In this ASHG 2020 PacBio Workshop Emily Farrow of Children’s Mercy Kansas City shares how the incorporation of long-read sequencing into the Genomic Answers for Kids research study is increasing diagnostic yields through the identification of novel genetic variation. Emily highlights several cases in which PacBio HiFi sequencing was able to provide insights where short-read sequencing alone was inconclusive, due to limitations stemming from repetitive regions and large structural variants.
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.
Peter Evans from the US FDA shares insights on whole-genome sequencing for bacteria of importance to public health. Comparing data across PacBio, 454, and MiSeq sequencers, he says having closed genomes, long reads, and methylation patterns are critical for gleaning comprehensive information about a microbe.
Ulf Gyllensten from Uppsala University used SMRT Sequencing to study multi-drug-resistant bacteria. Time to results was faster than other NGS platforms and generally resulted in complete genome assemblies, even for an organism with a 70% AT-rich genome. He also applied SMRT Sequencing for the characterization of HPV subtypes, important in cervical cancer.
Keith Robison, from Warp Drive Bio, discusses his experiences using PacBio for antibiotic drug discovery in GC-rich Streptomyces genomes
Ali Bashir from the Icahn Institute for Genomics and Multiscale Biology at Mount Sinai describes a tool to detect tandem repeats (PACMonSTR), which he believes are dramatically underrepresented in the human genome reference but that can be discovered with PacBio sequencing. In a collaboration with Cold Spring Harbor Laboratory and Cornell, Bashir and his team generated shotgun, whole-genome sequence data from human genomic DNA using PacBio sequencing. Their goal was to find structural variation features that are not present in the existing reference. He shows numerous examples wherein the long PacBio reads were able to resolve inversions in the sample,…
Dan Geraghty explains that while there have been decades’ worth of studies associating the genetics of the major histocompatibility complex (MHC), and the highly polymorphic HLA class 1 and 2 genes, we still haven’t found the key mutations for a variety of different autoimmune diseases such as type 1 diabetes, rheumatoid arthritis, multiple sclerosis, and others. Enormous amounts of linkage disequilibrium in these regions are one factor, as is getting information in phase, so larger stretches of sequence are needed. Recently Geraghty has begun using SMRT Technology with hopes of drilling down to the causal genetics.
Ulf Gyllensten speaks about advances in screening for HPV, his predictions for the widespread use of genome sequencing in the clinic, and applications using Single Molecule, Real-Time (SMRT) Sequencing for human genome studies.
Ulf Gyllensten from Uppsala University describes his AGBT poster showing the use of SMRT Sequencing for HLA allele typing. He says long reads are essential for sequencing the HLA genes because they link exons in a single read and do not introduce bias, as short-read sequencers can. Looking at fusion transcripts from CML patients generated information that couldn’t be achieved with any other technology, he adds.
Adam Ameur talks about a range of applications for which SMRT Sequencing had been useful in the SciLifeLab. Examples include analyzing a DNA translocation in chronic myeloid leukemia samples; studying the HPV genome; and sequencing the FADS region to understand fatty acid production.
The Mike Schatz lab at Cold Spring Harbor is well know for de novo genome assemblies and their work on structural variation in cancer genomes. In this Mendelspod podcast, lab leader, Mike Schatz, and doctorate student, Maria Nattestad tell of two new projects that include the de novo assembly of a very difficult but important flatworm genome and, secondly, making better variant calls for oncogenes such as HER2.
Ben Murrell presents how he is using SMRT Sequencing to generate full-length HIV-1 envelope gene sequences to study the phylogeny of viral genes in response to antibody evolution. Plus: an analysis pipeline that can be used for genes in other viruses.
In this poster presentation, PacBio scientist Ellen Paxinos describes an improved algorithm for circular consensus reads. Using this new algorithm, dubbed CCS2, it is possible to reach arbitrarily high quality across longer insert lengths at a lower cost and higher throughput than Sanger Sequencing. She shows results from the application of CCS2 to the characterization of the HIV-1 K103N drug-resistance associated mutation, which is both important clinically, and represents a challenge due to regional sequence context.
Swati Ranade from PacBio presents her AGBT poster demonstrating the use of SMRT Sequencing to characterize complex immune regions from human, macaque, and hummingbird. Included: a de novo assembly of complete KIR haplotypes, the MHC region, and MHC alleles.