In this PacBio User Group Meeting presentation, PacBio scientist Meredith Ashby shared several examples of analysis — from full-length 16S sequencing to shotgun sequencing — showing how SMRT Sequencing enables accurate representation for metagenomics and microbiome characterization, in some cases even without fully assembling genomes. New updates will provide users with a dedicated microbial assembly pipeline, optimized for all classes of bacteria, as well as increased multiplexing on the Sequel II System, now with 48 validated barcoded adapters. That throughput could reduce the cost of microbial analysis substantially.
To start Day 2 of the PacBio User Group Meeting, Jonas Korlach, PacBio CSO, provides an update on lowering DNA input amounts for SMRT Sequencing workflows. Updates include a more robust shearing method, a revised AMPure size selection, and introduction of multiplexing low input samples. Finally, the use of HiFi sequencing with low input results in a more complete genome assembly. Jonas closes by mentioning that the low DNA input protocol is now available and further advancements to lower input requirements even more will open opportunities for different samples, such as cancer needle biopsies.
In this PacBio User Group Meeting presentation, Mount Sinai’s Ethan Ellis presents results from the HLS-CATCH method, which involves the use of the SageHLS instrument with CRISPR design methods to target and extract large genomic fragments for sequencing while avoiding pseudogenes and other confounding regions.
In this PacBio User Group Meeting presentation, Ana Conesa Cegarra from the University of Florida spoke about Iso-Seq analysis tools developed by her group, which created the popular SQANTI tools for Iso-Seq data QC. They’re also working on IsoAnnot to perform functional annotation at isoform resolution; validation has already been done on various species. Currently it’s a set of scripts, but her team is working to produce a more user-friendly version. Finally, tappAS is for functional diversity analysis and for prioritizing genes for validation.
In this PacBio User Group Meeting lightning talk, NEB’s Kelly Zatopek shares data from RADAR-seq, an amplification-free method for detecting and quantifying a wide variety of DNA damage types across a genome.
In this PacBio User Group Meeting presentation, Nic Wheeler of University of Wisconsin-Madison, speaks about RNA sequencing for filarial nematodes associated with understudied tropical diseases. His team used Iso-Seq analysis to improve gene models and achieve better transcriptome coverage for these worms, which typically have poorly annotated and fragmented genome assemblies. While getting enough RNA to study is a technical challenge, the group still managed to generate full-length isoforms, many of which were novel or contained novel junctions.
In this PacBio User Group Meeting presentation, Mitchell Vollger of the University of Washington used HiFi reads from SMRT Sequencing to study segmental duplications in the human genome. The technique significantly reduced the complexity of accurately mapping these nearly identical sequences throughout the genome; it also reduced the amount of compute power needed compared to a previous PacBio assembly using continuous long reads instead of circular consensus sequencing. Despite generating less data with the HiFi assembly, the team still resolved 30% more segmental duplications with the new approach.
In this PacBio User Group Meeting lightning talk, Shawn Polson of the University of Delaware speaks about viral metagenomes, which are more challenging to distinguish than their bacterial counterparts because viruses have no 16S equivalent. By using SMRT Sequencing, his team generated higher-resolution data about viral genomes and aims to use this information as a guide to how these genomes function.
In this PacBio User Group Meeting lightning talk, Alexandra Pike of MIT presents a study of TIN2, a telomere-binding protein, which is mutated in some short telomere syndromes. By pairing the Iso-Seq method with CRISPR, her team revealed a previously uncharacterized TIN2 isoform that may have a functional difference for individuals with these syndromes.
In this PacBio User Group Meeting lightning talk, Masako Nakanishi presents a study of how the gut microbiome alters an organism’s susceptibility to colonic ulceration; next, she plans to examine cause and effect by evaluating results of fecal transplants in mice.
In this PacBio User Group Meeting presentation, Eugenio Daviso from Covaris talks about the use of adaptive focused acoustics for gentle cell lysis and extraction of high molecular weight DNA.
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.
In this PacBio User Group Meeting presentation, Shawn Trojahn of Washington State University describes transcriptome sequencing and analysis of grizzly bears focused on differential gene expression during hibernation and active cycles, potentially offering human-relevant information about muscle atrophy and insulin resistance. The team was able to identify more unique isoforms just from liver tissue than had been previously characterized in the entire reference genome. Of particular interest: more than 2,000 transcripts differentially expressed between hibernation and active season, including 86 genes that have isoforms expressed in opposite directions.
In this PacBio User Group Meeting presentation, Erin Bernberg from the University of Delaware reports on using the Agilent Femto Pulse System for high-resolution, highly sensitive fragment analysis and on the low DNA input protocol, which her team used for a recent study of ice worms.