Category: Papers by CGEB labs

Measures of phylogenetic differentiation provide robust and complementary insights into microbial communities.

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Measures of phylogenetic differentiation provide robust and complementary insights into microbial communities.

ISME J. 2013 Jan;7(1):173-83

Authors: Parks DH, Beiko RG

Abstract
High-throughput sequencing techniques have made large-scale spatial and temporal surveys of microbial communities routine. Gaining insight into microbial diversity requires methods for effectively analyzing and visualizing these extensive data sets. Phylogenetic β-diversity measures address this challenge by allowing the relationship between large numbers of environmental samples to be explored using standard multivariate analysis techniques. Despite the success and widespread use of phylogenetic β-diversity measures, an extensive comparative analysis of these measures has not been performed. Here, we compare 39 measures of phylogenetic β diversity in order to establish the relative similarity of these measures along with key properties and performance characteristics. While many measures are highly correlated, those commonly used within microbial ecology were found to be distinct from those popular within classical ecology, and from the recently recommended Gower and Canberra measures. Many of the measures are surprisingly robust to different rootings of the gene tree, the choice of similarity threshold used to define operational taxonomic units, and the presence of outlying basal lineages. Measures differ considerably in their sensitivity to rare organisms, and the effectiveness of measures can vary substantially under alternative models of differentiation. Consequently, the depth of sequencing required to reveal underlying patterns of relationships between environmental samples depends on the selected measure. Our results demonstrate that using complementary measures of phylogenetic β diversity can further our understanding of how communities are phylogenetically differentiated. Open-source software implementing the phylogenetic β-diversity measures evaluated in this manuscript is available at http://kiwi.cs.dal.ca/Software/ExpressBetaDiversity.

PMID: 22855211 [PubMed – indexed for MEDLINE]

Amoeba stages in the deepest branching heteroloboseans, including Pharyngomonas: evolutionary and systematic implications.

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Amoeba stages in the deepest branching heteroloboseans, including Pharyngomonas: evolutionary and systematic implications.
Protist. 2013 Mar;164(2):272-86
Authors: Harding T, Brown MW, Plotnikov A, Selivanov…

Ultrastructure and molecular phylogeny of the cryptomonad Goniomonas avonlea sp. nov.

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Ultrastructure and molecular phylogeny of the cryptomonad Goniomonas avonlea sp. nov.

Protist. 2013 Mar;164(2):160-82

Authors: Kim E, Archibald JM

Abstract
We describe a new species of cryptomonad, Goniomonas avonlea sp. nov., using molecular phylogeny and comprehensive microscopic investigation. G. avonlea is a marine bacterivorous flagellate, measuring 8-11 μm long and 6-7 μm wide, with two subequal flagella that are directed anteriorly and posteriorly. G. avonlea is morphologically and genetically distinct from three other Goniomonas species that have been described to date. SEM and TEM show that G. avonlea shares ultrastructural features with other Goniomonas and cryptomonads, including the presence of bipartite ejectisomes, double septa in the transition region, flat mitochondrial cristae, a furrow complex, a rhizostyle, rectangular periplast plates, and the infundibulum. The discharged large ejectisome is straight and has a unique loose, reticulate layer. The flagellar apparatus includes non-tubular roots, microtubular roots, and a compound root that is reminiscent of the multilayered structure (MLS) observed in the flagellate cells of streptophytes and a few other eukaryotes. Molecular phylogenies based on 18S and 28S rRNA genes suggest a specific affiliation of G. avonlea to marine Goniomonas species, and support the monophyly of Goniomonas to the exclusion of plastid-bearing cryptomonads. Our study adds to a growing body of evidence for the high level of diversity and antiquity of the genus Goniomonas.

PMID: 23127606 [PubMed – indexed for MEDLINE]

Improving evolutionary models for mitochondrial protein data with site-class specific amino acid exchangeability matrices.

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Improving evolutionary models for mitochondrial protein data with site-class specific amino acid exchangeability matrices.
PLoS One. 2013;8(1):e55816
Authors: Dunn KA, Jiang W, Field C, Bielawski JP

Validating the identity of Paramoeba invadens, the causative agent of recurrent mass mortality of sea urchins in Nova Scotia, Canada.

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Validating the identity of Paramoeba invadens, the causative agent of recurrent mass mortality of sea urchins in Nova Scotia, Canada.
Dis Aquat Organ. 2013 Apr 11;103(3):209-27
Authors: Feehan CJ, Johnson-Ma…

Broad distribution of TPI-GAPDH fusion proteins among eukaryotes: evidence for glycolytic reactions in the mitochondrion?

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Broad distribution of TPI-GAPDH fusion proteins among eukaryotes: evidence for glycolytic reactions in the mitochondrion?
PLoS One. 2012;7(12):e52340
Authors: Nakayama T, Ishida K, Archibald JM
Abst…

Is junk DNA bunk? A critique of ENCODE.

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Is junk DNA bunk? A critique of ENCODE.
Proc Natl Acad Sci U S A. 2013 Apr 2;110(14):5294-300
Authors: Doolittle WF
Abstract
Do data from the Encyclopedia Of DNA Elements (ENCODE) project ren…

Detecting the signatures of adaptive evolution in protein-coding genes.

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Detecting the signatures of adaptive evolution in protein-coding genes.
Curr Protoc Mol Biol. 2013 Jan;Chapter 19:Unit 19.1.
Authors: Bielawski JP
Abstract
The field of molecular evolution, w…

Proteomics reveals plastid- and periplastid-targeted proteins in the chlorarachniophyte alga Bigelowiella natans.

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Proteomics reveals plastid- and periplastid-targeted proteins in the chlorarachniophyte alga Bigelowiella natans.
Genome Biol Evol. 2012 Jan;4(12):1391-406
Authors: Hopkins JF, Spencer DF, Laboissiere S, Ne…

Lateral gene transfer of an ABC transporter complex between major constituents of the human gut microbiome.

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Lateral gene transfer of an ABC transporter complex between major constituents of the human gut microbiome.
BMC Microbiol. 2012;12:248
Authors: Meehan CJ, Beiko RG
Abstract
BACKGROUND: Sever…