In this ASHG 2016 virtual poster, Flora Tassone from UC Davis describes her study of the molecular mechanisms linked to fragile X syndrome and associated disorders, such as FXTAS. She is using SMRT Sequencing to resolve the FMR1 gene in premutation carriers because it’s the only technology that can generate full-length transcripts with the causative CGG repeat expansion. Plus: direct confirmation of predicted isoform configurations.
PacBio scientist Cheryl Heiner describes new low-input protocols for SMRT Sequencing library construction. With these revised methods, 2 kb libraries can be generated from as little as 10 ng of DNA, while 10 kb libraries require only 100 ng of sample.
Adam Ameur from the National Genomics Infrastructure at SciLifeLab presented this poster at AGBT 2017. In it, he details a validation study for the use of CRISPR/Cas9 to capture genomic targets without the use of amplification. Results from 12 Huntington’s patients indicate that this approach paired with SMRT Sequencing generates accurate repeat counts in the HTT gene.
Early detection of colorectal cancer (CRC) and its precursor lesions (adenomas) is crucial to reduce mortality rates. The fecal immunochemical test (FIT) is a non-invasive CRC screening test that detects the blood-derived protein hemoglobin. However, FIT sensitivity is suboptimal especially in detection of CRC precursor lesions. As adenoma-to-carcinoma progression is accompanied by alternative splicing, tumor-specific proteins derived from alternatively spliced RNA transcripts might serve as candidate biomarkers for CRC detection.
Bioinformatics scientist Chetanya Pandya from the Icahn School of Medicine at Mount Sinai presents a poster comparing short-read and long-read sequencing to detect somatic fusion events in cancer samples. SMRT Sequencing identified significantly more fusions, while many of the short-read calls may have been artifacts from challenging regions of the genome.
In this AGBT 2017 poster, the University of Helsinki’s Petri Auevinen reports on efforts to understand bacteria that grow on, and subsequently spoil, food. This analysis monitored DNA modifications and transcriptomic changes in three species of lactic acid bacteria. Scientists discovered that the organisms’ metabolic profiles change substantially when grown together compared to those cultured individually, and are now studying how Cas protein activity changes under these conditions too.
In this AGBT 2017 poster, Ulf Gyllensten from Uppsala University presents two local reference genomes generated with PacBio and Bionano Genomics data. These assemblies include structural variation and repetitive regions that have been missed with previous short-read efforts, including some new genes not annotated in the human reference genome.
Dan Geraghty from the Fred Hutchinson Cancer Research Center presents his AGBT poster on a new PacBio-based solution to sequence extended genomic regions — in this case, KIR and MHC, two of the most variable regions of the human genome. He reports data revealing for the first time regions that may be associated with autoimmune diseases such as diabetes, rheumatoid arthritis, and multiple sclerosis, and also shows that sequences were phased, complete, and highly accurate.
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 poster presentation, PacBio scientist Richard Hall describes a collaboration with the University of Minnesota to use long-read metagenomic profiling with SMRT Sequencing to analyze the gut microbiome of a patient who had undergone a fecal transplant after chronic C. difficile infection.
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.
In this ASHG 2016 poster video, Martin Pollard from the Wellcome Trust Sanger Institute and the University of Cambridge describes an ambitious project to better represent natural variation in the complex MHC region by sequencing the locus in thousands of people from various populations in Africa. A pilot project in five populations has already revealed a lot of diversity in the region, which is important for human disease, vaccine response, and organ transplantation. Pollard says SMRT Sequencing is the only technology that can deliver the full-length haplotypes necessary to identify complete variation in this highly polymorphic complex. Plus: plans to…
Robert Morey, from Synthetic Genomics shows how his team uses SMRT Sequencing to quickly and accurately confirm the content of long pieces of synthetic DNA. Included: a cost comparison for sequencing clones with Sanger Sequencing vs. SMRT Sequencing.
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.
In this AGBT poster, Cheryl Heiner from PacBio describes results from a variety of experiments optimizing a protocol for full-length 16S amplification for SMRT Sequencing.