Short‐distance migration of Wrynecks Jynx torquilla from Central European populations

European Wrynecks Jynx torquilla torquilla have generally been considered to be long‐distance Palaearctic–African migrants that spend the non‐breeding season in Sahelian Africa, where they have been reported regularly. Results from tracking individual birds showed that Wrynecks from two Central European populations migrated only relatively short distances to the Iberian Peninsula and northwestern Africa (c. 1500 km and 3000 km, respectively), compared with a minimum distance of about 4500 km to Sahelian Africa. Additionally, differences in wing lengths of populations from Central and Northern Europe support the idea of leap‐frog migration, populations from Northern Europe being long‐distance migrants with a non‐breeding distribution in Sahelian Africa.     

Accelerated Reendothelialization,Increased Neovascularization and Erythrocyte Extravasation after Arterial Injury in BAMBI?/? Mice

Background

Intimal injury rapidly activates TGFβ and enhances vascular repair by the growth of endothelial (EC) and vascular smooth muscle cells (VSMC). The response to the TGFβ family of growth factors can be modified by BAMBI (BMP, Activin, Membrane Bound Inhibitor) acting as a non-signaling, competitive antagonist of TGFβ type I receptors such as ALK 1 and 5. In vivo the effect of BAMBI will depend on its cell-specific expression and of that of the ALK type receptors. We recently reported EC restricted BAMBI expression and genetic elimination of BAMBI resulting in an in vitro and in vivo phenotype characterized by endothelial activation and proliferation involving alternative pathway activation by TGFβ through ALK 1.

Methodology/Principal Findings

To test the hypothesis that BAMBI modulates arterial response to injury via its effects on endothelial repair and arterial wall neovascularization we used a model of femoral arterial denudation injury in wild type (WT) and BAMBI^−/− mice. Arterial response was evaluated at 2 and 4 weeks after luminal endothelial denudation of femoral arteries. The BAMBI^−/− genotype mice showed accelerated luminal endothelial repair at 2 weeks and a highly unusual increase in arterial wall neovascularization compared to WT mice. The exuberant intimal and medial neovessel formation with BAMBI^−/− genotype was also associated with significant red blood cell extravasation. The bleeding into the neointima at 2 weeks transiently increased it’s area in the BAMBI^−/−genotype despite the faster luminal endothelial repair in this group. Vascular smooth muscle cells were decreased at 2 weeks in BAMBI^−/− mice, but comparable to wild type at 4 weeks.

Conclusions/Significance

The absence of BAMBI results in a highly unusual surge in arterial wall neovascularization that surprisingly mimiks features of intra-plaque hemorrhage of advanced atheroma in a mechanical injury model. This suggests important effects of BAMBI on arterial EC homeostasis that need to be further studied in a model of inflammatory atherosclerosis.     

Fractionation of three different lignins by thermal separation techniques—A comparative study

Separation of the heterogeneous lignin macromolecule in fractions with increased homogeneity, as well as different structural (molar mass) and functional (hydroxy groups, ‐OH) features is important in terms of its use as a chemical building block. For this purpose, three thermal separation techniques were investigated and compared: solvent extraction, successive precipitation and ultrafiltration. One important issue in this context is the utilization of organic solvents with low boiling points to ensure a simple and efficient recovery. In addition to a softwood Kraft lignin (Indulin AT) as reference lignin, two sulfur‐free Organosolv lignins from short rotation coppice (“poplar with bark”) and from the energy grass Miscanthus × gigantheus were investigated. The lignins were separated into low, medium and high molecular weight fractions. Due to the different initial structural features and the associated varying solubility properties in such lignins, different organic solvents were needed for dissolution and precipitation of the individual lignin fractions. The polarity of the used solvent is one key factor regarding the yield of the soluble fraction and the success of molecular sorting into low, medium, and high molecular weight. Further structural features, for example the aliphatic OH‐group content increased with rising molecular weight of poplar, miscanthus, and Kraft lignin from minimum 0.72, 0.3, and 1.6 mmol/g to maximum 2.4, 1.6, and 2.8 mmol/g, respectively. The number of phenolic OH‐groups decreased from maximum 3.8, 4.3, and 4.2 to minimum 1.4, 2.7, and 2.9, respectively. The presented work illustrate options regarding the molecular sorting of several lignin types with three thermal techniques into fractions differing in key properties (yield, molecular weight, polydispersity, functional groups) for material applications.     

Metabolism and foraging strategies of mid‐latitude mesozooplankton during cyanobacterial blooms as revealed by fatty acids,amino acids,and their stable carbon isotopes

Increasing sea surface temperatures (SST) and blooms of lipid‐poor, filamentous cyanobacteria can change mesozooplankton metabolism and foraging strategies in marine systems. Lipid shortage and imbalanced diet may challenge the build‐up of energy pools of lipids and proteins, and access to essential fatty acids (FAs) and amino acids (AAs) by copepods. The impact of cyanobacterial blooms on individual energy pools was assessed for key species temperate Temora longicornis and boreal Pseudo‐/Paracalanus spp. that dominated field mesozooplankton communities isolated by seasonal stratification in the central Baltic Sea during the hot and the cold summer. We looked at (a) total lipid and protein levels, (b) FA trophic markers and AA composition, and (c) compound‐specific stable carbon isotopes (δ¹³C) in bulk mesozooplankton and in a subset of parameters in particulate organic matter. Despite lipid‐poor cyanobacterial blooms, the key species were largely able to cover both energy pools, yet a tendency of lipid reduction was observed in surface animals. Omni‐ and carnivory feeding modes, FA trophic makers, and δ¹³C patterns in essential compounds emphasized that cyanobacterial FAs and AAs have been incorporated into mesozooplankton mainly via feeding on mixo‐ and heterotrophic (dino‐) flagellates and detrital complexes during summer. Foraging for essential highly unsaturated FAs from (dino‐) flagellates may have caused night migration of Pseudo‐/Paracalanus spp. from the deep subhalocline waters into the upper waters. Only in the hot summer (SST>19.0°C) was T. longicornis submerged in the colder subthermocline water (~4°C). Thus, the continuous warming trend and simultaneous feeding can eventually lead to competition on the preferred diet by key copepod species below the thermocline in stratified systems. A comparison of δ¹³C patterns of essential AAs in surface mesozooplankton across sub‐basins of low and high cyanobacterial biomasses revealed the potential of δ¹³C‐AA isoscapes for studies of commercial fish feeding trails across the Baltic Sea food webs.     

The role of changing pH on olfactory success of predator–prey interactions in green shore crabs,Carcinus maenas

Aquatic Ecology - Arguably climate change is one of the biggest challenges faced by many organisms. One of the more significant of these is the decreasing pH level of the ocean, a consequence of...     

Commensal Pseudomonas protect Arabidopsis thaliana from a coexisting pathogen via multiple lineage-dependent mechanisms

Plants are protected from pathogens not only by their own immunity but often also by colonizing commensal microbes. In Arabidopsis thaliana, a group of cryptically pathogenic Pseudomonas strains often dominates local populations. This group coexists in nature with commensal Pseudomonas strains that can blunt the deleterious effects of the pathogens in the laboratory. We have investigated the interaction between one of the Pseudomonas pathogens and 99 naturally co-occurring commensals, finding plant protection to be common among non-pathogenic Pseudomonas. While protective ability is enriched in one specific lineage, there is also a substantial variation for this trait among isolates of this lineage. These functional differences do not align with core-genome phylogenies, suggesting repeated gene inactivation or loss as causal. Using genome-wide association, we discovered that different bacterial genes are linked to plant protection in each lineage. We validated a protective role of several lineage-specific genes by gene inactivation, highlighting iron acquisition and biofilm formation as prominent mechanisms of plant protection in this Pseudomonas lineage. Collectively, our work illustrates the importance of functional redundancy in plant protective traits across an important group of commensal bacteria.Subject terms: Microbial ecology, Plant ecology     

Fatty Acids Induce Chloride Permeation in Rat Liver Mitochondria by Activation of the Inner Membrane Anion Channel (IMAC)

The inner membrane of freshly isolated mammalian mitochondria is poorly permeable to Cl(-). Low, nonlytic concentrations (< or =30 microM) of long-chain fatty acids or their branched-chain derivatives increase permeation of Cl(-) as indicated from rapid large-scale swelling of mitochondria suspended in slightly alkaline KCl medium (supplemented with valinomycin). Myristic, palmitic, or 5-doxylstearic acid are powerful inducers of Cl(-) permeation, whereas lauric, phytanic, stearic, or 16-doxylstearic acid stimulate Cl(-) permeation in a lesser extent. Fatty acid-induced Cl(-) permeation across the inner membrane correlates well with the property of nonesterified fatty acids to release endogenous Mg(2+) from mitochondria. Myristic acid stimulates anion permeation in a selective manner, similar as was described for A23187, an activator of the inner membrane anion channel (IMAC). Myristic acid-induced Cl(-) permeation is blocked by low concentrations of tributyltin chloride (IC(50) approximately 1.5 nmol/mg protein). Moreover, myristic acid activates a transmembrane ion current in patch-clamped mitoplasts (mitochondria with the outer membrane removed) exposed to alkaline KCl medium. This current is best ascribed to the opening of an ion channel with a single-channel conductance of 108 pS. We propose that long-chain fatty acids can activate IMAC by withdrawal of Mg(2+) from intrinsic binding sites.     

CEACAM1, a cell-cell adhesion molecule, directly associates with annexin II in a three-dimensional model of mammary morphogenesis

The epithelial cell adhesion molecule CEACAM1 (carcinoembryonic antigen cell adhesion molecule-1) is down-regulated in colon, prostate, breast, and liver cancer. Here we show that CEACAM1-4S, a splice form with four Ig-like ectodomains and a short cytoplasmic domain (14 amino acids), directly associates with annexin II, a lipid raft-associated molecule, which is also down-regulated in many cancers. Annexin II was identified using a glutathione S-transferase pull-down assay in which the cytoplasmic domain of CEACAM-4S was fused to glutathione S-transferase, the fusion protein was incubated with cell lysates, and isolated proteins were sequenced by mass spectrometry. The interaction was confirmed first by reciprocal immunoprecipitations using anti-CEACAM1 and anti-annexin II antibodies and second by confocal laser microscopy showing co-localization of CEACAM1 with annexin II in mammary epithelial cells grown in Matrigel. In addition, CEACAM1 co-localized with p11, a component of the tetrameric AIIt complex at the plasma membrane, and with annexin II in secretory vesicles. Immobilized, oriented peptides from the cytoplasmic domain of CEACAM1-4S were shown to directly associate with bovine AIIt, which is 98% homologous to human AIIt, with average KD values of about 30 nM using surface plasmon resonance, demonstrating direct binding of functionally relevant AIIt to the cytoplasmic domain of CEACAM1-4S.