Molecular systematics of marine gregarines (Apicomplexa) from North-eastern Pacific polychaetes and nemerteans, with descriptions of three novel species: Lecudina phyllochaetopteri sp. nov., Difficilina tubulani sp. nov. and Difficilina paranemertis sp. nov.

Rueckert, Sonja; Chantangsi, Chitchai; Leander, Brian S.

doi:10.1099/ijs.0.016436-0

Cited by 37 publications

(38 citation statements)

References 24 publications

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“…Phylogenetic placements of query OTU representatives that were taxonomically assigned to the Apicomplexa were conducted using a full-length reference multiple sequence alignment and corresponding phylogeny comprising 190 taxa from all major Alveolate clades (see Supplementary Data 3 and 4 for GenBank accession numbers, sequences and clade assignments). The taxon sampling was collated from a range of publications relating to eukaryotic diversity in general and Alveolata diversity and phylogeny in particular; for example, refs 20,[63][64][65][66][67][68][69] . It is also acknowledged that single gene trees are unable to resolve the backbone of the Alveolate phylogeny.…”

Section: Stampa Plotsmentioning

confidence: 99%

Parasites dominate hyperdiverse soil protist communities in Neotropical rainforests

et al. 2017

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High animal and plant richness in tropical rainforest communities has long intrigued naturalists. It is unknown if similar hyperdiversity patterns are reflected at the microbial scale with unicellular eukaryotes (protists). Here we show, using environmental metabarcoding of soil samples and a phylogeny-aware cleaning step, that protist communities in Neotropical rainforests are hyperdiverse and dominated by the parasitic Apicomplexa, which infect arthropods and other animals. These host-specific parasites potentially contribute to the high animal diversity in the forests by reducing population growth in a density-dependent manner. By contrast, too few operational taxonomic units (OTUs) of Oomycota were found to broadly drive high tropical tree diversity in a host-specific manner under the Janzen-Connell model. Extremely high OTU diversity and high heterogeneity between samples within the same forests suggest that protists, not arthropods, are the most diverse eukaryotes in tropical rainforests. Our data show that protists play a large role in tropical terrestrial ecosystems long viewed as being dominated by macroorganisms.S ince the works of early naturalists such as von Humboldt and Bonpland 1 , we have known that animal and plant communities in tropical rainforests are exceedingly species rich. For example, one hectare can contain more than 400 tree species 2 and one tree can harbour more than 40 ant species 3 . This hyperdiversity of trees has been partially explained by the Janzen-Connell model 4,5 , which hypothesizes that host-specific predators and parasites reduce plant population growth in a density-dependent manner 6,7 . Sampling up in the tree canopies and below on the ground has further led to the view that arthropods are the most diverse eukaryotes in tropical rainforests 8,9 .The focus on eukaryotic macroorganisms in these studies is primarily because they are familiar and readily observable to us. We do not know whether the less familiar and less readily observable protists-microbial eukaryotes that are not animals, plants or fungi 10 -inhabiting these same ecosystems exhibit similar diversity patterns. To evaluate if macroorganismic diversity patterns are reflected at the microbial scale with protists, we conducted an environmental DNA metabarcoding study by sampling soils in 279 locations in a variety of lowland Neotropical forest types in La Selva Biological Station, Costa Rica, Barro Colorado Island, Panama and Tiputini Biodiversity Station, Ecuador. This metabarcoding approach has the power to uncover known and new taxa on a massive scale 11 . By amplifying DNA extracted from the soils with broadly targeted primers for the V4 region of 18S rRNA and sequencing it using the Illumina MiSeq platform, we were able to detect most eukaryotic lineages, and assess the diversity and relative dominance of free-living and parasitic lineages.

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Section: Stampa Plotsmentioning

confidence: 99%

Parasites dominate hyperdiverse soil protist communities in Neotropical rainforests

et al. 2017

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“…Molecular phylogenetic studies of gregarines are limited in sampling and largely rely on small subunit (SSU or 18S) ribosomal DNA (rDNA) sequences (Carreno, Martin & Barta, 1999; Leander, Clopton & Keeling, 2003; Leander, Harper & Keeling, 2003; Leander et al, 2006; Leander, 2007; Lepelletier et al, 2014; Rueckert & Leander, 2008, 2009, 2010; Clopton, 2009; Rueckert, Chantangsi & Leander, 2010; Rueckert et al, 2011, 2015; Rueckert, Villette & Leander, 2011; Rueckert, Wakeman & Leander, 2013; Wakeman & Leander, 2013a; Wakeman & Leander, 2012, 2013b; Wakeman, Heintzelman & Leander, 2014; Wakeman et al, 2014; Diakin, Wakeman & Valigurová, 2017). Gregarines have been also detected in environmental sequence surveys from various marine and freshwater samples, possibly because oocysts are stable in the environment (Rueckert et al, 2011; Janouškovec et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

A new view on the morphology and phylogeny of eugregarines suggested by the evidence from the gregarineAncora sagittata(Leuckart, 1860) Labbé, 1899 (Apicomplexa: Eugregarinida)

Simdyanov

Guillou

Diakin

et al. 2017

PeerJ

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BackgroundGregarines are a group of early branching Apicomplexa parasitizing invertebrate animals. Despite their wide distribution and relevance to the understanding the phylogenesis of apicomplexans, gregarines remain understudied: light microscopy data are insufficient for classification, and electron microscopy and molecular data are fragmentary and overlap only partially.MethodsScanning and transmission electron microscopy, PCR, DNA cloning and sequencing (Sanger and NGS), molecular phylogenetic analyses using ribosomal RNA genes (18S (SSU), 5.8S, and 28S (LSU) ribosomal DNAs (rDNAs)).Results and DiscussionWe present the results of an ultrastructural and molecular phylogenetic study on the marine gregarine Ancora sagittata from the polychaete Capitella capitata followed by evolutionary and taxonomic synthesis of the morphological and molecular phylogenetic evidence on eugregarines. The ultrastructure of Ancora sagittata generally corresponds to that of other eugregarines, but reveals some differences in epicytic folds (crests) and attachment apparatus to gregarines in the family Lecudinidae, where Ancora sagittata has been classified. Molecular phylogenetic trees based on SSU (18S) rDNA reveal several robust clades (superfamilies) of eugregarines, including Ancoroidea superfam. nov., which comprises two families (Ancoridae fam. nov. and Polyplicariidae) and branches separately from the Lecudinidae; thus, all representatives of Ancoroidea are here officially removed from the Lecudinidae. Analysis of sequence data also points to possible cryptic species within Ancora sagittata and the inclusion of numerous environmental sequences from anoxic habitats within the Ancoroidea. LSU (28S) rDNA phylogenies, unlike the analysis of SSU rDNA alone, recover a well-supported monophyly of the gregarines involved (eugregarines), although this conclusion is currently limited by sparse taxon sampling and the presence of fast-evolving sequences in some species. Comparative morphological analyses of gregarine teguments and attachment organelles lead us to revise their terminology. The terms “longitudinal folds” and “mucron” are restricted to archigregarines, whereas the terms “epicystic crests” and “epimerite” are proposed to describe the candidate synapomorphies of eugregarines, which, consequently, are considered as a monophyletic group. Abolishing the suborders Aseptata and Septata, incorporating neogregarines into the Eugregarinida, and treating the major molecular phylogenetic lineages of eugregarines as superfamilies appear as the best way of reconciling recent morphological and molecular evidence. Accordingly, the diagnosis of the order Eugregarinida Léger, 1900 is updated.

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“…Among marine apicomplexans, use of the small subunit (SSU) rDNA sequences for evaluating the diversity of marine gregarines (an apicomplexan subclass) has been very informative for delimiting closely related species from one another and for discovering major clades of gregarine species (Rueckert et al 2010, Wakeman & Leander 2013. Apicomplexans with similar morphology to the APX zoites found in flat oysters in NZ have been reported from greenlipped mussel Perna canaliculus from the Marlborough Sounds (Diggles et al 2002).…”

Section: Discussionmentioning

confidence: 99%

“…The phylum Apicomplexa is a large and diverse group of parasitic protists that comprises almost 6000 described species of either facultative or obligate intracellular parasites (Adl et al 2007, Rueckert et al 2010. While some apicomplexans are well known and serve as models for understanding apicomplexan infection and disease (e.g.…”

Section: Introductionmentioning

confidence: 99%

Partial 18S rRNA sequences of apicomplexan parasite ‘X’ (APX), associated with flat oysters Ostrea chilensis in New Zealand

Suong

Webb²,

Banks³

et al. 2017

Dis. Aquat. Org.

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Apicomplexa is a large phylum of parasitic protists renowned for significant negative health impacts on humans and livestock worldwide. Despite the prevalence and negative impacts of apicomplexans across many animal groups, relatively little attention has been given to apicomplexan parasites of invertebrates, especially marine invertebrates. Previous work has reported an apicomplexan parasite 'X' (APX), a parasite that has been histologically and ultrastructurally identified from the commercially important flat oyster Ostrea chilensis in New Zealand. This apicomplexan may exacerbate host vulnerability to the infectious disease bonamiosis. In this study, we report 18S rRNA sequences amplified from APX-infected O. chilensis tissues. Phylogenetic analyses clearly established that the 18S sequences were of apicomplexan origin; however, their detailed relationship to known apicomplexan groups is less resolved. Two specific probes, designed from the putative APX 18S rRNA sequence, co-localised with APX cells in in situ hybridisations, further supporting our hypothesis that the 18S sequences were from APX. These sequences will facilitate the future development of inexpensive and sensitive molecular diagnostic tests for APX, thereby assisting research focussed on the biology and ecology of this organism and its role in morbidity and mortality of O. chilensis.

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Molecular systematics of marine gregarines (Apicomplexa) from North-eastern Pacific polychaetes and nemerteans, with descriptions of three novel species: Lecudina phyllochaetopteri sp. nov., Difficilina tubulani sp. nov. and Difficilina paranemertis sp. nov.

Cited by 37 publications

References 24 publications

Parasites dominate hyperdiverse soil protist communities in Neotropical rainforests

Parasites dominate hyperdiverse soil protist communities in Neotropical rainforests

A new view on the morphology and phylogeny of eugregarines suggested by the evidence from the gregarineAncora sagittata(Leuckart, 1860) Labbé, 1899 (Apicomplexa: Eugregarinida)

Partial 18S rRNA sequences of apicomplexan parasite ‘X’ (APX), associated with flat oysters Ostrea chilensis in New Zealand

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