55,883 research outputs found
Genome Evolution and Innovation across the Four Major Lineages of Cryptococcus gattii
We acknowledge the Broad Institute Sequencing Platform and Imperial College London for generating the DNA sequence described here (and R265 Illumina sequences described previously [4]). We thank Sinéad Chapman for coordinating sequencing at the Broad Institute and Margaret Priest for assistance in submitting assemblies to NCBI. This project was supported by the National Human Genome Research Institute, grant no. U54HG003067. R.A.F. is supported by the Wellcome Trust. R.C.M. is supported by the Lister Institute for Preventive Medicine, the Medical Research Council UK, and the European Research Council.Peer reviewedPublisher PD
Genomic innovations linked to infection strategies across emerging pathogenic chytrid fungi
We acknowledge the Broad Institute Sequencing Platform and Imperial College London for generating the DNA and RNA sequence described here. Financial support was provided by a UK Natural Environmental Research Council (NERC NE/K012509/1) grant to MCF, a Wellcome Trust Fellowship to RF, a Morris Animal Foundation grant to FP, and by the National Human Genome Research Institute grant number U54HG003067 to the Broad Institute. E.V. is supported by the Research Foundation Flanders (FWO grant 12E6616N).Peer reviewedPublisher PD
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Comprehensive genomic characterization defines human glioblastoma genes and core pathways.
Human cancer cells typically harbour multiple chromosomal aberrations, nucleotide substitutions and epigenetic modifications that drive malignant transformation. The Cancer Genome Atlas (TCGA) pilot project aims to assess the value of large-scale multi-dimensional analysis of these molecular characteristics in human cancer and to provide the data rapidly to the research community. Here we report the interim integrative analysis of DNA copy number, gene expression and DNA methylation aberrations in 206 glioblastomas--the most common type of adult brain cancer--and nucleotide sequence aberrations in 91 of the 206 glioblastomas. This analysis provides new insights into the roles of ERBB2, NF1 and TP53, uncovers frequent mutations of the phosphatidylinositol-3-OH kinase regulatory subunit gene PIK3R1, and provides a network view of the pathways altered in the development of glioblastoma. Furthermore, integration of mutation, DNA methylation and clinical treatment data reveals a link between MGMT promoter methylation and a hypermutator phenotype consequent to mismatch repair deficiency in treated glioblastomas, an observation with potential clinical implications. Together, these findings establish the feasibility and power of TCGA, demonstrating that it can rapidly expand knowledge of the molecular basis of cancer
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A framework for human microbiome research.
A variety of microbial communities and their genes (the microbiome) exist throughout the human body, with fundamental roles in human health and disease. The National Institutes of Health (NIH)-funded Human Microbiome Project Consortium has established a population-scale framework to develop metagenomic protocols, resulting in a broad range of quality-controlled resources and data including standardized methods for creating, processing and interpreting distinct types of high-throughput metagenomic data available to the scientific community. Here we present resources from a population of 242 healthy adults sampled at 15 or 18 body sites up to three times, which have generated 5,177 microbial taxonomic profiles from 16S ribosomal RNA genes and over 3.5 terabases of metagenomic sequence so far. In parallel, approximately 800 reference strains isolated from the human body have been sequenced. Collectively, these data represent the largest resource describing the abundance and variety of the human microbiome, while providing a framework for current and future studies
Toward 959 nematode genomes
The sequencing of the complete genome of the nematode Caenorhabditis elegans was a landmark achievement and ushered in a new era of whole-organism, systems analyses of the biology of this powerful model organism. The success of the C. elegans genome sequencing project also inspired communities working on other organisms to approach genome sequencing of their species. The phylum Nematoda is rich and diverse and of interest to a wide range of research fields from basic biology through ecology and parasitic disease. For all these communities, it is now clear that access to genome scale data will be key to advancing understanding, and in the case of parasites, developing new ways to control or cure diseases. The advent of second-generation sequencing technologies, improvements in computing algorithms and infrastructure and growth in bioinformatics and genomics literacy is making the addition of genome sequencing to the research goals of any nematode research program a less daunting prospect. To inspire, promote and coordinate genomic sequencing across the diversity of the phylum, we have launched a community wiki and the 959 Nematode Genomes initiative (www.nematodegenomes.org/). Just as the deciphering of the developmental lineage of the 959 cells of the adult hermaphrodite C. elegans was the gateway to broad advances in biomedical science, we hope that a nematode phylogeny with (at least) 959 sequenced species will underpin further advances in understanding the origins of parasitism, the dynamics of genomic change and the adaptations that have made Nematoda one of the most successful animal phyla
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Shotgun metagenome data of a defined mock community using Oxford Nanopore, PacBio and Illumina technologies.
Metagenomic sequence data from defined mock communities is crucial for the assessment of sequencing platform performance and downstream analyses, including assembly, binning and taxonomic assignment. We report a comparison of shotgun metagenome sequencing and assembly metrics of a defined microbial mock community using the Oxford Nanopore Technologies (ONT) MinION, PacBio and Illumina sequencing platforms. Our synthetic microbial community BMock12 consists of 12 bacterial strains with genome sizes spanning 3.2-7.2 Mbp, 40-73% GC content, and 1.5-7.3% repeats. Size selection of both PacBio and ONT sequencing libraries prior to sequencing was essential to yield comparable relative abundances of organisms among all sequencing technologies. While the Illumina-based metagenome assembly yielded good coverage with few misassemblies, contiguity was greatly improved by both, Illumina + ONT and Illumina + PacBio hybrid assemblies but increased misassemblies, most notably in genomes with high sequence similarity to each other. Our resulting datasets allow evaluation and benchmarking of bioinformatics software on Illumina, PacBio and ONT platforms in parallel
Metagenomic study of the human skin microbiome associated with acne
The human microbiota contributes to our normal postnatal development and plays a significant role in defining our physiology. To understand the role of microbiota in human health and disease, we study the skin microbiome in pilosebaceous units (hair follicles) and its association with acne.

Acne is one of the most common skin diseases. Although its etiology still needs to be defined, a bacterial factor has been suggested in the development of the disease. In fact, antibiotic therapy targeting _Propionibacterium acnes_ has been a mainstay treatment for more than 30 years.

Our preliminary study shows that the microcomedone, a specialized skin compartment where acne arises, has a tractable microbiome, with a single dominant species, _P. acnes_. This system offers a unique advantage allowing in-depth analysis of a human microbiome at the subspecies level by sequencing. Our preliminary study suggests that the microbiome associated with acne offers promise for understanding the correlation between the composition of the microbiome and human health and disease.

The goal of the project is to determine whether the microbiota in the pilosebaceous units contributes to acne. We plan to investigate the microbiome associated with acne in three directions. First, we plan to investigate the strain diversity of _P. acnes_ in a disease cohort and a normal cohort and examine whether certain strains of _P. acnes_ are correlated with the disease. Second, we plan to investigate the non- _P. acnes_ microbes in microcomedones and disease lesions and examine whether they correlate with acne pathogenesis. Third, we will examine the interactions between the microbes and the host by transcriptional profiling of both the microbiota and the host.

During the first year of this project, two main questions were asked. 1. Are certain strains of _P. acnes_ associated with acne, but rarely found in normal individuals? 2. If specific strains are associated with acne, what are the differences in their genetic composition compared to other _P. acnes_ strains that are not associated with acne? We collected microcomedone samples from more than 100 subjects, including acne patients and normal individuals. Genomic DNA was extracted from each sample, and 16S rDNA was amplified using universal primers (8F and 1510R), cloned and sequenced using Sanger method. Approximately 384 near full length 16S rDNA sequences were obtained for each sample. Some of the microcomedone samples were also cultured under anaerobic condition to isolate different P. acnes strains. Sixty-eight isolates were selected for whole genome shotgun sequencing using Solexa/Illumina platform. By the end of the first year of the project, we completed the sequencing of more than 40,000 16S rDNA clones and 68 genomes of _P. acnes_ isolates.

Illuminating Choices for Library Prep: A Comparison of Library Preparation Methods for Whole Genome Sequencing of Cryptococcus neoformans Using Illumina HiSeq.
The industry of next-generation sequencing is constantly evolving, with novel library preparation methods and new sequencing machines being released by the major sequencing technology companies annually. The Illumina TruSeq v2 library preparation method was the most widely used kit and the market leader; however, it has now been discontinued, and in 2013 was replaced by the TruSeq Nano and TruSeq PCR-free methods, leaving a gap in knowledge regarding which is the most appropriate library preparation method to use. Here, we used isolates from the pathogenic fungi Cryptococcus neoformans var. grubii and sequenced them using the existing TruSeq DNA v2 kit (Illumina), along with two new kits: the TruSeq Nano DNA kit (Illumina) and the NEBNext Ultra DNA kit (New England Biolabs) to provide a comparison. Compared to the original TruSeq DNA v2 kit, both newer kits gave equivalent or better sequencing data, with increased coverage. When comparing the two newer kits, we found little difference in cost and workflow, with the NEBNext Ultra both slightly cheaper and faster than the TruSeq Nano. However, the quality of data generated using the TruSeq Nano DNA kit was superior due to higher coverage at regions of low GC content, and more SNPs identified. Researchers should therefore evaluate their resources and the type of application (and hence data quality) being considered when ultimately deciding on which library prep method to use
Integrated DNA walking system to characterize a broad spectrum of GMOs in food/feed matrices
Background: In order to provide a system fully integrated with qPCR screening, usually used in GMO routine analysis, as well as being able to detect, characterize and identify a broad spectrum of GMOs in food/feed matrices, two bidirectional DNA walking methods targeting p35S or tNOS, the most common transgenic elements found in GM crops, were developed. These newly developed DNA walking methods are completing the previously implemented DNA walking method targeting the t35S pCAMBIA element.
Results: First, the newly developed DNA walking methods, anchored on the sequences used for the p35S or tNOS qPCR screening, were tested on Bt rice that contains these two transgenic elements. Second, the methods were assessed on a maize sample containing a low amount of the GM MON863 event, representing a more complex matrix in terms of genome size and sensitivity. Finally, to illustrate its applicability in GMO routine analysis by enforcement laboratories, the entire workflow of the integrated strategy, including qPCR screening to detect the potential presence of GMOs and the subsequent DNA walking methods to characterize and identify the detected GMOs, was applied on a GeMMA Scheme Proficiency Test matrix. Via the characterization of the transgene flanking region between the transgenic cassette and the plant genome as well as of a part of the transgenic cassette, the presence of GMOs was properly confirmed or infirmed in all tested samples.
Conclusion: Due to their simple procedure and their short time-frame to get results, the developed DNA walking methods proposed here can be easily implemented in GMO routine analysis by the enforcement laboratories. In providing crucial information about the transgene flanking regions and/or the transgenic cassettes, this DNA walking strategy is a key molecular tool to prove the presence of GMOs in any given food/feed matrix
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