Project description:To identify full-length cap-to-poly(A) mRNA isoforms of CD20 and rule out reverse transcription artifacts which are common in cDNA-seq approaches, long-read Oxford Nanopore direct RNA sequencing was performed on the Raji cell line.
Project description:Whole-genome bisulfite sequencing (WGBS) is currently the gold standard for DNA methylation (5-methylcytosine, 5mC) profiling, however the destructive nature of sodium bisulfite results in DNA fragmentation and subsequent biases in sequencing data. Such issues have led to the development of bisulfite-free methods for 5mC detection. Nanopore sequencing is a long read non-destructive approach that directly analyzes DNA and RNA fragments in real time. Recently, computational tools have been developed that enable base-resolution detection of 5mC from Oxford Nanopore sequencing data. In this chapter we provide a detailed protocol for preparation, sequencing, read assembly and analysis of genome-wide 5mC using Nanopore sequencing technologies.
Project description:While numerous studies have described the transcriptomes of EVs in different cellular contexts, these efforts have typically relied on sequencing methods requiring RNA fragmentation, which limits interpretations on the integrity and isoform diversity of EV-encapsulated RNA populations. Furthermore, it has been assumed that mRNA signatures in EVs are likely to be fragmentation products of the cellular mRNA material, and little is known about the extent to which full-length mRNAs are present within EVs. Using Oxford nanopore long-read RNA sequencing, we sought to characterize the full-length polyadenylated (poly-A) transcriptome of EVs released by human chronic myelogenous leukemia K562 cells. We detected 441 and 280 RNAs that were respectively enriched or depleted in EVs. EV-enriched poly-A transcripts consist of a variety of biotypes, including mRNAs, long non-coding RNAs, and pseudogenes. Our analysis revealed that 12.72% of all reads present in EVs corresponded to known full-length transcripts, 65.34% of which were mRNAs. We also observed that for many well-represented coding and non-coding genes, diverse full-length transcript isoforms were present in EV specimens, and these isoforms were reflective-of but often in different ratio compared to cellular samples. Here we report a full-length transcriptome from human EVs, as determined by long-read nanopore sequencing.
Project description:We report that retention of intron 2 which affects expression of CD19 in CART-19 relapsed leukemia occurs in the context of full length CD19 transcript using Oxford Nanopore sequencing technology. By performing Direct RNA sequencing on Reh leukemia cell lines, we showed that intron 2 retention is functionally equivalent to nonsense mutations.
Project description:In this study, based on Nanopore direct RNA-seq where native RNAs are sequenced directly as near full-length transcripts in the 3' to 5' direction, transcription units of the phytopathogen Dickeya dadantii 3937 were validated and transcriptional termination sites were determined. Briefly, D. dadantii cultures were grown in M63 medium supplemented with 0.2% glucose and 0.2% PGA, until the early exponential phase (A600nm = 0.2, condition 1), or the early stationary phase (A600nm = 1.8, condition 2). RNAs were extracted using a frozen acid-phenol method, as previously described (Hommais et al. 2008), and treated successively with Roche and Biolabs DNases. Two samples were prepared: 50 µg of RNAs from each condition were pulled into one sample (sample 1), whereas the other one contained 100 µg of RNAs from condition 2 (sample 2). Both samples were then supplied to Vertis Biotechnologie AG for Nanopore native RNA-seq: total RNA preparations were first examined by capillary electrophoresis. For sample 1, ribosomal RNA molecules were depleted using an in-house developed protocol (recovery rate = 84%), whereas no ribodepletion was performed for sample 2. 3' ends of RNA were then poly(A)-tailed using poly(A) polymerase, and the Direct RNA sequencing kit (SQK-RNA002) was used to prepare the library for 1D sequencing on the Oxford Nanopore sequencing device. The direct RNA libraries were sequenced on a MinION device (MIN-101B) using standard settings. Basecalling of the fast5 files was performed using Guppy (version 3.6.1) with the following settings: --flowcell FLO-MIN106 --kit SQK-RNA002 --cpu_threads_per_caller 12--compress_fastq --reverse_sequence true --trim_strategy rna. Reads smaller than 50 nt were removed. 466 393 and 556 850 reads were generated for sample 1 and 2, respectively.
Project description:Rapidly increased studies by third-generation sequencing [Pacific Biosciences (Pacbio) and Oxford Nanopore Technologies (ONT)] have been used in all kinds of research areas. Among them, the plant full-length single-molecule transcriptome studies were most used by Pacbio while ONT was rarely used. Therefore, in this study, we developed ONT RNA-sequencing methods in plants. We performed a detailed evaluation of reads from Pacbio and Nanopore PCR cDNA (ONT Pc) sequencing in plants (Arabidopsis), including the characteristics of raw data and identification of transcripts. We aimed to provide a valuable reference for applications of ONT in plant transcriptome analysis.
Project description:Transposon insertion site sequencing (TIS) is a powerful method for associating genotype to phenotype. However, all TIS methods described to date use short nucleotide sequence reads which cannot uniquely determine the locations of transposon insertions within repeating genomic sequences where the repeat units are longer than the sequence read length. To overcome this limitation, we have developed a TIS method using Oxford Nanopore sequencing technology that generates and uses long nucleotide sequence reads; we have called this method LoRTIS (Long Read Transposon Insertion-site Sequencing). This experiment data contains sequence files generated using Nanopore and Illumina platforms. Biotin1308.fastq.gz and Biotin2508.fastq.gz are fastq files generated from nanopore technology. Rep1-Tn.fastq.gz and Rep1-Tn.fastq.gz are fastq files generated using Illumina platform. In this study, we have compared the efficiency of two methods in identification of transposon insertion sites.