Aberrant Toxocara canis in a red fox

During necropsy of a red fox (Vulpes vulpes) heart an adult, male Toxocara canis was found under the pericardium at the junction of the right ventricle and right atrium. The life cycle of T. canis is complex and includes tracheal and somatic migrations of larvae, and they can be found in many tissues throughout the host's body. However, it is rare for adult ascarids to be recovered outside of the small intestine. This is the first report of an adult T. canis inside the pericardial space.     

Detection of two loci involved in (1-->3)-beta-glucan (curdlan) biosynthesis by Agrobacterium sp. ATCC31749, and comparative sequence analysis of the putative curdlan synthase gene

Genes essential for the production of a linear, bacterial (1-->3)-beta- glucan, curdlan, have been cloned for the first time from Agrobacterium sp. ATCC31749. The genes occurred in two, nonoverlapping, genomic fragments that complemented different sets of curdlan( crd )-deficient transposon-insertion mutations. These were detected as colonies that failed to stain with aniline blue, a (1-->3)-beta-glucan specific dye. One fragment carried a biosynthetic gene cluster (locus I) containing the putative curdlan synthase gene, crdS, and at least two other crd genes. The second fragment may contain only a single crd gene (locus II). Determination of the DNA sequence adjacent to several locus I mutations revealed homology to known sequences only in the cases of crdS mutations. Complete sequencing of the 1623 bp crdS gene revealed highest similarities between the predicted CrdS protein (540 amino acids) and glycosyl transferases with repetitive action patterns. These include bacterial cellulose synthases (and their homologs), which form (1-->4)-beta-glucans. No similarity was detected with putative (1-->3)- beta-glucan synthases from yeasts and filamentous fungi. Whatever the determinants of the linkage specificity of these beta-glucan synthases might be, these results raise the possibility that (1-->3)-beta-glucans and (1-->4)-beta-glucans are formed by related catalytic polypeptides.      

Modeling expression quantitative trait loci in data combining ethnic populations

Background  

Combining data from different ethnic populations in a study can increase efficacy of methods designed to identify expression quantitative trait loci (eQTL) compared to analyzing each population independently. In such studies, however, the genetic diversity of minor allele frequencies among populations has rarely been taken into account. Due to the fact that allele frequency diversity and population-level expression differences are present in populations, a consensus regarding the optimal statistical approach for analysis of eQTL in data combining different populations remains inconclusive.     

The lipopolysaccharides of Rhodospirillum rubrum,Rhodospirillum molischianum,and Rhodopila globiformis

The cell wall lipopolysaccharides from three phototrophic species of the alpha₁-group of Proteobacteria, Rhodospirillum rubrum, Rhodospirillum molischianum, and Rhodopila globiformis were isolated and chemically characterized. Sodium deoxycholate polyacrylamide gel electrophoresis patterns revealed that the lipopolysaccharides of all three species possess O-chains. They are composed of repeating units only in R. molischianum and R. globiformis. The presence of l-glycero-d-mannoheptose and 2-keto-3-deoxyoctonate indicated core structures in all three lipopolysaccharides. Glucosamine was found as backbone amino sugar in lipid A of R. molischianum and R. rubrum, while R. globiformis has 2,3-diaminoglucose as backbone amino sugar. The latter species also differed from the two former ones in its content of hydroxy fatty acids (3-OH-14:0, 3-OH-16:0 in R. rubrum and R. molischianum and 3-OH-14:0, 3-OH-18:0 and 3-OH-19:0 (possibly iso- or anteisobranched) in R. globiformis).Abbreviations DOC-PAGE sodium deoxycholate polyacrylamide gel electrophoresis - GC/MS combined gas-liquid chromatography/mass spectrometry - KDO 2-keto-3-deoxyoctonate     

Innovative method for quantification of cell-cell adhesion in 96-well plates

Cell adhesion is an important part of many complex biological processes. It plays crucial roles in cancer, development and maintenance of stem cell compartment. The measurement of adhesion under experimental conditions might provide important information for cell biology. There are several protocols to measure adhesion, usually based on washing or shaking to remove non-adherent cells. Here, we describe a quantification method based on gravitational force to measure adhesion in a 96-well format. Non-adherent cells are separated and only vital cells are quantified with a colorimetric assay. This assay can be used especially when the “anti-adhesion” effect is present only for a short period of time like is the case of peptides or cytokines since it provides a trap for non-adherent cells in a way that they can not touch again the adherent surface. As examples we provide the quantification of cell-cell interaction with blocking antibodies anti-CD44 in hematopoietic stem cells and the effect of the stromal cell derived factor-1 (SDF-1) in the Jurkat cell line when they are in contact with mesenchymal stromal cells. This method facilitates fast and reliable measurement of cell adhesion in multiwell format for screening assays.Key words: adhesion assay, adhesion, SDF-1, CD44, hematopoietic stem cells, leukemia cell lines     

Wood decomposition is more strongly controlled by temperature than by tree species and decomposer diversity in highly species rich subtropical forests

While the number of studies on the role of biodiversity on ecosystem functioning is steadily increasing, a key component of biogeochemical cycling in forests, dead wood decay, has been largely neglected. It remains widely unknown whether and how dead wood decay is affected by diversity loss in forests. We studied the hierarchical effects of tree species diversity on wood decay rates in a subtropical forest landscape in southeast China via its influence on fungal OTU richness and invertebrate diversity using piecewise structural equation models. The experiment was conducted in natural forest plots that span a wide gradient of tree species diversity embedded in a heterogeneous topography. To account for interactions between macro‐invertebrates and fungi, that potentially modify the influence of tree biodiversity and climate on dead wood decay, we compared a macro‐invertebrate exclusion treatment with a control treatment that allowed access to all types of decomposers. Diversity effects of trees on wood decay rates were mostly negative and mediated by the diversity of macro‐invertebrates. However, the effects of tree species diversity or fungal OTU richness and macro‐invertebrate diversity on wood decay rates were comparatively weak. Temperature affected decay rates positively and had the strongest influence in all treatments. While the exclusion of macro‐invertebrates did not lead to a reduction of wood decay rates, our results suggest that they may however have a mediating role in the process. In the presence of invertebrates the predictability of wood decay rates was higher and we observed a tendency of a stronger temperature control. Our results suggest that there is evidence for diversity effects on wood decomposition, but the temperature control is still more important. Thus, an increase in mean annual temperature will increase carbon and nutrient turnover through wood decomposition in subtropical forest irrespective of biotic composition.     

In vivo treatment with progestogens causes immunosuppression of carp Cyprinus carpio leucocytes by affecting nitric oxide production and arginase activity

In this study, carp Cyprinus carpio were injected with various steroid compounds, including synthetic and natural progestogens and the glucocorticoid cortisol, to investigate effects on leucocytes isolated from their kidneys. Injection of cortisol led to an increased spleeno-somatic index (I(S)) on day 21 post-injection (pi) and immunosuppressive effects measured as decreased nitric oxide (NO) production and increased arginase activity in isolated leucocytes on days 14 and 21 pi, respectively. Moreover, reduced NO production was also observed after injection of the synthetic progestogens, levonorgestrel (LEV) and medroxyprogesterone acetate. In addition, LEV influenced arginase activity in head kidney cells on day 14 and day 21 pi. This study is the first demonstration in fishes that the application of these steroid compounds in vivo affects NO production and arginase activity of isolated leucocytes.     

Association mapping for quality traits in soft winter wheat

Improvement of end-use quality in bread wheat (Triticum aestivum L.) depends on a thorough understanding of the genetic basis of important quality traits. The main goal of our study was to investigate the genetic basis of 1,000-kernel weight, protein content, sedimentation volume, test weight, and starch concentration using an association mapping approach. We fingerprinted 207 diverse European elite soft winter wheat lines with 115 SSR markers and evaluated the genotypes in multi-environment trials. The principal coordinate analysis revealed absence of a clear population but presence of a family structure. Therefore, we used linear mixed models and marker-based kinship matrices to correct for family structure. In genome-wide scans, we detected main effect QTL for all five traits. In contrast, epistatic QTL were only observed for sedimentation volume and test weight explaining a small proportion of the genotypic variation. Consequently, our findings suggested that integrating epistasis in marker-assisted breeding will not lead to substantially increased selection gain for quality traits in soft winter wheat.     

Tracking Cats: Problems with Placing Feline Carnivores on ��18O, ��D Isoscapes

Background

Several felids are endangered and threatened by the illegal wildlife trade. Establishing geographic origin of tissues of endangered species is thus crucial for wildlife crime investigations and effective conservation strategies. As shown in other species, stable isotope analysis of hydrogen and oxygen in hair (δD_h, δ¹⁸O_h) can be used as a tool for provenance determination. However, reliably predicting the spatial distribution of δD_h and δ¹⁸O_h requires confirmation from animal tissues of known origin and a detailed understanding of the isotopic routing of dietary nutrients into felid hair.

Methodology/Findings

We used coupled δD_h and δ¹⁸O_h measurements from the North American bobcat (Lynx rufus) and puma (Puma concolor) with precipitation-based assignment isoscapes to test the feasibility of isotopic geo-location of felidae. Hairs of felid and rabbit museum specimens from 75 sites across the United States and Canada were analyzed. Bobcat and puma lacked a significant correlation between H/O isotopes in hair and local waters, and also exhibited an isotopic decoupling of δ¹⁸O_h and δD_h. Conversely, strong δD and δ¹⁸O coupling was found for key prey, eastern cottontail rabbit (Sylvilagus floridanus; hair) and white-tailed deer (Odocoileus virginianus; collagen, bone phosphate).

Conclusions/Significance

Puma and bobcat hairs do not adhere to expected pattern of H and O isotopic variation predicted by precipitation isoscapes for North America. Thus, using bulk hair, felids cannot be placed on δ¹⁸O and δD isoscapes for use in forensic investigations. The effective application of isotopes to trace the provenance of feline carnivores is likely compromised by major controls of their diet, physiology and metabolism on hair δ¹⁸O and δD related to body water budgets. Controlled feeding experiments, combined with single amino acid isotope analysis of diets and hair, are needed to reveal mechanisms and physiological traits explaining why felid hair does not follow isotopic patterns demonstrated in many other taxa.