To make improvements to crops like corn, soybeans, and canola, scientists at Corteva are building a compendium of crop genomics resources to provide actionable sequence info for genetic discovery, gene-editing, and seed product development. Hear how Kevin Fengler, Comparative Genomics Lead of Data Science and Bioinformatics at Corteva, is using PacBio sequences to build visualization tools and genome assembly pipelines as a contribution to this effort.
In this presentation, Andrew Clark from Cornell University describes work from a collaboration with Manyuan Long of the University of Chicago and Rod Wing of the University of Arizona to look at heterochromatic regions with long simple satellite repeats in drosophila genomes. The group used PacBio sequencing to create new genome assemblies of 10 drosophila species, including de novo assemblies of two individual flies using as little as 26 ng of gDNA.
In this presentation, Sonja Vernes of the Max Plank Institute shares her work with the Bat1K project which aims to catalog the genetic diversity of all living bat species. She highlights the unique biology of bats, from their widely varying sizes to their capacity for healthy aging and disease resistance and provides recent findings from ongoing efforts to sequence and annotate the genomes of 21 phylogenetic families of bats.
In this presentation, Elizabeth Tseng explains how PacBio's full-length RNA Sequencing using the Iso-Seq method can characterize full-length transcripts without the need for computational transcript assembly. The Iso-Seq method is fully supported bioinformatically through PacBio's SMRT Analysis software that outputs high-quality, full-length transcript sequences that can be used for genome annotation and novel gene discovery. Elizabeth shows that the highly accurate reads can be used to discover allelic-specific isoform expressions in transcriptome data.
A high-quality reference genome is an essential tool for studies of plant and animal genomics. PacBio Single Molecule, Real-Time (SMRT) Sequencing generates long reads with uniform coverage and high consensus accuracy, making it a powerful technology for de novo genome assembly. PacBio is the core technology for many large genome initiatives, however, relatively high DNA input requirements (5 µg for standard library protocol) have placed PacBio out of reach for many projects on small, non-inbred organisms that may have lower DNA content. Here we present high-quality de novo genome assemblies from single invertebrate individuals for two different species: the Anopheles…
Recent improvements in sequencing chemistry and instrument performance combine to create a new PacBio data type, Single Molecule High-Fidelity reads (HiFi reads). Increased read length and improvement in library construction enables average read lengths of 10-20 kb with average sequence identity greater than 99% from raw single molecule reads. The resulting reads have the accuracy comparable to short read NGS but with 50-100 times longer read length. Here we benchmark the performance of this data type by sequencing and genotyping the Genome in a Bottle (GIAB) HG0002 human reference sample from the National Institute of Standards and Technology (NIST). We…
An important need in analyzing complex genomes is the ability to separate and phase haplotypes. While whole genome assembly can deliver this information, it cannot reveal whether there is allele-specific gene or isoform expression. The PacBio Iso-Seq method, which can produce high-quality transcript sequences of 10 kb and longer, has been used to annotate many important plant and animal genomes. We present an algorithm called IsoPhase that post-processes Iso-Seq data for transcript-based haplotyping. We applied IsoPhase to a maize Iso-Seq dataset consisting of two homozygous parents and two F1 cross hybrids. We validated the majority of the SNPs called with…
The PacBio Iso-Seq method produces high-quality, full-length transcripts of up to 10 kb and longer and has been used to annotate many important plant and animal genomes. Here we describe an improved, simplified library workflow and analysis pipeline that reduces library preparation time, RNA input, and cost. The Iso-Seq V2 Express workflow is a one day protocol that requires only ~300 ng of total RNA input while also reducing the number of reverse transcription and amplification steps down to single reactions. Compared with the previous workflow, the Iso-Seq V2 Express workflow increases the percentage of full-length (FL) reads while achieving…
Plant and animal whole genome sequencing has proven to be challenging, particularly due to genome size, high density of repetitive elements and heterozygosity. The Sequel System delivers long reads, high consensus accuracy and uniform coverage, enabling more complete, accurate, and contiguous assemblies of these large complex genomes. The latest Sequel chemistry increases yield up to 8 Gb per SMRT Cell for long insert libraries >20 kb and up to 10 Gb per SMRT Cell for libraries >40 kb. In addition, the recently released SMRTbell Express Template Prep Kit reduces the time (~3 hours) and DNA input (~3 µg), making the…
Structural variants (genomic differences =50 base pairs) contribute to the evolution of traits and disease. Most structural variants (SVs) are too small to detect with array comparative genomic hybridization and too large to reliably discover with short-read DNA sequencing.
Animals in the phylum Hemichordata have provided key understanding of the origins and development of body patterning and nervous system organization. However, efforts to sequence and assemble the genomes of highly heterozygous non-model organisms have proven to be difficult with traditional short read approaches. Long repetitive DNA structures, extensive structural variation between haplotypes in polyploid species, and large genome sizes are limiting factors to achieving highly contiguous genome assemblies. Here we present the highly contiguous de novo assembly and preliminary annotation of an indirect developing hemichordate genome, Schizocardium californicum, using SMRT Sequening long reads.
In this PAG 2018 presentation, Bill Ballard of University of New South Wales, presents research into the origins and potential domestication of the Australian dingo, winner of the 2017 SMRT Grant Program. Ballard used PacBio long-read whole genome sequencing to sequence and assemble the dingo genome. Ongoing work focuses on identifying common and unique genomic regions with a domestic dog genome to better understand shared ancestry and ultimately to aid in dingo conservation efforts.
In this PAG 2018 presentation, Marty Badgett of PacBio, shares updates on PacBio products and performance. He highlights high-quality genome assembles for Arabidopsis, rice, and maize, the SMRTbell Express Template Prep Kit, SMRT Analysis updates, and the Iso-Seq method for RNA sequencing.
In this PAG 2018 presentation, Tanya Renner of Pennsylvania State University shares research using PacBio SMRT Sequencing to understand the genomes and transcriptomes of carnivorous plants. She describes the humped bladderwort, Utricularia gibba, as having an extreme genome due to its small size (100 Mbp) despite containing numerous tandem gene duplications and having undergone two whole genome duplications. Renner shares ongoing research into two Drosera species, commonly known as sundews, which through whole genome sequencing are illuminating carnivorous plant genome structural evolution including the transition from monocentric to holocentric chromosomes.
In this PAG 2018 presentation, John Williams of University of Adelaide, presents research on using PacBio SMRT Sequencing to explore the genetic origins of cattle subspecies, Angus (Bos taurus taurus) and Brahman (Bos taurus indicus). He shares RNA sequencing data using the PacBio Iso-Seq method to compare transcriptomes and phase allelic expression and describes how the IsoPhase technique enables evaluation of SNPs through transcriptome mapping back to the single genome of a cross-bred individual. Using a genomic and transcriptomic approach, two high-quality genomes from a single individual and gene isoforms specific to each subspecies are being identified.