References of "Brinkmann, Henner"
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See detailChromera velia, Endosymbioses and the Rhodoplex Hypothesis - Plastid Evolution in Cryptophytes, Alveolates, Stramenopiles and Haptophytes (CASH Lineages)
Petersen, Jörn; Ludewig, Ann-Kathrin; Michael, Victoria et al

in Genome Biology and Evolution (2014)

The discovery of Chromera velia, a free-living photosynthetic relative of apicomplexan pathogens, has provided an unexpected opportunity to study the algal ancestry of malaria parasites. In this work we ... [more ▼]

The discovery of Chromera velia, a free-living photosynthetic relative of apicomplexan pathogens, has provided an unexpected opportunity to study the algal ancestry of malaria parasites. In this work we compared the molecular footprints of a eukaryote-to-eukaryote endosymbiosis in C. velia to their equivalents in peridinin-containing dinoflagellates (PCD) to re- evaluate recent claims in favor of a common ancestry of their plastids. To this end, we established the draft genome and a set of full-length cDNA sequences from C. velia via next- generation sequencing. We documented the presence of a single coxI gene in the mitochondrial genome, which thus represents the genetically most reduced aerobic organelle identified so far, but focused our analyses on five “lucky genes” of the Calvin cycle. These were selected because of their known support for a common origin of complex plastids from cryptophytes, alveolates (represented by PCDs), stramenopiles and haptophytes (CASH) via a single secondary endosymbiosis with a red alga. As expected, our broadly sampled phylogenies of the nuclear- encoded Calvin cycle markers support a rhodophycean origin for the complex plastid of Chromera. However, they also suggest an independent origin of apicomplexan and dinophycean (PCD) plastids via two eukaryote-to-eukaryote endosymbioses. Although at odds with the current view of a common photosynthetic ancestry for alveolates, this conclusion is nonetheless in line with the deviant plastome architecture in dinoflagellates and the morphological paradox of four versus three plastid membranes in the respective lineages. Further support for independent endosymbioses is provided by analysis of five additional markers, four of them involved in the plastid protein import machinery. Finally, we introduce the “rhodoplex hypothesis” as a convenient way to designate evolutionary scenarios where CASH plastids are ultimately the product of a single secondary endosymbiosis with a red alga, but were subsequently horizontally spread via higher-order eukaryote-to-eukaryote endosymbioses. [less ▲]

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See detailThe African coelacanth genome provides insights into tetrapod evolution.
Amemiya, Chris T.; Alfoldi, Jessica; Lee, Alison P. et al

in Nature (2013), 496(7445), 311-6

The discovery of a living coelacanth specimen in 1938 was remarkable, as this lineage of lobe-finned fish was thought to have become extinct 70 million years ago. The modern coelacanth looks remarkably ... [more ▼]

The discovery of a living coelacanth specimen in 1938 was remarkable, as this lineage of lobe-finned fish was thought to have become extinct 70 million years ago. The modern coelacanth looks remarkably similar to many of its ancient relatives, and its evolutionary proximity to our own fish ancestors provides a glimpse of the fish that first walked on land. Here we report the genome sequence of the African coelacanth, Latimeria chalumnae. Through a phylogenomic analysis, we conclude that the lungfish, and not the coelacanth, is the closest living relative of tetrapods. Coelacanth protein-coding genes are significantly more slowly evolving than those of tetrapods, unlike other genomic features. Analyses of changes in genes and regulatory elements during the vertebrate adaptation to land highlight genes involved in immunity, nitrogen excretion and the development of fins, tail, ear, eye, brain and olfaction. Functional assays of enhancers involved in the fin-to-limb transition and in the emergence of extra-embryonic tissues show the importance of the coelacanth genome as a blueprint for understanding tetrapod evolution. [less ▲]

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See detailResolving difficult phylogenetic questions: why more sequences are not enough.
Philippe, Hervé; Brinkmann, Henner; Lavrov, Dennis V et al

in PLoS Biology (2011), 9(3), 1000602

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See detailA phylogenomic falsification of the chromalveolate hypothesis
Baurain, Denis ULg; Brinkmann, Henner; Petersen, Jorn et al

Poster (2010, July)

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See detailPhylogenomic evidence for separate acquisition of plastids in cryptophytes, haptophytes, and stramenopiles
Baurain, Denis ULg; Brinkmann, Henner; Petersen, Jorn et al

in Molecular Biology and Evolution (2010), 27(7), 1698-709

According to the chromalveolate hypothesis (Cavalier-Smith T. 1999. Principles of protein and lipid targeting in secondary symbiogenesis: euglenoid, dinoflagellate, and sporozoan plastid origins and the ... [more ▼]

According to the chromalveolate hypothesis (Cavalier-Smith T. 1999. Principles of protein and lipid targeting in secondary symbiogenesis: euglenoid, dinoflagellate, and sporozoan plastid origins and the eukaryote family tree. J Eukaryot Microbiol 46:347-366), the four eukaryotic groups with chlorophyll c-containing plastids originate from a single photosynthetic ancestor, which acquired its plastids by secondary endosymbiosis with a red alga. So far, molecular phylogenies have failed to either support or disprove this view. Here, we devise a phylogenomic falsification of the chromalveolate hypothesis that estimates signal strength across the three genomic compartments: If the four chlorophyll c-containing lineages indeed derive from a single photosynthetic ancestor, then similar amounts of plastid, mitochondrial, and nuclear sequences should allow to recover their monophyly. Our results refute this prediction, with statistical support levels too different to be explained by evolutionary rate variation, phylogenetic artifacts, or endosymbiotic gene transfer. Therefore, we reject the chromalveolate hypothesis as falsified in favor of more complex evolutionary scenarios involving multiple higher order eukaryote-eukaryote endosymbioses. [less ▲]

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See detailOrigin and distribution of Calvin cycle fructose and sedoheptulose bisphosphatases in Plantae and complex algae: A single secondary origin of complex red plastids and subsequent propagation via tertiary endosymbioses
Teich, René; Zauner, Stefan; Baurain, Denis ULg et al

in Protist (2007), 158(3), 263-276

Sedoheptulose-1,7-bisphosphatase (SBPase) and fructose-1,6-bisphosphatase (FBPase) are essential nuclear-encoded enzymes involved in land plant Calvin cycle and gluconeogenesis. In this study, we cloned ... [more ▼]

Sedoheptulose-1,7-bisphosphatase (SBPase) and fructose-1,6-bisphosphatase (FBPase) are essential nuclear-encoded enzymes involved in land plant Calvin cycle and gluconeogenesis. In this study, we cloned seven SBP and seven FBP cDNAs/genes and established sequences from all lineages of photosynthetic eukaryotes, in order to investigate their origin and evolution. Our data are best explained by a single recruitment of plastid-targeted SBP in Plantae after primary endosymbiosis and a further distribution to algae with complex plastids. While SBP is universally found in photosynthetic lineages, its presence in apicomplexa, ciliates, trypanosomes, and ascomycetes is surprising given that no metabolic function beyond the one in the plastid Calvin cycle is described so far. Sequences of haptophytes, cryptophytes, diatoms, and peridinin-containing dinoflagellates (complex red lineage) strongly group together in the SBP tree and the same assemblage is recovered for plastid-targeted FBP sequences, although this is less supported. Both SBP and plastid-targeted FBP are most likely of red algal origin. Including phosphoribulokinase, fructose bisphosphate aldolase, and glyceraldehyde-3-phosphate dehydrogenase, a total of five independent plastid-related nuclear-encoded markers support a common origin of all complex rhodoplasts via a single secondary endosymbiosis event. However, plastid phylogenies are incongruent with those of the host cell, as illustrated by the cytosolic FBP isoenzyme. These results are discussed in the context of Cavalier-Smith's far-reaching chromalveolate hypothesis. In our opinion, a more plausible evolutionary scenario would be the establishment of a unique secondary rhodoplast and its subsequent spread via tertiary endosymbioses. (c) 2007 Elsevier GmbH. All rights reserved. [less ▲]

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See detailLack of resolution in the animal phylogeny: Closely spaced cladogeneses or undetected systematic errors?
Baurain, Denis ULg; Brinkmann, Henner; Philippe, Hervé

in Molecular Biology and Evolution (2007), 24(1), 6-9

A recent phylogenomic study reported that the animal phylogeny was unresolved despite the use of 50 genes. This lack of resolution was interpreted as "a positive signature of closely spaced cladogenetic ... [more ▼]

A recent phylogenomic study reported that the animal phylogeny was unresolved despite the use of 50 genes. This lack of resolution was interpreted as "a positive signature of closely spaced cladogenetic events." Here, we propose that this lack of resolution is rather due to the mutual cancellation of the phylogenetic signal (historical) and the nonphylogenetic signal (due to systematic errors) that results from inadequate taxon sampling and/or model of sequence evolution. Starting with a data set of comparable size, we use 3 different strategies to reduce the nonphylogenetic signal: 1) increasing the number of species; 2) replacing a fast-evolving species by a slowly evolving one; and 3) using a better model of sequence evolution. In all cases, the phylogenetic resolution is markedly improved, in agreement with our hypothesis that the originally reported lack of resolution was artifactual. [less ▲]

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See detailPhylogenomics: how far back in the past can we go?
Brinkmann, Henner; Baurain, Denis ULg; Philippe, Hervé

in Pudritz, Ralph; Higgs, Paul; Stone, Jonathan (Eds.) Planetary Systems and the Origins of Life (2007)

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See detailPhylogénomique des lignées photosynthétiques
Baurain, Denis ULg; Brinkmann, Henner; Philippe, Hervé

Scientific conference (2006, December 22)

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See detailAnimal evolution — A fully-resolved phylogenomic tree argues against the Cambrian explosion hypothesis
Philippe, Hervé; Brinkmann, Henner; Baurain, Denis ULg

Poster (2006, March)

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See detailThe animal phylogeny and the fundamental importance of taxon sampling
Philippe, Hervé; Brinkmann, Henner; Baurain, Denis ULg

Scientific conference (2006, February 20)

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