Cumaceans (Crustacea) from the Bellingshausen Sea and off the western Antarctic Peninsula: a deep-water link with fauna of the surrounding oceans

During the austral summers of 2003 and 2006, two cruise were carried out in the Bellingshausen Sea and west off Antarctic Peninsula on board of RV Hespérides. Samples were collected at 26 stations with a multinet Macer-GIROQ sled. A total of 557 cumaceans belonging to 36 species of five families were collected. Nannastacidae was the most abundant and speciose family. Hemilamprops pellucidus and Cyclaspis gigas were the most frequently collected species (38.5% of sampling stations). Cumella asutralis reached the highest density (514.7 individuals/1,000 m² at stn 7). Maximum species richness (S = 15) and diversity (H′ = 3.53) was observed at one of the deepest station. Positive correlations were found between the cumacean distribution and the organic content and percentage of coarse sand of the sediments. Predominance of Nannastacidae in front of other cumaceans could be explained by their type of feeding (i.e. predators or scavengers), which may be more successful in the deep seafloor of an oligotrophic sea such as studied herein. The presence in the deepest sampling sites of species shared with faunas of surrounding oceans suggests a link between these faunas and those of deep Antarctic waters.     

Methotrexate impacts conserved pathways in diverse human gut bacteria leading to decreased host immune activation

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Slide Flask direct amniotic fluid cultures.

Slide Flask direct amniotic fluid culture enabling: to decrease the risk of abnormalities caused by the technique itself, to facilitate laboratory work, to shorten culture time (8 to 13 days).     

Purification of an ovine, androgen-dependent epididymal protein. Evidence for a strong amino acid sequence homology with serum albumin.

An ovine, testosterone-dependent protein was purified from an extract of epididymides of orchidectomized-, testosterone-implanted rams by ethylene glycol precipitation, anion exchange chromatography, preparative non-denaturing PAGE at alkaline pH and gel filtration. The protein which had previously been named ovine prealbumin-epididymis-specific protein (oPES), migrated as a single band ahead of ovine serum albumin (oSA). A single component, with an apparent MW of 60 kDa, lower than that of oSA, was also observed in SDS-PAGE. oPES was cleaved after lysyl residues using endoproteinase Lys-C and the hydrolysate was fractionated in 2 steps by reverse-phase HPLC. Six oligopeptides were recovered and sequenced. They all displayed complete identity with regions of bovine serum albumin scattered in the two-third N-terminal part. However, in 2 of them, there was no complete identity with homologous parts of oSA. This indicates that oPES and oSA are probably encoded by different genes.     

A phenotype-driven ENU mutagenesis screen for the identification of dominant mutations involved in alcohol consumption

The aim of this study was the application of a phenotype-driven N-ethyl-N-nitrosourea (ENU) mutagenesis screen in mice for the identification of dominant mutations involved in the regulation and modulation of alcohol-drinking behavior. The chemical mutagen ENU was utilized in the generation of 131 male ENU-mutant C57BL/6J mice (G0). These ENU-treated mice were paired with wild-type C57BL/6J mice to generate G1 and subsequent generations. In total, 3327 mice were generated. Starting with G1, mice were screened for voluntary oral self-administration of 10% (v/v) alcohol vs. water in a two-bottle paradigm. From these mice, after a total period of 5 weeks of drinking, 43 mutants fulfilled the criteria of an “alcohol phenotype,” that is, high or low ethanol intake. They were then selected for breeding and tested in a “confirmation cross” (G2–G4) for inheritance. Although we did not establish stable high or low drinking lines, several results were obtained in the context of alcohol consumption. First, female mice drank more alcohol than their male counterparts. Second, the former demonstrated greater infertility. Third, all animals displayed relatively stable alcohol intake, although significantly different in two different laboratories. Finally, seasonal and monthly variability was observed, with the highest alcohol consumption occurring in spring and the lowest in autumn. In conclusion, it seems difficult to identify dominant mutations involved in the modulation or regulation of voluntary alcohol consumption via a phenotype-driven ENU mutagenesis screen. In accordance with the findings from knockout studies, we suggest that mainly recessive mutations contribute to an alcohol-drinking or alcohol-avoiding phenotype.     

Quantitative Microscopy: Protein Dynamics and Membrane Organisation

The mobility of membrane proteins is a critical determinant of their interaction capabilities and protein functions. The heterogeneity of cell membranes imparts different types of motion onto proteins; immobility, random Brownian motion, anomalous sub-diffusion, 'hop' or confined diffusion, or directed flow. Quantifying the motion of proteins therefore enables insights into the lateral organisation of cell membranes, particularly membrane microdomains with high viscosity such as lipid rafts. In this review, we examine the hypotheses and findings of three main techniques for analysing protein dynamics: fluorescence recovery after photobleaching, single particle tracking and fluorescence correlation spectroscopy. These techniques, and the physical models employed in data analysis, have become increasingly sophisticated and provide unprecedented details of the biophysical properties of protein dynamics and membrane domains in cell membranes. Yet despite these advances, there remain significant unknowns in the relationships between cholesterol-dependent lipid microdomains, protein-protein interactions, and the effect of the underlying cytoskeleton. New multi-dimensional microscopy approaches may afford greater temporal and spatial resolution resulting in more accurate quantification of protein and membrane dynamics in live cells.     

The influence of environmental conditions on the body mass of Barn Swallows (Hirundo rustica) during spring migration

The present study examines the effects of seven microclimatic factors on the arrival body mass of migrant Barn Swallows (Hirundo rustica) in the Aiguamolls de l’Empordà Natural Park, a site located in northeastern Spain. We used principal component analysis, followed by a general linear model procedure, to create a model that examines the relationships between body mass and weather-related events recently experienced during the spring migration. Our results suggest that local weather variation during the migratory flight clearly affects the body mass of Barn Swallows on a short time scale. This effect demonstrates the importance of the environmental conditions en route for migrating swallows and how these conditions might influence diverse events of the life cycle, such as the arrival time at the breeding grounds or the reproductive success.     

A likelihood ratio approach for identifying three-quarter siblings in genetic databases

The detection of family relationships in genetic databases is of interest in various scientific disciplines such as genetic epidemiology, population and conservation genetics, forensic science, and genealogical research. Nowadays, screening genetic databases for related individuals forms an important aspect of standard quality control procedures. Relatedness research is usually based on an allele sharing analysis of identity by state (IBS) or identity by descent (IBD) alleles. Existing IBS/IBD methods mainly aim to identify first-degree relationships (parent–offspring or full siblings) and second degree (half-siblings, avuncular, or grandparent–grandchild) pairs. Little attention has been paid to the detection of in-between first and second-degree relationships such as three-quarter siblings (3/4S) who share fewer alleles than first-degree relationships but more alleles than second-degree relationships. With the progressively increasing sample sizes used in genetic research, it becomes more likely that such relationships are present in the database under study. In this paper, we extend existing likelihood ratio (LR) methodology to accurately infer the existence of 3/4S, distinguishing them from full siblings and second-degree relatives. We use bootstrap confidence intervals to express uncertainty in the LRs. Our proposal accounts for linkage disequilibrium (LD) by using marker pruning, and we validate our methodology with a pedigree-based simulation study accounting for both LD and recombination. An empirical genome-wide array data set from the GCAT Genomes for Life cohort project is used to illustrate the method.Subject terms: Genetic markers, Population genetics