Scientists at UC Davis School of Medicine have used the PacBio RS to sequence a previously “unsequenceable” region of highly repetitive DNA on the X chromosome. Their research has provided a critical leap forward in understanding the genetic complexity of repeat expansion disorders such as Fragile X Syndrome. The new method provides a path towards the first accurate means of population screening for Fragile X Syndrome, which is the most common cause of inherited intellectual disability and the most common known genetic cause of autism.
Several new high-quality human genome assemblies produce ethnicity-specific reference sequences and show how scientists can use this genetic information to improve precision medicine studies in Asian sub- populations. These projects demonstrate how long- read SMRT Sequencing provides robust detection of polymorphic structural variants in clinically relevant gene coding regions and phases variants into haplotypes.
Explore the types of human genomic variation and the diseases known to be caused by structural variants.
Structural variation accounts for much of the variation among human genomes. Structural variants of all types are known to cause Mendelian disease and contribute to complex disease. Learn how long-read sequencing is enabling detection of the full spectrum of structural variants to advance the study of human disease, evolution and genetic diversity.
At DuPont Pioneer, DNA sequencing is paramount for R&D to reveal the genetic basis for traits of interest in commercial crops such as maize, soybean, sorghum, sunflower, alfalfa, canola, wheat, rice, and others. They cannot afford to wait the years it has historically taken for high-quality reference genomes to be produced. Nor can they rely on a single reference to represent the genetic diversity in its germplasm.
Explore how long-read sequencing enables solving of rare and mendelian diseases.
With highly accurate long reads (HiFi reads) from the Sequel II System, powered by Single Molecule, Real-Time (SMRT) Sequencing technology, you can comprehensively detect variants in a human genome. HiFi reads provide high precision and recall for single nucleotide variants (SNVs), indels, structural variants (SVs), and copy number variants (CNVs), including in difficult-to-map repetitive regions.
With the Sequel II System powered by Single Molecule, Real-Time (SMRT) Sequencing technology and SMRT Link v8.0, you can affordably and effectively detect structural variants (SVs), copy number variants, and large indels ranging in size from tens to thousands of base pairs. PacBio long-read whole genome sequencing comprehensively resolves variants in an individual with high precision and recall. For population genetics and pedigree studies, joint calling powers rapid discovery of common variants within a sample cohort.
The Sequel II System is powered by Single Molecule, Real-Time (SMRT) Sequencing, a technology proven to produce highly accurate long reads, known as HiFi reads, for sequencing data you and your customers can trust.
During the past decade, the search for pathogenic mutations in rare human genetic diseases has involved huge efforts to sequence coding regions, or the entire genome, using massively parallel short-read sequencers. However, the approximate current diagnostic rate is
The sequence and assembly of human genomes using long-read sequencing technologies has revolutionized our understanding of structural variation and genome organization. We compared the accuracy, continuity, and gene annotation of genome assemblies generated from either high-fidelity (HiFi) or continuous long-read (CLR) datasets from the same complete hydatidiform mole human genome. We find that the HiFi sequence data assemble an additional 10% of duplicated regions and more accurately represent the structure of tandem repeats, as validated with orthogonal analyses. As a result, an additional 5 Mbp of pericentromeric sequences are recovered in the HiFi assembly, resulting in a 2.5-fold increase in…
The widespread occurrence of repetitive stretches of DNA in genomes of organisms across the tree of life imposes fundamental challenges for sequencing, genome assembly, and automated annotation of genes and proteins. This multi-level problem can lead to errors in genome and protein databases that are often not recognized or acknowledged. As a consequence, end users working with sequences with repetitive regions are faced with ‘ready-to-use’ deposited data whose trustworthiness is difficult to determine, let alone to quantify. Here, we provide a review of the problems associated with tandem repeat sequences that originate from different stages during the sequencing-assembly-annotation-deposition workflow, and…
New technologies and analysis methods are enabling genomic structural variants (SVs) to be detected with ever-increasing accuracy, resolution, and comprehensiveness. Translating these methods to routine research and clinical practice requires robust benchmark sets. We developed the first benchmark set for identification of both false negative and false positive germline SVs, which complements recent efforts emphasizing increasingly comprehensive characterization of SVs. To create this benchmark for a broadly consented son in a Personal Genome Project trio with broadly available cells and DNA, the Genome in a Bottle (GIAB) Consortium integrated 19 sequence-resolved variant calling methods, both alignment- and de novo assembly-based,…
Sequencing technology and assembly algorithms have matured to the point that high-quality de novo assembly is possible for large, repetitive genomes. Current assemblies traverse transposable elements (TEs) and allow for annotation of TEs. There are numerous methods for each class of elements with unknown relative performance metrics. We benchmarked existing programs based on a curated library of rice TEs. Using the most robust programs, we created a comprehensive pipeline called Extensive de-novo TE Annotator (EDTA) that produces a condensed TE library for annotations of structurally intact and fragmented elements. EDTA is open-source and freely available: https://github.com/oushujun/EDTA.List of abbreviationsTETransposable ElementsLTRLong Terminal…
In the wake of constant improvements in sequencing technologies, numerous insect genomes have been sequenced. Currently, 1219 insect genome-sequencing projects have been registered with the National Center for Biotechnology Information, including 401 that have genome assemblies and 155 with an official gene set of annotated protein-coding genes. Comparative genomics analysis showed that the expansion or contraction of gene families was associated with well-studied physiological traits such as immune system, metabolic detoxification, parasitism and polyphagy in insects. Here, we summarize the progress of insect genome sequencing, with an emphasis on how this impacts research on pest control. We begin with a…