100 research outputs found
Evolutionary trajectories of the reproductive system of the Gastrotricha genus Urodasys (Macrodasyida, Gastrotricha) inferred from morphological and molecular data
Biodiversity, Distribution, and Conservation of Plants and Fungi: Effects of Global Warming and Environmental Stress
: The estimation of global biodiversity and its conservation is an old, but still unresolved, concern in biology [...]
The genus Cystolepiota (Agaricaceae, Basidiomycetes) in Israel
The genus Cystolepiota is new for Israel. In Israel it is represented by two species: Cystolepiota bucknallii and C. moelleri. Locations, dates of collections in Israel, general distribution, detailed macro- and micromorphological descriptions and illustrations are given
A New Species from Mountain Forest Soils in Japan: Porosia paracarinata sp. nov., and Taxonomic Concept of the Genus Porosia Jung, 1942
A new species, Porosia paracarinata, is described from mountain forest litter, Bijodaira, Japan. This is the second species in the genus Porosia; until now, the genus was monospecific with the type species Porosia bigibbosa. P. paracarinata sp. nov. is distinguished from P. bigibbosa by the presence of a wide lateral keel. Test ultrastructure of P. paracarinata sp. nov. was documented using light and scanning electron microscopy. Morphometric analyses showed that this species is only slightly variable. The main morphological variability is due to the size of the lateral keel, which can vary from very wide (13.13 μm) to very narrow (3.75 μm). Ecological notes and morphological comparisons between P. paracarinata and other closely related species are discussed. The taxonomic concept of previously monospecific genus Porosia is expended
The myxozoan minicollagen gene repertoire was not simplified by the parasitic lifestyle: computational identification of a novel myxozoan minicollagen gene
Background Lineage-specific gene expansions represent one of the driving forces in the evolutionary dynamics of unique phylum traits. Myxozoa, a cnidarian subphylum of obligate parasites, are evolutionarily altered and highly reduced organisms with a simple body plan including cnidarian-specific organelles and polar capsules (a type of nematocyst). Minicollagens, a group of structural proteins, are prominent constituents of nematocysts linking Myxozoa and Cnidaria. Despite recent advances in the identification of minicollagens in Myxozoa, the evolutionary history and diversity of minicollagens in Myxozoa and Cnidaria remain elusive. Results We generated new transcriptomes of two myxozoan species using a novel pipeline for filtering of closely related contaminant species in RNA-seq data. Mining of our transcriptomes and published omics data confirmed the existence of myxozoan Ncol-4, reported only once previously, and revealed a novel noncanonical minicollagen, Ncol-5, which is exclusive to Myxozoa. Phylogenetic analyses support a close relationship between myxozoan Ncol-1-3 with minicollagens of Polypodium hydriforme, but suggest independent evolution in the case of the myxozoan minicollagens Ncol-4 and Ncol-5. Additional genome- and transcriptome-wide searches of cnidarian minicollagens expanded the dataset to better clarify the evolutionary trajectories of minicollagen. Conclusions The development of a new approach for the handling of next-generation data contaminated by closely related species represents a useful tool for future applications beyond the field of myxozoan research. This data processing pipeline allowed us to expand the dataset and study the evolution and diversity of minicollagen genes in Myxozoa and Cnidaria. We identified a novel type of minicollagen in Myxozoa (Ncol-5). We suggest that the large number of minicollagen paralogs in some cnidarians is a result of several recent large gene multiplication events. We revealed close juxtaposition of minicollagens Ncol-1 and Ncol-4 in myxozoan genomes, suggesting their common evolutionary history. The unique gene structure of myxozoan Ncol-5 suggests a specific function in the myxozoan polar capsule or tubule. Despite the fact that myxozoans possess only one type of nematocyst, their gene repertoire is similar to those of other cnidarians
Environmental DNA COI barcoding for quantitative analysis of protists communities: A test using the <i>Nebela collaris</i> complex (Amoebozoa;Arcellinida; Hyalospheniidae)
Environmental DNA surveys are used for screening eukaryotic diversity. However, it is unclear how quantitative this approach is and to what extent results from environmental DNA studies can be used for ecological studies requiring quantitative data. Mitochondrial cytochrome oxidase (COI) is used for species-level taxonomic studies of testate amoebae and should allow assessing the community composition from environmental samples, thus bypassing biases due to morphological identification. We tested this using a COI clone library approach and focusing on the Nebela collaris complex. Comparisons with direct microscopy counts showed that the COI clone library diversity data matched the morphologically identified taxa, and that community com-position estimates using the two approaches were similar. However, this correlation was improved when microscopy counts were corrected for biovolume. Higher correlation with biovolume-corrected community data suggests that COI clone library data matches the ratio of mitochondria and that within closely-related taxa the density of mitochondria per unit biovolume is approximately constant. Further developments of this metabarcoding approach including quantifying the mitochondrial density among closely-related taxa, experiments on other taxonomic groups and using high throughput sequencing should make if possible to quantitatively estimate community composition of different groups, which would be invaluable for microbial food webs studies
Transcriptome of Sphaerospora molnari (Cnidaria, Myxosporea) blood stages provides proteolytic arsenal as potential therapeutic targets against sphaerosporosis in common carp
Background Parasites employ proteases to evade host immune systems, feed and replicate and are often the target of anti-parasite strategies to disrupt these interactions. Myxozoans are obligate cnidarian parasites, alternating between invertebrate and fish hosts. Their genes are highly divergent from other metazoans, and available genomic and transcriptomic datasets are limited. Some myxozoans are important aquaculture pathogens such asSphaerospora molnarireplicating in the blood of farmed carp before reaching the gills for sporogenesis and transmission. Proliferative stages cause a massive systemic lymphocyte response and the disruption of the gill epithelia by spore-forming stages leads to respiratory problems and mortalities. In the absence of aS. molnarigenome, we utilized a de novo approach to assemble the first transcriptome of proliferative myxozoan stages to identifyS. molnariproteases that are upregulated during the first stages of infection when the parasite multiplies massively, rather than in late spore-forming plasmodia. Furthermore, a subset of orthologs was used to characterize 3D structures and putative druggable targets. Results An assembled and host filtered transcriptome containing 9436 proteins, mapping to 29,560 contigs was mined for protease virulence factors and revealed that cysteine proteases were most common (38%), at a higher percentage than other myxozoans or cnidarians (25-30%). Two cathepsin Ls that were found upregulated in spore-forming stages with a presenilin like aspartic protease and a dipeptidyl peptidase. We also identified downregulated proteases in the spore-forming development when compared with proliferative stages including an astacin metallopeptidase and lipases (qPCR). In total, 235 transcripts were identified as putative proteases using a MEROPS database. In silico analysis of highly transcribed cathepsins revealed potential drug targets within this data set that should be prioritised for development. Conclusions In silico surveys for proteins are essential in drug discovery and understanding host-parasite interactions in non-model systems. The present study ofS. molnari's protease arsenal reveals previously unknown proteases potentially used for host exploitation and immune evasion. The pioneering dataset serves as a model for myxozoan virulence research, which is of particular importance as myxozoan diseases have recently been shown to emerge and expand geographically, due to climate change
Case 3782 – Nebela militaris Penard, 1890 (Arcellinida, Hyalospheniidae): proposed conservation of the specific name by giving it precedence over Nebela bursella Taranek, 1881
The purpose of this application, under Article 23.9.3 of the Code, is to conserve the specific name Nebela militaris Penard, 1890, a junior subjective synonym
of Nebela bursella Taranek, 1881 – referred to as Nebela bursella Vejdovský in the literature. Due to the absence of any type or reference specimen and due to the confusing original description, doubts about the taxonomic status of N. bursella persist. A review of the literature revealed that the names N. militaris and N. bursella originally referred to the same species, with the name N. bursella later being applied erroneously to another species. According to the Principle of Priority, N. bursella is the valid name of the species generally known as N. militaris, but there has been no mention of the former taxon since 1964 and its name is unknown to most active testate amoeba researchers. To avoid confusion, we propose to conserve the widely used species name Nebela militaris Penard, 1890 by granting it conditional precedence over Nebela bursella Taranek, 1881, and to designate a neotype
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