Free ranging ungulates, represented in Europe mostly by several deer species, are important hosts for ticks and reservoirs of tick-borne infections. A number of studies have focused on the prevalence of tick borne pathogens in deer chiefly with the aim to determine their potential role as reservoir hosts for important human and livestock pathogens. However, genetic similarity of Babesia spp. forming a group commonly termed as a clade VI that accommodates the deer piroplasms, complicates this task and has led to the description of a bewildering array of poorly characterised strains. This study aims to resolve this issue by using two independent genetic loci, nuclear 18S rRNA and mitochondrial cytochrome c oxidase subunit I genes, used in parallel to identify Babesia isolates in free-ranging red, sika, and roe deer in two areas of their co-occurrence in the Czech Republic. The COX1 loci, in contrast to 18S rRNA gene, shows a clear difference between interspecific and intraspecific variation at the nucleotide level. The findings confirm B. divergens, Babesia sp. EU1 and B. capreoli in studied deer species as well as common presence of another unnamed species that matches a taxon previously referred to as Babesia sp. or Babesia cf. odocoilei or Babesia CH1 group in several other sites throughout Europe. The invasive sika deers enter the life cycle of at least three piroplasmid species detected in native deer fauna. The presence of B. divergens in both sika and red deer in an area where bovine babesiosis is apparently absent raises important questions regarding the epidemiology, host specificity and taxonomic status of the parasite.
- MeSH
- Babesia classification genetics MeSH
- Babesiosis parasitology virology MeSH
- Cyclooxygenase 1 genetics MeSH
- Phylogeny MeSH
- Evolution, Molecular MeSH
- DNA, Protozoan genetics MeSH
- Protozoan Proteins genetics MeSH
- DNA, Ribosomal genetics MeSH
- RNA, Ribosomal, 18S genetics MeSH
- Sequence Analysis, DNA methods MeSH
- Deer parasitology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
Ectoparasitic monogeneans of the family Diplozoidae have direct and monoxenous life cycle. The cytogenetics of monogeneans in general and diplozoids in particular, is a relatively underexplored area. This is why each new detailed description of a karyotype provides significant information about the evolution of monogenean chromosomes and contributes to a better understanding of phylogenetic relationships within this group. This study offers new data on the chromosomes of Eudiplozoon nipponicum, an invasive parasite of the common carp. This species' karyotype consists of seven pairs of telocentric chromosomes (2n = 14 t). After DAPI staining, we marked heterochromatin blocks on all chromosomes in the pericentromeric region. Silver staining (AgNO3) and staining with fluorescent dye YOYO-1 revealed the presence of one large active nucleolus. Fluorescent in situ hybridization with an 18S rDNA probe revealed one cluster of ribosomal genes at the terminal part of the long arms of chromosome pair No. 7. We compared our results with studies on the phylogenetic relationships of diplozoids which applied a combination of molecular methods and classical morphological characterization and found that the results of our cytogenetic analysis are consistent with the hypothesis that E. nipponicum is more basal member of the family Diplozoidae.
- MeSH
- Staining and Labeling MeSH
- Cell Division * MeSH
- Cytogenetic Analysis MeSH
- Phylogeny MeSH
- In Situ Hybridization, Fluorescence MeSH
- Carps parasitology MeSH
- Karyotype MeSH
- RNA, Ribosomal, 18S genetics MeSH
- Spermatocytes physiology MeSH
- Trematoda genetics MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Canine babesiosis caused by Babesia canis sensu stricto became an emerging disease of dogs across Europe calling for attention also in countries where it was an only rare imported disease. An easy accessibility of molecular methods and the growing amount of sequencing data led to the description of intraspecific variability in 18S rDNA sequences designated as "genotypes". Using material from a homogenous cohort of dogs with microscopically confirmed canine babesiosis caused by B. canis, we evaluated Babesia intraspecific variability and amplification sensitivity of three different genes (18S rDNA, COI, Cytb) to assess their potential as diagnostic or phylogenetic markers. In raw sequencing data obtained, we observed at least 3 ambiguous positions in up to 86% of chromatograms within the ∼560 bp fragment of 18S rDNA suggesting the existence of several, not identical copies of this gene. Our COI haplotype analysis resulted in a star-like pattern indicating a recent origin of most haplotypes, but not supporting the existence of two dominant haplotypes. Similarly, the Cytb sequences obtained from samples with all variants of 18S rDNA were identical. We corroborate previous observations from three other European countries and bring the evidence of the existence of 18S rDNA paralogs in B. canis genome replacing currently used "genotype" theory.
- MeSH
- Babesia genetics MeSH
- Babesiosis blood diagnosis parasitology MeSH
- Phylogeny MeSH
- Genetic Variation * MeSH
- Genetic Markers MeSH
- Genome, Protozoan MeSH
- Genotype * MeSH
- Haplotypes MeSH
- Cohort Studies MeSH
- Mitochondria genetics MeSH
- Dog Diseases diagnosis parasitology MeSH
- DNA, Protozoan genetics MeSH
- Dogs MeSH
- RNA, Ribosomal, 18S genetics MeSH
- Sequence Analysis, DNA MeSH
- Animals MeSH
- Check Tag
- Dogs MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Europe MeSH
Metacestodes of Mesocestoides sp. were recorded from Sturnus vulgaris (Passeriformes: Stumidae) in the Czech Republic in April 2002. They were found in a cutaneous cyst and in the thoracic region of the body cavity of the bird. This is the first record of metacestodes of Mesocestoides sp. in this host species in Europe as well as the first finding of the formation of a cutaneous cyst provoked by this parasite. Additional specimens from Apodemus agrarius (Mammalia: Rodentia) from Bulgaria and Lacerta agilis (Reptilia: Squamata) from the Czech Republic were compared with that from S. vulgaris. Sequence data from the V4 variable region (18S rDNA) were used to compare genetic variability among these and previously characterized isolates of Mesocestoides spp. A number of distinct clades were recognized, with metacestodes from L. agilis showing the highest degree of relative divergence.
- MeSH
- Cestoda anatomy & histology genetics isolation & purification MeSH
- DNA, Helminth chemistry genetics MeSH
- Phylogeny MeSH
- Thorax parasitology MeSH
- Skin parasitology MeSH
- Molecular Sequence Data MeSH
- Polymerase Chain Reaction MeSH
- RNA, Ribosomal, 18S chemistry genetics MeSH
- Base Sequence MeSH
- Sequence Alignment MeSH
- Songbirds parasitology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The online resource http://www.plantrdnadatabase.com/ stores information on the number, chromosomal locations and structure of the 5S and 18S-5.8S-26S (35S) ribosomal DNAs (rDNA) in plants. This resource was exploited to study relationships between rDNA locus number, distribution, the occurrence of linked (L-type) and separated (S-type) 5S and 35S rDNA units, chromosome number, genome size and ploidy level. The analyses presented summarise current knowledge on rDNA locus numbers and distribution in plants. We analysed 2949 karyotypes, from 1791 species and 86 plant families, and performed ancestral character state reconstructions. The ancestral karyotype (2n = 16) has two terminal 35S sites and two interstitial 5S sites, while the median (2n = 24) presents four terminal 35S sites and three interstitial 5S sites. Whilst 86.57% of karyotypes show S-type organisation (ancestral condition), the L-type arrangement has arisen independently several times during plant evolution. A non-terminal position of 35S rDNA was found in about 25% of single-locus karyotypes, suggesting that terminal locations are not essential for functionality and expression. Single-locus karyotypes are very common, even in polyploids. In this regard, polyploidy is followed by subsequent locus loss. This results in a decrease in locus number per monoploid genome, forming part of the diploidisation process returning polyploids to a diploid-like state over time.
- MeSH
- Chromosomes, Plant genetics MeSH
- Databases, Genetic MeSH
- DNA, Plant genetics MeSH
- Phylogeny MeSH
- Genes, rRNA genetics MeSH
- Karyotype MeSH
- DNA, Ribosomal genetics MeSH
- RNA, Ribosomal, 18S genetics MeSH
- RNA, Ribosomal, 5S genetics MeSH
- Plants genetics MeSH
- Embryophyta genetics MeSH
- Publication type
- Journal Article MeSH
We examined chromosomal distribution of major ribosomal DNAs (rDNAs), clustered in the nucleolar organizer regions (NORs), in 18 species of moths and butterflies using fluorescence in situ hybridization with a codling moth (Cydia pomonella) 18S rDNA probe. Most species showed one or two rDNA clusters in their haploid karyotype but exceptions with 4-11 clusters also occurred. Our results in a compilation with previous data revealed dynamic evolution of rDNA distribution in Lepidoptera except Noctuoidea, which showed a highly uniform rDNA pattern. In karyotypes with one NOR, interstitial location of rDNA prevailed, whereas two-NOR karyotypes showed mostly terminally located rDNA clusters. A possible origin of the single interstitial NOR by fusion between two NOR-chromosomes with terminal rDNA clusters lacks support in available data. In some species, spreading of rDNA to new, mostly terminal chromosome regions was found. The multiplication of rDNA clusters without alteration of chromosome numbers rules out chromosome fissions as a major mechanism of rDNA expansion. Based on rDNA dynamics in Lepidoptera and considering the role of ordered nuclear architecture in karyotype evolution, we propose ectopic recombination, i.e., homologous recombination between repetitive sequences of non-homologous chromosomes, as a primary motive force in rDNA repatterning.
- MeSH
- Chromosomes genetics MeSH
- DNA genetics MeSH
- Species Specificity MeSH
- Phylogeny MeSH
- Genetic Variation MeSH
- Genome, Insect MeSH
- In Situ Hybridization, Fluorescence MeSH
- Karyotyping MeSH
- Evolution, Molecular MeSH
- Butterflies genetics MeSH
- Moths genetics MeSH
- Nucleolus Organizer Region genetics MeSH
- Recombination, Genetic MeSH
- Repetitive Sequences, Nucleic Acid MeSH
- DNA, Ribosomal genetics MeSH
- RNA, Ribosomal, 18S genetics MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- MeSH
- DNA, Helminth analysis MeSH
- Dracunculus Nematode genetics classification MeSH
- Research Support as Topic MeSH
- Phylogeny MeSH
- Nematoda genetics classification MeSH
- Humans MeSH
- DNA, Ribosomal analysis MeSH
- RNA, Ribosomal, 18S genetics MeSH
- Sequence Analysis, DNA MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
Cryptosporidium is an apicomplexan parasite that causes the disease cryptosporidiosis in humans, livestock, and other vertebrates. Much of the knowledge on Cryptosporidium diversity is derived from 18S rRNA gene (18S rDNA) phylogenies. Eukaryote genomes generally have multiple 18S rDNA copies that evolve in concert, which is necessary for the accurate inference of phylogenetic relationships. However, 18S rDNA copies in some genomes evolve by a birth-and-death process that can result in sequence divergence among copies. Most notably, divergent 18S rDNA paralogs in the apicomplexan Plasmodium share only 89-95% sequence similarity, encode structurally distinct rRNA molecules, and are expressed at different life cycle stages. In the present study, Cryptosporidium 18S rDNA was amplified from 28/72 (38.9%) eastern chipmunks (Tamias striatus). Phylogenetic analyses showed the co-occurrence of two 18S rDNA types, Type A and Type B, in 26 chipmunks, and Type B clustered with a sequence previously identified as Cryptosporidium chipmunk genotype II. Types A and B had a sister group relationship but shared less than 93% sequence similarity. In contrast, actin and heat shock protein 70 gene sequences were homogeneous in samples with both Types A and B present. It was therefore concluded that Types A and B are divergent 18S rDNA paralogs in Cryptosporidium chipmunk genotype II. Substitution patterns in Types A and B were consistent with functionally constrained evolution; however, Type B evolved more rapidly than Type A and had a higher G+C content (46.3% versus 41.0%). Oocysts of Cryptosporidium chipmunk genotype II measured 4.17 μm (3.73-5.04 μm) × 3.94 μm (3.50-4.98 μm) with a length-to-width ratio of 1.06 ± 0.06 μm, and infection occurred naturally in the jejunum, cecum, and colon of eastern chipmunks. The findings of this study have implications for the use of 18S rDNA sequences to infer phylogenetic relationships.
- MeSH
- Actins genetics MeSH
- Cryptosporidium genetics isolation & purification MeSH
- Phylogeny MeSH
- Genotype MeSH
- Cryptosporidiosis epidemiology MeSH
- Molecular Sequence Data MeSH
- Prevalence MeSH
- HSP70 Heat-Shock Proteins genetics MeSH
- RNA, Ribosomal, 18S genetics MeSH
- Sciuridae parasitology MeSH
- Base Sequence MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. 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 classification genetics isolation & purification ultrastructure MeSH
- Microscopy, Electron MeSH
- Phylogeny * MeSH
- Locomotion MeSH
- Microscopy MeSH
- Polychaeta parasitology MeSH
- DNA, Protozoan chemistry genetics MeSH
- DNA, Ribosomal chemistry genetics MeSH
- RNA, Ribosomal, 18S genetics MeSH
- RNA, Ribosomal, 28S genetics MeSH
- RNA, Ribosomal, 5.8S genetics MeSH
- Sequence Analysis, DNA MeSH
- Cluster Analysis MeSH
- Aquatic Organisms classification genetics isolation & purification ultrastructure MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
