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.
2023-12-08 | GSE243920 | GEO
Project description:Oxford Nanopore full-length HIV sequencing reads
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:To identify full-length circRNAs in lung normal and cancer cell lines, we enriched circRNAs by rRNA depletion, poly(A) tailing and Rnase R treatment and amplified circRNAs by rolling circular RT. We constructed library according to the protocol of Fangqing Zhao team's. Nanopore is used for full-length sequencing.
Project description:the hypothalamus tissues of high-reproduction small-tailed Han sheep and low-reproduction Wadi sheep were collected, and full-length transcriptome sequencing by Oxford Nanopore Technologies (ONT) was performed to explore the key functional genes associated with sheep fecundity. The differentially expressed genes (DEGs) were screened and enriched using DESeq2 software through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG).
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: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:All lentiviral vectors derived from HIV-1 have the major splice donor (SD1) in the 5’ leader region and splice acceptor 7 (SA7) within the env region. Splicing events decrease the amount of full-length RNA available for packaging into virions and could lead to packaging of genomes containing internal deletions. Because there are splice sites or splicing enhancer/silencer elements in both gag and env, we compared how deleting each region affected intracellular genomic RNA splicing in RNA isolated from transfected HEK293Tsa cells. Oxford Nanopore direct cDNA sequencing was used to characterize the splice variants because the long-read length allows full-length transcripts to be analyzed. We show that deleting 507 nt of env, including the SA7, decreased the number of splicing events per transcript and increased the proportion of unspliced genomic RNAs ~3-fold in the cell.
Project description:Analysis and understanding of transcript functions is greatly helped by knowing the full-length sequence of individual RNAs. New long-read sequencing devices such as Oxford Nanopore and Pacbio have the potential to sequence full-length transcripts, but standard methods lack the ability to capture true RNA 5’ ends and selects for poly-adenylated (pA+) transcripts. We present a method that, by utilizing cap-trapping and 3’ end adapter ligation, can sequence transcripts from the exact 5’ end to 3’ end regardless of whether they are poly-adenylated, with no need for ribosomal RNA depletion. We show that the method can faithfully detect 5’ ends, splice junctions and 3’ ends, has high reproducibility between runs and gene expression estimates from the method correlate well with short-read sequencing methods. We also demonstrate that the method can detect and sequence full-length pA- RNAs, including lncRNAs, promoter upstream transcripts (PROMPTs) and enhancer RNAs. TLDR-seq is therefore useful for the characterization of diverse capped RNA species.