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Sep 25

Identification of microRNAs in the Toxigenic Dinoflagellate Alexandrium catenella by High-Throughput Illumina Sequencing and Bioinformatic Analysis.

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Identification of microRNAs in the Toxigenic Dinoflagellate Alexandrium catenella by High-Throughput Illumina Sequencing and Bioinformatic Analysis.
PLoS One. 2015;10(9):e0138709
Authors: Geng H, S…

Sep 22

Projection scenarios of body mass index (2013-2030) for Public Health Planning in Quebec.

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Projection scenarios of body mass index (2013-2030) for Public Health Planning in Quebec.
BMC Public Health. 2014;14:996
Authors: Lo E, Hamel D, Jen Y, Lamontagne P, Martel S, Steensma C, Blouin C…

Sep 22

Phylogenomics Reveals Convergent Evolution of Lifestyles in Close Relatives of Animals and Fungi.

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Phylogenomics Reveals Convergent Evolution of Lifestyles in Close Relatives of Animals and Fungi.

Curr Biol. 2015 Sep 9;

Authors: Torruella G, de Mendoza A, Grau-Bové X, Antó M, Chaplin MA, Del Campo J, Eme L, Pérez-Cordón G, Whipps CM, Nichols KM, Paley R, Roger AJ, Sitjà-Bobadilla A, Donachie S, Ruiz-Trillo I

Abstract
The Opisthokonta are a eukaryotic supergroup divided in two main lineages: animals and related protistan taxa, and fungi and their allies [1, 2]. There is a great diversity of lifestyles and morphologies among unicellular opisthokonts, from free-living phagotrophic flagellated bacterivores and filopodiated amoebas to cell-walled osmotrophic parasites and saprotrophs. However, these characteristics do not group into monophyletic assemblages, suggesting rampant convergent evolution within Opisthokonta. To test this hypothesis, we assembled a new phylogenomic dataset via sequencing 12 new strains of protists. Phylogenetic relationships among opisthokonts revealed independent origins of filopodiated amoebas in two lineages, one related to fungi and the other to animals. Moreover, we observed that specialized osmotrophic lifestyles evolved independently in fungi and protistan relatives of animals, indicating convergent evolution. We therefore analyzed the evolution of two key fungal characters in Opisthokonta, the flagellum and chitin synthases. Comparative analyses of the flagellar toolkit showed a previously unnoticed flagellar apparatus in two close relatives of animals, the filasterean Ministeria vibrans and Corallochytrium limacisporum. This implies that at least four different opisthokont lineages secondarily underwent flagellar simplification. Analysis of the evolutionary history of chitin synthases revealed significant expansions in both animals and fungi, and also in the Ichthyosporea and C. limacisporum, a group of cell-walled animal relatives. This indicates that the last opisthokont common ancestor had a complex toolkit of chitin synthases that was differentially retained in extant lineages. Thus, our data provide evidence for convergent evolution of specialized lifestyles in close relatives of animals and fungi from a generalist ancestor.

PMID: 26365255 [PubMed – as supplied by publisher]

Sep 02

The genome of Aiptasia, a sea anemone model for coral symbiosis.

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The genome of Aiptasia, a sea anemone model for coral symbiosis.
Proc Natl Acad Sci U S A. 2015 Aug 31;
Authors: Baumgarten S, Simakov O, Esherick LY, Liew YJ, Lehnert EM, Michell CT, Li Y, Hambleto…

Sep 02

Diversity and origins of anaerobic metabolism in mitochondria and related organelles.

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Diversity and origins of anaerobic metabolism in mitochondria and related organelles.
Philos Trans R Soc Lond B Biol Sci. 2015 Sep 26;370(1678)
Authors: Stairs CW, Leger MM, Roger AJ
Abstrac…

Sep 02

Eukaryotes first: how could that be?

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Eukaryotes first: how could that be?
Philos Trans R Soc Lond B Biol Sci. 2015 Sep 26;370(1678)
Authors: Mariscal C, Doolittle WF
Abstract
In the half century since the formulation of…

Sep 01

Symbiosis becoming permanent: Survival of the luckiest.

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Symbiosis becoming permanent: Survival of the luckiest.
Proc Natl Acad Sci U S A. 2015 Aug 18;112(33):10101-3
Authors: Keeling PJ, McCutcheon JP, Doolittle WF
PMID: 26283342 [PubMed – in p…

Sep 01

Reply to Lane and Martin: Being and becoming eukaryotes.

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Reply to Lane and Martin: Being and becoming eukaryotes.
Proc Natl Acad Sci U S A. 2015 Aug 17;
Authors: Booth A, Doolittle WF
PMID: 26283404 [PubMed – as supplied by publisher]

Sep 01

Evolution: Gene transfer in complex cells.

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Evolution: Gene transfer in complex cells.
Nature. 2015 Aug 27;524(7566):423-4
Authors: Archibald JM
PMID: 26287464 [PubMed – in process]

Sep 01

Characterization of a Deep-Branching Heterolobosean, Pharyngomonas turkanaensis n. sp., Isolated From a Non-Hypersaline Habitat, and Ultrastructural Comparison of Cysts and Amoebae Among Pharyngomonas Strains.

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Characterization of a Deep-Branching Heterolobosean, Pharyngomonas turkanaensis n. sp., Isolated From a Non-Hypersaline Habitat, and Ultrastructural Comparison of Cysts and Amoebae Among Pharyngomonas Strains.

J Eukaryot Microbiol. 2015 Aug 20;

Authors: Park JS, Simpson AG

Abstract
An unusual heterolobosean amoeba, isolate LO, was isolated recently from a sample with a salinity of ~4‰, from Lake Turkana in East Africa. 18S rDNA phylogenies confirm that isolate LO branches among halophilic amoeboflagellates assigned to Pharyngomonas. We examined the ultrastructure of the amoeba and cyst stages of isolate LO, as well as the amoebae and cysts of Pharyngomonas kirbyi (isolates AS12B and SD1A). The amoebae of all three isolates lacked discrete dictyosomes and had discoidal/flattened mitochondrial cristae, but the mitochondria were not enrobed by rough endoplasmic reticulum. The cysts of all three isolates showed a thick, bipartite cyst wall, and lacked cyst pores. The cysts of isolate LO were distinct in that the ectocyst was very loose-fitting, and could contain ‘crypts’. No flagellate form of isolate LO has been observed to date, and a salinity-for-growth experiment showed that isolate LO can grow at 15‰ to 100‰ salinity, indicating that it is halotolerant. By contrast, other studied Pharyngomonas isolates are amoeboflagellates and true halophiles. Therefore, we propose isolate LO as a new species, Pharyngomonas turkanaensis n. sp. It is possible that P. turkanaensis descended from halophilic ancestors, and represents a secondary reestablishment of a physiology adapted for moderate salinity. This article is protected by copyright. All rights reserved.

PMID: 26291784 [PubMed – as supplied by publisher]