BACKGROUND: Ectoparasites from the family Diplozoidae (Platyhelminthes, Monogenea) belong to obligate haematophagous helminths of cyprinid fish. Current knowledge of these worms is for the most part limited to their morphological, phylogenetic, and population features. Information concerning the biochemical and molecular nature of physiological processes involved in host-parasite interaction, such as evasion of the immune system and its regulation, digestion of macromolecules, suppression of blood coagulation and inflammation, and effect on host tissue and physiology, is lacking. In this study, we report for the first time a comprehensive transcriptomic/secretome description of expressed genes and proteins secreted by the adult stage of Eudiplozoon nipponicum (Goto, 1891) Khotenovsky, 1985, an obligate sanguivorous monogenean which parasitises the gills of the common carp (Cyprinus carpio). RESULTS: RNA-seq raw reads (324,941 Roche 454 and 149,697,864 Illumina) were generated, de novo assembled, and filtered into 37,062 protein-coding transcripts. For 19,644 (53.0%) of them, we determined their sequential homologues. In silico functional analysis of E. nipponicum RNA-seq data revealed numerous transcripts, pathways, and GO terms responsible for immunomodulation (inhibitors of proteolytic enzymes, CD59-like proteins, fatty acid binding proteins), feeding (proteolytic enzymes cathepsins B, D, L1, and L3), and development (fructose 1,6-bisphosphatase, ferritin, and annexin). LC-MS/MS spectrometry analysis identified 721 proteins secreted by E. nipponicum with predominantly immunomodulatory and anti-inflammatory functions (peptidyl-prolyl cis-trans isomerase, homolog to SmKK7, tetraspanin) and ability to digest host macromolecules (cathepsins B, D, L1). CONCLUSIONS: In this study, we integrated two high-throughput sequencing techniques, mass spectrometry analysis, and comprehensive bioinformatics approach in order to arrive at the first comprehensive description of monogenean transcriptome and secretome. Exploration of E. nipponicum transcriptome-related nucleotide sequences and translated and secreted proteins offer a better understanding of molecular biology and biochemistry of these, often neglected, organisms. It enabled us to report the essential physiological pathways and protein molecules involved in their interactions with the fish hosts.
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 klasifikace genetika MeSH
- babezióza parazitologie virologie MeSH
- cyklooxygenasa 1 genetika MeSH
- fylogeneze MeSH
- molekulární evoluce MeSH
- protozoální DNA genetika MeSH
- protozoální proteiny genetika MeSH
- ribozomální DNA genetika MeSH
- RNA ribozomální 18S genetika MeSH
- sekvenční analýza DNA metody MeSH
- vysoká zvěř parazitologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Phytoplankton growth is limited in vast oceanic regions by the low bioavailability of iron. Iron fertilization often results in diatom blooms, yet the physiological underpinnings for how diatoms survive in chronically iron-limited waters and outcompete other phytoplankton when iron becomes available are unresolved. We show that some diatoms can use siderophore-bound iron, and exhibit a species-specific recognition for siderophore types. In Phaeodactylum tricornutum, hydroxamate siderophores are taken up without previous reduction by a high-affinity mechanism that involves binding to the cell surface followed by endocytosis-mediated uptake and delivery to the chloroplast. The affinity recorded is the highest ever described for an iron transport system in any eukaryotic cell. Collectively, our observations suggest that there are likely a variety of iron uptake mechanisms in diatoms besides the well-established reductive mechanism. We show that iron starvation-induced protein 1 (ISIP1) plays an important role in the uptake of siderophores, and through bioinformatics analyses we deduce that this protein is largely diatom-specific. We quantify expression of ISIP1 in the global ocean by querying the Tara Oceans atlas of eukaryotic genes and show a link between the abundance and distribution of diatom-associated ISIP1 with ocean provinces defined by chronic iron starvation.
- MeSH
- chloroplasty metabolismus MeSH
- druhová specificita MeSH
- endocytóza * MeSH
- genový knockdown MeSH
- rozsivky fyziologie MeSH
- siderofory metabolismus MeSH
- transport proteinů MeSH
- vodní organismy metabolismus MeSH
- železo metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Slow-fast analysis is a simple and effective method to reduce the influence of substitution saturation, one of the causes of phylogenetic noise and long branch attraction (LBA) artifacts. In several steps of increasing stringency, the slow-fast analysis omits the fastest substituting alignment positions from the analysed dataset and thus increases its signal/noise ratio. RESULTS: Our program SlowFaster automates the process of assessing the substitution rate of the alignment positions and the process of producing new alignments by deleting the saturated positions. Its use is very simple. It goes through the whole process in several steps: data input - necessary choices - production of new alignments. CONCLUSION: SlowFaster is a user-friendly tool providing new alignments prepared with slow-fast analysis. These data can be used for further phylogenetic analyses with lower risk of long branch attraction artifacts.
The protozoan genus Cochlosoma includes parasitic intestinal flagellates of birds and mammals of uncertain taxonomic classification. The presence of an adhesive disc, superficially similar to that of Giardia, led to a proposal that Cochlosoma should be classified as diplomonads. Careful morphological and ultrastructural observations, however, revealed conspicuous homologies to trichomonads. We addressed the question of classification and phylogenetic affiliation of Cochlosoma using the methods of molecular phylogenetics. Analyses based on the 16S rRNA gene sequence of the species Cochlosoma anatis very robustly placed Cochlosoma in the clade of the parabasalid subfamilies Trichomonadinae, Trichomitopsiinae and Pentatrichomonoidinae of the order Trichomonadida (bootstraps >94 %). The data did not provide robust support for any particular position of Cochlosoma within this clade because the sequence suffered from mutational saturation and produced a long branch. The most probable sister taxon of Cochlosoma is the genus Pentatrichomonas, because their relationship was supported specifically by the slowest-mutating, least-saturated positions as determined using the method slow-fast. Classification of the order Trichomonadida was revised to accommodate knowledge about its phylogeny - the family Cochlosomatidae and subfamilies Trichomitopsiinae and Pentatrichomonoidinae were abandoned, Trichomonadidae was amended and new families Tritrichomonadidae (formerly a subfamily) and Trichomitidae were proposed.
