PacBio 2013 User Group Meeting Presentation Slides: Lisbeth Guethlein from Stanford University School of Medicine looked at highly repetitive and variable immune regions of the orangutan genome. Guethlein reported that “PacBio managed to accomplish in a week what I have been working on for a couple years” (with Sanger sequencing), and the results were concordant. “Long story short, I was a happy customer.”
Clavibacter michiganensis subsp. michiganensis (Cmm) is a gram positive actinomycete, causing bacterial canker of tomato (Solanum lycopersicum) a disease that can cause significant losses in tomato production. In this study, we determined the complete genome sequence of 13 California Cmm strains and one saprophytic Clavibacter strain using a combination of Ilumina and PacBio sequencing. The California Cmm strains have genome size (3.2 -3.3 mb) similar to the reference strain NCPPB382 (3.3 mb) with =98% sequence identity. Cmm strains from California share =92% genes (8-10% are noble genes) with the reference Cmm strain NCPPB382. Despite this similarity, we detected significant alternatives…
While advances in RNA sequencing methods have accelerated our understanding of the human transcriptome, isoform discovery remains a challenge because short read lengths require complicated assembly algorithms to infer the contiguity of full-length transcripts. With PacBio’s long reads, one can now sequence full-length transcript isoforms up to 10 kb. The PacBio Iso- Seq protocol produces reads that originate from independent observations of single molecules, meaning no assembly is needed. Here, we sequenced the transcriptome of the human MCF-7 breast cancer cell line using the Clontech SMARTer® cDNA preparation kit and the PacBio RS II. Using PacBio Iso-Seq bioinformatics software, we…
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.
Recent advances in DNA sequencing technologies based on single-molecule detection now enable determination of full-length transcript sequences and, thus, all protein sequences in a sample. Utilizing data from this exciting technology, we have constructed customized, full-length protein databases that offer unprecedented advantages in proteomics database searching. Protein inference from bottom-up proteomics data can now be conducted using the set of correct protein sequences actually expressed in the sample, meaning that peptide identifications can be understood in the context of their corresponding full-length protein sequences. And most importantly, novel peptides or proteins originating from variations in the genome or transcriptome can…
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.
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.
Tremendous flexibility is maintained in the human proteome via alternative splicing, and cancer genomes often subvert this flexibility to promote survival. Identification and annotation of cancer-specific mRNA isoforms is critical to understanding how mutations in the genome affect the biology of cancer cells. While microarrays and other NGS-based methods have become useful for studying transcriptomes, these technologies yield short, fragmented transcripts that remain a challenge for accurate, complete reconstruction of splice variants. The Iso-Seq method developed at PacBio offers the only solution for direct sequencing of full-length, single-molecule cDNA sequences needed to discover biomarkers for early detection and cancer stratification,…
In this PacBio User Group Meeting presentation, PacBio scientist Kristin Mars speaks about recent updates, such as the single-day library prep that’s now possible with the Iso-Seq Express workflow. She also notes that one SMRT Cell 8M is sufficient for most Iso-Seq experiments for whole transcriptome sequencing at an affordable price.
Paracoccus sp. Arc7-R13, a silver nanoparticles (AgNPs) synthesizing bacterium, was isolated from Arctic Ocean sediment. Here we describe the complete genome of Paracoccus sp. Arc7-R13. The complete genome contains 4,040,012?bp with 66.66?mol%?G?+?C content, including one circular chromosome of 3,231,929?bp (67.45?mol%?G?+?C content), and eight plasmids with length ranging from 24,536?bp to 199,685?bp. The genome contains 3835 protein-coding genes (CDSs), 49 tRNA genes, as well as 3 rRNA operons as 16S-23S-5S rRNA. Based on the gene annotation and Swiss-Prot analysis, a total of 15 genes belonging to 11 kinds, including silver exporting P-type ATPase (SilP), alkaline phosphatase, nitroreductase, thioredoxin reductase, NADPH dehydrogenase…
Forest tree species are increasingly subject to severe mortalities from exotic pests, diseases, and invasive organisms, accelerated by climate change. Forest health issues are threatening multiple species and ecosystem sustainability globally. While sources of resistance may be available in related species, or among surviving trees, introgression of resistance genes into threatened tree species in reasonable time frames requires genome-wide breeding tools. Asian species of chestnut (Castanea spp.) are being employed as donors of disease resistance genes to restore native chestnut species in North America and Europe. To aid in the restoration of threatened chestnut species, we present the assembly of…
Pepper is an important vegetable with great economic value and unique biological features. In the past few years, significant development has been made towards understanding the huge complex pepper genome; however, pepper functional genomics has not been well studied. To better understand the pepper gene structure and pepper gene regulation, we conducted full-length mRNA sequencing by PacBio sequencing and obtained 57862 high-quality full-length mRNA sequences derived from 18362 previously annotated and 5769 newly detected genes. New gene models were built that combined the full-length mRNA sequences and corrected approximately 500 fragmented gene models from previous annotations. Based on the full-length…
Dysregulation of alpha-synuclein expression has been implicated in the pathogenesis of synucleinopathies, in particular Parkinsontextquoterights Disease (PD) and Dementia with Lewy bodies (DLB). Previous studies have shown that the alternatively spliced isoforms of the SNCA gene are differentially expressed in different parts of the brain for PD and DLB patients. Similarly, SNCA isoforms with skipped exons can have a functional impact on the protein domains. The large intronic region of the SNCA gene was also shown to harbor structural variants that affect transcriptional levels. Here we apply the first study of using long read sequencing with targeted capture of both…
Chemical defense against predators is widespread in natural ecosystems. Occasionally, taxonomically distant organisms share the same defense chemical. Here, we describe an unusual tripartite marine symbiosis, in which an intracellular bacterial symbiont (“Candidatus Endobryopsis kahalalidefaciens”) uses a diverse array of biosynthetic enzymes to convert simple substrates into a library of complex molecules (the kahalalides) for chemical defense of the host, the alga Bryopsis sp., against predation. The kahalalides are subsequently hijacked by a third partner, the herbivorous mollusk Elysia rufescens, and employed similarly for defense. “Ca E. kahalalidefaciens” has lost many essential traits for free living and acts as a…
Background: Salmonella Typhimurium ST313 exhibits signatures of adaptation to invasive human infection, including higher resistance to humoral immune responses than gastrointestinal isolates. Full resistance to antibody-mediated complement killing (serum resistance) among nontyphoidal Salmonellae is uncommon, but selection of highly resistant strains could compromise vaccine-induced antibody immunity. Here, we address the hypothesis that serum resistance is due to a distinct genotype or transcriptome response in S. Typhimurium ST313.