Project description:Higher-order chromatin structure arises from the combinatorial physical interactions of many genomic loci. To investigate this aspect of genome architecture we developed Pore-C, which couples chromatin conformation capture with Oxford Nanopore Technologies (ONT) long reads to directly sequence multi-way chromatin contacts without amplification.
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:Since the beginning of the Coronavirus Disease-19 (COVID-19) pandemic, multiple Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) mutations have been reported and led to the emergence of variants of concern (VOC) with increased transmissibility, virulence or immune escape. In parallel, the observation of viral fecal shedding led to the quantification of SARS-CoV-2 genomes in wastewater, providing information about the dynamics of SARS-CoV-2 infections within a population including symptomatic and asymptomatic individuals. Here, we aimed to adapt a sequencing technique initially designed for clinical samples to apply it to the challenging and mixed wastewater matrix, and hence identify the circulation of VOC at the community level. Composite raw sewage sampled over 24 h in two wastewater-treatment plants (WWTPs) from a city in western France were collected weekly and SARS-CoV-2 quantified by RT-PCR. Samples collected between October 2020 and May 2021 were submitted to whole-genome sequencing (WGS) using the primers and protocol published by the ARTIC Network and a MinION Mk1C sequencer (Oxford Nanopore Technologies, Oxford, United Kingdom). The protocol was adapted to allow near-full genome coverage from sewage samples, starting from ∼5% to reach ∼90% at depth 30. This enabled us to detect multiple single-nucleotide variant (SNV) and assess the circulation of the SARS-CoV-2 VOC Alpha, Beta, Gamma, and Delta. Retrospective analysis of sewage samples shed light on the emergence of the Alpha VOC with detection of first co-occurring signature mutations in mid-November 2020 to reach predominance of this variant in early February 2021. In parallel, a mutation-specific qRT-PCR assay confirmed the spread of the Alpha VOC but detected it later than WGS. Altogether, these data show that SARS-CoV-2 sequencing in sewage can be used for early detection of an emerging VOC in a population and confirm its ability to track shifts in variant predominance.
Project description:The adoption of Oxford Nanopore Technologies (ONT) sequencing as a tool in plant virology has been relatively slow despite its promise in more recent years to yield large quantities of long nucleotide sequences in real time without the need for prior amplification. The portability of the MinION and Flongle platforms combined with lowering costs and continued improvements in read accuracy make ONT an attractive method for both low- and high-scale virus diagnostics. Here, we provide a detailed step-by-step protocol using the ONT Flongle platform that we have developed for the routine application on a range of symptomatic post-entry quarantine and domestic surveillance plant samples. The aim of this methods paper is to highlight ONT's feasibility as a valuable component to the diagnostician's toolkit and to hopefully stimulate other laboratories towards the eventual goal of integrating high-throughput sequencing technologies as validated plant virus diagnostic methods in their own right.
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.