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.
Yunfei Guo, from the University of Southern California, presents his ASHG 2015 poster on a de novo assembly of a diploid Asian genome. The uniform coverage of long-read sequencing helped access regions previously unresolvable due to high GC bias or long repeats. The assembly allowed scientists to fill some 400 gaps in the latest human reference genome, including some as long as 50 kb.
See what PacBio users had to say about SMRT Sequencing at the Plant and Animal Genome (PAG) Conference in San Diego. This brief video captures highlights from posters, presentations, and the exhibit hall. See how SMRT Sequencing benefits plant and animal scientists in their genomic investigations. [Engligh, some Mandarin]
At PAG 2017, Rod Wing presented five new, high-quality rice genome assemblies developed with SMRT Sequencing, including one that has eight complete chromosomes including centromeres. He also offered an early look at data generated with the Sequel System for a new assembly underway. This work is done with the goal of developing rice varieties that will be better suited to feeding a rapidly growing global population.
In this PAG 2017 presentation, Ben Matthews describes a new genome assembly for Aedes aegypti, the mosquito responsible for spreading Zika virus, yellow fever, and other infectious diseases. By using PacBio long-read sequencing, scientists produced an assembly that is much more complete and contiguous than a previous assembly; 7,500 transcripts map to the new contigs but not to the old assembly. The genome is important for designing guide RNAs for CRISPR, understanding resistance to mosquito repellants, and much more.
At PAG 2017, Rockefeller University’s Erich Jarvis offered an in-depth comparison of methods for generating highly contiguous genome assemblies, using hummingbird as the basis to evaluate a number of sequencing and scaffolding technologies. Analyses include gene content, error rate, chromosome metrics, and more. Plus: a long-read look at four genes associated with vocal learning.
At AGBT 2017, Mike Schatz from Johns Hopkins University and Cold Spring Harbor Laboratory presented data from sequencing, assembling, and analyzing personalized, phased diploid genomes with either Illumina, 10x Genomics, and PacBio SMRT Sequencing. Compared to the short-read-based methods, PacBio data assembled in large, complete contigs and contained the broadest range of structural variants with the best resolution. Plus: unexpected translocation findings with SMRT Sequencing, validated in follow-up studies.
At AGBT 2017, Margaret Roy from Calico Life Sciences discussed a de novo genome sequencing effort for the naked mole rat. This animal has a remarkably long life span and resistance to cancer, both of which make it interesting for studies of life extension. The team is using SMRT Sequencing for a more complete, contiguous assembly than the two existing short-read-based assemblies. Included: data from the Sequel System.
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.
Genomic instability is one of the hallmarks of cancer, leading to widespread copy number variations, chromosomal fusions, and other structural variations. The breast cancer cell line SK-BR-3 is an important model for HER2+ breast cancers, which are among the most aggressive forms of the disease and affect one in five cases. Through short read sequencing, copy number arrays, and other technologies, the genome of SK-BR-3 is known to be highly rearranged with many copy number variations, including an approximately twenty-fold amplification of the HER2 oncogene. However, these technologies cannot precisely characterize the nature and context of the identified genomic events…
Single Molecule Real-Time (SMRT) Sequencing was used to generate long reads for whole genome shotgun sequencing of the genome of the`alala (Hawaiian crow). The ‘alala is endemic to Hawaii, and the only surviving lineage of the crow family, Corvidae, in the Hawaiian Islands. The population declined to less than 20 individuals in the 1990s, and today this charismatic species is extinct in the wild. Currently existing in only two captive breeding facilities, reintroduction of the ‘alala is scheduled to begin in the Fall of 2016. Reintroduction efforts will be assisted by information from the ‘alala genome generated and assembled by…
Transmission of arboviruses such as Dengue Virus by Aedes aegypti causes debilitating disease across the globe. Disease in humans can include severe acute symptoms such as hemorrhagic fever and organ failure, but mosquitoes tolerate high titers of virus in a persistent infection. The mechanisms responsible for this viral tolerance are unclear. Recent publications highlighted the integration of genetic material from non-retroviral RNA viruses into the genome of the host during infection that relies upon endogenous retro-transcriptase activity from transposons. These endogenous viral elements (EVEs) found in the genome are predicted to be ancient, and at least some EVEs are under…
Outside of the simplest cases (haploid, bacteria, or inbreds), genomic information is not carried in a single reference per individual, but rather has higher ploidy (n=>2) for almost all organisms. The existence of two or more highly related sequences within an individual makes it extremely difficult to build high quality, highly contiguous genome assemblies from short DNA fragments. Based on the earlier work on a polyploidy aware assembler, FALCON ( https://github.com/PacificBiosciences/FALCON) , we developed new algorithms and software (“FALCON-unzip”) for de novo haplotype reconstructions from SMRT Sequencing data. We generate two datasets for developing the algorithms and the prototype software:…
Outside of the simplest cases (haploid, bacteria, or inbreds), genomic information is not carried in a single reference per individual, but rather has higher ploidy (n=>2) for almost all organisms. The existence of two or more highly related sequences within an individual makes it extremely difficult to build high quality, highly contiguous genome assemblies from short DNA fragments. Based on the earlier work on a polyploidy aware assembler, FALCON (https://github.com/PacificBiosciences/FALCON), we developed new algorithms and software (FALCON-unzip) for de novo haplotype reconstructions from SMRT Sequencing data. We apply the algorithms and the prototype software for (1) a highly repetitive diploid…
Transmission of arboviruses such as Dengue and Zika viruses by Aedes aegypti causes widespread and debilitating disease across the globe. Disease in humans can include severe acute symptoms such as hemorrhagic fever, organ failure, and encephalitis; and yet, mosquitoes tolerate high titers of virus in a persistent infection. The mechanisms responsible for tolerance to viral infection in mosquitoes are still unclear. Recent publications have highlighted the integration of genetic material from non-retroviral RNA viruses into the genome of the host during infection that relies upon endogenous retro-transcriptase activity from transposons. These endogenous viral elements (EVEs) found in the genome are…