With Single Molecule, Real-Time (SMRT) Sequencing and the Sequel Systems, you can easily and affordably sequence complete transcript isoforms in genes of interest or across the entire transcriptome. The Iso-Seq method allows users to generate full-length cDNA sequences up to 10 kb in length — with no assembly required — to confidently characterize full-length transcript isoforms.
With Single Molecule, Real-Time (SMRT) Sequencing and the Sequel System, you can easily and cost effectively generate highly accurate long reads (HiFi reads, >99% single-molecule accuracy) from genes or regions of interest ranging in size from several hundred base pairs to 20 kb. Target all types of variation across relevant genomic regions, including low complexity regions like repeat expansions, promoters, and flanking regions of transposable elements.
The study of genomics has revolutionized our understanding of science, but the field of transcriptomics grew with the need to explore the functional impacts of genetic variation. While different tissues in an organism may share the same genomic DNA, they can differ greatly in what regions are transcribed into RNA and in their patterns of RNA processing. By reviewing the history of transcriptomics, we can see the advantages of RNA sequencing using a full-length transcript approach become clearer.
With the PacBio no-amplification (No-Amp) targeted sequencing method, you can now sequence through previously inaccessible regions of the genome to provide base-level resolution of disease-causing repeat expansions. By combining the CRISPR/Cas9 enrichment method with Single Molecule, Real-Time (SMRT) Sequencing on the Sequel Systems you are no longer limited by hard-to-amplify targets.
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.
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.
At the PacBio ASHG workshop, Hagen Tilgner describes how he used long-read sequencing with Iso-Seq method to generate the first personal transcriptomes for three individuals. From these three family members, he and his collaborators were able to unambigously assign allele-specific RNA haplotypes, including HLA haplotypes, and demonstrated Mendelian inheritance of RNA molecules.
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.
Alex Dainis, a graduate student in Euan Ashley’s lab at Stanford University, presents her ASHG 2015 poster on haplotyping for genes linked to hypertrophic cardiomyopathy. Using the Iso-Seq method with SMRT Sequencing, she sequenced full transcripts of two genes of interest, generating data on 150 different isoforms. Rare variants, which could not be found with other technologies, were associated with haplotypes.
One of the popular questions on the Mendelspod program is how those doing sequencing decide between the quality of PacBio’s long reads and the cheaper short read technology, such as that of Illumina or Thermo Fisher. Steve Marsh, the Director of Bioinformatics at the Anthony Nolan Research Institute in London, provides the most clear and dramatic answer yet: use the PacBio system exclusively. Established in 1974 by the mother of a boy with a rare blood disease, the Anthony Nolan Institute is a world leader in blood crossmatching and donor/patient registries. Steve and his team at the Institute have dramatically…
Jonas Korlach, Chief Scientific Officer at PacBio, discussed the technology waves that have followed the initial human genome sequencing project, where we are today, and where we are going. Today, we are in what Korlach calls the 4th wave, where more comprehensive whole-genome re-sequencing is occurring, and we are nearing the 5th, when we will actually be able to free ourselves from reference genomes and sequence everything de novo.
Jason Chin, senior director of bioinformatics at PacBio, talks about using long-read sequence data to generate diploid genome assemblies to produce comprehensive haplotype sequence reconstructions. In the presentation, Chin describes the FALCON Unzip process that combines SNP phasing with the assembly process and allows for determination of the haplotype sequences and identification of structural variants. He presents an example of diploid assembly from inbred Arabidopsis strains.
In this AGBT virtual poster video, Jason Chin, a bioinformatician at PacBio, describes a polyploidy-aware de novo assembly approach called FALCON and a new algorithm, dubbed FALCON-unzip, that involves “unzipping” diploid genomes for de novo haplotype reconstructions from SMRT Sequencing data. These methods are illustrated in a studies of fungal, Arabidopsis and human datasets for the resolution of structural variation and characterization of haplotypes.