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PacBio
20211116
Description +
We created the HiFiViral SARS-CoV-2 Kit for labs working on the front line of the COVID-19 pandemic — tracking and identifying the spread of novel variants in their communities. The kit is an easy-to-use, scalable, and highly accurate solution for sequencing the entire SARS-CoV-2 genome. The differentiated design approach is resilient to novel variants enabling comprehensive detection of all types of mutations.
2021
Summary +
Learn how Single Molecule, Real-Time (SMRT) Sequencing and the Sequel IIe System and will accelerate your research by delivering highly accurate long reads to provide the most comprehensive view of genomes, transcriptomes and epigenomes.
Summary +
HiFiViral for SARS-CoV-2 is a simple-to-use, scalable, cost-effective solution for sequencing the entire SARS-CoV-2 genome. This fully kitted solution uses a novel approach that is robust to new variants and comprehensively detects all types of mutations.
Summary +
With Single Molecule, Real-Time (SMRT) Sequencing and the Sequel Systems, you can affordably assemble reference-quality microbial genomes that are >99.999% (Q50) accurate.
Summary +
With PacBio Single Molecule, Real-Time (SMRT) Sequencing on the Sequel IIe System you can characterize whole genomes and transcriptomes with just one SMRT Cell. Explore our applications and pricing to get your sequencing project started.
Comparison of third-generation sequencing approaches to identify viral pathogens under public health emergency conditions
2020
Abstract +
The capability of high-throughput sequencing (HTS) for detection of known and unknown viruses timely makes it a powerful tool for public health emergency response. Third-generation sequencing (TGS) offers advantages in speed and length of detection over second-generation sequencing (SGS). Here, we presented the end-to-end workflows for both Oxford Nanopore MinION and Pacbio Sequel on a viral disease emergency event, along with Ion Torrent PGM as a reference. A specific pipeline for comparative analysis on viral genomes recovered by each platform was assembled, given the high errors of base-calling for TGS platforms. All the three platforms successfully identified and recovered at least 85% Norovirus GII genomes. Oxford Nanopore MinION spent the least sample-to-answer turnaround time with relatively low but enough accuracy for taxonomy classification. Pacbio Sequel recovered the most accurate viral genome, while spending the longest time. Overall, Nanopore metagenomics can rapidly characterize viruses, and Pacbio Sequel can accurately recover viruses. This study provides a framework for designing the appropriate experiments that are likely to lead to accurate and rapid virus emergency response.
High-throughput, single-copy sequencing reveals SARS-CoV-2 spike variants coincident with mounting humoral immunity during acute COVID-19
2021
Abstract +
Tracking evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within infected individuals will help elucidate coronavirus disease 2019 (COVID-19) pathogenesis and inform use of antiviral interventions. In this study, we developed an approach for sequencing the region encoding the SARS-CoV-2 virion surface proteins from large numbers of individual virus RNA genomes per sample. We applied this approach to the WA-1 reference clinical isolate of SARS-CoV-2 passaged in vitro and to upper respiratory samples from 7 study participants with COVID-19. SARS-CoV-2 genomes from cell culture were diverse, including 18 haplotypes with non-synonymous mutations clustered in the spike NH2-terminal domain (NTD) and furin cleavage site regions. By contrast, cross-sectional analysis of samples from participants with COVID-19 showed fewer virus variants, without structural clustering of mutations. However, longitudinal analysis in one individual revealed 4 virus haplotypes bearing 3 independent mutations in a spike NTD epitope targeted by autologous antibodies. These mutations arose coincident with a 6.2-fold rise in serum binding to spike and a transient increase in virus burden. We conclude that SARS-CoV-2 exhibits a capacity for rapid genetic adaptation that becomes detectable in vivo with the onset of humoral immunity, with the potential to contribute to delayed virologic clearance in the acute setting.
Rescue of codon-pair deoptimized respiratory syncytial virus by the emergence of genomes with very large internal deletions that complemented replication
2021
Abstract +
Recoding viral genomes by introducing numerous synonymous but suboptimal codon pairs—called codon-pair deoptimization (CPD)—provides new types of live-attenuated vaccine candidates. The large number of nucleotide changes resulting from CPD should provide genetic stability to the attenuating phenotype, but this has not been rigorously tested. Human respiratory syncytial virus in which the G and F surface glycoprotein ORFs were CPD (called Min B) was temperature-sensitive and highly restricted in vitro. When subjected to selective pressure by serial passage at increasing temperatures, Min B substantially regained expression of F and replication fitness. Whole-genome deep sequencing showed many point mutations scattered across the genome, including one combination of six linked point mutations. However, their reintroduction into Min B provided minimal rescue. Further analysis revealed viral genomes bearing very large internal deletions (LD genomes) that accumulated after only a few passages. The deletions relocated the CPD F gene to the first or second promoter-proximal gene position. LD genomes amplified de novo in Min B–infected cells were encapsidated, expressed high levels of F, and complemented Min B replication in trans. This study provides insight on a variation of the adaptability of a debilitated negative-strand RNA virus, namely the generation of defective minihelper viruses to overcome its restriction. This is in contrast to the common “defective interfering particles” that interfere with the replication of the virus from which they originated. To our knowledge, defective genomes that promote rather than inhibit replication have not been reported before in RNA viruses.
Complete Mapping of Mutations to the SARS-CoV-2 Spike Receptor-Binding Domain that Escape Antibody Recognition
2021
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Antibodies targeting the SARS-CoV-2 spike receptor-binding domain (RBD) are being developed as therapeutics and are a major contributor to neutralizing antibody responses elicited by infection. Here, we describe a deep mutational scanning method to map how all amino-acid mutations in the RBD affect antibody binding and apply this method to 10 human monoclonal antibodies. The escape mutations cluster on several surfaces of the RBD that broadly correspond to structurally defined antibody epitopes. However, even antibodies targeting the same surface often have distinct escape mutations. The complete escape maps predict which mutations are selected during viral growth in the presence of single antibodies. They further enable the design of escape-resistant antibody cocktails—including cocktails of antibodies that compete for binding to the same RBD surface but have different escape mutations. Therefore, complete escape-mutation maps enable rational design of antibody therapeutics and assessment of the antigenic consequences of viral evolution.
Introductions and early spread of SARS-CoV-2 in the New York City area
2020
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New York City (NYC) has emerged as one of the epicenters of the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. To identify the early transmission events underlying the rapid spread of the virus in the NYC metropolitan area, we sequenced the virus that causes coronavirus disease 2019 (COVID-19) in patients seeking care at the Mount Sinai Health System. Phylogenetic analysis of 84 distinct SARS-CoV-2 genomes indicates multiple, independent, but isolated introductions mainly from Europe and other parts of the United States. Moreover, we found evidence for community transmission of SARS-CoV-2 as suggested by clusters of related viruses found in patients living in different neighborhoods of the city.
Deep Mutational Scanning of SARS-CoV-2 Receptor Binding Domain Reveals Constraints on Folding and ACE2 Binding
2020
Abstract +
The receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein mediates viral attachment to ACE2 receptor and is a major determinant of host range and a dominant target of neutralizing antibodies. Here, we experimentally measure how all amino acid mutations to the RBD affect expression of folded protein and its affinity for ACE2. Most mutations are deleterious for RBD expression and ACE2 binding, and we identify constrained regions on the RBD’s surface that may be desirable targets for vaccines and antibody-based therapeutics. But a substantial number of mutations are well tolerated or even enhance ACE2 binding, including at ACE2 interface residues that vary across SARS-related coronaviruses. However, we find no evidence that these ACE2-affinity-enhancing mutations have been selected in current SARS-CoV-2 pandemic isolates. We present an interactive visualization and open analysis pipeline to facilitate use of our dataset for vaccine design and functional annotation of mutations observed during viral surveillance.
PacBio
20211018
Description +
PacBio Vice President of Segment Marketing, Dr. Jennifer Stone, demonstrates how HiFi sequencing is changing the game in human genetics by sharing some of the exciting milestones and seminal publications our technology has produced this year.
Children’s Mercy Kansas City
20211018
Description +
Genomic variation beyond single nucleotide variants, including structural variation (SV), copy number variants (CNV), and repeat expansions, plays a significant role in rare disease. However, current technologies require multiple tests to fully access these variants, resulting in complex testing algorithms and the potential for missed diagnoses. Long-read genome sequencing offers the ability to accurately detect SNV, CNV, SV, and expansions with a single test. This presentation will highlight the integrated analyses offered by HiFi sequencing, using case examples demonstrating the potential for a unified test.
Broad Institute
20211018
Description +
While RNA-sequencing has dramatically accelerated our understanding of biology, quantitation and discovery of full-length RNA isoforms resulting from alternative splicing remain poorly resolved. Alternative splicing is a core regulatory process that modulates the structure, expression, and localization of expressed proteins through differential exon and/or UTR splicing during transcript maturation. Beyond being an integral component of cellular development and homeostatic maintenance, RNA splicing is implicated in a wide range of pathologies with hallmark isoforms being linked to cardiovascular, neurological, and immunological diseases. Current limitations in isoform quantitation and discovery arise from the inability of existing sequencing platforms to scalably sequence full-length mRNAs – short-read approaches are unable to span most successive splice sites while long-read approaches are constrained by limited throughput. To enable scalable full-length RNA sequencing, we have developed the method Multiplexed Arrays sequencing (MAS-seq) which maximizes the sequencing potential of isoforms on the PacBio platform. Through the use of deoxy-uracil digestion followed by barcode-directed ligation of cDNAs, MAS-seq generates long multiplexed cDNA arrays with a length distribution that allows for both accurate consensus sequencing and optimal capacity utilization of PacBio sequencers. In combination with upstream artifact depletion measures, MAS-seq boosts the sequencing throughput to approximately 40 million full-length transcripts per SMRT Cell 8M, a >20-fold increase compared to PacBio’s scIso-Seq workflow. We sequenced synthetic RNA isoform standards (Lexogen) and demonstrate a 99.8% isoform identification accuracy using MAS-seq, far exceeding the 56.8% accuracy of Smart-seq3, the best-in-class short-read isoform identification protocol. MAS-seq-enabled single-cell RNA isoform sequencing of tumor infiltrating CD8+ T cells robustly identifies the canonical CD45 (PTPRC) isoforms associated with the range of observed T cell states – a finding additionally validated at the protein level via CITE-seq. Further, we demonstrate the impact of the long-read sequencing throughput gains on single-cell isoform analysis enabled by MAS-seq, providing a 44% increase in single-cell clustering capacity (adjusted Rand index) and a 34-fold gain in identifying differentially spliced genes amongst the CD8+ T cell subtypes. MAS-seq is a streamlined and cost-effective approach that enables scalable bulk and single-cell RNA isoform sequencing.
Amsterdam University Medical Center
20211018
Description +
Many neurological diseases result from expansion of unstable variable nucleotide tandem repeats (VNTRs) that influence gene transcription of neighboring genes. In this talk, Dr. Henne Holstege presents research that investigated VNTRs across several genomes including a 115-year-old cognitively healthy individual. She and her group found that the genes that contained most VNTRs, of which PTPRN2 and DLGAP2 are the most prominent examples, were found to be predominantly expressed in the brain and associated with a wide variety of neurological disorders.
Targeting Clinically Significant Dark Regions of the Human Genome with High-Accuracy, Long-Read Sequencing
2021
Abstract +
There are many clinically important genes in “dark” regions of the human genome. These regions are characterized as dark due to a paucity of NGS coverage as a result of short-read sequencing or mapping difficulties. Low NGS sequencing yield can arise in these regions due to the presence of various repeat elements or biased base composition while inaccurate mapping can result from segmental duplications. Long-read sequencing coupled with an optimized, robust enrichment method has the potential to illuminate these dark regions.
Resolving Complex Pathogenic Alleles using HiFi Long-Range Amplicon Data and a New Clustering Algorithm
2021
Abstract +
Many genetic diseases are mapped to structurally complex loci. These regions contain highly similar paralogous alleles (>99% identity) that span kilobases within the human genome. Comprehensive screening for pathogenic variants is incomplete and labor intensive using short-reads or optical mapping. In contrast, long-range amplification and PacBio HiFi sequencing fully and directly resolve and phase a wide range of pathogenic variants without inference. To capitalize on the accuracy of HiFi data we designed a new amplicon analysis tool, pbAA. pbAA can rapidly deconvolve a mixture of haplotypes, enabling precise diplotyping, and disease allele classification.
HiFiViral SARS-CoV-2: A Kitted Solution for Genome Surveillance that is Robust Across Sample Input Quantities and New Variants
2021
Abstract +
The COVID-19 pandemic continues to be a major global epidemiological challenge with the ongoing emergence of new strain lineages that are more contagious, more virulent, drug resistant and in some cases evade vaccine-induced immunity. In response, the HiFiViral SARS-CoV-2 kit (PacBio; Menlo Park, California) was developed as a scalable solution for the Sequel II and Sequel IIe systems. The HiFiViral SARS-CoV-2 is an easy to perform solution for surveillance of variants to support pandemic response by public health. With 80% of samples yielding complete genome coverage in a 96-plex run, the combination of long read lengths and a differentiated probe design provides highly accurate results and robust genome coverage across a range of Ct values.
2021
Abstract +
Targeted amplification of difficult pharmacogenetic loci with PacBio HiFi reads can resolve complex alleles in a single direct assay without imputation.
2021
Abstract +
With PacBio Single Molecule, Real-Time (SMRT) Sequencing on the Sequel IIe System you can characterize highly polymorphic CYP2D6 locus from 384 or more samples with just one SMRT Cell. Explore our applications and pricing to get your sequencing project started.