In this PacBio User Group Meeting presentation, PacBio scientist Kristin Mars speaks about recent updates, such as the single-day library prep that’s now possible with the Iso-Seq Express workflow. She also notes that one SMRT Cell 8M is sufficient for most Iso-Seq experiments for whole transcriptome sequencing at an affordable price.
In this Labroots webinar, Meredith Ashby, Director of Microbial Genomics at PacBio, describes the utility of highly accurate long-read sequencing, known as HiFi sequencing, to understand the SARs-CoV-2 viral genome. HiFi sequencing enables mutation phasing and rare variant detection to understand viral stability and mutation rates, as well as providing insights into viral population structure for monitoring viral evolution. Ashby also shares how HiFi sequencing can be used to explore the host immune response to COVID-19, specifically by providing full-length sequencing of the B cell repertoire, IGH locus and HLA genes. Access additional COVID-19 Sequencing Tools and Resources.
In this ASHG 2020 CoLab presentation hear Principal Scientists, Aaron Wenger and Elizabeth Tseng share how highly accurate long reads (HiFi reads) provide comprehensive variant detection for both genomes and transcriptomes. Aaron Wenger describes how new improvements in protocols and analysis methods have increased scalability and accuracy of variant calling. As demonstrated in the precisionFDA Truth Challenge V2, HiFi reads (>99% accurate, 15 kb – 20 kb) now outperform short reads for single nucleotide and structural variant calling and match for small indels. This includes calling >30,000 small variants and >10,000 structural variants missed by short reads, many in medically…
In this ASHG 2020 PacBio Workshop Jonas Korlach, CSO, shares how the new PacBio Sequel IIe System makes highly accurate long-read sequencing easy and affordable so?all scientists can gain comprehensive views of human genomes and transcriptomes. He goes on to provide updates on the applications including human WGS for variant detection, de novo genome assembly, single-cell full-length RNA sequencing, and targeted sequencing using PCR and No-Amp methods.
Most genes in eukaryotic organisms produce alternative isoforms, broadening the diversity of proteins and non-coding RNAs encoded by the genome. In contrast to other RNA sequencing platforms that rely on short-read sequencing, long accurate reads from PacBio Single Molecule, Real-Time (SMRT) Sequencing can characterize full-length transcripts without the need for assembly and inference. The PacBio isoform sequencing (Iso-Seq) method generates full-length sequences for transcripts up to 10 kb in length, with scalable throughput using barcoding approaches. The Iso-Seq application can be employed for a wide variety of studies, including improvement of gene annotation, identification of novel isoforms and fusion transcripts,…
To start Day 1 of the PacBio User Group Meeting, Jonas Korlach, PacBio CSO, provides an update on the latest releases and performance metrics for the Sequel II System. The longest reads generated on this system with the SMRT Cell 8M now go beyond 175,000 bases, while maintaining extremely high accuracy. HiFi mode, for example, uses circular consensus sequencing to achieve accuracy of Q40 or even Q50.
Ellen Paxinos, a scientist at PacBio, shares her AGBT poster on work done in collaboration with reference lab Monogram Biosciences using Single Molecule, Real-Time (SMRT) sequencing to detect minor species and variants in HCV. Using two genotypes mixed together, the team was able to detect variants down to 1% and to identify both viral haplotypes from the data. Paxinos says the study is a model for looking at genomic variation in chronic viral infection.
At AGBT 2017, Lars Paulin from the University of Helsinki presented this poster on whole genome sequencing of the virus responsible for progressive multifocal leukoencephalopathy, a rare and dangerous brain infection. His team used long amplicon analysis to resolve the whole virus genome from three patient samples, pooled them for SMRT Sequencing, and identified variants and rearrangements. This work represents the first time the viral genome was sequenced from patients.
In this AGBT 2017 talk, PacBio CSO Jonas Korlach provided a technology roadmap for the Sequel System, including plans the continue performance and throughput increases through early 2019. Per SMRT Cell throughput of the Sequel System is expected to double this year and again next year. Together with a new higher-capacity SMRT Cell expected to be released by the end of 2018, these improvements result in a ~30-fold increase or ~150 Gb / SMRT Cell allowing a real $1000 real de novo human genome assembly. Also discussed: Additional application protocol improvements, new chemistry and software updates, and a look at…
With PacBio single-cell RNA sequencing using the Iso-Seq method, you can now distinguish between alternative transcript isoforms at the single-cell level. The highly accurate long reads (HiFi reads) can span the entire 5′ to 3′ end of a transcript, allowing a high-resolution view of isoform diversity and revealing cell-to-cell heterogeneity without the need for assembly.
Although antiretroviral therapy (ART) is highly effective at suppressing HIV-1 replication, the virus persists as a latent reservoir in resting CD4+ T cells during therapy. This reservoir forms even when ART is initiated early after infection, but the dynamics of its formation are largely unknown. The viral reservoirs of individuals who initiate ART during chronic infection are generally larger and genetically more diverse than those of individuals who initiate therapy during acute infection, consistent with the hypothesis that the reservoir is formed continuously throughout untreated infection. To determine when viruses enter the latent reservoir, we compared sequences of replication-competent viruses…
Thermoactinomyces vulgaris strain CDF was isolated from soil and shown to have the ability to degrade chicken feathers at high temperatures. Here, we report the complete genome sequence of this bacterium, which is 2,595,509?bp long with 2,642 predicted genes and an average G+C content of 48.14%.Copyright © 2019 Li et al.
Kaposi sarcoma-associated herpesvirus (KSHV) is an emerging pathogen and is the causative infectious agent of Kaposi sarcoma and two malignancies of B cell origin. To date, there is no licensed KSHV vaccine. Development of an effective vaccine against KSHV continues to be limited by a poor understanding of how the virus initiates acute primary infection in vivo in diverse human cell types. The role of glycoprotein H (gH) in herpesvirus entry mechanisms remains largely unresolved. To characterize the requirement for KSHV gH in the viral life cycle and in determination of cell tropism, we generated and characterized a mutant KSHV…
Increasing evidence indicates that broadly neutralizing antibodies (bNAbs) play an important role in immune-mediated control of hepatitis C virus (HCV) infection, but the relative contribution of neutralizing antibodies targeting antigenic sites across the HCV envelope (E1 and E2) proteins is unclear. Here, we isolated thirteen E1E2-specific monoclonal antibodies (MAbs) from B cells of a single HCV-infected individual who cleared one genotype 1a infection and then became persistently infected with a second genotype 1a strain. These MAbs bound six distinct discontinuous antigenic sites on the E1 protein, the E2 protein, or the E1E2 heterodimer. Three antigenic sites, designated AS108, AS112 (an…
HIV elite controllers represent a remarkable minority of patients who maintain normal CD4+ T-cell counts and low or undetectable viral loads for decades in the absence of antiretroviral therapy. To examine the possible contribution of virus attenuation to elite control, we obtained a primary HIV-1 isolate from an elite controller who had been infected for 19?years, the last 10 of which were in the absence of antiretroviral therapy. Full-length sequencing of this isolate revealed a highly unusual V1 domain in Envelope (Env). The V1 domain in this HIV-1 strain was 49 amino acids, placing it in the top 1% of…