Oxford Nanopore MinION sequencer to identify 7,899 'full-length' isoforms expressed from four Drosophila genes, Dscam1, MRP, Mhc, and Rdl. These results demonstrate that nanopore sequencing can be used to deconvolute individual isoforms and that it has the p ...[more]

PMID: 26420219

Similar Datasets

Determining Exon Connectivity in Complex mRNAs by Nanopore Sequencing

Project description:Sequencing of targeted cDNAs with the Oxford Nanopore MinION

| PRJEB9782 | ENA

Targeted nanopore sequencing enables complete characterisation of structural deletions initially identified using exon-based short-read sequencing strategies.

Project description:BackgroundThe widespread adoption of exome sequencing has greatly increased the rate of genetic diagnosis for inherited conditions. However, the detection and validation of large deletions remains challenging. While numerous bioinformatics approaches have been developed to detect deletions from whole - exome sequencing and targeted panels, further work is typically required to define the physical breakpoints or integration sites. Accurate characterisation requires either expensive follow - up whole - genome sequencing or the time - consuming, laborious process of PCR walking, both of which are challenging when dealing with the repeat sequences which frequently intersect deletion breakpoints. The aim of this study was to develop a cost-effective, long-range sequencing method to characterise deletions.MethodsGenomic DNA was amplified with primers spanning the deletion using long-range PCR and the products purified. Sequencing was performed on MinION flongle flowcells. The resulting fast5 files were basecalled using Guppy, trimmed using Porechop and aligned using Minimap2. Filtering was performed using NanoFilt. Nanopore sequencing results were verified by Sanger sequencing.ResultsFour cases with deletions detected following comparative read-depth analysis of targeted short-read sequencing were analysed. Nanopore sequencing defined breakpoints at the molecular level in all cases including homozygous breakpoints in EYS, CNGA1 and CNGB1 and a heterozygous deletion in PRPF31. All breakpoints were verified by Sanger sequencing.ConclusionsIn this study, a quick, accurate and cost - effective method is described to characterise deletions identified from exome, and similar data, using nanopore sequencing.

| S-EPMC10265035 | biostudies-literature

Resolving the complex Bordetella pertussis genome using barcoded nanopore sequencing.

Project description:The genome of Bordetella pertussis is complex, with high G+C content and many repeats, each longer than 1000 bp. Long-read sequencing offers the opportunity to produce single-contig B. pertussis assemblies using sequencing reads which are longer than the repetitive sections, with the potential to reveal genomic features which were previously unobservable in multi-contig assemblies produced by short-read sequencing alone. We used an R9.4 MinION flow cell and barcoding to sequence five B. pertussis strains in a single sequencing run. We then trialled combinations of the many nanopore user community-built long-read analysis tools to establish the current optimal assembly pipeline for B. pertussis genome sequences. This pipeline produced closed genome sequences for four strains, allowing visualization of inter-strain genomic rearrangement. Read mapping to the Tohama I reference genome suggests that the remaining strain contains an ultra-long duplicated region (almost 200 kbp), which was not resolved by our pipeline; further investigation also revealed that a second strain that was seemingly resolved by our pipeline may contain an even longer duplication, albeit in a small subset of cells. We have therefore demonstrated the ability to resolve the structure of several B. pertussis strains per single barcoded nanopore flow cell, but the genomes with highest complexity (e.g. very large duplicated regions) remain only partially resolved using the standard library preparation and will require an alternative library preparation method. For full strain characterization, we recommend hybrid assembly of long and short reads together; for comparison of genome arrangement, assembly using long reads alone is sufficient.

| S-EPMC6321869 | biostudies-literature

Nanopore sequencing of brain-derived full-length circRNAs reveals circRNA-specific exon usage, intron retention and microexons.

Project description:Circular RNA (circRNA) is a class of covalently joined non-coding RNAs with functional roles in a wide variety of cellular processes. Their composition shows extensive overlap with exons found in linear mRNAs making it difficult to delineate their composition using short-read RNA sequencing, particularly for long and multi-exonic circRNAs. Here, we use long-read nanopore sequencing of nicked circRNAs (circNick-LRS) and characterize a total of 18,266 and 39,623 circRNAs in human and mouse brain, respectively. We further develop an approach for targeted long-read sequencing of a panel of circRNAs (circPanel-LRS), eliminating the need for prior circRNA enrichment and find >30 circRNA isoforms on average per targeted locus. Our data show that circRNAs exhibit a large number of splicing events such as novel exons, intron retention and microexons that preferentially occur in circRNAs. We propose that altered exon usage in circRNAs may reflect resistance to nonsense-mediated decay in the absence of translation.

| S-EPMC8355340 | biostudies-literature

Determining protein complex connectivity using a probabilistic deletion network derived from quantitative proteomics.

Project description:Protein complexes are key molecular machines executing a variety of essential cellular processes. Despite the availability of genome-wide protein-protein interaction studies, determining the connectivity between proteins within a complex remains a major challenge. Here we demonstrate a method that is able to predict the relationship of proteins within a stable protein complex. We employed a combination of computational approaches and a systematic collection of quantitative proteomics data from wild-type and deletion strain purifications to build a quantitative deletion-interaction network map and subsequently convert the resulting data into an interdependency-interaction model of a complex. We applied this approach to a data set generated from components of the Saccharomyces cerevisiae Rpd3 histone deacetylase complexes, which consists of two distinct small and large complexes that are held together by a module consisting of Rpd3, Sin3 and Ume1. The resulting representation reveals new protein-protein interactions and new submodule relationships, providing novel information for mapping the functional organization of a complex.

| S-EPMC2751824 | biostudies-literature

A comprehensive examination of Nanopore native RNA sequencing for characterization of complex transcriptomes.

Project description:A platform for highly parallel direct sequencing of native RNA strands was recently described by Oxford Nanopore Technologies, but despite initial efforts it remains crucial to further investigate the technology for quantification of complex transcriptomes. Here we undertake native RNA sequencing of polyA + RNA from two human cell lines, analysing ~5.2 million aligned native RNA reads. To enable informative comparisons, we also perform relevant ONT direct cDNA- and Illumina-sequencing. We find that while native RNA sequencing does enable some of the anticipated advantages, key unexpected aspects currently hamper its performance, most notably the quite frequent inability to obtain full-length transcripts from single reads, as well as difficulties to unambiguously infer their true transcript of origin. While characterising issues that need to be addressed when investigating more complex transcriptomes, our study highlights that with some defined improvements, native RNA sequencing could be an important addition to the mammalian transcriptomics toolbox.

| S-EPMC6668388 | biostudies-literature

WarpSTR: determining tandem repeat lengths using raw nanopore signals.

Project description:MotivationShort tandem repeats (STRs) are regions of a genome containing many consecutive copies of the same short motif, possibly with small variations. Analysis of STRs has many clinical uses but is limited by technology mainly due to STRs surpassing the used read length. Nanopore sequencing, as one of long-read sequencing technologies, produces very long reads, thus offering more possibilities to study and analyze STRs. Basecalling of nanopore reads is however particularly unreliable in repeating regions, and therefore direct analysis from raw nanopore data is required.ResultsHere, we present WarpSTR, a novel method for characterizing both simple and complex tandem repeats directly from raw nanopore signals using a finite-state automaton and a search algorithm analogous to dynamic time warping. By applying this approach to determine the lengths of 241 STRs, we demonstrate that our approach decreases the mean absolute error of the STR length estimate compared to basecalling and STRique.Availability and implementationWarpSTR is freely available at https://github.com/fmfi-compbio/warpstr.

| S-EPMC10307940 | biostudies-literature

Nanopore sequencing in microgravity.

Project description:Rapid DNA sequencing and analysis has been a long-sought goal in remote research and point-of-care medicine. In microgravity, DNA sequencing can facilitate novel astrobiological research and close monitoring of crew health, but spaceflight places stringent restrictions on the mass and volume of instruments, crew operation time, and instrument functionality. The recent emergence of portable, nanopore-based tools with streamlined sample preparation protocols finally enables DNA sequencing on missions in microgravity. As a first step toward sequencing in space and aboard the International Space Station (ISS), we tested the Oxford Nanopore Technologies MinION during a parabolic flight to understand the effects of variable gravity on the instrument and data. In a successful proof-of-principle experiment, we found that the instrument generated DNA reads over the course of the flight, including the first ever sequenced in microgravity, and additional reads measured after the flight concluded its parabolas. Here we detail modifications to the sample-loading procedures to facilitate nanopore sequencing aboard the ISS and in other microgravity environments. We also evaluate existing analysis methods and outline two new approaches, the first based on a wave-fingerprint method and the second on entropy signal mapping. Computationally light analysis methods offer the potential for in situ species identification, but are limited by the error profiles (stays, skips, and mismatches) of older nanopore data. Higher accuracies attainable with modified sample processing methods and the latest version of flow cells will further enable the use of nanopore sequencers for diagnostics and research in space.

| S-EPMC5515536 | biostudies-literature

Freshwater monitoring by nanopore sequencing.

Project description:While traditional microbiological freshwater tests focus on the detection of specific bacterial indicator species, including pathogens, direct tracing of all aquatic DNA through metagenomics poses a profound alternative. Yet, in situ metagenomic water surveys face substantial challenges in cost and logistics. Here, we present a simple, fast, cost-effective and remotely accessible freshwater diagnostics workflow centred around the portable nanopore sequencing technology. Using defined compositions and spatiotemporal microbiota from surface water of an example river in Cambridge (UK), we provide optimised experimental and bioinformatics guidelines, including a benchmark with twelve taxonomic classification tools for nanopore sequences. We find that nanopore metagenomics can depict the hydrological core microbiome and fine temporal gradients in line with complementary physicochemical measurements. In a public health context, these data feature relevant sewage signals and pathogen maps at species level resolution. We anticipate that this framework will gather momentum for new environmental monitoring initiatives using portable devices.

| S-EPMC7815314 | biostudies-literature

Nanopore DNA sequencing with MspA.

Project description:Nanopore sequencing has the potential to become a direct, fast, and inexpensive DNA sequencing technology. The simplest form of nanopore DNA sequencing utilizes the hypothesis that individual nucleotides of single-stranded DNA passing through a nanopore will uniquely modulate an ionic current flowing through the pore, allowing the record of the current to yield the DNA sequence. We demonstrate that the ionic current through the engineered Mycobacterium smegmatis porin A, MspA, has the ability to distinguish all four DNA nucleotides and resolve single-nucleotides in single-stranded DNA when double-stranded DNA temporarily holds the nucleotides in the pore constriction. Passing DNA with a series of double-stranded sections through MspA provides proof of principle of a simple DNA sequencing method using a nanopore. These findings highlight the importance of MspA in the future of nanopore sequencing.

| S-EPMC2941267 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data