European Journal of Protistology

Benthic foraminifera are unicellular eukaryotic protists that construct an organic, agglutinated, or calcareous test wall. Although single-chambered (monothalamous) foraminifera are ubiquitous in marine habitats worldwide, they are poorly known compared to their multi-chambered relatives, notably from the tropical marine environments of India. In this study, we describe two new species of marine monothalamid genus Psammophaga Arnold, 1982, from the Rajapuri Creek, coastal Maharashtra, India (Arabian Sea). Psammophaga holzmannae sp...

We present the description of the new suctorian genus Copterus gen. n. with type species Copterus tyloloricatus sp. n. from the family Acinetidae, inhabiting the prosomes and urosomes of calanoid copepods from the northern North Pacific Ocean. The new taxon is characterized by (i) an ellipsoidal to triangular, asymmetric, dorsoventrally flattened cell body, which lies horizontally on the lorica surface; (ii) an unflattened lorica; and (iii) the presence of three to five radially arranged bundles of tentacles positioned at the edge of the body or on actinophores...

Cercozoans and heterolobose amoebae are found across terrestrial habitats where they feed on other unicellular microbes, including bacteria, fungi and microalgae. They constitute a significant fraction of soil ecosystems and are integral members of plant microbiota. Here, we present the results on the isolation of protozoans from the rhizosphere and phyllosphere of Browningia candelaris (Meyen) in the Andean Altiplano and Eulychnia taltalensis (F. Ritter) from the Coastal Cordillera of the Atacama Desert, both endemic to this ancient desert...

Tetrahymena thermophila is a promising host for recombinant protein production, but its utilization in biotechnology is mostly limited due to the presence of intracellular and extracellular papain-family cysteine proteases (PFCPs). In this study, we employed bioinformatics approaches to investigate the T. thermophila PFCP genes and their encoded proteases (TtPFCPs), the most prominent protease family in the genome. Results from the multiple sequence alignment, protein modeling, and conserved motif analyses revealed that all TtPFCPs showed considerably high homology with mammalian cysteine cathepsins and contained conserved amino acid motifs...

Acanthamoeba castellanii is a free-living amoeba that acts as an opportunistic pathogen for humans and is the pathogenic agent of Acanthamoeba keratitis (AK). A. castellanii may present as proliferative and infective trophozoites or as resistant cysts during their life cycle. The immune response against AK is still poorly explored; however, it is well established that macrophages and neutrophils play essential roles in controlling corneal infection during the disease outcome. The release of NETs is one of the innate immune strategies to prevent parasite infection, especially when neutrophils interact with microorganisms that are too large to be phagocytosed, which is the case for amoeba species...

Erniella Foissner, 1987 is a poorly known genus with its available information limited solely to morphological characteristics. In this study, the type species E. filiformis, isolated from highly saline water in China, was investigated for morphology, morphogenesis, and phylogeny based on small subunit ribosomal DNA sequences. The main characteristic events during morphogenesis in Erniella filiformis are as follows: (1) in the proter, only the posterior part of the parental adoral zone is renewed and undulating membranes anlage is formed from the dedifferentiation of the old structure; (2) the oral primordium is formed intrakinetally in the opisthe; (3) frontoventral-transverse cirral anlagen II-IV develop in the primary mode, anlage V develops intrakinetally in the proter; and (4) the right frontoventral row is formed by a single anlage...

We studied a large species of Thecamoeba found in a glass dish with soaked moss and obtained 18s rRNA gene sequence of this organism. Morphologically, the strain was most similar to T. terricola sensu Page, but had significant differences in cell size and nuclear morphology. A more complete similarity was found with the original description of "Amoeba terricola" by Greeff, as well as with Penard's descriptions and slides. The analysis of literature data shows that the strain described by Page in 1977 as a re-isolated T...

Amoebae of the genus Leptomyxa have variable morphologies and can only be reliably identified using molecular data. However, species distinction based on the 18S rRNA gene sequence is difficult due to the very low level of sequence divergence among morphologically different species. The database for other genes is much smaller, and genomic data on Leptomyxa is almost absent. In this study, we describe two new terrestrial species of the genus Leptomyxa isolated from Northwestern Russia, Leptomyxa botanica n...

In this study, we presented the results of our molecular phylogenetic analysis of Archamoebae using a newly obtained sequence of the 18S rRNA gene of Mastigamoeba aspera, the type species of the genus. In addition, we characterized the general organization of the tubulin cytoskeleton of M. aspera by immunofluorescent microscopy and TEM. Our findings allowed us to revise the family Mastigamoebidae and establish within it two subfamilies: Mastigamoebinae for the genus Mastigamoeba and Seraviniinae subfam. nov...

No abstract text is available yet for this article.

Acanthamoeba castellanii is a free-living amoeba and an opportunistic pathogen for humans that can cause encephalitis and, more commonly, Acanthamoeba keratitis. During its life cycle, A. castellanii may present as proliferative and infective trophozoites or resistant cysts. The adhesion of trophozoites to host cells is a key first step in the pathogenesis of infection. A major virulence protein of Acanthamoeba is a mannose-binding protein (MBP) that mediates the adhesion of amoebae to cell surfaces. Ectophosphatases are ecto-enzymes that can dephosphorylate extracellular substrates and have already been described in several microorganisms...

Trachelocercids are common ciliates in marine sandy intertidal zones, however, only few species have been described using modern taxonomic techniques, with several earlier descriptions still lacking primary data, such as a detailed description of the oral ciliature. For this reason, systematics of the family Trachelocercidae Kent, 1881 resulted in paraphyletic genera and needs a critical revision. As an attempt to fill the gap of knowledge for this group, this study presents one new species description, Tracheloraphis apodiscolor n...

Diplomonadida is a lineage of anaerobic protists belonging to Fornicata, Metamonada. Most diplomonads are endobiotic or parasitic, such as Giardia intestinalis, which is a famous human pathogen, but several free-living species exist as well. Although it has been proposed that the free-living diplomonads are descendants of endobiotic organisms and thus interesting from the evolutionary point of view, they have been largely neglected. We obtained 58 cultures of free-living diplomonads belonging to four genera (Hexamita, Trepomonas, Gyromonas, and Trimitus) and six strains of endobiotic diplomonads and analyzed their SSU rRNA gene sequences...

Edward Heron-Allen and Arthur Earland were among the last great amateur foraminifera researchers. Their partnership began in 1907 and ended in 1932. While close in age to one another, they shared little more than a fascination for forams and a lack of any university training. In most other aspects, the two men were completely different. Heron-Allen was a famous upper class polymath, expert not only on forams, but also on the Persian language, violins, palm reading, history, asparagus, and barnacles. He was also an accomplished novelist and poet, who frequented literary circles...

Apocarchesium rosettum and A. arndti were originally discovered in Japan (Lake Biwa) and Germany (River Rhine), respectively. We report the first record of A. arndti in the Danube and provide a detailed description of its colony development. Our findings support the theory of moderate endemicity and reveal a new, smaller zooid type in A. arndti. This zooid remains attached to the colony, connected to the stalk myoneme but lacks an aboral ciliary wreath. Unlike microzooids, it is incapable of leaving the colony...

Non-marine monothalamous foraminifera are common in freshwater and soil habitats. They comprise a poorly-known group lacking sufficient information about diversity, morphology, reproduction, distribution and ecology. Based on an integrative morphological and molecular approach we describe a new family, a new genus and six new species of freshwater monothalamids from different localities in the Netherlands and France. We establish Astroperula as a new genus of organic walled freshwater foraminifera that contains two species, Astroperula dumacki and Astroperula parvipila...

Arcellinida is ascending in importance in protistology, but description of their diversity still presents multiple challenges. Furthermore, applicable tools for surveillance of these organisms are still in developing stages. Importantly, a good database that sets a correspondence between molecular barcodes and species morphology is lacking. Cytochrome oxidase (COI) has been suggested as the most relevant marker for species discrimination in Arcellinida. However, some major groups of Arcellinida are still lacking a COI sequence...

More than 1272 myxomycetes species have been described, accounting for more than half of all Amoebozoa species. However, the genome size of only three myxomycetes species has been reported. Therefore, we used flow cytometry to present an extensive survey and a phylogeny-based analysis of genome size and GC content evolution in 144 myxomycetes species. The genome size of myxomycetes ranged from 18.7 Mb to 470.3 Mb, and the GC content ranged from 38.7% to 70.1%. Bright-spored clade showed larger genome sizes and more intra-order genome size variations than the dark-spored clade...

Coccidiosis, a serious intestinal parasitic disease caused by Eimeria spp., can result in huge annual economic losses to the poultry industry worldwide. At present, coccidiosis is mainly controlled by anticoccidial drugs. However, drug resistance has developed in Eimeria because of the long-term and unreasonable use of the drugs currently available. In our previous study, RNA-seq showed that the expression of methionine aminopeptidase1 (EtMetAP1) was up-regulated in diclazuril-resistant (DZR) and maduramicin-resistant (MRR) strains compared to drug-sensitive (DS) strain of Eimeria tenella...

No abstract text is available yet for this article.