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Thomas Cavaliersmith - One of the best experts on this subject based on the ideXlab platform.
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multiple origins of heliozoa from flagellate ancestors new cryptist subphylum corbihelia superclass corbistoma and monophyly of haptista cryptista hacrobia and Chromista
Molecular Phylogenetics and Evolution, 2015Co-Authors: Thomas Cavaliersmith, Ema E. Chao, Rhodri LewisAbstract:Abstract Heliozoan protists have radiating cell projections (axopodia) supported by microtubular axonemes nucleated by the centrosome and bearing granule-like extrusomes for catching prey. To clarify previously confused heliozoan phylogeny we sequenced partial transcriptomes of two tiny naked heliozoa, the endohelean Microheliella maris and centrohelid Oxnerella marina, and the cercozoan pseudoheliozoan Minimassisteria diva. Phylogenetic analysis of 187 genes confirms that all are chromists; but centrohelids (microtubules arranged as hexagons and triangles) are not sisters to Endohelea having axonemes in transnuclear cytoplasmic channels (triangular or square microtubular arrays). Centrohelids are strongly sister to haptophytes (together phylum Haptista); we explain the common origins of their axopodia and haptonema. Microheliella is sister to new superclass Corbistoma (zooflagellate Telonemea and Picomonadea, with asymmetric microfilamentous pharyngeal basket), showing that these axopodial protists evolved independently from zooflagellate ancestors. We group Corbistoma and Endohelea as new cryptist subphylum Corbihelia with dense fibrillar interorganellar connections; endohelean axopodia and Telonema cortex are ultrastructurally related. Differently sampled trees clarify why corticate multigene eukaryote phylogeny is problematic: long-branch artefacts probably distort deep multigene phylogeny of corticates (Plantae, Chromista); basal radiations may be contradictorily reconstructed because of their extreme closeness and the Bayesian star-tree paradox. Haptista and Hacrobia are holophyletic, and Chromista probably are.
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kingdoms protozoa and Chromista and the eozoan root of the eukaryotic tree
Biology Letters, 2010Co-Authors: Thomas CavaliersmithAbstract:I discuss eukaryotic deep phylogeny and reclassify the basal eukaryotic kingdom Protozoa and derived kingdom Chromista in the light of multigene trees. I transfer the formerly protozoan Heliozoa and infrakingdoms Alveolata and Rhizaria into Chromista, which is sister to kingdom Plantae and arguably originated by synergistic double internal enslavement of green algal and red algal cells. I establish new subkingdoms (Harosa; Hacrobia) for the expanded Chromista. The protozoan phylum Euglenozoa differs immensely from other eukaryotes in its nuclear genome organization (trans-spliced multicistronic transcripts), mitochondrial DNA organization, cytochrome c-type biogenesis, cell structure and arguably primitive mitochondrial protein-import and nuclear DNA prereplication machineries. The bacteria-like absence of mitochondrial outer-membrane channel Tom40 and DNA replication origin-recognition complexes from trypanosomatid Euglenozoa roots the eukaryotic tree between Euglenozoa and all other eukaryotes (neokaryotes), or within Euglenozoa. Given their unique properties, I segregate Euglenozoa from infrakingdom Excavata (now comprising only phyla Percolozoa, Loukozoa, Metamonada), grouping infrakingdoms Euglenozoa and Excavata as the ancestral protozoan subkingdom Eozoa. I place phylum Apusozoa within the derived protozoan subkingdom Sarcomastigota. Clarifying early eukaryote evolution requires intensive study of properties distinguishing Euglenozoa from neokaryotes and Eozoa from neozoa (eukaryotes except Eozoa; ancestrally defined by haem lyase).
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myosin domain evolution and the primary divergence of eukaryotes
Nature, 2005Co-Authors: Thomas A Richards, Thomas CavaliersmithAbstract:Eukaryotic cells have two contrasting cytoskeletal and ciliary organizations. The simplest involves a single cilium-bearing centriole, nucleating a cone of individual microtubules (probably ancestral for unikonts: animals, fungi, Choanozoa and Amoebozoa). In contrast, bikonts (plants, chromists and all other protozoa) were ancestrally biciliate with a younger anterior cilium, converted every cell cycle into a dissimilar posterior cilium and multiple ciliary roots of microtubule bands. Here we show by comparative genomic analysis that this fundamental cellular dichotomy also involves different myosin molecular motors. We found 37 different protein domain combinations, often lineage-specific, and many previously unidentified. The sequence phylogeny and taxonomic distribution of myosin domain combinations identified five innovations that strongly support unikont monophyly and the primary bikont/unikont bifurcation. We conclude that the eukaryotic cenancestor (last common ancestor) had a cilium, mitochondria, pseudopodia, and myosins with three contrasting domain combinations and putative functions.
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phylogeny of choanozoa apusozoa and other protozoa and early eukaryote megaevolution
Journal of Molecular Evolution, 2003Co-Authors: Thomas Cavaliersmith, Ema E-y. ChaoAbstract:Abstract The primary diversification of eukaryotes involved protozoa, especially zooflagellates—flagellate protozoa without plastids. Understanding the origins of the higher eukaryotic kingdoms (two purely heterotrophic, Animalia and Fungi, and two primarily photosynthetic, Plantae and Chromista) depends on clarifying evolutionary relationships among the phyla of the ancestral kingdom Protozoa. We therefore sequenced 18S rRNA genes from 10 strains from the protozoan phyla Choanozoa and Apusozoa. Eukaryote diversity is encompassed by three early-radiating, arguably monophyletic groups: Amoebozoa, opisthokonts, and bikonts. Our taxon-rich rRNA phylogeny for eukaryotes allowing for intersite rate variation strongly supports the opisthokont clade (animals, Choanozoa, Fungi). It agrees with the view that Choanozoa are sisters of or ancestral to animals and reveals a novel nonflagellate choanozoan lineage, Ministeriida, sister either to choanoflagellates, traditionally considered animal ancestors, or to animals. Maximum likelihood trees suggest that within animals Placozoa are derived from medusozoan Cnidaria (we therefore place Placozoa as a class within subphylum Medusozoa of the Cnidaria) and hexactinellid sponges evolved from demosponges. The bikont and amoebozoan radiations are both very ill resolved. Bikonts comprise the kingdoms Plantae and Chromista and three major protozoan groups: alveolates, excavates, and Rhizaria. Our analysis weakly suggests that Apusozoa, represented by Ancyromonas and the apusomonads (Apusomonas and the highly diverse and much more ancient genus Amastigomonas, from which it evolved), are not closely related to other Rhizaria and may be the most divergent bikont lineages. Although Ancyromonas and apusomonads appear deeply divergent in 18S rRNA trees, the trees neither refute nor support the monophyly of Apusozoa. The bikont phylum Cercozoa weakly but consistently appears as sister to Retaria (Foraminifera; Radiolaria), together forming a hitherto largely unrecognized major protozoan assemblage (core Rhizaria) in the eukaryote tree. Both 18S rRNA sequence trees and a rare deletion show that nonciliate haplosporidian and paramyxid parasites of shellfish (together comprising the Ascetosporea) are not two separate phyla, as often thought, but part of the Cercozoa, and may be related to the plant-parasitic plasmodiophorids and phagomyxids, which were originally the only parasites included in the Cercozoa. We discuss rRNA trees in relation to other evidence concerning the basal diversification and root of the eukaryotic tree and argue that bikonts and opisthokonts, at least, are holophyletic. Amoebozoa and bikonts may be sisters—jointly called anterokonts, as they ancestrally had an anterior cilium, not a posterior one like opisthokonts; this contrasting ciliary orientation may reflect a primary divergence in feeding mode of the first eukaryotes. Anterokonts also differ from opisthokonts in sterol biosynthesis (cycloartenol versus lanosterol pathway), major exoskeletal polymers (cellulose versus chitin), and mitochondrial cristae (ancestrally tubular not flat), possibly also primary divergences.
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membrane heredity and early chloroplast evolution
Trends in Plant Science, 2000Co-Authors: Thomas CavaliersmithAbstract:Membrane heredity was central to the unique symbiogenetic origin from cyanobacteria of chloroplasts in the ancestor of Plantae (green plants, red algae, glaucophytes) and to subsequent lateral transfers of plastids to form even more complex photosynthetic chimeras. Each symbiogenesis integrated disparate genomes and several radically different genetic membranes into a more complex cell. The common ancestor of Plantae evolved transit machinery for plastid protein import. In later secondary symbiogeneses, signal sequences were added to target proteins across host perialgal membranes: independently into green algal plastids (euglenoids, chlorarachneans) and red algal plastids (alveolates, chromists). Conservatism and innovation during early plastid diversification are discussed.
Ovidiu Constantinescu - One of the best experts on this subject based on the ideXlab platform.
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a new downy mildew of the rosaceae peronospora oblatispora sp nov Chromista peronosporales
Nova Hedwigia, 2007Co-Authors: Choi Youngjoon, Ovidiu Constantinescu, Shin HyeondongAbstract:Peronospora oblatispora sp. nov., parasitic on Potentilla chrysantha, P. paradoxa, P. supina and Aphanes microcarpa, is described from 11 specimens collected in France, Korea and Romania. By its oblate conidia it differs morphologically from both P. sparsa and P. potentillae. The morphological discrepancy is supported by high genetic distances to the other two species and the larger insertions in ITS rDNA.
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revision of plasmopara Chromista peronosporales parasitic on geraniaceae
Fungal Biology, 2006Co-Authors: Hermann Voglmayr, Jamshid Fatehi, Ovidiu ConstantinescuAbstract:Following a phenetic and phylogenetic analysis, five species of Plasmopara are recognized on Geraniaceae: P. pusilla and P. geranii-sylvatici in Eurasia, P. geranii in North America, P. praetermissa sp. nov. in Eurasia and North America, and P. wilsonii sp. nov. in North America and Far East Asia. Both the D1/D2 domains of the nuLSU-rDNA and the complete ITS1-5.8S rDNA-ITS2 region were analysed with MP and Bayesian methods to reveal phylogenetic relationships of the species. All species formed highly supported monophyletic lineages, which is corroborated by their distinct morphology. A key for identification, detailed descriptions, illustrations, and data on distribution are provided.
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dimorphism of sporangia in albuginaceae Chromista peronosporomycetes
Sydowia, 2006Co-Authors: Ovidiu Constantinescu, Marco ThinesAbstract:By using light- and scanning electron microscopy, the dimorphism of sporangia in Albuginales is demonstrated in 220 specimens of Albugo, Pustula and Wilsoniana, parasitic on plants belonging to 13 families. The presence of two kinds of sporangia is due to the sporangiogenesis and considered to be present in all representatives of the Albuginales. Primary and secondary sporangia are the term recommended to be used for these dissemination organs.
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preliminary check list of albuginales and peronosporales Chromista reported from the iberian peninsula and balearic islands
Mycotaxon, 2006Co-Authors: Gema Garciablazquez, Ovidiu Constantinescu, Teresa M Telleria, Maria P MartinAbstract:The scrutiny of ca. 188 publications issued between 1867 and 2005 revealed that ca. 1500 fungus/host combinations of white rusts and downy mildews (Albuginales and Peronosporales) have been reported from Iberian Peninsula and Balearic Islands. The fungi belong to 13 genera and 101 species, and are parasitic on 266 plants belonging to 146 genera and 32 families. The hosts represent about 3.3 % of the total number of plants known from this territory. It is concluded that the probable number of fungi belonging to these two orders should be sensibly higher in this area, and that more collecting is necessary. The complete list can be accessed at: http://www.mycotaxon.com/resources/weblists.html.
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plasmoverna gen nov and the taxonomy and nomenclature of plasmopara Chromista peronosporales
Taxon, 2005Co-Authors: Ovidiu Constantinescu, Jamshid Fatehi, Hermann Voglmayr, Marco ThinesAbstract:After a review of the taxonomy and nomenclature of Plasmopara, it is concluded that this genus contains at least two groups of fungi that can be differentiated on both morphological and molecular g ...
Thomas Cavalier-smith - One of the best experts on this subject based on the ideXlab platform.
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Multigene phylogeny and cell evolution of chromist infrakingdom Rhizaria: contrasting cell organisation of sister phyla Cercozoa and Retaria
Protoplasma, 2018Co-Authors: Thomas Cavalier-smith, Ema E. Chao, Rhodri LewisAbstract:Infrakingdom Rhizaria is one of four major subgroups with distinct cell body plans that comprise eukaryotic kingdom Chromista. Unlike other chromists, Rhizaria are mostly heterotrophic flagellates, amoebae or amoeboflagellates, commonly with reticulose (net-like) or filose (thread-like) feeding pseudopodia; uniquely for eukaryotes, cilia have proximal ciliary transition-zone hub-lattices. They comprise predominantly flagellate phylum Cercozoa and reticulopodial phylum Retaria, whose exact phylogenetic relationship has been uncertain. Given even less clear relationships amongst cercozoan classes, we sequenced partial transcriptomes of seven Cercozoa representing five classes and endomyxan retarian Filoreta marina to establish 187-gene multiprotein phylogenies. Ectoreta (retarian infraphyla Foraminifera, Radiozoa) branch within classical Cercozoa as sister to reticulose Endomyxa. This supports recent transfer of subphylum Endomyxa from Cercozoa to Retaria alongside subphylum Ectoreta which embraces classical retarians where capsules or tests subdivide cells into organelle-containing endoplasm and anastomosing pseudopodial net-like ectoplasm. Cercozoa are more homogeneously filose, often with filose pseudopodia and/or posterior ciliary gliding motility: zooflagellate Helkesimastix and amoeboid Guttulinopsis form a strongly supported clade, order Helkesida. Cercomonads are polyphyletic (Cercomonadida sister to glissomonads; Paracercomonadida deeper). Thecofilosea are a clade, whereas Imbricatea may not be; Sarcomonadea may be paraphyletic. Helkesea and Metromonadea are successively deeper outgroups within cercozoan subphylum Monadofilosa; subphylum Reticulofilosa (paraphyletic on site-heterogeneous trees) branches earliest, Granofilosea before Chlorarachnea. Our multiprotein trees confirm that Rhizaria are sisters of infrakingdom Halvaria (Alveolata, Heterokonta) within chromist subkingdom Harosa (= SAR); they further support holophyly of chromist subkingdom Hacrobia, and are consistent with holophyly of Chromista as sister of kingdom Plantae. Site-heterogeneous rDNA trees group Kraken with environmental DNA clade ‘eSarcomonad’, not Paracercomonadida. Ectoretan fossil dates evidence ultrarapid episodic stem sequence evolution. We discuss early rhizarian cell evolution and multigene tree coevolutionary patterns, gene-paralogue evidence for chromist monophyly, and integrate this with fossil evidence for the age of Rhizaria and eukaryote cells, and revise rhizarian classification.
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Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences
Protoplasma, 2018Co-Authors: Thomas Cavalier-smithAbstract:In 1981 I established kingdom Chromista, distinguished from Plantae because of its more complex chloroplast-associated membrane topology and rigid tubular multipartite ciliary hairs. Plantae originated by converting a cyanobacterium to chloroplasts with Toc/Tic translocons; most evolved cell walls early, thereby losing phagotrophy. Chromists originated by enslaving a phagocytosed red alga, surrounding plastids by two extra membranes, placing them within the endomembrane system, necessitating novel protein import machineries. Early chromists retained phagotrophy, remaining naked and repeatedly reverted to heterotrophy by losing chloroplasts. Therefore, Chromista include secondary phagoheterotrophs (notably ciliates, many dinoflagellates, Opalozoa, Rhizaria, heliozoans) or walled osmotrophs (Pseudofungi, Labyrinthulea), formerly considered protozoa or fungi respectively, plus endoparasites (e.g. Sporozoa) and all chromophyte algae (other dinoflagellates, chromeroids, ochrophytes, haptophytes, cryptophytes). I discuss their origin, evolutionary diversification, and reasons for making chromists one kingdom despite highly divergent cytoskeletons and trophic modes, including improved explanations for periplastid/chloroplast protein targeting, derlin evolution, and ciliary/cytoskeletal diversification. I conjecture that transit-peptide-receptor-mediated ‘endocytosis’ from periplastid membranes generates periplastid vesicles that fuse with the arguably derlin-translocon-containing periplastid reticulum (putative red algal trans -Golgi network homologue; present in all chromophytes except dinoflagellates). I explain chromist origin from ancestral corticates and neokaryotes, reappraising tertiary symbiogenesis; a chromist cytoskeletal synapomorphy, a bypassing microtubule band dextral to both centrioles, favoured multiple axopodial origins. I revise chromist higher classification by transferring rhizarian subphylum Endomyxa from Cercozoa to Retaria; establishing retarian subphylum Ectoreta for Foraminifera plus Radiozoa, apicomonad subclasses, new dinozoan classes Myzodinea (grouping Colpovora gen. n., Psammosa ), Endodinea, Sulcodinea, and subclass Karlodinia; and ranking heterokont Gyrista as phylum not superphylum.
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Phylogeny and Megasystematics of Phagotrophic Heterokonts (Kingdom Chromista)
Journal of Molecular Evolution, 2006Co-Authors: Thomas Cavalier-smith, Ema E-y. ChaoAbstract:Heterokonts are evolutionarily important as the most nutritionally diverse eukaryote supergroup and the most species-rich branch of the eukaryotic kingdom Chromista. Ancestrally photosynthetic/phagotrophic algae (mixotrophs), they include several ecologically important purely heterotrophic lineages, all grossly understudied phylogenetically and of uncertain relationships. We sequenced 18S rRNA genes from 14 phagotrophic non-photosynthetic heterokonts and a probable Ochromonas , performed phylogenetic analysis of 210–430 Heterokonta, and revised higher classification of Heterokonta and its three phyla: the predominantly photosynthetic Ochrophyta; the non-photosynthetic Pseudofungi; and Bigyra (now comprising subphyla Opalozoa, Bicoecia, Sagenista). The deepest heterokont divergence is apparently between Bigyra, as revised here, and Ochrophyta/Pseudofungi. We found a third universal heterokont signature sequence, and deduce three independent losses of ciliary hairs, several of 1-2 cilia, 10 of photosynthesis, but perhaps only two plastid losses. In Ochrophyta, heterotrophic Oikomonas is sister to the photosynthetic Chrysamoeba , whilst the abundant freshwater predator Spumella is biphyletic; neither clade is specifically related to Paraphysomonas , indicating four losses of photosynthesis by chrysomonads. Sister to Chrysomonadea (Chrysophyceae) is Picophagea cl. nov. ( Picophagus, Chlamydomyxa ). The diatom-parasite Pirsonia belongs in Pseudofungi. Heliozoan-like actinophryids (e.g. Actinosphaerium ) are Opalozoa, not related to pedinellids within Hypogyristea cl. nov. of Ochrophyta as once thought. The zooflagellate class Bicoecea (perhaps the ancestral phenotype of Bigyra) is unexpectedly diverse and a major focus of our study. We describe four new biciliate bicoecean genera and five new species: Nerada mexicana, Labromonas fenchelii (=Pseudobodo tremulans sensu Fenchel), Boroka karpovii (= P . tremulans sensu Karpov), Anoeca atlantica and Cafeteria mylnikovii; several cultures were previously misidentified as Pseudobodo tremulans. Nerada and the uniciliate Paramonas are related to Siluania and Adriamonas ; this clade (Pseudodendromonadales emend.) is probably sister to Bicosoeca . Genetically diverse Caecitellus is probably related to Anoeca, Symbiomonas and Cafeteria (collectively Anoecales emend.). Boroka is sister to Pseudodendromonadales/Bicoecales/Anoecales. Placidiales are probably divergent bicoeceans (the GenBank Placidia sequence is a basidiomycete/heterokont chimaera). Two GenBank ‘opalinid’ sequences are fungal; Pseudopirsonia is cercozoan; two previous GenBank ‘ Caecitellus ’ sequences are Adriamonas .
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Endomembrane structure and the chloroplast protein targeting pathway in Heterosigma akashiwo (raphidophyceae, Chromista)
Journal of Phycology, 2000Co-Authors: Ken-ichiro Ishida, Thomas Cavalier-smith, Beverley R GreenAbstract:Chloroplasts in heterokont algae are surrounded by four membranes and probably originated from a red algal endosymbiont that was engulfed and retained by eukaryotic host. Understanding how nuclear-encoded chloroplast proteins are translocated from the cytoplasm into the chloroplast across these membranes could give us some insights about how the endosymbiont was integrated into the host cell in the process of secondary symbiogenesis. In multiplastid heterokont algae such as raphidophytes, it has been unclear if the outermost of the four membranes surrounding the chloroplast (the chloroplast endoplasmic reticulum [CER] membrane) is continuous with the nuclear envelope and rough endoplasmic reticulum (ER). Here, we report detailed ultrastructural observations of the raphidophyte Heterosigma akashiwo (Hada) Hada ex Y. Hara et Chihara that show that the CER membranes were continuous with ER membranes that had attached ribosomes, implying that the chloroplast with three envelope membranes is located within the ER lumen, that is, topologically the same structure as that of monoplastid heterokont algae. However, the CER membrane of H. akashiwo had very few, if any, ribosomes attached, unlike the CER membranes in other heterokont algae. To verify that proteins are first targeted to the ER, we assayed protein import into canine microsomes using a precursor for a nuclear-encoded chloroplast protein, the fucoxanthin-chlorophyll a/c protein of H. akashiwo. This demonstrated that the precursor has a functional signal sequence for ER targeting and is cotranslationally translocated into the ER, where a signal sequence of about 17 amino acids is removed. Based on these data, we hypothesize that in H. akashiwo, nuclear-encoded chloroplast protein precursors that have been cotranslationally transported into the ER lumen are sorted in the ER and transported to the chloroplasts through the ER lumen.
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Phylogeny of ultra-rapidly evolving dinoflagellate chloroplast genes: a possible common origin for sporozoan and dinoflagellate plastids.
Journal of Molecular Evolution, 2000Co-Authors: Zhaoduo Zhang, Beverley R Green, Thomas Cavalier-smithAbstract:Complete chloroplast 23S rRNA and psbA genes from five peridinin-containing dinoflagellates (Heterocapsa pygmaea, Heterocapsa niei, Heterocapsa rotun-data, Amphidinium carterae, and Protoceratium reticulatum) were amplified by PCR and sequenced; partial sequences were obtained from Thoracosphaera heimii and Scrippsiella trochoidea. Comparison with chloroplast 23S rRNA and psbA genes of other organisms shows that dinoflagellate chloroplast genes are the most divergent and rapidly evolving of all. Quartet puzzling, maximum likelihood, maximum parsimony, neighbor joining, and LogDet trees were constructed. Intersite rate variation and invariant sites were allowed for with quartet puzzling and neighbor joining. All psbA and 23S rRNA trees showed peridinin-containing dinoflagellate chloroplasts as monophyletic. In psbA trees they are related to those of chromists and red algae. In 23S rRNA trees, dinoflagellates are always the sisters of Sporozoa (apicomplexans); maximum likelihood analysis of Heterocapsa triquetra 16S rRNA also groups the dinoflagellate and sporozoan sequences, but the other methods were inconsistent. Thus, dinoflagellate chloroplasts may actually be related to sporozoan plastids, but the possibility of reproducible long-branch artifacts cannot be strongly ruled out. The results for all three genes fit the idea that dinoflagellate chloroplasts originated from red algae by a secondary endosymbiosis, possibly the same one as for chromists and Sporozoa. The marked disagreement between 16S rRNA trees using different phylogenetic algorithms indicates that this is a rather poor molecule for elucidating overall chloroplast phylogeny. We discuss possible reasons why both plastid and mitochondrial genomes of alveolates (Dinozoa, Sporozoa and Ciliophora) have ultra-rapid substitution rates and a proneness to unique genomic rearrangements.
Viviane Moreira De Lima - One of the best experts on this subject based on the ideXlab platform.
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eimeria ferreirai n sp Chromista miozoa eimeriidae from doves leptotila spp columbiformes columbidae from brazil
Zootaxa, 2020Co-Authors: Mariana De Souza Oliveira, Jhon Lennon Genovezoliveira, Carlos Nei Ortuzarferreira, Carla Maronezi, Sergio Thodefilho, Sergian Vianna Cardozo, Aguida Aparecida De Oliveira, Viviane Moreira De Lima, Bruno Pereira BertoAbstract:The doves and pigeons constitute a taxonomic group (Columbiformes: Columbidae) of granivorous and frugivorous birds with a worldwide distribution. The current work aims to describe morphologically and molecularly a new protozoan from white-tipped doves Leptotila verreauxi Bonaparte, 1855 and grey-fronted doves Leptotila rufaxilla (Richard Bernard, 1792) in Southeastern Brazil. Eimeria ferreirai n. sp. has oocysts that are sub-spherical to ellipsoidal, 21.4 × 18.8 μm, with smooth, bilayered wall, ~1.6 μm thick. Micropyle present. Oocyst residuum absent, but one to two polar granules are present. Sporocysts are elongate ovoidal to boomerang-shaped, 13.4 × 6.9 μm. Stieda body triangular to lozengal. Sporocyst residuum is composed of granules of different sizes. Sporozoites are vermiform with refractile body and nucleus. Sequencing of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene and the subsequent phylogenetic molecular comparisons supported the description of the new species, since the maximum similarity was 90-95% with eimeriid species of Columbiformes, Anseriformes, Galliformes and Passeriformes. Thus, this is the first coccidian species reported from Leptotila spp. and the twentieth description of an eimerian from Columbiformes in the World.
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Coccidia of Columbiformes: a taxonomic review of its Eimeriidae species and Eimeria columbinae n. sp. from Columbina talpacoti (Temminck, 1809) from Brazil.
Parasitology Research, 2019Co-Authors: Carlos Nei Ortúzar-ferreira, Mariana De Souza Oliveira, Sergian Vianna Cardozo, Aguida Aparecida De Oliveira, Viviane Moreira De Lima, Jhon Lennon Genovez-oliveira, Heider Alves Franco, Sergio Thode-filho, Ildemar Ferreira, Bruno Pereira BertoAbstract:Coccidia (Chromista: Miozoa: Eimeriidae) of columbiform birds (Aves: Columbiformes) have been described since the end of the nineteenth century; however, some of these descriptions were poorly detailed or inconclusive. In this sense, the current work makes a detailed taxonomic revision reconsidering and organizing 18 Eimeria spp. and two Isospora spp. previously described or reported of Columbiformes. Along with this, a new species of Eimeria is morphologically and molecularly identified by the mitochondrial cytochrome c oxidase subunit 1 (COI) gene and by the 18S small subunit ribosomal RNA (18S) gene from the ruddy ground-dove Columbina talpacoti (Temminck, 1809) in the Medio Paraiba region of the State of Rio de Janeiro, southeastern Brazil. Eimeria columbinae n. sp. has subspheroidal oocysts, 14.7 × 13.2 μm, with smooth, bi-layered wall, ~ 1.1 μm and length/width ratio of 1.1. Micropyle and oocyst residuum are present, but polar granule is absent. Sporocysts are ellipsoidal to slightly asymmetrical, 9.0 × 5.1 μm, with both Stieda and sub-Stieda bodies. Sporocyst residuum present and sporozoites with refractile body and nucleus. This is the 19th description of an eimerian from Columbiformes in the World, and the second to have a molecular identification of the COI and 18S genes.
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Isospora borbai n. sp. (Chromista: Apicomplexa: Eimeriidae) from gnateaters Conopophaga spp. (Passeriformes: Tyranni: Conopophagidae) in South America
Acta Parasitologica, 2019Co-Authors: Lidiane Maria Silva-carvalho, Aguida Aparecida De Oliveira, Carlos Nei Ortúzar-ferreira, Jhon Lennon Genovez-oliveira, Heider Alves Franco, Sergio Thode-filho, Mariana Oliveira, Mariana Borges Rodrigues, Saulo Tavares Abreu, Viviane Moreira De LimaAbstract:Background The gnateaters Conopophaga spp. are insectivorous passerines commonly observed in high and humid forests, where they remain lodged in thin branches and, sometimes, they fly to the ground to catch insects. The insectivorous feeding habit is related to low prevalence and density of coccidians in passerines; however, several coccidian species are recorded for families of insectivorous passerines. Purpose This study aimed to examine the feces from gnateaters Conopophaga spp. captured in the municipality of Barra Mansa and in the Itatiaia National Park, State of Rio de Janeiro, Southeastern Brazil, to determine what coccidian parasites were present. Methods Nine gnateaters were captured with mist nets. Coccidian oocysts were recovered from the fecal samples by flotation in Sheather’s saturated solution. Morphological observations, line drawings, photomicrographs and measurements were made in optical microscopy and digitally edited. The molecular analysis included the study of the sequence of the mitochondrial cytochrome c oxidase subunit 1 ( cox1 ) gene, with phylogenetic reconstructions based on the neighbor-joining and maximum likelihood analysis. Results Four Conopophaga spp. were positive for oocysts. An Isospora sp. considered as new to science is described and identified from Conopophaga melanops (Vieillot, 1818) and Conopophaga lineata (Wied, 1831). Isospora borbai n. sp. has oocysts that are subspheroidal, 17–22 × 15–22 (20.2 × 19.1) µm, with rough, bilayered wall, c. 1.7 μm thick. Micropyle present, but without micropyle cap. Oocyst residuum absent, but one or two polar granules are present. Sporocysts are ellipsoidal, 12–15 × 8–11 (14.1 × 9.1) µm. The Stieda body is knob-like to half-moon-shaped and sub-Stieda body is rounded. Sporocyst residuum is present, composed of scattered spherules of different sizes. Sporozoites are vermiform with refractile body and nucleus. Molecular analysis at the cox1 gene exhibited similarity greater than 99% with Isospora spp. isolates from other Neotropical passerine birds. Conclusion Based on the morphological and molecular features, I. borbai is considered as new to science and the first coccidian species recorded from Conopophagidae.
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isospora borbai n sp Chromista apicomplexa eimeriidae from gnateaters conopophaga spp passeriformes tyranni conopophagidae in south america
Acta Parasitologica, 2019Co-Authors: Lidiane Maria Da Silvacarvalho, Mariana De Souza Oliveira, Jhon Lennon Genovezoliveira, Carlos Nei Ortuzarferreira, Sergio Thodefilho, Aguida Aparecida De Oliveira, Heider Alves Franco, Mariana Borges Rodrigues, Saulo Tavares Abreu, Viviane Moreira De LimaAbstract:The gnateaters Conopophaga spp. are insectivorous passerines commonly observed in high and humid forests, where they remain lodged in thin branches and, sometimes, they fly to the ground to catch insects. The insectivorous feeding habit is related to low prevalence and density of coccidians in passerines; however, several coccidian species are recorded for families of insectivorous passerines. This study aimed to examine the feces from gnateaters Conopophaga spp. captured in the municipality of Barra Mansa and in the Itatiaia National Park, State of Rio de Janeiro, Southeastern Brazil, to determine what coccidian parasites were present. Nine gnateaters were captured with mist nets. Coccidian oocysts were recovered from the fecal samples by flotation in Sheather’s saturated solution. Morphological observations, line drawings, photomicrographs and measurements were made in optical microscopy and digitally edited. The molecular analysis included the study of the sequence of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, with phylogenetic reconstructions based on the neighbor-joining and maximum likelihood analysis. Four Conopophaga spp. were positive for oocysts. An Isospora sp. considered as new to science is described and identified from Conopophaga melanops (Vieillot, 1818) and Conopophaga lineata (Wied, 1831). Isospora borbai n. sp. has oocysts that are subspheroidal, 17–22 × 15–22 (20.2 × 19.1) µm, with rough, bilayered wall, c.1.7 μm thick. Micropyle present, but without micropyle cap. Oocyst residuum absent, but one or two polar granules are present. Sporocysts are ellipsoidal, 12–15 × 8–11 (14.1 × 9.1) µm. The Stieda body is knob-like to half-moon-shaped and sub-Stieda body is rounded. Sporocyst residuum is present, composed of scattered spherules of different sizes. Sporozoites are vermiform with refractile body and nucleus. Molecular analysis at the cox1 gene exhibited similarity greater than 99% with Isospora spp. isolates from other Neotropical passerine birds. Based on the morphological and molecular features, I. borbai is considered as new to science and the first coccidian species recorded from Conopophagidae.
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revision of plasmopara Chromista peronosporales parasitic on geraniaceae
Fungal Biology, 2006Co-Authors: Hermann Voglmayr, Jamshid Fatehi, Ovidiu ConstantinescuAbstract:Following a phenetic and phylogenetic analysis, five species of Plasmopara are recognized on Geraniaceae: P. pusilla and P. geranii-sylvatici in Eurasia, P. geranii in North America, P. praetermissa sp. nov. in Eurasia and North America, and P. wilsonii sp. nov. in North America and Far East Asia. Both the D1/D2 domains of the nuLSU-rDNA and the complete ITS1-5.8S rDNA-ITS2 region were analysed with MP and Bayesian methods to reveal phylogenetic relationships of the species. All species formed highly supported monophyletic lineages, which is corroborated by their distinct morphology. A key for identification, detailed descriptions, illustrations, and data on distribution are provided.
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plasmoverna gen nov and the taxonomy and nomenclature of plasmopara Chromista peronosporales
Taxon, 2005Co-Authors: Ovidiu Constantinescu, Jamshid Fatehi, Hermann Voglmayr, Marco ThinesAbstract:After a review of the taxonomy and nomenclature of Plasmopara, it is concluded that this genus contains at least two groups of fungi that can be differentiated on both morphological and molecular g ...