Project description:To identify aberrant splicing isoforms and potential neoantigens, we performed full-length cDNA sequencing of lung adenocarcinoma cell lines using a long-read sequencer MinION. We constructed a comprehensive catalog of aberrant splicing isoforms and detected isoform-specific peptides using proteome analysis.
2020-12-09 | PXD019915 | JPOST Repository
Project description:full-length isoform of endosperm from Nongda3672
Project description:We developed a hybrid-sequencing workflow, combining next-generation and third-generation sequencing, to reconstruct full-length transcriptomes. Integrating with polysome profiling and ribosome footprinting data, we predicted isoform–specific translational status and reconstructed ORFeome. Moreover, we identified isoforms with specific subcellular localization pattern in neurons.
Project description:We consturcted a full-length transcript reference of CD4SP and CD8SP T cells using TGS (PacBio) data. We then used SGS (Illumina) CD4SP and CD8SP data to quantify isoform expressions and study alternative splicing patterns against the full-length transcript reference between CD4SP and CD8SP cells.
Project description:Deregulated gene expression is a hallmark of cancer, however most studies to date have analyzed short-read RNA-sequencing data with inherent limitations. Here, we combine PacBio long-read isoform sequencing (Iso-Seq) and Illumina paired-end short read RNA sequencing to comprehensively survey the transcriptome of gastric cancer (GC), a leading cause of global cancer mortality. We performed full-length transcriptome analysis across 10 GC cell lines covering four major GC molecular subtypes (chromosomal unstable, Epstein-Barr positive, genome stable and microsatellite unstable). We identify 60,239 non-redundant full-length transcripts, of which >66% are novel compared to current transcriptome databases. Novel isoforms are more likely to be cell-line and subtype specific, expressed at lower levels with larger number of exons, with longer isoform/coding sequence lengths. Most novel isoforms utilize an alternate first exon, and compared to other alternative splicing categories are expressed at higher levels and exhibit higher variability. Collectively, we observe alternate promoter usage in 25% of detected genes, with the majority (84.2%) of known/novel promoter pairs exhibiting potential changes in their coding sequences. Mapping these alternate promoters to TCGA GC samples, we identify several cancer-associated isoforms, including novel variants of oncogenes. Tumor-specific transcript isoforms tend to alter protein coding sequences to a larger extent than other isoforms. Analysis of outcome data suggests that novel isoforms may impart additional prognostic information. Our results provide a rich resource of full-length transcriptome data for deeper studies of GC and other gastrointestinal malignancies.
Project description:Single-cell isoform regulation is increasingly being studied. To get a full view of alternative isoform usage, from transcription start site and alternative splicing to transcription termination site, full-length sequences have to be studied. Here we use PacBio long read sequencing technology combined with unique molecular identities to get a full and accurate picture of alternative isoform usage of different stages in maturing oligodendrocyte single cells. We see that the majority of molecules in single-cells are separate isoforms, even after applying a conservative definition of what constitutes an isoform. Few isoforms are common between cells of the same cell-type but the common isoforms are higher expressed. We also see that exon junctions in coding regions are better regulated than exon junctions in non-coding regions and that genes often express more than one coding isoform.
Project description:A novel alternative splicing isoform of LOXL2 △e13 was expressed ubiquitously in all cell lines and ESCC tissues. In contrast to the impaired deamination enzymatic activity compared with full length LOXL2, LOXL2 △e13 showed an enhanced ability to promote cell mobility and invasiveness in ESCC cells than full length LOXL2 through a different mechanism.
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.