Mastophorus muris (Gmelin, 1790) is a globally distributed parasitic nematode of broad range mammals. The taxonomy within the genus Mastophorus and the cryptic diversity among the genus are controversial among taxonomists. This study provides a detailed morphological description of M. muris from Mus musculus combined with a molecular phylogenetic approach. Moreover, descriptions and molecular data of M. muris from non-Mus rodents and wildcats complement our findings and together provide new insights into their taxonomy. The analysis of M. muris was based on light microscopy and scanning electron microscopy. The morphological description focused on the dentition pattern of the two trilobed pseudolabia. Additionally, we described the position of the vulva, arrangement of caudal pairs of papillae, spicules and measured specimens from both sexes and the eggs. For the molecular phylogenetic approach, we amplified the small subunit ribosomal RNA gene and the internal transcribed spacer, and the cytochrome c oxidase subunit 1. Mastophorus morphotypes based on dentition patterns and phylogenetic clustering indicate a subdivision of the genus in agreement with their host. We recognize two groups without a change to formal taxonomy: One group including those specimens infecting Mus musculus, and the second group including organisms infecting non-Mus rodents. Our genetic and morphological data shed light into the cryptic diversity within the genus Mastopohorus. We identified two host-associated groups of M. muris. The described morphotypes and genotypes of M. muris allow a consistent distinction between host-associated parasites.
- Klíčová slova
- Mastophorus muris, Mus musculus, Nematoda, Phylogeny, Scanning electron microscopy,
- MeSH
- DNA helmintů genetika MeSH
- fylogeneze * MeSH
- genetická variace MeSH
- mezerníky ribozomální DNA genetika MeSH
- mikroskopie elektronová rastrovací * MeSH
- mikroskopie MeSH
- molekulární sekvence - údaje MeSH
- myši MeSH
- respirační komplex IV genetika MeSH
- ribozomální DNA genetika MeSH
- sekvenční analýza DNA MeSH
- shluková analýza MeSH
- Spiruroidea klasifikace genetika anatomie a histologie izolace a purifikace ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA helmintů MeSH
- mezerníky ribozomální DNA MeSH
- respirační komplex IV MeSH
- ribozomální DNA MeSH
Deficiency in chromatin assembly factor-1 (CAF-1) in plants through dysfunction of its components, FASCIATA1 and 2 (FAS1, FAS2), leads to the specific and progressive loss of rDNA and telomere repeats in plants. This loss is attributed to defective repair mechanisms for the increased DNA breaks encountered during replication, a consequence of impaired replication-dependent chromatin assembly. In this study, we explore the role of KU70 in these processes. Our findings reveal that, although the rDNA copy number is reduced in ku70 mutants when compared with wild-type plants, it is not markedly affected by diverse KU70 status in fas1 mutants. This is consistent with our previous characterisation of rDNA loss in fas mutants as a consequence part of the single-strand annealing pathway of homology-dependent repair. In stark contrast to rDNA, KU70 dysfunction fully suppresses the loss of telomeres in fas1 plants and converts telomeres to their elongated and heterogeneous state typical for ku70 plants. We conclude that the alternative telomere lengthening pathway, known to be activated in the absence of KU70, overrides progressive telomere loss due to CAF-1 dysfunction.
- Klíčová slova
- 45S rDNA, ALT, Arabidopsis thaliana, CAF‐1, FAS1, KU70, genome instability, telomeres,
- MeSH
- Arabidopsis * genetika metabolismus fyziologie MeSH
- DNA vazebné proteiny MeSH
- faktor 1 pro uspořádání chromatinu metabolismus genetika MeSH
- homeostáza telomer * MeSH
- mutace MeSH
- proteiny huseníčku * genetika metabolismus MeSH
- ribozomální DNA * genetika metabolismus MeSH
- telomery * metabolismus genetika MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA vazebné proteiny MeSH
- faktor 1 pro uspořádání chromatinu MeSH
- FAS protein, Arabidopsis MeSH Prohlížeč
- KU70 protein, Arabidopsis MeSH Prohlížeč
- proteiny huseníčku * MeSH
- ribozomální DNA * MeSH
The relationships of the mainly free living, obligately anaerobic ciliated protists belonging to order Metopida continue to be clarified and now comprise three families: Metopidae, Tropidoatractidae, and Apometopidae. The most species-rich genus of the Metopidae, Metopus has undergone considerable subdivision into new genera in recent years as more taxa are characterized by modern morphologic and molecular methods. The genus, Castula, was established to accommodate setae-bearing species previously assigned to Metopus: C. setosa and C. fusca, and one new species, C. flexibilis. Another new species, C. specialis, has been added since. Here we redescribe another species previously included in Metopus, using morphologic and molecular methods, and transfer it to Castula as C. strelkowi n. comb. (original combination Metopus strelkowi). We also reassess the monotypic genus, Pileometopus, which nests within the strongly supported Castula clade in 18S rRNA gene trees and conclude that it represents a morphologically divergent species of Castula.
- Klíčová slova
- 18S rRNA gene, Anaerobic ciliate, Metopidae, Phylogeny, Scanning electron microscopy,
- MeSH
- Ciliophora klasifikace genetika cytologie MeSH
- druhová specificita MeSH
- fylogeneze * MeSH
- protozoální DNA genetika MeSH
- ribozomální DNA genetika MeSH
- RNA ribozomální 18S genetika MeSH
- sladká voda * parazitologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- protozoální DNA MeSH
- ribozomální DNA MeSH
- RNA ribozomální 18S MeSH
The Australian skink Egernia stokesii had been recognised as a host of two species of Plasmodium, Plasmodium mackerrasae and P. circularis; nevertheless, molecular data are available for only a single haemosporidian species of this host. Its sequences are labelled as "Plasmodium sp." or "Plasmodium mackerrasae", but morphological characteristics of this isolate are unavailable. Phylogenetic analyses of these sequences placed them into the clade of the genus Haemocystidium. In this study, blood samples of six E. stokesii were analysed by both, molecular and microscopic methods to clarify the haemosporidia of this lizard. Application of these approaches offered discordant results. Whereas sequence analysis clustered our isolates with lizard species of Haemocystidium, morphology of blood stages is more akin to Plasmodium than Haemocystidium. However, limited sampling, indistinguishable nuclei/merozoites and risk of possible hidden presence of mixed infection prevent reliable species identification of detected parasites or their description as new species of Haemocystidium.
- Klíčová slova
- Egernia stokesii, Haemocystidium, Plasmodium mackerrasae, Australia, Haemosporidia, Lizard,
- MeSH
- fylogeneze * MeSH
- Haemosporida * genetika klasifikace izolace a purifikace MeSH
- ještěři * parazitologie MeSH
- krev parazitologie MeSH
- mikroskopie MeSH
- molekulární sekvence - údaje MeSH
- protozoální DNA genetika MeSH
- protozoální infekce zvířat parazitologie MeSH
- ribozomální DNA 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
- Geografické názvy
- Austrálie MeSH
- Názvy látek
- protozoální DNA MeSH
- ribozomální DNA MeSH
- RNA ribozomální 18S MeSH
The phylogenetic and taxonomic affinities of lineages currently assigned to the non-monophyletic ciliate order Loxocephalida Jankowski (1980) within subclass Scuticociliatia Small (1967) remain unresolved. In the current study, we redescribe the morphology of the type species, Loxocephalus luridus Eberhard (1862) based on two Czech populations and include the first scanning and transmission electron microscopy images of the species. We provide the first 18S rRNA gene sequences for L. luridus and consider its phylogenetic position. Our results support the separation of Dexiotricha from Loxocephalus; however, the former genus is recovered as non-monophyletic. The monophyly of genus Dexiotricha and that of Loxocephalus + Dexiotricha is rejected. Loxocephalus luridus, together with Dexiotricha species, nests within a fully supported clade with Conchophthirus species, long presumed to belong to the Pleuronematida. Haptophrya is recovered as sister to this clade. The monophyly of the Astomatia Schewiakoff (1896) including Haptophrya is rejected. No clear morphologic synapomorphy is identified for the fully supported clade consisting of Haptophrya, Dexiotricha, Loxocephalus, and Conchophthirus.
- Klíčová slova
- Conchophthirus, Dexiotricha, Haptophrya, 18S rRNA gene, freshwater sapropel, scanning electron microscopy, transmission electron microscopy,
- MeSH
- Ciliophora klasifikace genetika ultrastruktura MeSH
- fylogeneze * MeSH
- mikroskopie elektronová rastrovací MeSH
- molekulární sekvence - údaje MeSH
- protozoální DNA * genetika MeSH
- ribozomální DNA genetika MeSH
- RNA ribozomální 18S * genetika MeSH
- sekvenční analýza DNA MeSH
- transmisní elektronová mikroskopie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Cryptosporidium spp., Enterocytozoon bieneusi and Encephalitozoon spp. are the most common protistan parasites of vertebrates. The results show that pigeon populations in Central Europe are parasitised by different species of Cryptosporidium and genotypes of microsporidia of the genera Enterocytozoon and Encephalitozoon. A total of 634 and 306 faecal samples of captive and feral pigeons (Columba livia f. domestica) from 44 locations in the Czech Republic, Slovakia and Poland were analysed for the presence of parasites by microscopy and PCR/sequence analysis of small subunit ribosomal RNA (18S rDNA), 60 kDa glycoprotein (gp60) and internal transcribed spacer (ITS) of SSU rDNA. Phylogenetic analyses revealed the presence of C. meleagridis, C. baileyi, C. parvum, C. andersoni, C. muris, C. galli and C. ornithophilus, E. hellem genotype 1A and 2B, E. cuniculi genotype I and II and E. bieneusi genotype Peru 6, CHN-F1, D, Peru 8, Type IV, ZY37, E, CHN4, SCF2 and WR4. Captive pigeons were significantly more frequently parasitised with screened parasite than feral pigeons. Cryptosporidium meleagridis IIIa and a new subtype IIIl have been described, the oocysts of which are not infectious to immunodeficient mice, whereas chickens are susceptible. This investigation demonstrates that pigeons can be hosts to numerous species, genotypes and subtypes of the studied parasites. Consequently, they represent a potential source of infection for both livestock and humans.
- Klíčová slova
- Birds, Experimental infection, Genotyping, PCR,
- MeSH
- Columbidae MeSH
- Cryptosporidium * genetika MeSH
- Encephalitozoon * genetika MeSH
- Enterocytozoon * genetika MeSH
- feces parazitologie MeSH
- fylogeneze MeSH
- genetická variace MeSH
- genotyp MeSH
- kryptosporidióza * epidemiologie parazitologie MeSH
- kur domácí MeSH
- lidé MeSH
- mikrosporidióza * epidemiologie veterinární parazitologie MeSH
- myši MeSH
- ribozomální DNA MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa epidemiologie MeSH
- Názvy látek
- ribozomální DNA MeSH
Dermoergasilus madagascarensis n. sp. is described from the gills of Paretroplus polyactis, an endemic cichlid fish in Madagascar, using a combined morphological (light microscopy and SEM) and molecular approach (partial 18S rDNA, 28S rDNA, and COI sequences). The new species is characterized mainly by possessing: (i) roughly pentagonal cephalosome; (ii) antennal endopodal segments covered with slightly inflated membrane; (iii) maxillule bearing 2 equally long outer setae and a minute inner seta; (iv) interpodal sternites of swimming legs ornamented with 3–4 rows of spinules; (v) genital segment and first abdominal somite both barrel-shaped; and (vi) a caudal ramus projecting into a digitiform process with inconspicuous terminal seta and bearing 3 terminal setae. The obtained DNA sequences of Malagasy species represent the first molecular data for species of Dermoergasilus. The 28S rDNA phylogeny showed the affiliation of D. madagascarensis n. sp. to Ergasilidae and its sister relationship with cosmopolitan Ergasilus sieboldi von Nordmann, 1832. The first checklist for all species of Dermoergasilus is provided.
- Klíčová slova
- COI, Cichlids, Dermoergasilus, Ergasilidae, Madagascar, diversity, parasitic crustaceans, phylogeny, rDNA,
- MeSH
- cichlidy * genetika MeSH
- Copepoda * genetika MeSH
- ribozomální DNA genetika MeSH
- žábry MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Madagaskar MeSH
- Názvy látek
- ribozomální DNA MeSH
Although both are salient features of genomes, at first glance ribosomal DNAs and transposable elements are genetic elements with not much in common: whereas ribosomal DNAs are mainly viewed as housekeeping genes that uphold all prime genome functions, transposable elements are generally portrayed as selfish and disruptive. These opposing characteristics are also mirrored in other attributes: organization in tandem (ribosomal DNAs) versus organization in a dispersed manner (transposable elements); evolution in a concerted manner (ribosomal DNAs) versus evolution by diversification (transposable elements); and activity that prolongs genomic stability (ribosomal DNAs) versus activity that shortens it (transposable elements). Re-visiting relevant instances in which ribosomal DNA-transposable element interactions have been reported, we note that both repeat types share at least four structural and functional hallmarks: (1) they are repetitive DNAs that shape genomes in evolutionary timescales, (2) they exchange structural motifs and can enter co-evolution processes, (3) they are tightly controlled genomic stress sensors playing key roles in senescence/aging, and (4) they share common epigenetic marks such as DNA methylation and histone modification. Here, we give an overview of the structural, functional, and evolutionary characteristics of both ribosomal DNAs and transposable elements, discuss their roles and interactions, and highlight trends and future directions as we move forward in understanding ribosomal DNA-transposable element associations.
- Klíčová slova
- concerted evolution, genome size, genome stability, homogenization, housekeeping genes, long-read sequencing, molecular cytogenetics, recombination, repetitive DNA, ribosomal DNA, transposable elements, transposition,
- MeSH
- cytogenetické vyšetření MeSH
- genomika * MeSH
- metylace DNA MeSH
- molekulární evoluce MeSH
- ribozomální DNA MeSH
- transpozibilní elementy DNA * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- ribozomální DNA MeSH
- transpozibilní elementy DNA * MeSH
The Labeoninae subfamily is a highly diversified but demonstrably monophyletic lineage of cyprinid fishes comprising five tribes and six incertae sedis genera. This widely distributed assemblage contains some 48 genera and around 480 recognized species distributed in freshwaters of Africa and Asia. In this study, the karyotypes and other chromosomal properties of five Labeoninae species found in Thailand Labeo chrysophekadion (Labeonini) and Epalzeorhynchos bicolor, Epalzeorhynchos munense, Henicorhynchus siamensis, Thynnichthys thynnoides (´Osteochilini´) were examined using conventional and molecular cytogenetic protocols. Our results confirmed a diploid chromosome number (2n) invariably 2n = 50, but the ratio of uni- and bi-armed chromosomes was highly variable among their karyotypes, indicating extensive structural chromosomal rearrangements. Karyotype of L. chrysophekadion contained 10m+6sm+20st+14a, 32m+10sm+8st for H. siamensis, 20m+12sm+10st+8a in E. bicolor, 20m+8sm+8st+14a in E. munense, and 18m+24sm+8st in T. thynnoides. Except for H. siamensis, which had four sites of 5S rDNA sites, other species under study had only one chromosome pair with those sites. In contrast, only one pair containing 18S rDNA sites were found in the karyotypes of three species, whereas two sites were found in that of E. bicolor. These cytogenetic patterns indicated that the cytogenomic divergence patterns of these labeonine species largely corresponded to the inferred phylogenetic tree. In spite of the 2n stability, diverse patterns of rDNA and microsatellite distribution as well as their various karyotype structures demonstrated significant evolutionary differentiation of Labeoninae genomes as exemplified in examined species. Labeoninae offers a traditional point of view on the evolutionary forces fostering biological diversity, and the recent findings add new pieces to comprehend the function of structural chromosomal rearrangements in adaption and speciation.
- MeSH
- chromozomální aberace MeSH
- chromozomy * genetika MeSH
- Cyprinidae * genetika MeSH
- fylogeneze MeSH
- karyotyp MeSH
- molekulární evoluce MeSH
- ribozomální DNA genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Thajsko MeSH
- Názvy látek
- ribozomální DNA MeSH
Cestodes of the family Anoplocephalidae parasitize a wide range of usually herbivorous hosts including e.g. rodents, ungulates, primates, elephants and hyraxes. While in some hosts, the epidemiology of the infection is well studied, information is lacking in others. In this study of mountain gorillas in the Virunga Massif, an extensive sample set comprising adult cestodes collected via necropsies, proglottids shed in feces, and finally, fecal samples from both night nests and identified individuals were analysed. Anoplocephala gorillae was the dominant cestode species detected in night nest samples and individually known gorillas, of which only 1 individual hosted a Bertiella sp. It was shown that the 2 species can be distinguished through microscopy based on egg morphology and polymerase chain reaction (PCR) assays for diagnostics of both species were provided. Sequences of mitochondrial (cox 1) and nuclear (ITS1, 18S rDNA, 28S rDNA) markers were used to evaluate the phylogenetic position of the 2 cestodes detected in mountain gorillas. Both types of fecal samples, from night nests and from identified individuals, provided comparable information about the prevalence of anoplocephalid cestodes, although the analysis of samples collected from identified gorilla individuals showed significant intra-individual fluctuation of A. gorillae egg shedding within a short period. Therefore, multiple samples should be examined to obtain reliable data for wildlife health management programmes, especially when application of anthelmintic treatment is considered. However, while A. gorillae is apparently a common symbiont of mountain gorillas, it does not seem to impair the health of its host.
- Klíčová slova
- Anoplocephala, Anoplocephalidae, Bertiella, Gorilla beringei, Rwanda, mountain gorilla, parasite ecology, parasite epidemiology,
- MeSH
- Cestoda * genetika MeSH
- fylogeneze MeSH
- Gorilla gorilla * MeSH
- ribozomální DNA MeSH
- veřejné parky MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Rwanda epidemiologie MeSH
- Názvy látek
- ribozomální DNA MeSH
