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Břetislav Koudela - One of the best experts on this subject based on the ideXlab platform.
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evolutionary relationships among cyst forming coccidia sarcocystis spp alveolata apicomplexa coccidea in endemic african tree vipers and perspective for evolution of heteroxenous life cycle
Molecular Phylogenetics and Evolution, 2003Co-Authors: Jan Slapeta, Jan Votýpka, David Modrý, Milan Jirků, Břetislav KoudelaAbstract:Cyst-forming coccidia of the genus Sarcocystis (Alveolata: Apicomplexa: Coccidea) parasitize vertebrates worldwide. Data from the small subunit rRNA genes (SSU) and the D2 domain of the large subunit rRNA genes were used to reconstruct phylogeny for all species in the Sarcocystidae for which sequences are currently available. We have focused on the evolutionary history of species that circulate between snakes as definitive hosts and rodents as intermediate hosts. Trees were reconstructed using maximum parsimony, minimum evolution, maximum likelihood and the bayesian phylogenetics. Our reconstructions support monophyly of Sarcocystidae but fail to robustly resolve the relationship within clades. Using a concatenated dataset of available rDNAs, the “isosporoid” coccidia Neospora, Toxoplasma, Besnoitia, Isospora and Hyaloklossia form a sister group to the monophyletic Sarcocystis. Moreover, we show that Sarcocystis from arboreal vipers of the genus Atheris, which are endemic to the mountain rain forests of the Equatorial Africa, are monophyletic, with sister species parasitizing the desert viper Pseudocerastes persicus from the Near East. We report the co-evolution of Sarcocystis spp. with their final snake hosts. The geological history of the African continent, mountain ranges, forests and general SSU rDNA rates were used to construct a linearized tree. Possible origin of the heteroxenous life cycle of Sarcocystis is discussed.
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the phylogeny of goussia and choleoeimeria apicomplexa eimeriorina and the evolution of excystation structures in coccidia
Protist, 2002Co-Authors: Milan Jirků, David Modrý, Jan Slapeta, Břetislav KoudelaAbstract:Summary The phylogenetic relationships of Goussia janae and Choleoeimeria sp. were analyzed using the small subunit ribosomal RNA gene (SSU rDNA). This is a first attempt to study the molecular phylogeny of coccidian genera parasitizing strictly poikilotherm hosts. The biliary Eimeria -like coccidia of reptiles classified into the genus Choleoeimeria form a sister clade to the family Eimeriidae, which confirms the separate generic status of the genus Choleoeimeria . The position of Goussia is less robustly resolved, since it forms a trichotomy with the Eimeriidae and Sarcocystidae, or alternatively constitutes the earliest branch of the coccidian lineage. Morphological similarities, namely the extracytoplasmic location of the endogenous stages, and the presence of sutures in the sporocyst wall are discussed in the context of the traditional classification of eimeriids. In contrast to the morphology-based systematics, the monophyly of Goussia and Choleoeimeria is not supported by the SSU rDNA data.
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Notes on coccidian phylogeny, based on the apicoplast small subunit ribosomal DNA
Parasitology research, 2002Co-Authors: Miroslav Oborník, Břetislav Koudela, Jan Slapeta, David Modrý, Milan Jirků, Julius LukešAbstract:We performed a phylogenetic analysis, based on the partial small subunit rRNA gene (SSU rRNA) sequences from 13 apicoplasts (including new sequences of Sarcocystis muris and Hyaloklossia lieberkuehni) and 16 other plastids, with cyanobacteria as an outgroup. The apicoplast sequences formed a highly supported monophyletic clade with two distinct clades, representing coccidia and haemosporidia, with coccidia divided into Eimeriidae and Sarcocystidae subclades. We confirmed the phylogenetic position of H. lieberkuehni within the Sarcocistidae, as a sister to the Toxoplasma/Neospora group. The coccidian plastid sequences appear to evolve slowly, while their homologues from haemosporidians are more rapidly evolving. We suggest that the higher evolutionary rate is reflected by the increase in the AT content and the possible reduction of the outer apicoplast membrane in some haemosporidians. Since the apicoplast SSU rRNA gene sequences, when compared with their nuclear homologues, offer a higher number of informative positions, they can be used for phylogenetic inference within the Apicomplexa.
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Phylogenetic position of a renal coccidium of the European green frogs, 'Isospora' lieberkuehni Labbé, 1894 (Apicomplexa: Sarcocystidae) and its taxonomic implications.
International Journal of Systematic and Evolutionary Microbiology, 2001Co-Authors: David Modrý, Jan Slapeta, Milan Jirků, Miroslav Oborník, Julius Lukeš, Břetislav KoudelaAbstract:'Isospora' lieberkuehni, an unusual isosporoid renal coccidium that parasitizes the European water frog was isolated from the edible frog, Rana kl. esculenta, in the Czech Republic. Sequencing of the small-subunit (SSU) rRNA gene showed that it belongs to the family Sarcocystidae, being closely related to a clade comprising members of the subfamily Toxoplasmatinae. The position within Sarcocystidae correlates with the mode of excystation via collapsible plates as postulated by previous authors. Phylogenetic, morphological and biological differences between 'Isospora' lieberkuehni and the other Stiedabody-lacking members of the genus Isospora justify separation of this coccidium on a generic level. Hyaloklossia Labbe, 1896 is the oldest available synonym and is herein re-erected. The original definition of the genus Hyaloklossia is emended based on recent observations.
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Multiple origin of the dihomoxenous life cycle in sarcosporidia.
International journal for parasitology, 2001Co-Authors: Jan Slapeta, Břetislav Koudela, Jan Votýpka, David Modrý, Milan Jirků, Julius LukešAbstract:Although their ssrRNA gene sequences are closely related, the lizard sarcosporidia (Apicomplexa, Sarcocystidae) Sarcocystis lacertae and Sarcocystis gallotiae posses heteroxenous and dihomoxenous life cycles, respectively. When aligned with available sarcosporidian ssrRNA genes, both species constitute a monophyletic clade that is only distantly related with sarcosporidia that have a viperid snake as their definitive host (Sarcocystis sp., Sarcocystis atheridis). To test the phyletic status of the dihomoxenous life style, Sarcocystis rodentifelis and Sarcocystis muris, two dihomoxenous parasites of mammals were included into this study. All studied species group together with former Frenkelia spp., Sarcocystis neurona and related marsupial and bird sarcosporidia in a monophyletic clade. However, the available dataset supports independent appearance of the dihomoxenous life cycle at least twice during the evolution of the Sarcocystidae.
Jitender P. Dubey - One of the best experts on this subject based on the ideXlab platform.
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Histologically, immunohistochemically, ultrastructurally, and molecularly confirmed neosporosis abortion in an aborted equine fetus.
Veterinary Parasitology, 2019Co-Authors: Joseph A. Anderson, Daniel K Howe, Derron A. Alves, Camila K. Cerqueira-cézar, Andressa F. Da Silva, Fernando Henrique Antunes Murata, Jamie K. Norris, Jitender P. DubeyAbstract:Abstract Neosporosis is a common cause of abortion in cattle worldwide but is rare in horses. Here, the first case of histologically, ultrastructurally, immunohistochemically, and molecularly confirmed equine abortion caused by neosporosis is reported. Samples of lung, heart, liver, skeletal muscle, tongue, brain, and the placenta from a female fetus aborted at 280 days of gestation were fixed in formalin and submitted for diagnosis. Histologically, there was disseminated neosporosis with severe lesions in lungs, liver and the heart. Protozoal tachyzoites in all tissues reacted with polyclonal anti-Neospora caninum rabbit antibodies. Transmission electron microscopic observation on lung tissue revealed tachyzoites consistent with Neospora, including many rhoptries. Polymerase-chain reaction (PCR) using primers designed to amplify the rRNA gene internal transcribed spacer 1 (ITS1) of the Sarcocystidae was performed on DNA extracted from fetal tissues. Comparison of the ITS1 amplified from the foal tissue to sequences available in GenBank revealed 100% sequence identity to the ITS1 from three isolates of Neospora hughesi.
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Life Cycle of Hammondia hammondi (Apicomplexa: Sarcocystidae) in Cats.
The Journal of eukaryotic microbiology, 2014Co-Authors: Jitender P. Dubey, David J. P. FergusonAbstract:Hammondia hammondi and Toxoplasma gondii are feline coccidians that are morphologically, antigenically, and phylogenitically related. Both parasites multiply asexually and sexually in feline intestinal enterocytes, but H. hammondi remains confined to enterocytes whereas T. gondii also parasitizes extra-intestinal tissues of the cat. Here, we studied multiplication of H. hammondi in feline intestine and compared with T. gondii cycle. Five parasite-free cats were inoculated orally with tissue cysts and free bradyzoites from skeletal muscles of gamma interferon gene knockout mice and killed at 1, 3, 4, 6, and 7 d later. At 1 and 3 d post inoculation (DPI), numerous individual intracellular bradyzoites were detected in histological sections of small intestine. At 4 DPI only schizonts were found and they were located in enterocyte cytoplasm above the host cell nucleus. At 6 and 7 DPI both schizonts and gamonts were seen and they were located in enterocytes. Ultrastucturally, schizogonic and gametogonic development of H. hammondi was similar to T. gondii. However, in H. hammondi merozoites rhoptries were longer, and coiled and contained more micronemes than in T. gondii. Ultrastructural development is illustrated in detail.
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Developmental biology of Cystoisospora (Apicomplexa: Sarcocystidae) monozoic tissue cysts.
The Journal of parasitology, 2014Co-Authors: David S. Lindsay, Alice E. Houk, Sheila M. Mitchell, Jitender P. DubeyAbstract:Abstract: Tissue cyst stages are an intriguing aspect of the developmental cycle and transmission of species of Sarcocystidae. Tissue-cyst stages of Toxoplasma, Hammondia, Neospora, Besnoitia, and Sarcocystis contain many infectious stages (bradyzoites). The tissue cyst stage of Cystoisospora (syn. Isospora) possesses only 1 infectious stage (zoite), and is therefore referred to as a monozoic tissue cyst (MZTC). No tissue cyst stages are presently known for members of Nephroisospora. The present report examines the developmental biology of MZTC stages of Cystoisospora Frenkel, 1977. These parasites cause intestinal coccidiosis in cats, dogs, pigs, and humans. The MZTC stages of C. belli are believed to be associated with reoccurrence of clinical disease in humans.
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Redescription of the Sarcocysts of Sarcocystis rileyi (Apicomplexa: Sarcocystidae)
The Journal of eukaryotic microbiology, 2003Co-Authors: Jitender P. Dubey, Richard J Cawthorn, C. A. Speer, G. A. WobeserAbstract:Abstract The intermediate hosts for Sarcocystis rileyi (Stiles 1893) Minchin 1913 are ducks (Anas spp.), and the striped skunk (Mephitis mephitis) is its definitive host. The structure of sarcocysts from an experimentally infected shoveler duck (Anas cylpeata) fed sporocysts from an experimentally-infected M. mephitis was studied and compared with type specimens from a naturally infected duck. The experimentally infected duck was killed 154 d after feeding sporocysts. By light microscopy the sarcocyst wall was 3–5 μm thick with indistinct villar protrusions. Ultrastructurally, the sarcocyst wall was a type-23 cyst wall with anastomosing villar protrusions that were up to 7.5 μm long. The villar projections contained filamentous structures. The bradyzoites were 12–14 μm long. Structurally, the sarcocyst from the naturally infected and experimentally infected ducks appeared similar.
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Systemic sarcocystosis in a wild turkey from Georgia.
Journal of wildlife diseases, 2000Co-Authors: Jitender P. Dubey, C. F. Quist, D. L. FritzAbstract:Acute sarcocystosis was diagnosed in an adult female wild turkey (Meleagris gallopavo) that was collected from Early County (Georgia, USA) in February of 1998. Marked inflammatory lesions were seen in the heart, lung, and liver and were associated with protozoal schizonts and merozoites. The organisms were identified as Sarcocystis sp. (Acomplexa: Sarcocystidae) based on structure and antigenicity. Protozoa divided by endopolygeny, merozoites lacked rhoptries, and the organisms did not react to anti-S. falcatula antibodies but reacted to anti-S. cruzi antibodies.
David Modrý - One of the best experts on this subject based on the ideXlab platform.
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evolutionary relationships among cyst forming coccidia sarcocystis spp alveolata apicomplexa coccidea in endemic african tree vipers and perspective for evolution of heteroxenous life cycle
Molecular Phylogenetics and Evolution, 2003Co-Authors: Jan Slapeta, Jan Votýpka, David Modrý, Milan Jirků, Břetislav KoudelaAbstract:Cyst-forming coccidia of the genus Sarcocystis (Alveolata: Apicomplexa: Coccidea) parasitize vertebrates worldwide. Data from the small subunit rRNA genes (SSU) and the D2 domain of the large subunit rRNA genes were used to reconstruct phylogeny for all species in the Sarcocystidae for which sequences are currently available. We have focused on the evolutionary history of species that circulate between snakes as definitive hosts and rodents as intermediate hosts. Trees were reconstructed using maximum parsimony, minimum evolution, maximum likelihood and the bayesian phylogenetics. Our reconstructions support monophyly of Sarcocystidae but fail to robustly resolve the relationship within clades. Using a concatenated dataset of available rDNAs, the “isosporoid” coccidia Neospora, Toxoplasma, Besnoitia, Isospora and Hyaloklossia form a sister group to the monophyletic Sarcocystis. Moreover, we show that Sarcocystis from arboreal vipers of the genus Atheris, which are endemic to the mountain rain forests of the Equatorial Africa, are monophyletic, with sister species parasitizing the desert viper Pseudocerastes persicus from the Near East. We report the co-evolution of Sarcocystis spp. with their final snake hosts. The geological history of the African continent, mountain ranges, forests and general SSU rDNA rates were used to construct a linearized tree. Possible origin of the heteroxenous life cycle of Sarcocystis is discussed.
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the phylogeny of goussia and choleoeimeria apicomplexa eimeriorina and the evolution of excystation structures in coccidia
Protist, 2002Co-Authors: Milan Jirků, David Modrý, Jan Slapeta, Břetislav KoudelaAbstract:Summary The phylogenetic relationships of Goussia janae and Choleoeimeria sp. were analyzed using the small subunit ribosomal RNA gene (SSU rDNA). This is a first attempt to study the molecular phylogeny of coccidian genera parasitizing strictly poikilotherm hosts. The biliary Eimeria -like coccidia of reptiles classified into the genus Choleoeimeria form a sister clade to the family Eimeriidae, which confirms the separate generic status of the genus Choleoeimeria . The position of Goussia is less robustly resolved, since it forms a trichotomy with the Eimeriidae and Sarcocystidae, or alternatively constitutes the earliest branch of the coccidian lineage. Morphological similarities, namely the extracytoplasmic location of the endogenous stages, and the presence of sutures in the sporocyst wall are discussed in the context of the traditional classification of eimeriids. In contrast to the morphology-based systematics, the monophyly of Goussia and Choleoeimeria is not supported by the SSU rDNA data.
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Phylogeny and sequence variability of the Sarcocystis singaporensis Zaman and Colley, (1975) 1976 ssrDNA
Parasitology research, 2002Co-Authors: Jan Slapeta, David Modrý, Iveta Kyselová, Aaron O. Richardson, Julius LukešAbstract:The coccidium Sarcocystis singaporensis (Apicomplexa: Sarcocystidae) is a cyst-forming parasite with potential as a biological agent for the control of wild populations of rodents in non-native environments. Phylogenetic analysis based on the ssrDNA supports S. singaporensis isolates as a sister species to sarcosporidians transmitted between snakes and rodents but an association with the carnivore-ruminant Sarcocystis spp. could not be rejected by likelihood ratio tests. Four complete and six partial ssrDNA sequences representing this species are monophyletic in any tree reconstruction method; however, they possess very high pairwise distances of up to 0.053. The obtained sequences suggest the probable existence of at least two divergent paralogous ssrDNAs. Moreover, our results support the co-evolution of lsrDNA and ssrDNA in S. singaporensis. The utility of coccidian lsrDNA and ssrDNA for evolutionary studies and their abundance in the primary nucleotide databases is discussed.
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Notes on coccidian phylogeny, based on the apicoplast small subunit ribosomal DNA
Parasitology research, 2002Co-Authors: Miroslav Oborník, Břetislav Koudela, Jan Slapeta, David Modrý, Milan Jirků, Julius LukešAbstract:We performed a phylogenetic analysis, based on the partial small subunit rRNA gene (SSU rRNA) sequences from 13 apicoplasts (including new sequences of Sarcocystis muris and Hyaloklossia lieberkuehni) and 16 other plastids, with cyanobacteria as an outgroup. The apicoplast sequences formed a highly supported monophyletic clade with two distinct clades, representing coccidia and haemosporidia, with coccidia divided into Eimeriidae and Sarcocystidae subclades. We confirmed the phylogenetic position of H. lieberkuehni within the Sarcocistidae, as a sister to the Toxoplasma/Neospora group. The coccidian plastid sequences appear to evolve slowly, while their homologues from haemosporidians are more rapidly evolving. We suggest that the higher evolutionary rate is reflected by the increase in the AT content and the possible reduction of the outer apicoplast membrane in some haemosporidians. Since the apicoplast SSU rRNA gene sequences, when compared with their nuclear homologues, offer a higher number of informative positions, they can be used for phylogenetic inference within the Apicomplexa.
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Phylogenetic position of a renal coccidium of the European green frogs, 'Isospora' lieberkuehni Labbé, 1894 (Apicomplexa: Sarcocystidae) and its taxonomic implications.
International Journal of Systematic and Evolutionary Microbiology, 2001Co-Authors: David Modrý, Jan Slapeta, Milan Jirků, Miroslav Oborník, Julius Lukeš, Břetislav KoudelaAbstract:'Isospora' lieberkuehni, an unusual isosporoid renal coccidium that parasitizes the European water frog was isolated from the edible frog, Rana kl. esculenta, in the Czech Republic. Sequencing of the small-subunit (SSU) rRNA gene showed that it belongs to the family Sarcocystidae, being closely related to a clade comprising members of the subfamily Toxoplasmatinae. The position within Sarcocystidae correlates with the mode of excystation via collapsible plates as postulated by previous authors. Phylogenetic, morphological and biological differences between 'Isospora' lieberkuehni and the other Stiedabody-lacking members of the genus Isospora justify separation of this coccidium on a generic level. Hyaloklossia Labbe, 1896 is the oldest available synonym and is herein re-erected. The original definition of the genus Hyaloklossia is emended based on recent observations.
Jan Slapeta - One of the best experts on this subject based on the ideXlab platform.
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Sarcocystis bertrami in skeletal muscles of donkeys (Equus africanus asinus) from Southern Italy.
Veterinary parasitology regional studies and reports, 2019Co-Authors: Giuseppe Passantino, Jan Slapeta, Riccardo Paolo Lia, Stefania Latrofa, Giada Annoscia, Domenico Otranto, Roberta Rossi, Nicola ZizzoAbstract:Abstract Among the protozoa of the genus Sarcocystis (Apicomplexa; Sarcocystidae), Sarcocystis bertrami (syn. Sarcocystis fayeri) is an obligate intracellular parasite of donkeys and horses with worldwide distribution. Here, we report the detection of S. bertrami in naturally infected donkeys from southern Italy and describe their structure by light microscopy (LM) and transmission electron microscopy (TEM). Protozoal cysts were detected both morphologically and molecularly in skeletal muscles of 28.57% (40/140) donkeys. Mature cysts of S. bertrami were found in skeletal muscle measuring 31–102 μm long and 19–83 μm wide with radially striated thick cyst wall. The high prevalence of infected donkeys suggests that dogs, the definitive hosts of S. bertrami, are contaminating environment with environmentally resistant sporocysts. Considering the increased consumption of raw donkey meat results also suggest a potential risk for human health.
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Monophyly of marsupial intraerythrocytic apicomplexan parasites from South America and Australia.
Parasitology, 2009Co-Authors: Santiago Merino, Javier Martínez, Rodrigo A. Vásquez, Jan SlapetaAbstract:Intraerythrocytic parasites (Apicomplexa: Sarcocystidae) of the South American mouse opossum (Thylamys elegans) from Chile, South America, and of the yellow-bellied glider (Petaurus australis) from Australia were found to be monophyletic using SSU rDNA and partial LSU rDNA sequences. Phylogenetic reconstruction placed both species within the family Sarcocystidae. These intraerythrocytic parasites of marsupials represent an as yet unnamed genus predicted to have bisporocystic oocysts and tetrazoic sporocysts, which is a characteristic feature of all members of the family Sarcocystidae. These results show that erythrocytic parasites share a common ancestor and suggest co-evolution with their vertebrate host.
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evolutionary relationships among cyst forming coccidia sarcocystis spp alveolata apicomplexa coccidea in endemic african tree vipers and perspective for evolution of heteroxenous life cycle
Molecular Phylogenetics and Evolution, 2003Co-Authors: Jan Slapeta, Jan Votýpka, David Modrý, Milan Jirků, Břetislav KoudelaAbstract:Cyst-forming coccidia of the genus Sarcocystis (Alveolata: Apicomplexa: Coccidea) parasitize vertebrates worldwide. Data from the small subunit rRNA genes (SSU) and the D2 domain of the large subunit rRNA genes were used to reconstruct phylogeny for all species in the Sarcocystidae for which sequences are currently available. We have focused on the evolutionary history of species that circulate between snakes as definitive hosts and rodents as intermediate hosts. Trees were reconstructed using maximum parsimony, minimum evolution, maximum likelihood and the bayesian phylogenetics. Our reconstructions support monophyly of Sarcocystidae but fail to robustly resolve the relationship within clades. Using a concatenated dataset of available rDNAs, the “isosporoid” coccidia Neospora, Toxoplasma, Besnoitia, Isospora and Hyaloklossia form a sister group to the monophyletic Sarcocystis. Moreover, we show that Sarcocystis from arboreal vipers of the genus Atheris, which are endemic to the mountain rain forests of the Equatorial Africa, are monophyletic, with sister species parasitizing the desert viper Pseudocerastes persicus from the Near East. We report the co-evolution of Sarcocystis spp. with their final snake hosts. The geological history of the African continent, mountain ranges, forests and general SSU rDNA rates were used to construct a linearized tree. Possible origin of the heteroxenous life cycle of Sarcocystis is discussed.
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the phylogeny of goussia and choleoeimeria apicomplexa eimeriorina and the evolution of excystation structures in coccidia
Protist, 2002Co-Authors: Milan Jirků, David Modrý, Jan Slapeta, Břetislav KoudelaAbstract:Summary The phylogenetic relationships of Goussia janae and Choleoeimeria sp. were analyzed using the small subunit ribosomal RNA gene (SSU rDNA). This is a first attempt to study the molecular phylogeny of coccidian genera parasitizing strictly poikilotherm hosts. The biliary Eimeria -like coccidia of reptiles classified into the genus Choleoeimeria form a sister clade to the family Eimeriidae, which confirms the separate generic status of the genus Choleoeimeria . The position of Goussia is less robustly resolved, since it forms a trichotomy with the Eimeriidae and Sarcocystidae, or alternatively constitutes the earliest branch of the coccidian lineage. Morphological similarities, namely the extracytoplasmic location of the endogenous stages, and the presence of sutures in the sporocyst wall are discussed in the context of the traditional classification of eimeriids. In contrast to the morphology-based systematics, the monophyly of Goussia and Choleoeimeria is not supported by the SSU rDNA data.
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Phylogeny and sequence variability of the Sarcocystis singaporensis Zaman and Colley, (1975) 1976 ssrDNA
Parasitology research, 2002Co-Authors: Jan Slapeta, David Modrý, Iveta Kyselová, Aaron O. Richardson, Julius LukešAbstract:The coccidium Sarcocystis singaporensis (Apicomplexa: Sarcocystidae) is a cyst-forming parasite with potential as a biological agent for the control of wild populations of rodents in non-native environments. Phylogenetic analysis based on the ssrDNA supports S. singaporensis isolates as a sister species to sarcosporidians transmitted between snakes and rodents but an association with the carnivore-ruminant Sarcocystis spp. could not be rejected by likelihood ratio tests. Four complete and six partial ssrDNA sequences representing this species are monophyletic in any tree reconstruction method; however, they possess very high pairwise distances of up to 0.053. The obtained sequences suggest the probable existence of at least two divergent paralogous ssrDNAs. Moreover, our results support the co-evolution of lsrDNA and ssrDNA in S. singaporensis. The utility of coccidian lsrDNA and ssrDNA for evolutionary studies and their abundance in the primary nucleotide databases is discussed.
Julius Lukeš - One of the best experts on this subject based on the ideXlab platform.
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Phylogeny and sequence variability of the Sarcocystis singaporensis Zaman and Colley, (1975) 1976 ssrDNA
Parasitology research, 2002Co-Authors: Jan Slapeta, David Modrý, Iveta Kyselová, Aaron O. Richardson, Julius LukešAbstract:The coccidium Sarcocystis singaporensis (Apicomplexa: Sarcocystidae) is a cyst-forming parasite with potential as a biological agent for the control of wild populations of rodents in non-native environments. Phylogenetic analysis based on the ssrDNA supports S. singaporensis isolates as a sister species to sarcosporidians transmitted between snakes and rodents but an association with the carnivore-ruminant Sarcocystis spp. could not be rejected by likelihood ratio tests. Four complete and six partial ssrDNA sequences representing this species are monophyletic in any tree reconstruction method; however, they possess very high pairwise distances of up to 0.053. The obtained sequences suggest the probable existence of at least two divergent paralogous ssrDNAs. Moreover, our results support the co-evolution of lsrDNA and ssrDNA in S. singaporensis. The utility of coccidian lsrDNA and ssrDNA for evolutionary studies and their abundance in the primary nucleotide databases is discussed.
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Notes on coccidian phylogeny, based on the apicoplast small subunit ribosomal DNA
Parasitology research, 2002Co-Authors: Miroslav Oborník, Břetislav Koudela, Jan Slapeta, David Modrý, Milan Jirků, Julius LukešAbstract:We performed a phylogenetic analysis, based on the partial small subunit rRNA gene (SSU rRNA) sequences from 13 apicoplasts (including new sequences of Sarcocystis muris and Hyaloklossia lieberkuehni) and 16 other plastids, with cyanobacteria as an outgroup. The apicoplast sequences formed a highly supported monophyletic clade with two distinct clades, representing coccidia and haemosporidia, with coccidia divided into Eimeriidae and Sarcocystidae subclades. We confirmed the phylogenetic position of H. lieberkuehni within the Sarcocistidae, as a sister to the Toxoplasma/Neospora group. The coccidian plastid sequences appear to evolve slowly, while their homologues from haemosporidians are more rapidly evolving. We suggest that the higher evolutionary rate is reflected by the increase in the AT content and the possible reduction of the outer apicoplast membrane in some haemosporidians. Since the apicoplast SSU rRNA gene sequences, when compared with their nuclear homologues, offer a higher number of informative positions, they can be used for phylogenetic inference within the Apicomplexa.
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Phylogenetic position of a renal coccidium of the European green frogs, 'Isospora' lieberkuehni Labbé, 1894 (Apicomplexa: Sarcocystidae) and its taxonomic implications.
International Journal of Systematic and Evolutionary Microbiology, 2001Co-Authors: David Modrý, Jan Slapeta, Milan Jirků, Miroslav Oborník, Julius Lukeš, Břetislav KoudelaAbstract:'Isospora' lieberkuehni, an unusual isosporoid renal coccidium that parasitizes the European water frog was isolated from the edible frog, Rana kl. esculenta, in the Czech Republic. Sequencing of the small-subunit (SSU) rRNA gene showed that it belongs to the family Sarcocystidae, being closely related to a clade comprising members of the subfamily Toxoplasmatinae. The position within Sarcocystidae correlates with the mode of excystation via collapsible plates as postulated by previous authors. Phylogenetic, morphological and biological differences between 'Isospora' lieberkuehni and the other Stiedabody-lacking members of the genus Isospora justify separation of this coccidium on a generic level. Hyaloklossia Labbe, 1896 is the oldest available synonym and is herein re-erected. The original definition of the genus Hyaloklossia is emended based on recent observations.
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Multiple origin of the dihomoxenous life cycle in sarcosporidia.
International journal for parasitology, 2001Co-Authors: Jan Slapeta, Břetislav Koudela, Jan Votýpka, David Modrý, Milan Jirků, Julius LukešAbstract:Although their ssrRNA gene sequences are closely related, the lizard sarcosporidia (Apicomplexa, Sarcocystidae) Sarcocystis lacertae and Sarcocystis gallotiae posses heteroxenous and dihomoxenous life cycles, respectively. When aligned with available sarcosporidian ssrRNA genes, both species constitute a monophyletic clade that is only distantly related with sarcosporidia that have a viperid snake as their definitive host (Sarcocystis sp., Sarcocystis atheridis). To test the phyletic status of the dihomoxenous life style, Sarcocystis rodentifelis and Sarcocystis muris, two dihomoxenous parasites of mammals were included into this study. All studied species group together with former Frenkelia spp., Sarcocystis neurona and related marsupial and bird sarcosporidia in a monophyletic clade. However, the available dataset supports independent appearance of the dihomoxenous life cycle at least twice during the evolution of the Sarcocystidae.
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Phylogenetic analysis of Sarcocystis spp. of mammals and reptiles supports the coevolution of Sarcocystis spp. with their final hosts
International journal for parasitology, 1999Co-Authors: David Doležel, Břetislav Koudela, Jan Slapeta, Jan Votýpka, David Modrý, Milan Jirků, Miroslav Oborník, Václav Hypša, Julius LukešAbstract:Sequences of the small subunit rRNA genes were obtained for two coccidians, Sarcocystis dispersa and an unnamed Sarcocystis sp. which parasitise the European barn owl and an African viperid snake as their final host, respectively, and share mouse as their intermediate host. Phylogenetic analysis of the sequence data showed that Sarcocystis sp. from the viperid snake is most closely related to another Sarcocystis sp. isolated from an American crotalid snake, while S. dispersa grouped with other bird-transmitted species. The available dataset failed to resolve the evolutionary relationships among four major branches into which all Sarcocystidae and Isospora spp. were split. However, within these branches, the phylogenetic relationships of the majority of analysed members of the genus Sarcocystis reflected coevolution with their final, rather than intermediate hosts.
