Parabasalia

Čepička, Ivan; Dolan, Michael F.; Gile, Gillian H.

doi:10.1007/978-3-319-32669-6_9-1

Cited by 12 publications

(8 citation statements)

References 145 publications

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“…Its members are characterized by the presence of many flagella organized in bands that spiral clockwise away from the cell apex (Brugerolle and Lee ; Čepička et al. ). The class includes eleven genera ( Cononympha , Holomastigotes , Holomastigotoides , Microjoenia , Micromastigotes, Rostronympha , Spiromastigotes , Spironympha , Spirotrichonympha , Spirotrichonymphella , and Uteronympha ) that were historically grouped into three families (Holomastigotidae, Holomastigotoididae, and Spirotrichonymphidae), though more recent taxonomic schemes lump all the genera into Holomastigotoididae (Čepička et al.…”

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confidence: 99%

Molecular Identity of Holomastigotes (Spirotrichonymphea, Parabasalia) with Descriptions of Holomastigotes flavipes n. sp. and Holomastigotes tibialis n. sp.

Taerum

Jasso‐Selles

Wilson

et al. 2019

J Eukaryotic Microbiology

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Holomastigotes is a protist genus (Parabasalia: Spirotrichonymphea) that resides in the hindguts of “lower” termites. It can be distinguished from other parabasalids by spiral flagellar bands that run along the entire length of the cell, an anterior nucleus, a reduced or absent axostyle, the presence of spherical vesicles inside the cells, and the absence of ingested wood particles. Eight species have been described based on their morphology so far, although no molecular data were available prior to this study. We determined the 18S rRNA gene sequences of Holomastigotes from the hindguts of Hodotermopsis sjostedti, Reticulitermes flavipes, Reticulitermes lucifugus, and Reticulitermes tibialis. Phylogenetic analyses placed all sequences in an exclusive and well‐supported clade with the type species, Holomastigotes elongatum from R. lucifugus. However, the phylogenetic position of Holomastigotes within the Spirotrichonymphea was not resolved. We describe two new species, Holomastigotes flavipes n. sp. and Holomastigotes tibialis n. sp., inhabiting the hindguts of R. flavipes and R. tibialis, respectively.

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confidence: 99%

Molecular Identity of Holomastigotes (Spirotrichonymphea, Parabasalia) with Descriptions of Holomastigotes flavipes n. sp. and Holomastigotes tibialis n. sp.

Taerum

Jasso‐Selles

Wilson

et al. 2019

J Eukaryotic Microbiology

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“…Third, the EASs may have been considered as an artifact and just ignored or underappreciated by the investigators. In this regard, different authors using staining methods for light microscopy have described that the flagella of several parabasalids, including T. vaginalis and T. foetus , usually end with a granular or small swelling structure called “knob” ( Kirby, 1951 ; Honigberg and King, 1964 ; Čepička et al., 2016 ); however, it has been suggested that “knobs” may be artifacts due to cell shrinkage during the fixation for protargol staining ( Ceza et al., 2015 ; Čepička et al., 2016 ). Based on their location and morphologic similarities, we hypothesize that the EASs described here and the previously described “knobs” might be the same structure.…”

Section: Discussionmentioning

confidence: 99%

Ultrastructural and Functional Analysis of a Novel Extra-Axonemal Structure in Parasitic Trichomonads

Cóceres¹,

Iriarte²,

Miranda-Magalhães³

et al. 2021

Front. Cell. Infect. Microbiol.

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Trichomonas vaginalis and Tritrichomonas foetus are extracellular flagellated parasites that inhabit humans and other mammals, respectively. In addition to motility, flagella act in a variety of biological processes in different cell types, and extra-axonemal structures (EASs) have been described as fibrillar structures that provide mechanical support and act as metabolic, homeostatic, and sensory platforms in many organisms. It has been assumed that T. vaginalis and T. foetus do not have EASs. However, here, we used complementary electron microscopy techniques to reveal the ultrastructure of EASs in both parasites. Such EASs are thin filaments (3–5 nm diameter) running longitudinally along the axonemes and surrounded by the flagellar membrane, forming prominent flagellar swellings. We observed that the formation of EAS increases after parasite adhesion on the host cells, fibronectin, and precationized surfaces. A high number of rosettes, clusters of intramembrane particles that have been proposed as sensorial structures, and microvesicles protruding from the membrane were observed in the EASs. Our observations demonstrate that T. vaginalis and T. foetus can connect to themselves by EASs present in flagella. The protein VPS32, a member of the ESCRT-III complex crucial for diverse membrane remodeling events, the pinching off and release of microvesicles, was found in the surface as well as in microvesicles protruding from EASs. Moreover, we demonstrated that the formation of EAS also increases in parasites overexpressing VPS32 and that T. vaginalis-VPS32 parasites showed greater motility in semisolid agar. These results provide valuable data about the role of the flagellar EASs in the cell-to-cell communication and pathogenesis of these extracellular parasites.

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“…Third, the EASs may have been considered as an artefact and just ignored or underappreciated by the investigators. In this regard, different authors using staining methods for light microscopy have described that the flagella of several parabasalids, including T. vaginalis and T. foetus, usually end with a granular or small swelling structure called "knob" (Čepička, 2016;Honigberg & King, 1964;Kirby, 1951); however, it has suggested that "knobs" may be artifacts due to the cell shrinkage during the fixation for protargol staining (Čepička, 2016;Ceza et al, 2015).…”

Section: Discussionmentioning

confidence: 99%

Ultrastructural and functional analysis of extra-axonemal structures in trichomonads

Cóceres

Iriarte

Miranda-Magalhães

et al. 2021

Preprint

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Trichomonas vaginalis and Tritrichomonas foetus are extracellular flagellated parasites that inhabit humans and other mammals, respectively. In addition to motility, flagella act in a variety of biological processes in different cell types; and extra-axonemal structures (EASs) has been described as fibrillar structures that provide mechanical support and act as metabolic, homeostatic and sensory platforms in many organisms. Here, we identified the presence of EASs forming prominent flagellar swellings in T. vaginalis and T. foetus and we observed that their formation was associated with the parasites adhesion on the host cells, fibronectin, and precationized surfaces; and parasite:parasite interaction. A high number of rosettes, clusters of intramembrane particles that has been proposed as sensorial structures, and microvesicles protruding from the membrane were observed in the EASs. The protein VPS32, a member of the ESCRT-III complex crucial for diverse membrane remodeling events, the pinching off and release of microvesicles, was found in the surface as well as in microvesicles protruding from EASs. Moreover, we demonstrated that overexpression of VPS32 protein induce EAS formation and increase parasite motility in semi-solid medium. These results provide valuable data about the role of the flagellar EASs in the cell-to-cell communication and pathogenesis of these extracellular parasites.

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Parabasalia

Cited by 12 publications

References 145 publications

Molecular Identity of Holomastigotes (Spirotrichonymphea, Parabasalia) with Descriptions of Holomastigotes flavipes n. sp. and Holomastigotes tibialis n. sp.

Molecular Identity of Holomastigotes (Spirotrichonymphea, Parabasalia) with Descriptions of Holomastigotes flavipes n. sp. and Holomastigotes tibialis n. sp.

Ultrastructural and Functional Analysis of a Novel Extra-Axonemal Structure in Parasitic Trichomonads

Ultrastructural and functional analysis of extra-axonemal structures in trichomonads

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