Mitochondrial dysfunction might have a central role in the pathophysiology of depression. Phenotypically, depression is characterized by lack of energy, concentration problems and fatigue. These symptoms might be partially explained by reduced availability of adenosine triphosphate (ATP) as a consequence of impaired mitochondrial functioning. This study investigated mitochondrial respiration in peripheral blood mononuclear cells (PBMCs), an established model to investigate the pathophysiology of depression. Mitochondrial respiration was assessed in intact PBMCs in 22 individuals with a diagnosis of major depression (MD) compared with 22 healthy age-matched controls using high-resolution respirometry. Individuals with MD showed significantly impaired mitochondrial functioning: routine and uncoupled respiration as well as spare respiratory capacity, coupling efficiency and ATP turnover-related respiration were significantly lower in the MD compared with the control group. Furthermore, mitochondrial respiration was significantly negatively correlated with the severity of depressive symptoms, in particular, with loss of energy, difficulties concentrating and fatigue. The results suggest that mitochondrial dysfunction contributes to the biomolecular pathophysiology of depressive symptoms. The decreased immune capability observed in MD leading to a higher risk of comorbidities could be attributable to impaired energy supply due to mitochondrial dysfunction. Thus mitochondrial respiration in PBMCs and its functional consequences might be an interesting target for new therapeutical approaches in the treatment of MD and immune-related comorbidities.

No abstract

Using a combined set of sequences of SSU and ITS regions of nuclear-encoded ribosomal DNA, the concept of the experimental algal genus Chlorella was evaluated. Conventionally in the genus Chlorella, only coccoid, solitary algae with spherical morphology that do not possess any mucilaginous envelope were included. All Chlorella species reproduce asexually by autospores. However, phylogenetic analyses showed that within the clade of 'true'Chlorella species (Chlorella vulgaris, C. lobophora, and C. sorokiniana), taxa with a mucilaginous envelope and colonial lifeform have also evolved. These algae, formerly designated as Dictyosphaerium, are considered as members of the genus Chlorella. In close relationship to Chlorella, five different genera were supported by the phylogenetic analyses: Micractinium (spherical cells, colonial, with bristles), Didymogenes (ellipsoidal cells, two-celled coenobia, with or without two spines per cell), Actinastrum (ellipsoidal cells within star-shaped coenobia), Meyerella (spherical cells, solitary, without pyrenoids), and Hegewaldia (spherical cells, colonial, with or without bristles, oogamous propagation). Based on the secondary structures of SSU and ITS rDNA sequences, molecular signatures are provided for each genus of the Chlorella clade.

Protists influence ecosystems by modulating microbial population size, diversity, metabolic outputs and gene flow. In this study we used eukaryotic ribosomal amplicon diversity from 218 European freshwater lakes sampled in August 2012 to assess the effect of mountain ranges as biogeographic barriers on spatial patterns and microbial community structure in European freshwaters. The diversity of microbial communities as reflected by amplicon clusters suggested that the eukaryotic microbial inventory of lakes was well-sampled at the European and at the local scale. Our pan-European diversity analysis indicated that biodiversity and richness of high mountain lakes differed from that of lowland lakes. Further, the taxon inventory of high-mountain lakes strongly contributed to beta-diversity despite a low taxon inventory. Even though ecological factors, in general, strongly affect protist community pattern, we show that geographic distance and geographic barriers significantly contribute to community composition particularly for high mountain regions which presumably act as biogeographic islands. However, community composition in lowland lakes was also affected by geographic distance but less pronounced as in high mountain regions. In consequence protist populations are locally structured into distinct biogeographic provinces and community analyses revealed biogeographic patterns also for lowland lakes whereby European mountain ranges act as dispersal barriers in particular for short to intermediate distances whereas the effect of mountain ranges levels off on larger scale.protists (algae) are the dominant primary producers in aquatic ecosystems and contribute roughly 50 % to global primary production, i.e. they are of similar importance as land plants. Heterotrophic protists, on the other hand, are the primary agents of the top-down control of bacteria and primary producers and are thus key organisms in determining the fate and transport of organic matter in nature (Boenigk and Arndt 2002, Caron 2001, Foissner 1987, Sherr et al. 2007) .Increasing our knowledge of biodiversity distribution patterns at any level of the tree of life is of paramount ecological and evolutionary significance (Campo et al.

Abstract:After the description of Chlorella vulgaris by Beijerinck, 120 years ago, members of the genus Chlorella belong to the best studied green algae worldwide. However, numerous open questions remained regarding their systematics. Recent molecular studies showed the polyphyly of the genus within the Chlorophyceae and Trebouxiophyceae. Chlorella-species were traditionally characterized by spherical to oval cell shape, solitary lifeform and the absence of mucilaginous envelopes. The challenge in the past was how to distinguish species due to their high phylogenetic diversity combined with a limited amount of morphological characters. Using a polyphasic approach of SSU-and ITS rDNA phylogeny, secondary structure of the ITS and light microscopic observations, we were able to detect six lineages with Dictyosphaerium-like strains in close relationship to C. vulgaris, here described or combined newly as C. coloniales sp. nov., C. pituita sp. nov., C. pulchelloides sp. nov., C. singularis sp. nov., C. elongata comb. nov. and C. chlorelloides comb. nov. Furthermore, three new species without mucilage were described as C. lewinii sp. nov., C. rotunda sp. nov. and C. volutis sp. nov. Using the 5.8S rRNA and part of the ITS-2 as molecular signature (barcode), we were able to distinguish not only the five already known species of Chlorella, C. vulgaris, C. sorokiniana, C. heliozoae, C. lobophora and C. variabilis but the seven new species and two new combinations as well. CBCs and hemi-CBCs within the secondary structure of the ITS-2 confirmed the separation of the species. Our study led to a new understanding of the evolution of morphology within the genus Chlorella and to an emendation of the generic description.

No abstract

This review provides a comprehensive and sound summary of the current state of research on the prevalence of GDM in advances economies as a fi rst step in identifying starting points for future interventions.

Colourless, nonscaled chrysophytes comprise morphologically similar or even indistinguishable flagellates which are important bacterivors in water and soil crucial for ecosystem functioning. However, phylogenetic analyses indicate a multiple origin of such colourless, nonscaled flagellate lineages. These flagellates are often referred to as “Spumella‐like flagellates” in ecological and biogeographic studies. Although this denomination reflects an assumed polyphyly, it obscures the phylogenetic and taxonomic diversity of this important flagellate group and, thus, hinders progress in lineage‐ and taxon‐specific ecological surveys. The smallest representatives of colourless chrysophytes have been addressed in very few taxonomic studies although they are among the dominant flagellates in field communities. To overcome the blurred picture and set the field for further investigation in biogeography and ecology of the organisms in question, we studied a set of strains of specifically small, colourless, nonscaled chrysomonad flagellates by means of electron microscopy and molecular analyses. They were isolated by a filtration‐acclimatisation approach focusing on flagellates of around 5 μm. We present the phylogenetic position of eight different lineages on both the ordinal and the generic level. Accordingly, we describe the new genera Apoikiospumella, Chromulinospumella, Segregatospumella, Cornospumella and Acrispumella Boenigk et Grossmann n. g. and different species within them.