Intertidal macroinvertebrate community structure in a subtropical channel is driven by sediment properties across different land-use types.

Macroinvertebrate community in the intertidal setup plays an important role in coastal ecosystem functions and biogeochemical cycle. However, different land use pattern may influence on their community structure, diversity, and composition in the coastal ecosystems. Using Van-Veen grab sampler, 60 sediment samples were seasonally collected from mangroves-dominated, aquaculture-dominated, and anthropogenically affected area in the lower intertidal zone of the Kohelia channel of Bangladesh, the Northern Bay of Bengal. We have tasted the variation in sediment properties across three land-use types in this intertidal habitat. To understand the patterns of benthic macroinvertebrate distribution, a neutral community model was applied. Our results showed that community composition and biodiversity of the benthic macroinvertebrate communities varied significantly between mangrove-dominated area with anthropogenically affected areas among the four seasons. The neutral community model revealed that community assembly of benthic macroinvertebrates in the lower intertidal habitats is structured by stochastic processes while sediment properties have significant influence on species distribution and interactions. Results suggested that land-use changes altered sediment properties and could change the diversity and distribution of the macroinvertebrate communities in the lower intertidal habitats.

Incorporating mitogenome sequencing into integrative taxonomy: The multidisciplinary redescription of the ciliate Thuricola similis (Peritrichia, Vaginicolidae) provides new insights into the evolutionary relationships among Oligohymenophorea subclasses.

The evolutionary relationships among Oligohymenophorea subclasses are under debate as the phylogenomic analysis using a large dataset of nuclear coding genes is significantly different to the 18S rDNA phylogeny, and it is unfortunately not stable within and across different published studies. In addition to nuclear genes, the faster-evolving mitochondrial genes have also shown the ability to solve phylogenetic problems in many ciliated taxa. However, due to the paucity of mitochondrial data, the corresponding work is scarce, let alone the phylogenomic analysis based on mitochondrial gene dataset. In this work, we presented the characterization on Thuricola similis Bock, 1963, a loricate peritrich (Oligohymenophorea), incorporating mitogenome sequencing into integrative taxonomy. As the first mitogenome for the subclass Peritrichia, it is linear, 38,802 bp long, and contains two rRNAs, 12 tRNAs, and 43 open reading frames (ORFs). As a peculiarity, it includes a central repeated region composed of tandemly repeated A-T rich units working as a bi-transcriptional start. Moreover, taking this opportunity, the phylogenomic analyses based on a set of mitochondrial genes were also performed, revealing that T. similis, as a representative of Peritrichia subclass, branches basally to other three Oligohymenophorea subclasses, namely Hymenostomatia, Peniculia, and Scuticociliatia. Evolutionary relationships among those Oligohymenophorea subclasses were discussed, also in the light of recent phylogenomic reconstructions based on a set of nuclear genes. Besides, as a little-known species, T. similis was also redescribed and neotypified based on data from two populations collected from wastewater treatment plants (WWTPs) in Brazil and Italy, by means of integrative methods (i.e., living observation, silver staining methods, scanning and transmission electron microscopy, and 18S rDNA phylogeny). After emended diagnosis, it is characterized by: (1) the sewage habitat; (2) the lorica with a single valve and small undulations; (3) the 7-22 µm-long inner stalk; and (4) the presence of only a single postciliary microtubule on the left side of the aciliferous row in the haplokinety. Among Vaginicolidae family, our 18S rRNA gene-based phylogenetic analysis revealed that Thuricola and Cothurnia are monophyletic genera, and Vaginicola could be a polyphyletic genus.

Investigation of trace metals in riverine waterways of Bangladesh using multivariate analyses: spatial toxicity variation and potential health risk assessment.

Minute quantities of trace metals have delirious effects in the human body causing acute and chronic toxicities. These trace metals have the ability to bind with enzymes and proteins causing an alteration in their activity, and, consequently, their damage. In this study, water samples were collected from five sites in Rupsa River (Bangladesh) during dry and wet seasons aiming to assess the trace metal concentration and the correlated health risk for people living in the area. Six trace metals, namely arsenic (Ar), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and nickel (Ni), were measured for further analyzing their spatial and seasonal variations. The measured trace metal concentrations followed this decreasing order: Cr > Pb > As > Cu > Ni > Cd for the dry season, and Cr > Pb > As > Cu > Ni > Cd for the wet season. Among the trace metals, As, Ni, Cr, and Pb exhibited a statistically significative variation throughout the study period. The PCA analysis accounted for 64.5% and 64.4% total variations of the trace metals in dry and wet seasons, respectively. The Euclidean distance of trace metals in water samples across five sites showed significantly different distribution patterns, which were further confirmed by PERMANOVA. Furthermore, CAP model disclosed that trace metals are source-specific: brickfields and sewage effluents were potential sources for Cd, whereas different industries were potential sources for As, Cr, Cu, Ni, and Pb. Correlation analysis showed that Ni and Cr significantly correlated with pH and electrical conductivity. Correlation among the trace metals unveiled that they depended on each other as for their origin, magnitude, and existence in the riverine waterways. As for the health risk assessment, a non-carcinogenic health hazard due to ingestion during regular activities and dermal contact during fishing activity to all kind of people (adult males, adult females, and children) in the studied area was retrieved based on the hazard index (HI) of trace metals, which was higher than the recommended value (HI > 1). Moreover, also the carcinogenic risks of Ni and As due to regular activities via ingestion and dermal contact pathways were higher than the standard value (CR > 1.0E-04), suggesting the occurrence of cancer risk to humans in the study area.

'Candidatus Sarmatiella mevalonica' endosymbiont of the ciliate Paramecium provides insights on evolutionary plasticity among Rickettsiales.

Members of the bacterial order Rickettsiales are obligatorily associated with a wide range of eukaryotic hosts. Their evolutionary trajectories, in particular concerning the origin of shared or differential traits among distant sub-lineages, are still poorly understood. Here, we characterized a novel Rickettsiales bacterium associated with the ciliate Paramecium tredecaurelia and phylogenetically related to the Rickettsia genus. Its genome encodes significant lineage-specific features, chiefly the mevalonate pathway gene repertoire, involved in isoprenoid precursor biosynthesis. Not only this pathway has never been described in Rickettsiales, it also is very rare among bacteria, though typical in eukaryotes, thus likely representing a horizontally acquired trait. The presence of these genes could enable an efficient exploitation of host-derived intermediates for isoprenoid synthesis. Moreover, we hypothesize the reversed reactions could have replaced canonical pathways for producing acetyl-CoA, essential for phospholipid biosynthesis. Additionally, we detected phylogenetically unrelated mevalonate pathway genes in metagenome-derived Rickettsiales sequences, likely indicating evolutionary convergent effects of independent horizontal gene transfer events. Accordingly, convergence, involving both gene acquisitions and losses, is highlighted as a relevant evolutionary phenomenon in Rickettsiales, possibly favoured by plasticity and comparable lifestyles, representing a potentially hidden origin of other more nuanced similarities among sub-lineages.

The neotypification of Frontonia vernalis (Ehrenberg, 1833) Ehrenberg, 1838 and the description of Frontonia paravernalis sp. nov. trigger a critical revision of frontoniid systematics.

BACKGROUND: Among Oligohymenophorea (Ciliophora, Alveolata) the subclass Peniculia stands as one of the most well-known groups. Frontonia is the largest genus of Peniculia, and its representatives are spread in any type of water bodies as well as in soil. At a first glance, Frontonia species exhibit an overall similar morphology, and form a well-recognizable taxon of ciliates. Despite the general morphological homogeneity, the phylogenetic analysis based on the 18S rDNA sequencing showed that Frontonia is a non-monophyletic group. The systematics of this genus should be deeply reviewed, although additional issues complicate the task solving. First, type species of the genus is not yet clearly established, and no type material is available. In this context, the situation of F. vernalis, one of the first Frontonia ever described, is somehow puzzled: the description of this ciliate made by Ehrenberg (in 1833 and 1838) contains several inaccuracies and subsequent misidentifications by other authors occurred. Moreover, the 18S rDNA sequence of a putative F. vernalis is available on GenBank, but no morphological description of the correspondent specimens is provided; thus, in our opinion, it should be only prudently associated with F. vernalis or at least indicated as "F. vernalis". RESULTS: In the present work, we provide the neotypification of F. vernalis newly found in Italy, presenting its multidisciplinary description and its neotype material. Similarly, we describe a novel species bearing Chlorella-like endosymbionts, Frontonia paravernalis sp. nov., retrieved in two far distant locations (Italy, Russia). A critical discussion on the status of Frontonia taxonomy and phylogeny is also presented, based on the 18S rDNA sequencing of both these two newly collected species and other 14 frontoniids isolated in different parts of the world. Finally, in the present study F. leucas was neotypified and proposed as the type species of the genus. CONCLUSIONS: Green frontoniids form a monophyletic clade of freshwater organisms characterized by having a single contractile vacuole and bearing intracytoplasmatic Chlorella-like symbionts. With the neotypification of F. vernalis and F. leucas a fundamental step in Frontonia systematics was taken, and the bases for further taxonomic studies were laid.

Morphology, ultrastructure, genomics, and phylogeny of Euplotes vanleeuwenhoeki sp. nov. and its ultra-reduced endosymbiont "Candidatus Pinguicoccus supinus" sp. nov.

Taxonomy is the science of defining and naming groups of biological organisms based on shared characteristics and, more recently, on evolutionary relationships. With the birth of novel genomics/bioinformatics techniques and the increasing interest in microbiome studies, a further advance of taxonomic discipline appears not only possible but highly desirable. The present work proposes a new approach to modern taxonomy, consisting in the inclusion of novel descriptors in the organism characterization: (1) the presence of associated microorganisms (e.g.: symbionts, microbiome), (2) the mitochondrial genome of the host, (3) the symbiont genome. This approach aims to provide a deeper comprehension of the evolutionary/ecological dimensions of organisms since their very first description. Particularly interesting, are those complexes formed by the host plus associated microorganisms, that in the present study we refer to as "holobionts". We illustrate this approach through the description of the ciliate Euplotes vanleeuwenhoeki sp. nov. and its bacterial endosymbiont "Candidatus Pinguicoccus supinus" gen. nov., sp. nov. The endosymbiont possesses an extremely reduced genome (~ 163 kbp); intriguingly, this suggests a high integration between host and symbiont.

5-Fluorouracil-treated planarians, a versatile model system for studying stem cell heterogeneity and tissue aging.

BACKGROUND INFORMATION: Planarians are a sound, well-established model system for molecular studies in the field of stem cells, cell differentiation, developmental biology and translational research. Treated stem cell-less planarians produced by X-ray treatment are commonly used to study stem cell transcriptional profile and their role in planarian biological processes. X-ray induces oxidative and DNA damage to differentiated cells, requires expensive radiation machines that are not available in most of the research centres and demand rigorous risk management and dedicated staff. RESULTS: We tested the use of the well-known antimetabolite genotoxic drug 5-fluorouracil which mainly affects proliferating cells in way to demonstrate its use in replacing X-ray treatment. We succeeded in demonstrating ability of high doses of 5-fluorouracil to deplete Dugesia japonica stem cells and in identifying a 5-fluorouracil transiently resistant population of lineage committed stem cells. CONCLUSIONS AND SIGNIFICANCE: Our results encourage the use of 5-fluorouracil-treated planarians as a model system for studying mechanisms of resistance to genotoxicants, planarian stem cell heterogeneity and molecular cascades of tissue aging.

"Candidatus Trichorickettsia mobilis", a Rickettsiales bacterium, can be transiently transferred from the unicellular eukaryote Paramecium to the planarian Dugesia japonica.

Most of the microorganisms responsible for vector-borne diseases (VBD) have hematophagous arthropods as vector/reservoir. Recently, many new species of microorganisms phylogenetically related to agents of VBD were found in a variety of aquatic eukaryotic hosts; in particular, numerous new bacterial species related to the genus Rickettsia (Alphaproteobacteria, Rickettsiales) were discovered in protist ciliates and other unicellular eukaryotes. Although their pathogenicity for humans and terrestrial animals is not known, several indirect indications exist that these bacteria might act as etiological agents of possible VBD of aquatic organisms, with protists as vectors. In the present study, a novel strain of the Rickettsia-Like Organism (RLO) endosymbiont "Candidatus (Ca.) Trichorickettsia mobilis" was identified in the macronucleus of the ciliate Paramecium multimicronucleatum. We performed transfection experiments of this RLO to planarians (Dugesia japonica) per os. Indeed, the latter is a widely used model system for studying bacteria pathogenic to humans and other Metazoa. In transfection experiments, homogenized paramecia were added to food of antibiotic-treated planarians. Treated and non-treated (i.e. control) planarians were investigated at day 1, 3, and 7 after feeding for endosymbiont presence by means of PCR and ultrastructural analyses. Obtained results were fully concordant and suggest that this RLO endosymbiont can be transiently transferred from ciliates to metazoans, being detected up to day 7 in treated planarians' enterocytes. Our findings might offer insights into the potential role of ciliates or other protists as putative vectors for diseases caused by Rickettsiales or other RLOs and occurring in fish farms or in the wild.

Role of bacterivorous organisms on fungal-based systems for natural tannin degradation.

Tannery wastewater presents high concentrations of organic load and pollutant recalcitrant molecules (e.g. tannins), which reduce the efficiency of biological treatment processes. Recent studies showed that several fungal species and strains are effective in the degradation of tannins. However, high bacterial load can negatively affect fungal growth, reducing system stability and degradation performances. The aim of the present study was to evaluate the effects of the introduction of bacterivorous grazers (ciliates and/or rotifers) in batch scale experiments using fungi to remove Tara tannin, i.e. to check the potential synergistic effect between fungi and bacterivorous grazers in the degradation of recalcitrant compounds. In this context, the ciliated grazers Paramecium calkinsi, Tetrahymena sp., Pseudovorticella sp., and the rotifer Lecane inermis, preliminary selected according to their ability to grow in a solution prepared with Tara tannin, were separately tested. Activated sludge, including a complex mixture of native grazers, was used as experimental control. The following parameters were monitored: bacterial load, number of grazers/mL and Soluble Chemical Oxygen Demand (SCOD). Colony Forming Unit (CFU)/grazers ratio was also calculated. Particular attention was paid to: i) bacterial load reduction and ii) enhancement of recalcitrant compounds degradation, and we observed that in all experimental conditions where grazers occurred bacterial load was significantly reduced and the system achieved a higher SCOD removal in a shorter time. Our findings provide useful insights for the stabilization of fungal-based systems in non-sterile conditions.

Parablepharisma (Ciliophora) is not a Heterotrich: A Phylogenetic and Morphological Study with the Proposal of New Taxa.

The genus Parablepharisma Jankowski, 2007 at present includes five species, most of which have not been studied in detail, therefore phylogenetic affinities remained uninvestigated up to now. Parablepharisma is traditionally placed within Heterotrichea based on insufficient existing morphological data, and there are no available Parablepharisma gene sequences in molecular databases to support this placement. This work presents an 18S rDNA-based phylogeny of P. bacteriophora (Kahl, 1932) Jankowski, 2007 and P. brasiliensis sp. nov. We also provide a redescription of P. bacteriophora and P. chlamydophorum (Kahl, 1932) Jankowski, 2007 based on live morphological observations combined with silver impregnation and scanning and transmission electron microscopy. According to characters such as macro- and micronucleus number, the position of the ectosymbiotic bacteria, and the presence/absence of caudal cilia, two new species are described, i.e. P. granulata sp. nov. and P. brasiliensis sp. nov. In addition, we establish Kahlium gen. nov. to include P. chlamydophorum, which has a segmented anterior paroral portion and a twisted posterior paroral section as diagnostic features. To include Parablepharisma and Kahlium gen. nov., we propose Parablepharismidae fam. nov. According to our phylogenetic analyses, Parablepharisma belongs to SAL (Spirotrichea, Armophorea, Litostomatea), being a sister group of Cariacotrichea.

Seropositivity to Midichloria mitochondrii (order Rickettsiales) as a marker to determine the exposure of humans to tick bite.

Ixodes ricinus is the most common tick species parasitizing humans in Europe, and the main vector of Borrelia burgdorferi sensu lato, the causative agent of Lyme disease in the continent. This tick species also harbors the endosymbiont Midichloria mitochondrii, and there is strong evidence that this bacterium is inoculated into the vertebrate host during the blood meal. A high proportion of tick bites remains unnoticed due to rarity of immediate symptoms, implying the risk of occult tick-borne infections in turn a potential risk factor for the onset of chronic-degenerative diseases. Since suitable tools to determine the previous exposure to I. ricinus bites are needed, this work investigated whether seropositivity toward a protein of M. mitochondrii (rFliD) could represent a marker for diagnosis of I. ricinus bite. We screened 274 sera collected from patients from several European countries, at different risk of tick bite, using an ELISA protocol. Our results show a clear trend indicating that positivity to rFliD is higher where the tick bite can be regarded as certain/almost certain, and lower where there is an uncertainty on the bite, with the highest positivity in Lyme patients (47.30%) and the lowest (2.00%) in negative controls. According to the obtained results, M. mitochondrii can be regarded as a useful source of antigens, with the potential to be used to assess the exposure to ticks harboring this bacterium. In prospect, additional antigens from M. mitochondrii and tick salivary glands should be investigated and incorporated in a multi-antigen test for tick bite diagnosis.

Deianiraea, an extracellular bacterium associated with the ciliate Paramecium, suggests an alternative scenario for the evolution of Rickettsiales.

Rickettsiales are a lineage of obligate intracellular Alphaproteobacteria, encompassing important human pathogens, manipulators of host reproduction, and mutualists. Here we report the discovery of a novel Rickettsiales bacterium associated with Paramecium, displaying a unique extracellular lifestyle, including the ability to replicate outside host cells. Genomic analyses show that the bacterium possesses a higher capability to synthesise amino acids, compared to all investigated Rickettsiales. Considering these observations, phylogenetic and phylogenomic reconstructions, and re-evaluating the different means of interaction of Rickettsiales bacteria with eukaryotic cells, we propose an alternative scenario for the evolution of intracellularity in Rickettsiales. According to our reconstruction, the Rickettsiales ancestor would have been an extracellular and metabolically versatile bacterium, while obligate intracellularity would have evolved later, in parallel and independently, in different sub-lineages. The proposed new scenario could impact on the open debate on the lifestyle of the last common ancestor of mitochondria within Alphaproteobacteria.

Harmful Effect of Rheinheimera sp. EpRS3 (Gammaproteobacteria) Against the Protist Euplotes aediculatus (Ciliophora, Spirotrichea): Insights Into the Ecological Role of Antimicrobial Compounds From Environmental Bacterial Strains.

Rheinheimera sp. strain EpRS3, isolated from the rhizosphere of Echinacea purpurea, is already known for its ability to produce antibacterial compounds. By use of culture experiments, we verified and demonstrated its harmful effect against the ciliated protist Euplotes aediculatus (strain EASCc1), which by FISH experiments resulted to harbor in its cytoplasm the obligate bacterial endosymbiont Polynucleobacter necessarius (Betaproteobacteria) and the secondary endosymbiont "Candidatus Nebulobacter yamunensis" (Gammaproteobacteria). In culture experiments, the number of ciliates treated both with liquid broth bacteria-free (Supernatant treatment) and bacteria plus medium (Tq treatment), decreases with respect to control cells, with complete disappearance of ciliates within 6 h after Tq treatment. Results suggest that Rheinheimera sp. EpRS3 produces and releases in liquid culture one or more bioactive molecules affecting E. aediculatus survival. TEM analysis of control (not treated) ciliates allowed to morphologically characterize both kind of E. aediculatus endosymbionts. In treated ciliates, collected soon after the arising of cell suffering leading to death, TEM observations revealed some ultrastructural damages, indicating that P. necessarius endosymbionts went into degradation and vacuolization after both Supernatant and Tq treatments. Additionally, TEM investigation showed that when the ciliate culture was inoculated with Tq treatment, both a notable decrease of P. necessarius number and an increase of damaged and degraded mitochondria occur. FISH experiments performed on treated ciliates confirmed TEM results and, by means of the specific probe herein designed, disclosed the presence of Rheinheimera sp. EpRS3 both inside phagosomes and free in cytoplasm in ciliates after Tq treatment. This finding suggests a putative ability of Rheinheimera sp. EpRS3 to reintroduce itself in the environment avoiding ciliate digestion.

Diversity and environmental distribution of the cosmopolitan endosymbiont "Candidatus Megaira".

Members of the order Rickettsiales are often found in association with ciliated protists. An interesting case is the bacterial endosymbiont "Candidatus Megaira", which is phylogenetically closely related to the pathogen Rickettsia. "Candidatus Megaira" was first described as an intracellular bacterium in several ciliate species. Since then it has been found in association with diverse evolutionary distantly-related hosts, among them other unicellular eukaryotes, and also algae, and metazoa, such as cnidarians. We provide the characterization of several new strains of the type species "Candidatus Megaira polyxenophila", and the multidisciplinary description of a novel species, "Candidatus Megaira venefica", presenting peculiar features, which highlight the diversity and variability of these widespread bacterial endosymbionts. Screening of the 16S rRNA gene short amplicon database and phylogenetic analysis of 16S rRNA gene hypervariable regions revealed the presence of further hidden lineages, and provided hints on the possibility that these bacteria may be horizontally transmitted among aquatic protists and metazoa. The phylogenetic reconstruction supports the existence of at least five different separate species-level clades of "Candidatus Megaira", and we designed a set of specific probes allowing easy recognition of the four major clades of the genus.

"Candidatus Hafkinia simulans" gen. nov., sp. nov., a Novel Holospora-Like Bacterium from the Macronucleus of the Rare Brackish Water Ciliate Frontonia salmastra (Oligohymenophorea, Ciliophora): Multidisciplinary Characterization of the New Endosymbiont and Its Host.

We characterized a novel Holospora-like bacterium (HLB) (Alphaproteobacteria, Holosporales) living in the macronucleus of the brackish water ciliate Frontonia salmastra. This bacterium was morphologically and ultrastructurally investigated, and its life cycle and infection capabilities were described. We also obtained its 16S rRNA gene sequence and performed in situ hybridization experiments with a specifically-designed probe. A new taxon, "Candidatus Hafkinia simulans", was established for this HLB. The phylogeny of the family Holosporaceae based on 16S rRNA gene sequences was inferred, adding to the already available data both the sequence of the novel bacterium and those of other Holospora and HLB species recently characterized. Our phylogenetic analysis provided molecular support for the monophyly of HLBs and placed the new endosymbiont as the sister genus of Holospora. Additionally, the host ciliate F. salmastra, recorded in Europe for the first time, was concurrently described through a multidisciplinary study. Frontonia salmastra's phylogenetic position in the subclass Peniculia and the genus Frontonia was assessed according to 18S rRNA gene sequencing. Comments on the biodiversity of this genus were added according to past and recent literature.

The Hidden World of Rickettsiales Symbionts: "Candidatus Spectririckettsia obscura," a Novel Bacterium Found in Brazilian and Indian Paramecium caudatum.

Symbioses between bacteria and eukaryotes are widespread and may have significant impact on the evolutionary history of symbiotic partners. The order Rickettsiales is a lineage of intracellular Alphaproteobacteria characterized by an obligate association with a wide range of eukaryotic hosts, including several unicellular organisms, such as ciliates and amoebas. In this work, we characterized the Rickettsiales symbionts associated with two different genotypes of the freshwater ciliate Paramecium caudatum originated from freshwater environments in distant geographical areas. Phylogenetic analyses based on 16S rRNA gene showed that the two symbionts are closely related to each other (99.4% identity), belong to the family Rickettsiaceae, but are far-related with respect to previously characterized Rickettsiales. Consequently, they were assigned to a new species of a novel genus, namely "Candidatus Spectririckettsia obscura." Screening on a database of short reads from 16S rRNA gene amplicon-based profiling studies confirmed that bacterial sequences related to the new symbiont are preferentially retrieved from freshwater environments, apparently with extremely scarce occurrence (< 0.1% positive samples). The present work provides new information on the still under-explored biodiversity of Rickettsiales, in particular those associated to ciliate host cells.

ED-B fibronectin expression is a marker of epithelial-mesenchymal transition in translational oncology.

Fibronectin is a component of the extracellular matrix that links collagen fibers to integrins on the cell's surface. The splicing isoforms, containing the ED-B domain, are not expressed in adult tissues but only in tumor stroma or during embryonic development. Fibroblasts and endothelial cells express ED-B fibronectin during angiogenesis. Also cancer cells can synthetize ED-B fibronectin, but its function in tumor growth needs to be further elucidated.We evaluated the expression of ED-B fibronectin in prostate cancer cell lines: PC3 and DU145. Using TGF-ß, we induced epithelial to mesenchymal transition in culture and observed an increase of ED-B fibronectin expression. Thereafter, we evaluated the expression of ED-B fibronectin in multipotent mesangiogenic progenitor cells, and in mesenchymal stromal cells. The expression of ED-B fibronectin was much higher in mesenchymal than prostate cancer cells even after the epithelial to mesenchymal transition.Epithelial to mesenchymal transition is a key step for tumor progression contributing to the metastatic spread. Therefore, circulating cancer cells could seed into the metastatic niche taking advantage from the ED-B fibronectin that secrete their own.

Ciliate communities and hidden biodiversity in freshwater biotopes of the Pistoia province (Tuscany, Italy).

Ciliates are essential components of aquatic environments, playing a pivotal role in microbial loops. Thus, the composition and dynamics of ciliate communities have been subjected to intense studying. Morphological methods have been traditionally employed, until the development of next-generation sequencing recently allowed to explore the topic with exclusively molecular techniques. However, the results of the two approaches are hardly comparable, and the pictures they offer can be quite different. This may be due, among other reasons, to two factors: (1) morphological descriptions may miss a large portion of "hidden biodiversity" (including rare species and resistance forms) that is detected instead by molecular methods; (2) identification errors may arise due to difficulties in recognizing microbial taxa without in-depth analyses. In this survey of freshwater systems of the Pistoia province (Tuscany, Italy) we address both issues, trying to quantify the hidden diversity through prolonged observations of differentially treated sample aliquots, combining morphological identification with Sanger sequencing. We provide the first insights into the ciliate fauna of this area presenting results that are suitable for future comparisons thanks to their multidisciplinary origin, and supply the first molecular data on well-known taxa such as Linostomella and Disematostoma.

Morphology, ultrastructure, and molecular phylogeny of the ciliate Sonderia vorax with insights into the systematics of order Plagiopylida.

BACKGROUND: Ciliates of the family Sonderiidae are common members of the eukaryotic communities in various anoxic environments. They host both ecto- and endosymbiotic prokaryotes (the latter associated with hydrogenosomes) and possess peculiar morpho-ultrastructural features, whose functions and homologies are not known. Their phylogenetic relationships with other ciliates are not completely resolved and the available literature, especially concerning electron microscopy and molecular studies, is quite scarce. RESULTS: Sonderia vorax Kahl, 1928 is redescribed from an oxygen-deficient, brackish-water pond along the Ligurian Sea coastlines of Italy. Data on morphology, morphometry, and ultrastructure are reported. S. vorax is ovoid-ellipsoid in shape, dorsoventrally flattened, 130 x 69 µm (mean in vivo); it shows an almost spherical macronucleus, and one relatively large micronucleus. The ventral kinetom has a "secant system" including fronto-ventral and fronto-lateral kineties. A distinctive layer of bacteria laying between kineties covers the ciliate surface. Two types of extrusomes and hydrogenosomes-endosymbiotic bacteria assemblages are present in the cytoplasm. The phylogeny based on 18S rRNA gene sequences places S. vorax among Plagiopylida; Sonderiidae clusters with Plagiopylidae, although lower-level relationships remain uncertain. The studied population is fixed as neotype and the ciliate is established as type species of the genus, currently lacking. CONCLUSIONS: This is the first description of a representative of Sonderiidae performed with both morphological and molecular data. To sum up, many previous hypotheses on this interesting, poorly known taxon are confirmed but confusion and contradictory data are as well highlighted.

Morphological, ultrastructural, and molecular characterization of Euplotidium rosati n. sp. (Ciliophora, Euplotida) from Guam.

We combined morphological (i.e. live, stained, scanning, and transmission electron microscopy) with morphometric and molecular analysis to describe a ciliate species collected from shallow reefs in Guam, grown, and maintained in our laboratory. The species was recognized as a member of Euplotidium, and compared with established species of the genus: Euplotidium itoi Ito 1958; Euplotidium psammophilus (Vacelet 1961) Borror 1972; Euplotidium arenarium Magagnini and Nobili 1964; Euplotidium helgae Hartwig 1980; Euplotidium prosaltans Tuffrau 1985, and Euplotidium smalli Lei, Choi and Xu, 2002. To obtain more elements to compare the species, new morphometric data and additional SSU rRNA gene sequences of E. itoi and of E. arenarium are reported. On the basis of this comparison, we established the new species Euplotidium rosati that has a cirral pattern composed of 12 frontoventral and six transverse cirri, and lacks the left marginal cirrus. Euplotidium rosati harbors on its dorsal surface epixenosomes, the peculiar extrusive symbionts described in other Euplotidium species. The whole body of our observations together with the analysis of the data available in the literature leads us to propose a redefinition of the genus. The results may also be useful to clarify the tangled relationship between Euplotidium and Gastrocirrhus.