BACKGROUND: Apicomplexa is a diverse phylum comprising unicellular endobiotic animal parasites and contains some of the most well-studied microbial eukaryotes including the devastating human pathogens Plasmodium falciparum and Cryptosporidium hominis. In contrast, data on the invertebrate-infecting gregarines remains sparse and their evolutionary relationship to other apicomplexans remains obscure. Most apicomplexans retain a highly modified plastid, while their mitochondria remain metabolically conserved. Cryptosporidium spp. inhabit an anaerobic host-gut environment and represent the known exception, having completely lost their plastid while retaining an extremely reduced mitochondrion that has lost its genome. Recent advances in single-cell sequencing have enabled the first broad genome-scale explorations of gregarines, providing evidence of differential plastid retention throughout the group. However, little is known about the retention and metabolic capacity of gregarine mitochondria. RESULTS: Here, we sequenced transcriptomes from five species of gregarines isolated from cockroaches. We combined these data with those from other apicomplexans, performed detailed phylogenomic analyses, and characterized their mitochondrial metabolism. Our results support the placement of Cryptosporidium as the earliest diverging lineage of apicomplexans, which impacts our interpretation of evolutionary events within the phylum. By mapping in silico predictions of core mitochondrial pathways onto our phylogeny, we identified convergently reduced mitochondria. These data show that the electron transport chain has been independently lost three times across the phylum, twice within gregarines. CONCLUSIONS: Apicomplexan lineages show variable functional restructuring of mitochondrial metabolism that appears to have been driven by adaptations to parasitism and anaerobiosis. Our findings indicate that apicomplexans are rife with convergent adaptations, with shared features including morphology, energy metabolism, and intracellularity.

• MeSH
• analýza jednotlivých buněk MeSH
• Apicomplexa * genetika   MeSH
• fylogeneze MeSH
• lidé MeSH
• mitochondrie * genetika   MeSH
• transkriptom MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

A novel species of aseptate eugregarine, Ganymedes yurii sp. n., is described using microscopic and molecular approaches. It inhabits the intestine of Gondogeneia sp., a benthic amphipod found along the shore of James Ross Island, Weddell Sea, Antarctica. The prevalence of the infection was very low and only a few caudo-frontal syzygies were found. Morphologically, the new species is close to a previously described amphipod gregarine, Ganymedes themistos, albeit with several dissimilarities in the structure of the contact zone between syzygy partners, as well as other characteristics. Phylogenetic analysis of the 18S rDNA from G. yurii supported a close relationship between these species. These two species were grouped with other gregarines isolated from crustaceans hosts (Cephaloidophoroidea); however, statistical support throughout the clade of Cephaloidophoroidea gregarines was minimal using the available dataset.

• MeSH
• Amphipoda parazitologie   MeSH
• Apicomplexa klasifikace   genetika   ultrastruktura   MeSH
• fylogeneze MeSH
• mikroskopie MeSH
• protozoální DNA genetika   MeSH
• ribozomální DNA genetika   MeSH
• RNA ribozomální 18S genetika   MeSH
• sekvence nukleotidů MeSH
• sekvenční analýza DNA MeSH
• transmisní elektronová mikroskopie MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Antarktida MeSH

Phlebotomus sergenti Parrot, 1917 is the main vector of Leishmania tropica; however, its broad geographical range and molecular heterogeneity suggest possible variability in vector competence. We infected laboratory-reared P. sergenti originating from Turkey and Israel to compare their susceptibility to L. tropica. In both tested groups, heavy late-stage infections with the presence of metacyclic forms and colonization of the stomodeal valve were observed. The similar development of Leishmania in both sand fly colonies indicates that the different geographical origin of P. sergenti is not reflected by a different vector competence to L. tropica. Additionally, we tested the effect of the gregarine Psychodiella sergenti on L. tropica coinfections; no apparent differences were found between P. sergenti infected or not infected by gregarines.

• MeSH
• Apicomplexa fyziologie   MeSH
• hmyz - vektory parazitologie   MeSH
• interakce hostitele a parazita * MeSH
• Leishmania tropica růst a vývoj   MeSH
• Psychodidae parazitologie   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

BACKGROUND: In mosquitoes, it has previously been shown that rearing conditions of immature stages have an effect on the vector competence of adults. Here, we studied the impact of different larval rearing temperatures (27 °C versus 32 °C) on the sand fly Phlebotomus sergenti Parrot, 1917 and its susceptibility to two parasites: Leishmania tropica Wright, 1903, a dixenous trypanosomatid transmissible from sand flies to humans, and Psychodiella sergenti Lantova, Volf & Votypka, 2010, a monoxenous sand fly gregarine. RESULTS: Increased rearing temperature (32 °C) affected the larval developmental times and size of P. sergenti adults but had no effect on the susceptibility of P. sergenti to L. tropica. No differences were found in Leishmania infection rates or in the intensities of Leishmania infection. Interestingly, increased larval rearing temperature significantly suppressed the development of gregarines. All 117 control sand flies tested were infected with Ps. sergenti, and the mean number of gamonts per individual was 29.5. In contrast, only three of 120 sand flies maintained at 32 °C were infected and the mean number of gamonts per individual was just 0.04. CONCLUSIONS: We demonstrated that the increased rearing temperature of P. sergenti larvae had no impact on the development of L. tropica in adult sand flies but had a profound effect on the gregarine Ps. sergenti. We suggest that increasing the larval rearing temperature by 5 °C is a simple and effective way to clean sand fly colonies infected by gregarines.

• MeSH
• Apicomplexa fyziologie   MeSH
• dezinsekce MeSH
• hmyz - vektory parazitologie   MeSH
• interakce hostitele a parazita MeSH
• larva fyziologie   MeSH
• Leishmania tropica fyziologie   MeSH
• Phlebotomus růst a vývoj   parazitologie   MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Stomatocystis goerresi sp. n., a gregarine (phylum Apicomplexa, Monocystidae) parasite of an important invasive earthworm in North America, Amynthas tokioensis (Beddard), is described. This is the second species placed into the genus, and details of its morphology and life cycle support Stomatocystis Bandyopadhyay, Mitra et Göçmen, 2006 as a valid taxon. The new species is described using standard nomenclature, measurements, shape descriptors, and photographs of living cells. The parasite was found only in A. tokioensis, and absent in sympatric earthworm species, suggesting it arrived when the earthworms were introduced from their origin from Japan. The species is distinctive from the type species in the genus, S. indica Bandyopadhyay, Mitra et Göçmen, 2006, in being substantially larger in all stages, found in only the host's seminal vesicles, and found in a different host species from East Asia. The distinctive trophozoites/gamonts develop a large funnel structure ringed with a collar of pronounced ridges, and the funnel appears even in the smallest cells. This funnel varies greatly in relative size (to the cell body) and shape, sometimes forming a large fan. The life cycle of S. goerresi is described including distinctive syzygy in which the funnels fuse and then produce a large cell with local centres of isogamete production (thus sex without gender). Gametes are large ( ~5 μm) spheres with complex tips. Oocyst production is large, > 1,000 per mature gametocyst. The genus Stomatocystis is placed into the Monocystidae, but the life cycle of the new species differs from those of other monocystid taxa, which may mean the Monocystidae are not monophyletic or life cycles are variable within the family. Prevalence of S. goerresi at the type locality was high (~ 90%). The parasites destroy the earthworm's organ of sperm self-storage thus eliminating the male function in the hermaphroditic host which may influence the ability of the earthworm to invade and be successful at new sites.

• MeSH
• Apicomplexa klasifikace   genetika   růst a vývoj   izolace a purifikace   MeSH
• Oligochaeta parazitologie   MeSH
• stadia vývoje MeSH
• zavlečené druhy MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Japonsko MeSH

This study focused on the attachment strategy, cell structure and the host-parasite interactions of the protococcidian Eleutheroschizon duboscqi, parasitising the polychaete Scoloplos armiger. The attached trophozoites and gamonts of E. duboscqi were detected at different development stages. The parasite develops epicellularly, covered by a host cell-derived, two-membrane parasitophorous sac forming a caudal tipped appendage. Staining with Evans blue suggests that this tail is protein-rich, supported by the presence of a fibrous substance in this area. Despite the ultrastructural evidence for long filaments in the tail, it stained only weakly for F-actin, while spectrin seemed to accumulate in this area. The attachment apparatus consists of lobes arranged in one (trophozoites) or two (gamonts) circles, crowned by a ring of filamentous fascicles. During trophozoite maturation, the internal space between the parasitophorous sac and parasite turns translucent, the parasite trilaminar pellicle seems to reorganise and is covered by a dense fibrous glycocalyx. The parasite surface is organised in broad folds with grooves in between. Micropores are situated at the bottom of the grooves. A layer of filaments organised in bands, underlying the folds and ending above the attachment fascicles, was detected just beneath the pellicle. Confocal microscopy, along with the application of cytoskeletal drugs (jasplakinolide, cytochalasin D, oryzalin) confirmed the presence of actin and tubulin polymerised forms in both the parasitophorous sac and the parasite, while myosin labelling was restricted to the sac. Despite positive tubulin labelling, no microtubules were detected in mature stages. The attachment strategy of E. duboscqi shares features with that of cryptosporidia and gregarines, i.e. the parasite itself conspicuously resembles an epicellularly located gregarine, while the parasitophorous sac develops in a similar manner to that in cryptosporidia. This study provides a re-evaluation of epicellular development in other apicomplexans and directly compares their niche with that of E. duboscqi.

• MeSH
• aktiny ultrastruktura   MeSH
• Apicomplexa klasifikace   fyziologie   ultrastruktura   MeSH
• interakce hostitele a parazita MeSH
• Polychaeta parazitologie   MeSH
• protozoální proteiny ultrastruktura   MeSH
• trofozoiti fyziologie   MeSH
• tubulin ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Mosquitoes and sand flies are important blood-sucking vectors of human diseases such as malaria or leishmaniasis. Nevertheless, these insects also carry their own parasites, such as gregarines; these monoxenous pathogens are found exclusively in invertebrates, and some of them have been considered useful in biological control. Mosquito and sand fly gregarines originally belonging to a single genus Ascogregarina were recently divided into two genera, Ascogregarina comprising parasites of mosquitoes, bat flies, hump-backed flies and fleas and Psychodiella parasitizing sand flies. Currently, nine mosquito Ascogregarina and five Psychodiella species are described. These gregarines go through an extraordinarily interesting life cycle; the mosquito and sand fly larvae become infected by oocysts, the development continues transtadially through the larval and pupal stages to adults and is followed by transmission to the offspring by genus specific mechanisms. In adult mosquitoes, ascogregarines develop in the Malpighian tubules, and oocysts are defecated, while in the sand flies, the gregarines are located in the body cavity, their oocysts are injected into the accessory glands of females and released during oviposition. These life history differences are strongly supported by phylogenetical study of SSU rDNA proving disparate position of Ascogregarina and Psychodiella gregarines. This work reviews the current knowledge about Ascogregarina and Psychodiella gregarines parasitizing mosquitoes and sand flies, respectively. It gives a comprehensive insight into their taxonomy, life cycle, host specificity and pathogenicity, showing a very close relationship of gregarines with their hosts, which suggests a long and strong parasite-host coevolution.

• MeSH
• Culicidae klasifikace   fyziologie   MeSH
• hostitelská specificita MeSH
• interakce hostitele a parazita MeSH
• interakce hostitele a patogenu MeSH
• Psychodidae klasifikace   fyziologie   MeSH
• stadia vývoje MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Urosporids (Apicomplexa: Urosporidae) are eugregarines that parasitise marine invertebrates, such as annelids, molluscs, nemerteans and echinoderms, inhabiting their coelom and intestine. Urosporids exhibit considerable morphological plasticity, which correlates with their different modes of motility and variations in structure of their cortical zone, according to the localisation within the host. The gregarines Urospora ovalis and U. travisiae from the marine polychaete Travisia forbesii were investigated with an emphasis on their general morphology and phylogenetic position. Solitary ovoid trophozoites and syzygies of U. ovalis were located free in the host coelom and showed metabolic activity, a non-progressive movement with periodic changes of the cell shape. Solitary trophozoites of U. travisiae, attached to the host tissue or free floating in the coelom, were V-shaped. Detached trophozoites demonstrated gliding motility, a progressive movement without observable cell body changes. In both gregarines, the cortex formed numerous epicytic folds, but superfolds appeared exclusively on the surface of U. ovalis during metabolic activity. SSU rDNA sequences obtained from U. ovalis and U. travisiae revealed that they belong to the Lecudinoidea clade; however, they are not affiliated with other coelomic urosporids (Pterospora spp. and Lithocystis spp.), but surprisingly with intestinal lecudinids (Difficilina spp.) parasitising nemerteans.

• MeSH
• Apicomplexa klasifikace   cytologie   genetika   izolace a purifikace   MeSH
• fylogeneze MeSH
• lokomoce MeSH
• mikroskopie MeSH
• Polychaeta parazitologie   MeSH
• protozoální DNA chemie   genetika   MeSH
• ribozomální DNA chemie   genetika   MeSH
• RNA ribozomální 18S genetika   MeSH
• sekvenční analýza DNA MeSH
• shluková analýza MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Archigregarines are a key group for understanding the early evolution of Apicomplexa. Here we report morphological, ultrastructural, and molecular phylogenetic evidence from two archigregarine species: Selenidium pygospionis sp. n. and S. pherusae sp. n. They exhibited typical features of archigregarines. Additionally, an axial row of vacuoles of a presumably nutrient distribution system was revealed in S. pygospionis. Intracellular stages of S. pygospionis found in the host intestinal epithelium may point to the initial intracellular localization in the course of parasite development. Available archigregarine SSU (18S) rDNA sequences formed four major lineages fitting the taxonomical affiliations of their hosts, but not the morphological or biological features used for the taxonomical revision by Levine (1971). Consequently, the genus Selenidioides Levine, 1971 should be abolished. The branching order of these lineages was unresolved; topology tests rejected neither para- nor monophyly of archigregarines. We provided phylogenies based on LSU (28S) rDNA and near-complete ribosomal operon (concatenated SSU, 5.8S, LSU rDNAs) sequences including S. pygospionis sequences. Although being preliminary, they nevertheless revealed the monophyly of gregarines previously challenged by many molecular phylogenetic studies. Despite their molecular-phylogenetic heterogeneity, archigregarines exhibit an extremely conservative plesiomorphic structure; their ultrastructural key features appear to be symplesiomorphies rather than synapomorphies.

• MeSH
• Apicomplexa klasifikace   genetika   izolace a purifikace   ultrastruktura   MeSH
• elektronová mikroskopie MeSH
• fylogeneze * MeSH
• lokomoce MeSH
• mikroskopie MeSH
• Polychaeta parazitologie   MeSH
• protozoální DNA chemie   genetika   MeSH
• ribozomální DNA chemie   genetika   MeSH
• RNA ribozomální 18S genetika   MeSH
• RNA ribozomální 28S genetika   MeSH
• RNA ribozomální 5.8S genetika   MeSH
• sekvenční analýza DNA MeSH
• shluková analýza MeSH
• vodní organismy klasifikace   genetika   izolace a purifikace   ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Phlebotomine sand flies (Diptera, Psychodidae) are important vectors of human pathogens. Moreover, they possess monoxenous parasites, including gregarines of the genus Psychodiella Votypka, Lantova, and Volf, which can negatively affect laboratory-reared colonies, and have been considered as potential candidates in biological control. In this study, effects of the gregarine Psychodiella sergenti Lantova, Volf, and Votypka on its natural host Phlebotomus sergenti Parrot were evaluated. The gregarines increased the mortality of immature sand fly stages, and this effect was even more apparent when the infected larvae were reared in more dense conditions. Similarly, the gregarines negatively affected the survival of adult males and females. However, no impact was observed on the mortality of blood-fed females, the proportion of females that laid eggs, and the number of eggs oviposited. The 10-times higher infection dose (50 versus five gregarine oocysts per one sand fly egg) led to -10 times more gamonts in fourth-instar larvae and two or three times more gamonts in females and males, respectively. Our study clearly shows that Ps. sergenti is harmful to its natural host under laboratory conditions. However, its potential for use in biological control is questionable as a result of several factors, including this parasite's strict host specificity.

• MeSH
• Apicomplexa fyziologie   MeSH
• biologická kontrola škůdců MeSH
• dezinsekce MeSH
• interakce hostitele a parazita MeSH
• kladení vajíček MeSH
• organismy bez specifických patogenů MeSH
• Phlebotomus parazitologie   MeSH
• populační dynamika MeSH
• stravovací zvyklosti MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH