Pulmonary non-tuberculous mycobacterial (PNTM) infections occur in patients with chronic lung disease, but also in a distinct group of elderly women without lung defects who share a common body morphology: tall and lean with scoliosis, pectus excavatum, and mitral valve prolapse. In order to characterize the human host susceptibility to PNTM, we performed whole exome sequencing (WES) of 44 individuals in extended families of patients with active PNTM as well as 55 additional unrelated individuals with PNTM. This unique collection of familial cohorts in PNTM represents an important opportunity for a high yield search for genes that regulate mucosal immunity.…
Single Molecule, Real-Time (SMRT) Sequencing holds promise for addressing new frontiers in large genome complexities, such as long, highly repetitive, low-complexity regions and duplication events, and differentiating between transcript isoforms that are difficult to resolve with short-read technologies. We present solutions available for both reference genome improvement (>100 MB) and transcriptome research to best leverage long reads that have exceeded 20 Kb in length. Benefits for these applications are further realized with consistent use of size-selection of input sample using the BluePippin™ device from Sage Science. Highlights from our genome assembly projects using the latest P5-C3 chemistry on model organisms…
The developments in DNA sequencing technology over the past several years have enabled large number of scientists to obtain sequences for the genomes of their interest at a fairly low cost. Illumina Sequencing was the dominant whole genome sequencing technology over the past few years due to its low cost. The Illumina reads are short (up to 300bp) and thus most of those draft genomes produced from Illumina data are very fragmented which limits their usability in practical scenarios. Longer reads are needed for more contiguous genomes. Recently Pacbio sequencing made significant advances in developing cost-effective long-read (>10000bp) sequencing technology…
Leaky gut, or intestinal barrier immaturity with elevated intestinal permeability, is the proximate cause of susceptibility to necrotizing enterocolitis in preterm neonates. We recently revealed intestinal barrier maturation was associated with exclusive breastfeeding, less antibiotic exposure, most importantly, altered composition of the gut microbiota. However, sequencing short regions of 16S rRNA gene amplicon failed to identify the specific bacterial groups associated with improved or aberrant intestinal permeability. In this study, we performed high-throughput amplicon sequencing of the full length 16S rRNA gene with single-nucleotide resolution for a cohort of 66 preterm neonates born at 24-33 weeks of gestation who had…
Bacterial Vaginosis Associated bacterium 1 (BVAB1) is an as-yet uncultured bacterial species found in the human vagina that belongs to the family Lachnospiraceae within the order Clostridiales. As its name suggests, this bacterium is often associated with bacterial vaginosis (BV), a common vaginal disorder that has been shown to increase a woman’s risk for HIV, Chlamydia trachomatis, and Neisseria gonorrhoeae infections as well as preterm birth. Further, BVAB1 is associated with the persistence of BV following metronidazole treatment, increased vaginal inflammation, and adverse obstetrics outcomes. There is no available complete genome sequence of BVAB1, which has made it di?cult to…
In this webinar, Jonas Korlach, Chief Scientific Officer, PacBio provides an overview of the features and the advantages of the new Sequel II System. Kiran Garimella, Senior Computational Scientist, Broad Institute of MIT and Harvard University, describes his work sequencing humans with HiFi reads enabling discovery of structural variants undetectable in short reads. Luke Tallon, Scientific Director, Genomics Resource Center, Institute for Genome Sciences, University of Maryland School of Medicine, covers the GRC’s work on bacterial multiplexing, 16S microbiome profiling, and shotgun metagenomics. Finally, Shane McCarthy, Senior Research Associate, University of Cambridge, focuses on the scaling and affordability of high-quality…
In this presentation, Emily Hatas of PacBio offers a look a how SMRT Sequencing has changed over the years as well as the most common applications in human genome analysis: high-throughput structural variant detection; comprehensive variant detection; and de novo assembly of reference genomes.
In this talk at PAG 2020, PacBio Plant and Animal Sciences Marketing Manager Michelle Vierra discusses recent updates to Single Molecule, Real-Time (SMRT) Sequencing technology, including the Sequel II System, updated protocols for low-input as well as other upcoming developments.
In this webinar, Dr. Ashby gives attendees a brief update on PacBio’s metagenomics solutions on the Sequel II System. Then, Dr. Ma, University of Maryland School of Medicine, discusses her work using long read sequencing to identify high-resolution microbial biomarkers associated with leaky gut syndrome in premature infants. Finally, Dr. Weinstock, The Jackson Laboratory, talks about the potential of highly accurate long reads to enable strain-level resolution of the human gut microbiome by resolving intraspecies variation in multiple copies of the 16S gene.
Neisseria gonorrhoeae, the sole causative agent of gonorrhea, constitutively undergoes diversification of the Type IV pilus. Gene conversion occurs between one of the several donor silent copies located in distinct loci and the recipient pilE gene, encoding the major pilin subunit of the pilus. A guanine quadruplex (G4) DNA structure and a cis-acting sRNA (G4-sRNA) are located upstream of the pilE gene and both are required for pilin antigenic variation (Av). We show that the reduced sRNA transcription lowers pilin Av frequencies. Extended transcriptional elongation is not required for Av, since limiting the transcript to 32 nt allows for normal…
Existing long-read assemblers require tens of thousands of CPU hours to assemble a human genome and are being outpaced by sequencing technologies in terms of both throughput and cost. We developed a novel long-read assembler wtdbg2 that, for human data, is tens of times faster than published tools while achieving comparable contiguity and accuracy. It represents a significant algorithmic advance and paves the way for population-scale long-read assembly in future.
Genome-wide association studies (GWAS) have identified many genomic loci associated with risk for schizophrenia, but unambiguous identification of the relationship between disease-associated variants and specific genes, and in particular their effect on risk conferring transcripts, has proven difficult. To better understand the specific molecular mechanism(s) at the schizophrenia locus in 11q25, we undertook cis expression quantitative trait loci (cis-eQTL) mapping for this 2 megabase genomic region using postmortem human brain samples. To comprehensively assess the effects of genetic risk upon local expression, we evaluated multiple transcript features: genes, exons, and exon-exon junctions in multiple brain regions-dorsolateral prefrontal cortex (DLPFC), hippocampus,…
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…
Enterococcus faecalis strain SGAir0397 was isolated from a tropical air sample collected in Singapore. Its genome was assembled using single-molecule real-time sequencing data and comprises one circular chromosome with a length of 2.69 Mbp. The genome contains 2,595 protein-coding genes, 59 tRNAs, and 12 rRNAs.Copyright © 2019 Purbojati et al.