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Petr Horák - One of the best experts on this subject based on the ideXlab platform.
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Historical analysis of the type species of the genus Trichobilharzia Skrjabin et Zakharov, 1920 (Platyhelminthes: Schistosomatidae)
Zootaxa, 2016Co-Authors: Jitka A. Aldhoun, Petr Kment, Petr HorákAbstract:Trichobilharzia Skrjabin & Zakharov, 1920 is known as the most species-rich genus of the blood fluke family Schistosomatidae. To date, more than 40 species have been described, even though validity of some of them is questionable (Horak et al . 2002). Members of the genus use various birds as final hosts, but they attract attention mostly as causative agents of hypersensitive skin reaction (cercarial dermatitis or swimmer’s itch) in mammals including humans. As this is one of the
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The phylogeny of the Schistosomatidae based on three genes with emphasis on the interrelationships of Schistosoma Weinland, 1858.
Parasitology, 2003Co-Authors: Anne E. Lockyer, Peter D. Olson, Pia Ostergaard, David Rollinson, David A. Johnston, S. W. Attwood, Vr Southgate, Petr Horák, S. D. SnyderAbstract:Schistosomes are digenean flukes, parasitic of birds, mammals and crocodiles. The family Schistosomatidae contains species of considerable medical and veterinary importance, which cause the disease schistosomiasis. Previous studies, both morphological and molecular, which have provided a good deal of information on the phylogenetics of this group, have been limited in the number of species investigated or the type or extent of molecular data used. This paper presents the most comprehensive phylogeny to date, based on the sequences of 3 genes, complete ribosomal small subunit rRNA and large ribosomal subunit rRNA, and mitochondrial cytochrome oxidase 1, sequenced from 30 taxa including at least 1 representative from 10 of the 13 known genera of the Schistosomatidae and 17 of the 20 recognized Schistosoma species. The phylogeny is examined using morphological characters, intermediate and definitive host associations and biogeography. Theories as to the origins and spread of Schistosoma are also explored. The principal findings are that Ornithobilharzia and Austrobilharzia form a sister group to the Schistosoma; mammalian schistosomes appear paraphyletic and 2 Trichobilharzia species, T. ocellata and T. szidati, seem to be synonymous. The position of Orientobilharzia within the Schistosoma is confirmed, as is an Asian origin for the Schistosoma, followed by subsequent dispersal through India and Africa.
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Karyotype of an avian schistosome Trichobilharzia szidati (Digenea: Schistosomatidae)
International journal for parasitology, 1996Co-Authors: Marta Špakulová, Petr Horák, Ivica Král’ováAbstract:Abstract Somatic chromosomes of Trichobilharzia szidati Neuhaus, 1952 are described from larval stages dissected from snoils, air-dried on slides and stained with Giemsa and C-banding technique, used for the first time in Trichobilharzia sp. The karyotype consisted of 7 autosomal pairs and 1 pair of sex chromosomes, ZZ in the male and ZW in the female, where Z and W chromosomes are of different sizes and both are classified as submetaceatric. C-banding aided in identification of chromosomes Nos 4, satellited 6 and 8. No heterochromatin was observed in the W chromosome. The results were not in agreement with those previously reported and represent new findings. The possible explanation for this fact is given.
Jérôme Boissier - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE Open Access Mating system drives negative associations between morphological features in
2013Co-Authors: Sophie Beltran, Yves Desdevises, Julien Portela, Jérôme BoissierAbstract:Background: Sexual morphological features are known to be associated with the mating systems of several animal groups. However, it has been suggested that morphological features other than sexual characteristics could also be constrained by the mating system as a consequence of negative associations. Schistosomatidae are parasitic organisms that vary in mating system and can thus be used to explore links between the mating system and negative associations with morphological features. Results: A comparative analysis of Schistosomatidae morphological features revealed an association between the mating system (monogamous versus polygynandrous) and morphological characteristics of reproduction, nutrition, and locomotion. Conclusions: The mating system drives negative associations between somatic and sexual morphological features. In monogamous species, males display a lower investment in sexual tissues and a higher commitment of resources to tissues involved in female transport, protection, and feeding assistance. In contrast, males of polygynandrous species invest to a greater extent in sexual tissues at the cost of reduced commitment to female care. Background A mating system reflects the manner in which member
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Mating system drives negative associations between morphological features in Schistosomatidae.
BMC Evolutionary Biology, 2010Co-Authors: Sophie Beltran, Yves Desdevises, Julien Portela, Jérôme BoissierAbstract:BACKGROUND: Sexual morphological features are known to be associated with the mating systems of several animal groups. However, it has been suggested that morphological features other than sexual characteristics could also be constrained by the mating system as a consequence of negative associations. Schistosomatidae are parasitic organisms that vary in mating system and can thus be used to explore links between the mating system and negative associations with morphological features. RESULTS: A comparative analysis of Schistosomatidae morphological features revealed an association between the mating system (monogamous versus polygynandrous) and morphological characteristics of reproduction, nutrition, and locomotion. CONCLUSIONS: The mating system drives negative associations between somatic and sexual morphological features. In monogamous species, males display a lower investment in sexual tissues and a higher commitment of resources to tissues involved in female transport, protection, and feeding assistance. In contrast, males of polygynandrous species invest to a greater extent in sexual tissues at the cost of reduced commitment to female care.
Timothy D J Littlewood - One of the best experts on this subject based on the ideXlab platform.
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orientobilharzia dutt srivastava 1955 trematoda Schistosomatidae a junior synonym of schistosoma weinland 1858
Systematic Parasitology, 2012Co-Authors: Jitka A. Aldhoun, Timothy D J LittlewoodAbstract:In the last few decades, phylogenetic studies of the family Schistosomatidae based on molecular markers have revealed that members of the genus Orientobilharzia Dutt & Srivastava, 1955 belong within Schistosoma Weinland, 1858. In this study, the original descriptions and redescriptions of Orientobilharzia species and related revisions are reviewed, and it is confirmed that the morphological characters correspond with the results of the molecular studies. The two genera differ only in the number of testes; however, this character varies to a large extent within particular genera of the subfamily Schistosomatinae and cannot be used to justify the separation of Orientobilharzia from Schistosoma. Also, we have verified claims suggesting the synonymy of certain species of Orientobilharzia; the four valid species of this genus are transferred to Schistosoma and two new synonymies are formally presented. The following nomenclatural changes are made: Schistosoma Weinland, 1858 [syn. Orientobilharzia Dutt & Srivastava, 1955 (syn. nov.)]; Schistosoma bomfordi Montgomery, 1906 (comb. restit.); S. turkestanicum Skrjabin, 1913 (comb. restit.) [syns Ori. turkestanica var. tuberculata (Bhalerao, 1932) (syn. nov.) and Ori. cheni Hsu & Yang, 1957 (syn. nov.)]; S. dattai (Dutt & Srivastava, 1952) n. comb.; and S. harinasutai (Kruatrachue, Bhaibulaya & Harinasuta, 1965) n. comb. The generic diagnosis of Schistosoma is amended and a revised key to the subfamily Schistosomatinae Stiles & Hassall, 1898 is presented.
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mitochondrial gene order change in schistosoma platyhelminthes digenea Schistosomatidae
International Journal for Parasitology, 2012Co-Authors: Bonnie L Webster, Timothy D J LittlewoodAbstract:Abstract In the flatworm genus Schistosoma , species of which include parasites of biomedical and veterinary importance, mitochondrial gene order is radically different in some species. A PCR-based survey of 19 schistosomatid spp. established which of 14 Schistosoma spp. have the ancestral (plesiomorphic) or derived gene order condition. A phylogeny for Schistosoma was estimated and used to infer the origin of the gene order change which is present in all members of a clade containing Schistosoma incognitum and members of the traditionally recognised Schistosoma indicum , Schistosoma mansoni and Schistosoma haematobium spp. groups. Schistosoma turkestanicum , with the plesiomorphic gene order state, is sister to this clade. Common interval analysis suggests change in gene order, from ancestral to derived, consisted of two sequential transposition events: (a) nad1 _ nad3 to nad3 _ nad1 and (b) [ atp6 , nad2 ]_[ nad3 , nad1 , cox1 , rrnL , rrnS , cox2 , nad6 ] to [ nad3 , nad1 , cox1 , rrnL , rrnS , cox2 , nad6 ]_[ atp6 , nad2 ], where gene order of fragments within square brackets remain unchanged. Gene order change is rare in parasitic flatworms and is a robust synapomorphy for schistosome spp. that exhibit it. The schistosomatid phylogeny casts some doubt on the origin of Schistosoma (Asian or African), highlights the propensity for species to host switch amongst mammalian (definitive) hosts, and indicates the likely importance of snail (intermediate) hosts in determining and defining patterns of schistosome radiation and continental invasion. Mitogenomic sampling of Schistosoma dattai and Schistosoma harinasutai to determine gene order, and within key species, especially S. turkestanicum and S. incognitum , to determine ancestral ranges, may help discover the geographic origins of gene order change in the genus. Samples of S. incognitum from India and Thailand suggest this taxon may include cryptic species.
Sophie Beltran - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE Open Access Mating system drives negative associations between morphological features in
2013Co-Authors: Sophie Beltran, Yves Desdevises, Julien Portela, Jérôme BoissierAbstract:Background: Sexual morphological features are known to be associated with the mating systems of several animal groups. However, it has been suggested that morphological features other than sexual characteristics could also be constrained by the mating system as a consequence of negative associations. Schistosomatidae are parasitic organisms that vary in mating system and can thus be used to explore links between the mating system and negative associations with morphological features. Results: A comparative analysis of Schistosomatidae morphological features revealed an association between the mating system (monogamous versus polygynandrous) and morphological characteristics of reproduction, nutrition, and locomotion. Conclusions: The mating system drives negative associations between somatic and sexual morphological features. In monogamous species, males display a lower investment in sexual tissues and a higher commitment of resources to tissues involved in female transport, protection, and feeding assistance. In contrast, males of polygynandrous species invest to a greater extent in sexual tissues at the cost of reduced commitment to female care. Background A mating system reflects the manner in which member
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Mating system drives negative associations between morphological features in Schistosomatidae.
BMC Evolutionary Biology, 2010Co-Authors: Sophie Beltran, Yves Desdevises, Julien Portela, Jérôme BoissierAbstract:BACKGROUND: Sexual morphological features are known to be associated with the mating systems of several animal groups. However, it has been suggested that morphological features other than sexual characteristics could also be constrained by the mating system as a consequence of negative associations. Schistosomatidae are parasitic organisms that vary in mating system and can thus be used to explore links between the mating system and negative associations with morphological features. RESULTS: A comparative analysis of Schistosomatidae morphological features revealed an association between the mating system (monogamous versus polygynandrous) and morphological characteristics of reproduction, nutrition, and locomotion. CONCLUSIONS: The mating system drives negative associations between somatic and sexual morphological features. In monogamous species, males display a lower investment in sexual tissues and a higher commitment of resources to tissues involved in female transport, protection, and feeding assistance. In contrast, males of polygynandrous species invest to a greater extent in sexual tissues at the cost of reduced commitment to female care.
Alexey P. Ryskov - One of the best experts on this subject based on the ideXlab platform.
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The complete mitochondrial genome of the causative agent of the human cercarial dermatitis, the visceral bird schistosome species Trichobilharzia szidati (platyhelminthes: Trematoda: Schistosomatidae)
Mitochondrial DNA Part B, 2017Co-Authors: S. K. Semyenova, G. G. Chrisanfova, Ludmila Mozharovskaya, Andrei S. Guliaev, Alexey P. RyskovAbstract:We report the first complete mitochondrial genome of visceral bird schistosome Trichobilharzia szidati (Platyhelminthes, Trematoda: Schistosomatidae). The circular genome is 14293 bp in length and ...
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the complete mitochondrial genome of the causative agent of the human cercarial dermatitis the visceral bird schistosome species trichobilharzia szidati platyhelminthes trematoda Schistosomatidae
Mitochondrial DNA Part B, 2017Co-Authors: S. K. Semyenova, G. G. Chrisanfova, Ludmila Mozharovskaya, Andrei S. Guliaev, Alexey P. RyskovAbstract:We report the first complete mitochondrial genome of visceral bird schistosome Trichobilharzia szidati(Platyhelminthes, Trematoda: Schistosomatidae). The circular genome is 14293 bp in length and contains 12 protein-coding genes, 12S and 16S rRNAs genes, 22 tRNAs and one non-coding region (202 bp) (accession number MF136777). Phylogenetic relationships based on 12 protein-coding gene sequences (PCG) of mitogenomes of a number of trematode and cestode species have shown that T. szidati is the closest genetic relative to nasal bird schistosome T. regenti. The complete mitogenome sequence of T. szidati may serve as a resource for comparative mitogenomics and trematode evolution studies.
