Illumination or confusion? Dinoflagellate molecular phylogenetic data viewed from a primarily morphological standpoint

Taylor, F. J. R.

doi:10.1111/j.1440-183.2004.00360.x

Cited by 22 publications

(31 citation statements)

References 62 publications

(97 reference statements)

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“…The dinokaryotes are by far the most studied group of dinoflagellates, and are widely acknowledged to have very unique morphological characters, such as dinokaryon, the cell with epicone and hypocone, the undulating tranverse flagellum [7], [49], as well as a variety of unusual molecular and genomic characteristics such as mitochondrial RNA editing, plastid mini-circle genome, and the addition of spliced-leaders to cytosolic transcripts [8], [9], [10], [11], [12], [13], [14]. Those features must have been acquired relatively early in the evolution of the dinoflagellates, but many are missing from the, perkinsids, suggesting that the the order of some steps in this evolution may yet be elucidated by examining the state of early-branching lineages such as Psammosa , Oxyrrhis , and syndineans for possible intermediates [62], [63].…”

Section: Discussionmentioning

confidence: 99%

“…The ellobiopsids, consisting of Ellobiopsis and Thalassomyces, form an independent and fast evolving lineage that does not belong to either of these major clades [32], [38]. Although the branching order of these early diverging lineages and the dinokaryotes has not been satisfactorily resolved, their early divergence from the ancestor of dinokaryotes is generally supported by molecular phylogenetic data and “syndinean-like” nuclear morphology sensu Leander & Hoppenrath [47] i.e., centrally located nucleolus with peripherally condensed chromatins that are also found in some perkinsids and colpodellids, as well as the intra nuclear spindle during nucleokinesis, which are shared with the apicomplexans [7], [40], [43], [48], [49]. Those basal dinoflagellates may hold the keys to understanding many aspects of dinoflagellate early evolution.…”

Section: Introductionmentioning

confidence: 99%

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Description of Two Species of Early Branching Dinoflagellates, Psammosa pacifica n. g., n. sp. and P. atlantica n. sp

2012

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In alveolate evolution, dinoflagellates have developed many unique features, including the cell that has epicone and hypocone, the undulating transverse flagellum. However, it remains unclear how these features evolved. The early branching dinoflagellates so far investigated such as Hematodinium, Amoebophrya and Oxyrrhis marina differ in many ways from of core dinoflagellates, or dinokaryotes. Except those handful of well studied taxa, the vast majority of early branching dinoflagellates are known only by environmental sequences, and remain enigmatic. In this study we describe two new species of the early branching dinoflagellates, Psammosa pacifica n. g., n. sp. and P. atlantica n. sp. from marine intertidal sandy beach. Molecular phylogeny of the small subunit (SSU) ribosomal RNA and Hsp90 gene places Psammosa spp. as an early branch among the dinoflagellates. Morphologically (1) they lack the typical dinoflagellate epicone–hypocone structure, and (2) undulation in either flagella. Instead they display a mosaïc of dinokaryotes traits, i.e. (3) presence of bi-partite trychocysts; Oxyrrhis marina–like traits, i.e. (4) presence of flagellar hairs, (5) presence of two-dimensional cobweb scales ornamenting both flagella (6) transversal cell division; a trait shared with some syndineansand Parvilucifera spp. i.e. (7) a nucleus with a conspicuous nucleolus and condensed chromatin distributed beneath the nuclear envelope; as well as Perkinsus marinus -like features i.e. (8) separate ventral grooves where flagella emerge and (9) lacking dinoflagellate-type undulating flagellum. Notably Psammosa retains an apical complex structure, which is shared between perkinsids, colpodellids, chromerids and apicomplexans, but is not found in dinokaryotic dinoflagellates.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Description of Two Species of Early Branching Dinoflagellates, Psammosa pacifica n. g., n. sp. and P. atlantica n. sp

2012

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“…However, the interrelationships of the major subgroups of dinoflagellates are still unresolved using current molecular markers, mainly because of a lack of statistical support (i.e., phylogenetic signal) for the branching order near the phylogenetic backbone of the group [12]–[14]. The evolutionary relationships of dinoflagellates were initially inferred from a comparison of morphological characters [15], and these data are very important for evaluating weakly resolved branching patterns inferred from molecular markers [13], [16]. Accordingly, the poor phylogenetic resolution associated with the molecular markers employed so far prolongs our reliance on morphological characters when making inferences about dinoflagellate evolutionary history [12], [13], [16].…”

Section: Introductionmentioning

confidence: 99%

“…The evolutionary relationships of dinoflagellates were initially inferred from a comparison of morphological characters [15], and these data are very important for evaluating weakly resolved branching patterns inferred from molecular markers [13], [16]. Accordingly, the poor phylogenetic resolution associated with the molecular markers employed so far prolongs our reliance on morphological characters when making inferences about dinoflagellate evolutionary history [12], [13], [16]. As such, inferences based on morphology have yet to be adequately tested with molecular markers that provide sufficient signal at the deepest levels in the dinoflagellate phylogenetic tree.…”

Section: Introductionmentioning

confidence: 99%

“…Molecular phylogenetic analyses of rDNA sequences and heat shock protein gene (Hsp90) sequences plus the absence of a dinokaryon in the trophont stage suggested that Noctiluca was an early diverging lineage of dinoflagellates that retained several ancestral states for the group as a whole (e.g., a pre-dinokaryotic nucleus) [31]–[34]. However, the molecular phylogenetic position of Noctiluca is inconsistent in different analyses, and these cells possess several very novel morphological features, so some authors have questioned the interpretation that this lineage is basal among dinoflagellates [13], [16].…”

Section: Introductionmentioning

confidence: 99%

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Dinoflagellate Phylogeny as Inferred from Heat Shock Protein 90 and Ribosomal Gene Sequences

Hoppenrath

Leander

2010

PLoS ONE

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BackgroundInterrelationships among dinoflagellates in molecular phylogenies are largely unresolved, especially in the deepest branches. Ribosomal DNA (rDNA) sequences provide phylogenetic signals only at the tips of the dinoflagellate tree. Two reasons for the poor resolution of deep dinoflagellate relationships using rDNA sequences are (1) most sites are relatively conserved and (2) there are different evolutionary rates among sites in different lineages. Therefore, alternative molecular markers are required to address the deeper phylogenetic relationships among dinoflagellates. Preliminary evidence indicates that the heat shock protein 90 gene (Hsp90) will provide an informative marker, mainly because this gene is relatively long and appears to have relatively uniform rates of evolution in different lineages.Methodology/Principal FindingsWe more than doubled the previous dataset of Hsp90 sequences from dinoflagellates by generating additional sequences from 17 different species, representing seven different orders. In order to concatenate the Hsp90 data with rDNA sequences, we supplemented the Hsp90 sequences with three new SSU rDNA sequences and five new LSU rDNA sequences. The new Hsp90 sequences were generated, in part, from four additional heterotrophic dinoflagellates and the type species for six different genera. Molecular phylogenetic analyses resulted in a paraphyletic assemblage near the base of the dinoflagellate tree consisting of only athecate species. However, Noctiluca was never part of this assemblage and branched in a position that was nested within other lineages of dinokaryotes. The phylogenetic trees inferred from Hsp90 sequences were consistent with trees inferred from rDNA sequences in that the backbone of the dinoflagellate clade was largely unresolved.Conclusions/SignificanceThe sequence conservation in both Hsp90 and rDNA sequences and the poor resolution of the deepest nodes suggests that dinoflagellates reflect an explosive radiation in morphological diversity in their recent evolutionary past. Nonetheless, the more comprehensive analysis of Hsp90 sequences enabled us to infer phylogenetic interrelationships of dinoflagellates more rigorously. For instance, the phylogenetic position of Noctiluca, which possesses several unusual features, was incongruent with previous phylogenetic studies. Therefore, the generation of additional dinoflagellate Hsp90 sequences is expected to refine the stem group of athecate species observed here and contribute to future multi-gene analyses of dinoflagellate interrelationships.

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Morphological observations of the marine planktonic dinoflagellate Phalacroma turbineum Kofoid et Michener (Dinophyta), with discussion on its taxonomy and distribution

Parra-Toriz

Esqueda-Lara

Hernández‐Becerril

2012

European Journal of Protistology

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Illumination or confusion? Dinoflagellate molecular phylogenetic data viewed from a primarily morphological standpoint

Cited by 22 publications

References 62 publications

Description of Two Species of Early Branching Dinoflagellates, Psammosa pacifica n. g., n. sp. and P. atlantica n. sp

Description of Two Species of Early Branching Dinoflagellates, Psammosa pacifica n. g., n. sp. and P. atlantica n. sp

Dinoflagellate Phylogeny as Inferred from Heat Shock Protein 90 and Ribosomal Gene Sequences

Morphological observations of the marine planktonic dinoflagellate Phalacroma turbineum Kofoid et Michener (Dinophyta), with discussion on its taxonomy and distribution

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