LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 4 of total 4

Search options

  1. Article ; Online: Effects of OTU clustering and PCR artifacts on microbial diversity estimates.

    Patin, Nastassia V / Kunin, Victor / Lidström, Ulrika / Ashby, Matthew N

    Microbial ecology

    2012  Volume 65, Issue 3, Page(s) 709–719

    Abstract: Next-generation sequencing has increased the coverage of microbial diversity surveys by orders of magnitude, but differentiating artifacts from rare environmental sequences remains a challenge. Clustering 16S rRNA sequences into operational taxonomic ... ...

    Abstract Next-generation sequencing has increased the coverage of microbial diversity surveys by orders of magnitude, but differentiating artifacts from rare environmental sequences remains a challenge. Clustering 16S rRNA sequences into operational taxonomic units (OTUs) organizes sequence data into groups of 97 % identity, helping to reduce data volumes and avoid analyzing sequencing artifacts by grouping them with real sequences. Here, we analyze sequence abundance distributions across environmental samples and show that 16S rRNA sequences of >99 % identity can represent functionally distinct microorganisms, rendering OTU clustering problematic when the goal is an accurate analysis of organism distribution. Strict postsequencing quality control (QC) filters eliminated the most prevalent artifacts without clustering. Further experiments proved that DNA polymerase errors in polymerase chain reaction (PCR) generate a significant number of substitution errors, most of which pass QC filters. Based on our findings, we recommend minimizing the number of PCR cycles in DNA library preparation and applying strict postsequencing QC filters to reduce the most prevalent artifacts while maintaining a high level of accuracy in diversity estimates. We further recommend correlating rare and abundant sequences across environmental samples, rather than clustering into OTUs, to identify remaining sequence artifacts without losing the resolution afforded by high-throughput sequencing.
    MeSH term(s) Actinomycetales/classification ; Actinomycetales/genetics ; Actinomycetales/isolation & purification ; Biodiversity ; DNA Primers/genetics ; DNA, Bacterial/genetics ; High-Throughput Nucleotide Sequencing ; Polymerase Chain Reaction/methods ; Polymerase Chain Reaction/standards ; RNA, Ribosomal, 16S/genetics
    Chemical Substances DNA Primers ; DNA, Bacterial ; RNA, Ribosomal, 16S
    Language English
    Publishing date 2012-12-12
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1462065-0
    ISSN 1432-184X ; 0095-3628
    ISSN (online) 1432-184X
    ISSN 0095-3628
    DOI 10.1007/s00248-012-0145-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article: Effects of OTU Clustering and PCR Artifacts on Microbial Diversity Estimates

    Patin, Nastassia V / Kunin, Victor / Lidström, Ulrika / Ashby, Matthew N

    Microbial ecology. 2013 Apr., v. 65, no. 3

    2013  

    Abstract: Next-generation sequencing has increased the coverage of microbial diversity surveys by orders of magnitude, but differentiating artifacts from rare environmental sequences remains a challenge. Clustering 16S rRNA sequences into operational taxonomic ... ...

    Abstract Next-generation sequencing has increased the coverage of microbial diversity surveys by orders of magnitude, but differentiating artifacts from rare environmental sequences remains a challenge. Clustering 16S rRNA sequences into operational taxonomic units (OTUs) organizes sequence data into groups of 97 % identity, helping to reduce data volumes and avoid analyzing sequencing artifacts by grouping them with real sequences. Here, we analyze sequence abundance distributions across environmental samples and show that 16S rRNA sequences of >99 % identity can represent functionally distinct microorganisms, rendering OTU clustering problematic when the goal is an accurate analysis of organism distribution. Strict postsequencing quality control (QC) filters eliminated the most prevalent artifacts without clustering. Further experiments proved that DNA polymerase errors in polymerase chain reaction (PCR) generate a significant number of substitution errors, most of which pass QC filters. Based on our findings, we recommend minimizing the number of PCR cycles in DNA library preparation and applying strict postsequencing QC filters to reduce the most prevalent artifacts while maintaining a high level of accuracy in diversity estimates. We further recommend correlating rare and abundant sequences across environmental samples, rather than clustering into OTUs, to identify remaining sequence artifacts without losing the resolution afforded by high-throughput sequencing.
    Keywords DNA libraries ; DNA-directed DNA polymerase ; filters ; nucleotide sequences ; polymerase chain reaction ; quality control ; ribosomal RNA ; surveys
    Language English
    Dates of publication 2013-04
    Size p. 709-719.
    Publishing place Springer-Verlag
    Document type Article
    ZDB-ID 1462065-0
    ISSN 1432-184X ; 0095-3628
    ISSN (online) 1432-184X
    ISSN 0095-3628
    DOI 10.1007/s00248-012-0145-4
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  3. Article ; Online: Microbialite genetic diversity and composition relate to environmental variables.

    Centeno, Carla M / Legendre, Pierre / Beltrán, Yislem / Alcántara-Hernández, Rocío J / Lidström, Ulrika E / Ashby, Matthew N / Falcón, Luisa I

    FEMS microbiology ecology

    2012  Volume 82, Issue 3, Page(s) 724–735

    Abstract: Microbialites have played an important role in the early history of life on Earth. Their fossilized forms represent the oldest evidence of life on our planet dating back to 3500 Ma. Extant microbialites have been suggested to be highly productive and ... ...

    Abstract Microbialites have played an important role in the early history of life on Earth. Their fossilized forms represent the oldest evidence of life on our planet dating back to 3500 Ma. Extant microbialites have been suggested to be highly productive and diverse communities with an evident role in the cycling of major elements, and in contributing to carbonate precipitation. Although their ecological and evolutionary importance has been recognized, the study of their genetic diversity is yet scanty. The main goal of this study was to analyse microbial genetic diversity of microbialites living in different types of environments throughout Mexico, including desert ponds, coastal lagoons and a crater-lake. We followed a pyrosequencing approach of hypervariable regions of the 16S rRNA gene. Results showed that microbialite communities were very diverse (H' = 6-7) and showed geographic variation in composition, as well as an environmental effect related to pH and conductivity, which together explained 33% of the genetic variation. All microbialites had similar proportions of major bacterial and archaeal phyla.
    MeSH term(s) Archaea/classification ; Archaea/genetics ; Bacteria/classification ; Bacteria/genetics ; Biodiversity ; Biological Evolution ; Fossils ; Fresh Water/chemistry ; Fresh Water/microbiology ; Genetic Variation ; Lakes/chemistry ; Lakes/microbiology ; Mexico ; Phylogeny ; RNA, Archaeal/genetics ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics
    Chemical Substances RNA, Archaeal ; RNA, Bacterial ; RNA, Ribosomal, 16S
    Language English
    Publishing date 2012-12
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 283722-5
    ISSN 1574-6941 ; 0168-6496
    ISSN (online) 1574-6941
    ISSN 0168-6496
    DOI 10.1111/j.1574-6941.2012.01447.x
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article: Serial analysis of rRNA genes and the unexpected dominance of rare members of microbial communities.

    Ashby, Matthew N / Rine, Jasper / Mongodin, Emmanuel F / Nelson, Karen E / Dimster-Denk, Dago

    Applied and environmental microbiology

    2007  Volume 73, Issue 14, Page(s) 4532–4542

    Abstract: The accurate description of a microbial community is an important first step in understanding the roles of its components in ecosystem function. A method for surveying microbial communities termed serial analysis of rRNA genes (SARD) is described here. ... ...

    Abstract The accurate description of a microbial community is an important first step in understanding the roles of its components in ecosystem function. A method for surveying microbial communities termed serial analysis of rRNA genes (SARD) is described here. Through a series of molecular cloning steps, short DNA sequence tags are recovered from the fifth variable (V5) region of the prokaryotic 16S rRNA genes from microbial communities. These tags are ligated to form concatemers comprised of 20 to 40 tags which are cloned and identified by DNA sequencing. Four agricultural soil samples were profiled with SARD to assess the method's utility. A total of 37,008 SARD tags comprising 3,127 unique sequences were identified. A comparison of duplicate profiles from one soil genomic DNA preparation revealed that the method was highly reproducible. The large numbers of singleton tags, together with nonparametric richness estimates, indicated that a significant amount of sequence tag diversity remained undetected with this level of sampling. The abundance classes of the observed tags were scale-free and conformed to a power law distribution. Numerically, the majority of the total tags observed belonged to abundance classes that were each present at less than 1% of the community. Over 99% of the unique tags individually made up less than 1% of the community. Therefore, from either a numerical or diversity standpoint, taxa with low abundance comprised a significant proportion of the microbial communities examined and could potentially make a large contribution to ecosystem function. SARD may provide a means to explore the ecological roles of these rare members of microbial communities in qualitative and quantitative terms.
    MeSH term(s) Bacteria/classification ; Bacteria/genetics ; Bacteria/isolation & purification ; Bacteriological Techniques/methods ; Biodiversity ; Cloning, Molecular ; Cluster Analysis ; DNA, Bacterial/genetics ; DNA, Bacterial/isolation & purification ; DNA, Ribosomal/genetics ; DNA, Ribosomal/isolation & purification ; Genes, rRNA ; Molecular Sequence Data ; Phylogeny ; Reproducibility of Results ; Sequence Analysis, DNA ; Soil Microbiology
    Chemical Substances DNA, Bacterial ; DNA, Ribosomal
    Language English
    Publishing date 2007-07
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 223011-2
    ISSN 1098-5336 ; 0099-2240
    ISSN (online) 1098-5336
    ISSN 0099-2240
    DOI 10.1128/AEM.02956-06
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top