Project description:The LRGASP challenge encompasses different human, mouse, and manatee samples sequenced using multiple combinations of protocols and platforms. Different challenges will use distinct subsets of the samples for evaluation. The long-read sequencing platforms used in these challenges are the Pacific Biosciences (PacBio) Sequel II, Oxford Nanopore (ONT) MinION and PromethION. Samples will also be sequenced on the Illumina HiSeq 2500. The primary LRGASP library prep protocols are “standard” cDNA sequencing, direct RNA sequencing, R2C2, and CapTrap. Each sample will also include Lexogen SIRV-Set 4 spike-ins. We will also provide simulated PacBio and ONT data as part of the evaluations. This particular study focuses on single strand CAGE sequencing of human iPSCs, defining CAGE peaks from Illumina HiSeq 2500 (SR: 150 cycles) of two biological replicates for use in the LRGASP challenge.
Project description:The methylation landscape of the cattle Y-chromosome was characterized using methylated cytosine data produced from PacBio and ONT long reads sequencing platforms.
Project description:The methylation landscape of the sheep Y-chromosome was characterized using methylated cytosine data produced from PacBio and ONT long reads sequencing platforms. The study aimed to corroborate the presumptive locus of the sheep Y-chromosome centromere.
Project description:Purpose: The aim of this study is to compare different long-read sequencing platforms using reference lung adenocarcinoma cell lines and spike-in controls. Methods - Cell Culture: Lung adenocarcinoma cell lines NCI-H1975 and HCC827 from a range of passages (2-4) were grown on 3 separate occasions in Roswell Park Memorial Institute (RPMI) 1640 medium with 10% fetal calf serum and 1% penicillin-streptomycin. Methods - RNA preparation: mRNA was extracted using a Qiagen RNA miniprep kit and purified using the NEBNext® Poly(A) mRNA Magnetic Isolation Module (E7490). Purified mRNA spiked with sequins was used for Next Generation Sequencing library preparation using the NEBNext Ultra II Directional RNA Library Prep Kit (Illumina) and the cRNA-PCR Barcoding (SQK-PCS109 with SQK-PBK004) kit (ONT). Completed libraries were sequenced on NextSeq 500 (Illumina) and PromethION (ONT). Iso-Seq libraries were prepared and sequenced by Novogene on Sequel II (PacBio). Reads were mapped to known genomic features of the GRCH38 reference genome and RNA sequin decoy chromosome combined sequences at the gene-level and single reads were then summarized into gene-level counts using featureCounts software (Liao et al. 2014).
Project description:Here we describe CapTrap-Seq, an experimental workflow designed to address the problem of reduced transcript end detection by long-read RNA sequencing methods, especially at the 5' ends. We apply CapTrap-Seq to profile transcriptomes of the human heart and brain and we compared the obtained results with other library preparation approaches. CapTrap-Seq is a platform-agnostic method and here tested the method by using 3 different long-read sequencing platforms: MinION (ONT), Sequel (PacBaio) and Sequel II (PacBio).
Project description:Sequencing was performed to assess the ability of Nanopore direct cDNA and native RNA sequencing to characterise human transcriptomes. Total RNA was extracted from either HAP1 or HEK293 cells, and the polyA+ fraction isolated using oligodT dynabeads. Libraries were prepared using Oxford Nanopore Technologies (ONT) kits according to manufacturers instructions. Samples were then sequenced on ONT R9.4 flow cells to generate fast5 raw reads in the ONT MinKNOW software. Fast5 reads were then base-called using the ONT Albacore software to generate Fastq reads.
Project description:Zebrafish is a widely used model organism for investigating human diseases, including hematopoietic disorders. However, a comprehensive methylation baseline for zebrafish primary hematopoietic organ, the kidney marrow (KM), is still lacking. We employed Oxford Nanopore Technologies (ONT) sequencing to profile DNA methylation in zebrafish KM by generating four KM datasets, with two groups based on the presence or absence of red blood cells. Our findings revealed that blood contamination in the KM samples reduced read quality and altered methylation patterns. Compared with whole-genome bisulfite sequencing (WGBS), the ONT-based methylation profiling can cover more CpG sites (92.4% vs 70%-80%), and exhibit less GC bias with more even genomic coverage. And the ONT methylation calling results showed a high correlation with WGBS results when using shared sites. This study establishes a comprehensive methylation profile for zebrafish KM, paving the way for further investigations into epigenetic regulation and the development of targeted therapies for hematopoietic disorders.
Project description:Alternative splicing contributes to transcriptomic complexity and plays a role in the regulation of cellular identity and function, but the correct assembly of transcripts of complex loci as well as their quantification based on short-read sequencing is non-trivial. Recent long-read sequencing methods such as those from ONT and PacBio overcome these problems by potentially sequencing full transcripts. The activation of brown adipose tissue e.g., by reduced ambient temperature (cold) exposure, positively affects metabolism by increasing energy expenditure and releasing endocrine factors and has been shown to involve specific alternative splicing events. Here we assessed important features of ONT long read sequencing protocols in relation to Illumina short read sequencing: (i) Alignment characteristics to the reference genome and transcriptome, (ii) Gene and transcript detection and quantification, (iii) Detection of differential gene and transcript expression events, (iv) Transcriptome reannotation and (v) Detection of differential transcript usage events. We find that ONT long-read sequencing is advantageous in terms of transcriptome reassembly, especially when the reads are enriched for full length reads. Illumina sequencing, due to the higher number of counts available, has a higher statistical power for calling differentiall expressed/used features, whereas long-read sequencing has a lower risk of calling false positive events due to the better ability to unambiguously map reads to transcripts. Finally we describe novel transcript isoforms in cold-activated murine iBAT reassembled from ONT long reads.