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Adult trematodes of the genera Conodiplostomum Dubois, 1937 and Neodiplostomum Railliet, 1919 (Trematoda: Diplostomidae) parasitize the intestines of birds of prey, owls and, rarely, passeriform birds. Although the family is taxonomically unsettled, molecular phylogenetics have not been applied to analyze Conodiplostomum and Neodiplostomum and the reference DNA sequences from adult Diplostomidae are scarce and limit studies of their indistinct larval forms. We analyze the Conodiplostomum and Neodiplostomum spp. found during the examination of Czech birds performed from 1962 to 2017, and we provide comparative measurements and host spectra, including prevalence and intensity; we also provide and analyze the sequences of four DNA loci from eight diplostomid species. Molecular phylogenetic analysis suggested that Conodiplostomum spathula (Creplin, 1829), the type species of this genus, is nested in Neodiplostomum. Thus, we suggest the rejection of Conodiplostomum spathula (Creplin, 1829) and the resurrection of Neodiplostomum spathula (Creplin, 1829) La Rue, 1926 and reclassification of all species of Conodiplostomum with the neodiplostomulum type of metacercariae to Neodiplostomum as well. Conodiplostomum canaliculatum (Nicoll, 1914) is reclassified as Neodiplostomum spathulaeforme (Brandes, 1888). The molecular analysis suggested that Conodiplostomum perlatum (Ciurea, 1911), the species with the neascus type of metacercariae, belongs to Crassiphialinae Sudarikov, 1960. We erect the genus Ciureatrema gen. nov. Heneberg & Sitko and reclassify Conodiplostomum perlatum (Ciurea, 1911) as Ciureatrema perlatum (Ciurea, 1911) and establish it as a type species of Ciureatrema gen. nov. Further research should focus on the evolution of the neascus and neodiplostomulum types of metacercariae, as well as the evolution of the genital cone and pseudosuckers in Diplostomidae.
- MeSH
- fylogeneze * MeSH
- infekce červy třídy Trematoda veterinární MeSH
- mitochondriální DNA genetika MeSH
- prevalence MeSH
- ptáci parazitologie MeSH
- Stringiformes parazitologie MeSH
- Trematoda anatomie a histologie klasifikace MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Based on molecular data three major clades have been recognized within Bilateria: Deuterostomia, Ecdysozoa, and Spiralia. Within Spiralia, small-sized and simply organized animals such as flatworms, gastrotrichs, and gnathostomulids have recently been grouped together as Platyzoa. However, the representation of putative platyzoans was low in the respective molecular phylogenetic studies, in terms of both, taxon number and sequence data. Furthermore, increased substitution rates in platyzoan taxa raised the possibility that monophyletic Platyzoa represents an artifact due to long-branch attraction. In order to overcome such problems, we employed a phylogenomic approach, thereby substantially increasing 1) the number of sampled species within Platyzoa and 2) species-specific sequence coverage in data sets of up to 82,162 amino acid positions. Using established and new measures (long-branch score), we disentangled phylogenetic signal from misleading effects such as long-branch attraction. In doing so, our phylogenomic analyses did not recover a monophyletic origin of platyzoan taxa that, instead, appeared paraphyletic with respect to the other spiralians. Platyhelminthes and Gastrotricha formed a monophylum, which we name Rouphozoa. To the exclusion of Gnathifera, Rouphozoa and all other spiralians represent a monophyletic group, which we name Platytrochozoa. Platyzoan paraphyly suggests that the last common ancestor of Spiralia was a simple-bodied organism lacking coelomic cavities, segmentation, and complex brain structures, and that more complex animals such as annelids evolved from such a simply organized ancestor. This conclusion contradicts alternative evolutionary scenarios proposing an annelid-like ancestor of Bilateria and Spiralia and several independent events of secondary reduction.
- MeSH
- cizopasní červi klasifikace genetika MeSH
- fylogeneze MeSH
- genom u helmintů MeSH
- genomika metody MeSH
- molekulární evoluce MeSH
- ploštěnci klasifikace genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Marine alveolates (MALVs) are diverse and widespread early-branching dinoflagellates, but most knowledge of the group comes from a few cultured species that are generally not abundant in natural samples, or from diversity analyses of PCR-based environmental SSU rRNA gene sequences. To more broadly examine MALV genomes, we generated single cell genome sequences from seven individually isolated cells. Genes expected of heterotrophic eukaryotes were found, with interesting exceptions like presence of proteorhodopsin and vacuolar H+-pyrophosphatase. Phylogenetic analysis of concatenated SSU and LSU rRNA gene sequences provided strong support for the paraphyly of MALV lineages. Dinoflagellate viral nucleoproteins were found only in MALV groups that branched as sister to dinokaryotes. Our findings indicate that multiple independent origins of several characteristics early in dinoflagellate evolution, such as a parasitic life style, underlie the environmental diversity of MALVs, and suggest they have more varied trophic modes than previously thought.
Small subunit rRNA sequences were obtained from 38 representatives mainly of the nematode orders Spirurida (Camallanidae, Cystidicolidae, Daniconematidae, Philometridae, Physalopteridae, Rhabdochonidae, Skrjabillanidae) and, in part, Ascaridida (Anisakidae, Cucullanidae, Quimperiidae). The examined nematodes are predominantly parasites of fishes. Their analyses provided well-supported trees allowing the study of phylogenetic relationships among some spirurine nematodes. The present results support the placement of Cucullanidae at the base of the suborder Spirurina and, based on the position of the genus Philonema (subfamily Philoneminae) forming a sister group to Skrjabillanidae (thus Philoneminae should be elevated to Philonemidae), the paraphyly of the Philometridae. Comparison of a large number of sequences of representatives of the latter family supports the paraphyly of the genera Philometra, Philometroides and Dentiphilometra. The validity of the newly included genera Afrophilometra and Caranginema is not supported. These results indicate geographical isolation has not been the cause of speciation in this parasite group and no coevolution with fish hosts is apparent. On the contrary, the group of South-American species of Alinema, Nilonema and Rumai is placed in an independent branch, thus markedly separated from other family members. Molecular data indicate that the skrjabillanid subfamily Esocineminae (represented by Esocinema bohemicum) should be either elevated to the rank of an independent family or Daniconematidae (Mexiconema africanum) should be decreased to Daniconematinae and transferred to the family Skrjabillanidae. Camallanid genera Camallanus and Procamallanus, as well as the subgenera Procamallanus and Spirocamallanus are confirmed to be paraphyletic. Paraphyly has also been found within Filarioidea, Habronematoidea and Thelazioidea and in Cystidicolidae, Physalopteridae and Thelaziidae. The results of the analyses also show that Neoascarophis, Spinitectus and Rhabdochona are monophyletic, in contrast to the paraphyletic genus Ascarophis. They further confirm the independence of two subgenera, Rhabdochona and Globochona, in the genus Rhabdochona. The necessity of further studies of fish-parasitizing representatives of additional nematode families not yet studied by molecular methods, such as Guyanemidae, Lucionematidae or Tetanonematidae, is underscored.
- MeSH
- DNA helmintů genetika chemie MeSH
- financování organizované MeSH
- fylogeneze MeSH
- hlístice genetika klasifikace patogenita MeSH
- molekulární sekvence - údaje MeSH
- nematodózy parazitologie veterinární MeSH
- nemoci ryb parazitologie MeSH
- ribozomální DNA genetika chemie MeSH
- ryby MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA veterinární MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
Using ITS2 gene sequences, the validity of the tapeworm Diphyllobothrium pacificum (Nybelin, 1931), infecting humans on the Pacific coast of South America and in Japan, was assessed. ITS2 sequences of this cestode differed markedly (sequence similarity 79.0-80.2%) from those of the most common human-infecting cestode, the broad fish tapeworm Diphyllobothrium latum (L.), as well as other four species of Diphyllobothrium, including potential human parasites (D. cordatum, D. dendriticum, and D. lanceolatum) and two species of Spirometra (sequence similarity 77.5-81.9%). Interspecific sequence similarity between all but one (D. pacificum) species was 86.1-99.6%, whereas individual isolates of D. dendriticum and D. ditremum exhibited intraspecific sequence similarity of 97.0-98.0% and 98.2-99.9%, respectively. Phylogenetic trees constructed from ITS2 sequences show a markedly distant position of D. pacificum from other species analyzed and also indicate the possible paraphyly of Spirometra.
- MeSH
- difylobotriáza parazitologie MeSH
- Diphyllobothrium genetika klasifikace MeSH
- financování organizované MeSH
- fylogeneze MeSH
- Herpestidae MeSH
- lachtani rodu Arctocephalus a Callorhinus MeSH
- lidé MeSH
- mezerníky ribozomální DNA genetika MeSH
- molekulární sekvence - údaje MeSH
- mroži MeSH
- Puma MeSH
- ryby MeSH
- sekvenční homologie nukleových kyselin MeSH
- zeměpis MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
- Geografické názvy
- Jižní Amerika MeSH
We describe four new species of Flabellula, Leptomyxa and Rhizamoeba and publish new SSU rRNA gene and actin gene sequences of leptomyxids. Using these data we provide the most comprehensive SSU phylogeny of leptomyxids to date. Based on the analyses of morphological data and results of the SSU rRNA gene phylogeny we suggest changes in the systematics of the order Leptomyxida (Amoebozoa: Lobosa: Tubulinea). We propose to merge the genera Flabellula and Paraflabellula (the genus Flabellula remains valid by priority rule). The genus Rhizamoeba is evidently polyphyletic in all phylogenetic trees; we suggest retaining the generic name Rhizamoeba for the group unifying R. saxonica, R.matisi n. sp. and R. polyura, the latter remains the type species of the genus Rhizamoeba. Based on molecular and morphological evidence we move all remaining Rhizamoeba species to the genus Leptomyxa. New family Rhizamoebidae is established here in order to avoid paraphyly of the family Leptomyxidae. With the suggested changes both molecular and morphological systems of the order Leptomyxida are now fully congruent to each other.
Phylogenetic analyses based on partial 18S rDNA sequences of polyonchoinean monogeneans were conducted in order to investigate the relationships between selected families and subfamilies of the Dactylogyrinea, mainly within the Dactylogyridae. We tested the status of the Ancyrocephalidae sensu Bychowsky & Nagibina (1978) and the Ancyrocephalinae sensu Kritsky & Boeger (1989). Within the Dactylogyrinea, the Diplectanidae and Dactylogyridae are well supported by maximum likelihood and maximum parsimony analyses, but their phylogenetic relationship with the Pseudomurraytrematidae remains unresolved. Phylogenetic relationships between the Pseudodactylogyrinae, Ancyrocephalinae, Ancylodiscoidinae and Dactylogyrinae indicate paraphyly of the Ancyrocephalidae sensu Bychowsky & Nagibina (1978). The group of species recently considered as the Dactylogyridae sensu Kritsky & Boeger (1989) comprises two sister groups. The first group includes the freshwater Ancyrocephalinae and the Ancylodiscoidinae. The second group includes the Pseudodactylogyrinae, Dactylogyrinae and the Ancyrocephalinae from the fish species Siganus doliatus and Tetraodon fluviatilis. The non-monophyly of the Ancyrocephalinae (i.e. the non-monophyly of the group of species recently considered as members of Ancyrocephalinae), previously suggested by Kritsky & Boeger (1989) using the morphological characters, indicates that classification of the Dactylogyridae needs to be revised.
- MeSH
- DNA helmintů chemie genetika MeSH
- fylogeneze MeSH
- molekulární sekvence - údaje MeSH
- polymerázová řetězová reakce MeSH
- ryby parazitologie MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- Trematoda klasifikace genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- Finsko MeSH
- Rakousko MeSH
Trimastigids are free-living, anaerobic protists that are closely related to the symbiotic oxymonads, forming together the taxon Preaxostyla (Excavata: Metamonada). We isolated fourteen new strains morphologically corresponding to two species assigned to Trimastix (until now the only genus of trimastigids), Trimastix marina and Trimastix pyriformis. Unexpectedly, marine strains of Trimastix marina branch separately from freshwater strains of this morphospecies in SSU rRNA gene trees, and instead form the sister group of all other Preaxostyla. This position is confirmed by three-gene phylogenies. Ultrastructural examination of a marine isolate of Trimastix marina demonstrates a combination of trimastigid-like features (e.g. preaxostyle-like I fibre) and ancestral characters (e.g. absence of thickened flagellar vane margins), consistent with inclusion of marine T. marina within Preaxostyla, but also supporting its distinctiveness from 'freshwater T. marina' and its deep-branching position within Preaxostyla. Since these results indicate paraphyly of Trimastix as currently understood, we transfer the other better-studied trimastigids to Paratrimastix n. gen. and Paratrimastigidae n. fam. The freshwater form previously identified as T. marina is described as Paratrimastix eleionoma n. sp., and Trimastix pyriformis becomes Paratrimastix pyriformis n. comb. Because of its phylogenetic position, 'true' Trimastix is potentially important for understanding the evolution of mitochondrion-related organelles in metamonads.
- MeSH
- druhová specificita MeSH
- Eukaryota klasifikace genetika izolace a purifikace ultrastruktura MeSH
- flagella ultrastruktura MeSH
- fylogeneze * MeSH
- organely ultrastruktura MeSH
- RNA ribozomální 18S genetika MeSH
- vodní organismy klasifikace genetika izolace a purifikace ultrastruktura MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
New data on spermiogenesis and the ultrastructure of spermatozoa of 'true' tapeworms (Eucestoda) are summarized. Since 2001, more than 50 species belonging to most orders of the Eucestoda have been studied or reinvestigated, particularly members of the Caryophyllidea, Spathebothriidea, Diphyllobothriidea, Bothriocephalidea, Trypanorhyncha, Tetraphyllidea, Proteocephalidea, and Cyclophyllidea. A new classification of spermatozoa of eucestodes into seven basic types is proposed and a key to their identification is given. For the first time, a phylogenetic tree inferred from spermatological characters is provided. New information obtained in the last decade has made it possible to fill numerous gaps in the character data matrix, enabling us to carry out a more reliable analysis of the evolution of ultrastructural characters of sperm and spermiogenesis in eucestodes. The tree is broadly congruent with those based on morphological and molecular data, indicating that convergent evolution of sperm characters in cestodes may not be as common as in other invertebrate taxa. The main gaps in the current knowledge of spermatological characters are mapped and topics for future research are outlined, with special emphasis on those characters that might provide additional information about the evolution of tapeworms and their spermatozoa. Future studies should be focused on representatives of those major groups (families and orders) in which molecular data indicate paraphyly or polyphyly (e.g. 'Tetraphyllidea' and Trypanorhyncha) and on those that have a key phylogenetic position among eucestodes (e.g. Diphyllidea, 'Tetraphyllidea', Lecanicephalidea, Nippotaeniidea).
- MeSH
- biologická evoluce MeSH
- Cestoda genetika fyziologie MeSH
- druhová specificita MeSH
- fylogeneze MeSH
- spermie ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
