Project description:We used endpoint PCR to verify the presence of a new subgenomic RNA in SARS-CoV-2 (termed N.iORF3) and verify using nanopore sequencing that this is expressed via a newly evolved transcription regulatory sequence (TRS). We further show that this encodes a truncated C-terminal portion of Nucleocapsid, which is an antagonist of type I interferon production. Using reverse genetics-derived viruses we show N.iORF3 contributes to viral fitness during infection and observe distinct phenotypes when the Nucleocapsid coding sequence is mutated compared to when the TRS alone is ablated.
Project description:For the assessment of host response dynamics to SARS-CoV and SARS-CoV-2 infections in human airway epithelial cells at ambient temperature corresponding to the upper or lower respiratory tract. We performed a temporal transcriptome analysis on human airway epithelial cell (hAEC) cultures infected with SARS-CoV and SARS-CoV-2, as well as uninfected hAEC cultures, incubated either at 33°C or 37°C. hAEC cultures were harvested at 24, 48 72, 96 hpi and processed for Bulk RNA Barcoding and sequencing (BRB-seq), which allows a rapid and sensitive genome-wide transcriptomic analysis in a highly multiplexed manner. Transcriptome data was obtained from a total of 7 biological donors for pairwise comparisons of SARS-CoV or SARS-CoV-2 virus-infected to unexposed hAEC cultures at respective time points and temperatures.
Project description:A recombinant SARS-CoV lacking the envelope (E) protein is attenuated in vivo. Here we report that E protein PDZ-binding motif (PBM), a domain involved in protein-protein interactions, is a major virulence determinant in vivo. Elimination of SARS-CoV E protein PBM by using reverse genetics led to attenuated viruses (SARS-CoV-mutPBM) and to a reduction in the deleterious exacerbate immune response triggered during infection with the parental virus (SARS-CoV-wt). Cellular protein syntenin bound E protein PBM during SARS-CoV infection. Syntenin activates p38 MAPK leading to overexpression of inflammatory cytokines, and we have shown that active p38 MAPK was reduced in lungs of mice infected with SARS-CoVs lacking E protein PBM (SARS-CoV-mutPBM) as compared with the parental virus (SARS-CoV-wt), leading to a decreased expression of inflammatory cytokines and to viral attenuation. Therefore, E protein PBM is a virulence factor that activates pathogenic immune response most likely by using syntenin as a mediator of p38 MAPK induced inflammation. Three biological replicates were independently hybridized (one channel per slide) for each sample type (SARS-CoV-wt, SARS-CoV-mutPBM, Mock). Slides were Sure Print G3 Agilent 8x60K Mouse (G4852A-028005)
Project description:Nanopore sequencing has revolutionized genetic analysis by offering linkage information across megabase-scale genomes. However, the high intrinsic error rate of nanopore sequencing impedes the analysis of complex heterogeneous samples, such as viruses, bacteria, and edited cell lines. Achieving high accuracy in single-molecule sequence identification would significantly advance the study of quasi-species genomic populations, crucial for fields like immunology, pathology, epidemiology, and synthetic biology, where clonal isolation is traditionally employed for complete genomic frequency analysis. Here, we introduce ConSeqUMI, an innovative experimental and analytical pipeline designed to address long-read sequencing error rates using unique molecular indices for precise consensus sequence determination. ConSeqUMI processes nanopore sequencing data without the need for reference sequences, enabling accurate assembly of individual molecular sequences from complex mixtures. We establish robust benchmarking criteria for this platform’s performance and demonstrate its utility across diverse experimental contexts, including mixed plasmid pools, recombinant adeno-associated virus genome integrity, and CRISPR/Cas9-induced genomic alterations. Furthermore, ConSeqUMI enables detailed profiling of human pathogenic infections, as shown by our analysis of SARS-CoV-2 spike protein variants, revealing substantial intra-patient genetic heterogeneity. Lastly, we demonstrate how individual clonal isolates can be extracted directly from sequencing libraries at low cost, allowing for post-sequencing identification validation of observed variants. Our findings highlight the robustness of ConSeqUMI in processing sequencing data from degenerate UMI-labeled molecules, offering a critical tool for advancing genomic research.
Project description:A new genome of Fraxinus excelsior was assembled using a hybrid approach combining Nanopore and Illumina data (BioProject PRJNA865134, SAMN30100368, genome JANJPF000000000 ). Methylation was also assessed in the genome. Manuscript title: Fraxinus excelsior updated long-read genome reveals the importance of MADS-box genes in tolerance mechanisms against ash dieback, G3:Genes|Genomes|Genetics
Project description:The SARS-CoV-2 virus is continuously evolving, with appearance of new variants characterized by multiple genomic mutations, some of which can affect functional properties, including infectivity, interactions with host immunity, and disease severity. The rapid spread of new SARS-CoV-2 variants has highlighted the urgency to trace the virus evolution, to help limit its diffusion, and to assess effectiveness of containment strategies. We propose here a PCR-based rapid, sensitive and low-cost allelic discrimination assay panel for the identification of SARS-CoV-2 genotypes, useful for detection in different sample types, such as nasopharyngeal swabs and wastewater. The tests carried out demonstrate that this in-house assay, whose results were confirmed by SARS-CoV-2 whole-genome sequencing, can detect variations in up to 10 viral genome positions at once and is specific and highly sensitive for identification of all tested SARS-CoV-2 clades, even in the case of samples very diluted and of poor quality, particularly difficult to analyze.
Project description:RNA-seq of SARS-CoV-2 infected lungs from mice sensitized for SARS-CoV-2 infection by Ad5-hACE2 transduction compared to non-sensitized mice
