Two classes of glutathione S-transferase genes with different response profiles to bacterial challenge in Venerupis philippinarum

Glutathione S-transferase (GST) is major cytosolic detoxification enzymes involved in many pathological and physiological processes. In the present study, two classes of GSTs (VpGST-1 and VpGST-2) were cloned from Venerupis philippinarum haemocytes by cDNA library and RACE approaches. Sequence alignments and phylogenetic analysis together supported that they belonged to a new member of sigma and pi classes GSTs protein family, respectively. The expression profiles of these two genes under Vibrio anguillarum challenge were investigated by quantitative RT-PCR. The bacterial challenge could significantly up-regulate the mRNA expression of both VpGST-1 and VpGST-2 with larger amplitude in VpGST-2, and the feedback speed for VpGST-2 was more rapid than that of VpGST-1. The differences in the response to bacterial challenge indicated that they were functional diversity and probably played cooperative roles in mediating the Vibrio challenge in clam.     

Rooting strategy of naturally regenerated beech in Silver birch and Scots pine woodlands

This study investigated the belowground development and strategy of late-successional European beech (Fagus sylvatica L.) in ageing natural Scots pine (Pinus sylvestris L.) and Silver birch (Betula pendula Roth.) woodlands in a French volcanic mid-elevation area. For this purpose root biomass, root profile and fine-root architecture of competitor trees were examined in 53 mixed pine–beech and 42 birch–beech woodlands along a stand maturation gradient, using the root auger technique (0–75-cm). The total beech fine-root biomass highly correlated with aerial dimensions such as stem height and girth, whereas it moderately correlated with its age, thus indicating the effects of competition. Basic stand biometric data such as stand density and basal area had no significant effect on beech root biomass. Conversely, competition indices taking into account the vertical dimensions of competitor trees were efficient, probably due to redundancy with beech height. At similar age and height, beeches under birch had a greater belowground development than beeches under pine. Each species exhibited specific rooting pattern and plasticity of fine-root architecture along the gradients of stand maturation and competition. Beech had a heart-shaped rooting habit in both mixings, which strongly increased along stand maturation. Its fine-root system adopted a foraging strategy to respond to increasing stand competition. The Scots pine fine-root system was plate-like and showed a low morphological plasticity, thus presumably a conservative strategy. Silver birch exhibited a high biomass and a foraging capacity in the topsoil but a loose root system in the subsoil. The coexistence of pine and beech roots in the upper soil presumably leads to a high belowground competition. Beech root system becomes predominant throughout the soil profile and it adopts an efficient foraging strategy, but at the expense of its belowground development. Conversely, the niche partitioning strategy between beech and birch may explain why beech develops strongly belowground in spite of the fact that birch has a dense rooting and a competitive fine-root architecture. As a consequence, beech mid-term regeneration and development may be facilitated under birch as compared with pine.     

Loss of plasmids of Borrelia burgdorferi sensu lato during prolonged in vitro cultivation

In the present study we analyzed stability of plasmid content in 34 Borrelia strains of three different species (13 Borrelia afzelii, 10 Borrelia garinii and 11 Borrelia burgodorferi sensu stricto) using pulse field gel electrophoresis (PFGE). During long-term in vitro cultivation consisting of 50 passages, plasmid loss was established in 46% of B. afzelii, 40% of B. garinii and 36% of B. burgdorferi sensu stricto strains. Loss of plasmids occurred as early as between the 5th and 10th passage, affected only plasmids in the range 9-41 kb but not plasmids in the range 50-68 kb and manifested with the loss of one to up to three plasmids.     

Aging bone marrow mesenchymal stromal cells have altered membrane glycerophospholipid composition and functionality

Human mesenchymal stem/stromal cells (hMSC) are increasingly used in advanced cellular therapies. The clinical use of hMSCs demands sequential cell expansions. As it is well established that membrane glycerophospholipids (GPL) provide precursors for signaling lipids that modulate cellular functions, we studied the effect of the donor''s age and cell doublings on the GPL profile of human bone marrow MSC (hBMSC). The hBMSCs, which were harvested from five young and five old adults, showed clear compositional changes during expansion seen at the level of lipid classes, lipid species, and acyl chains. The ratio of phosphatidylinositol to phosphatidylserine increased toward the late-passage samples. Furthermore, 20:4n-6-containing species of phosphatidylcholine and phosphatidylethanolamine accumulated while the species containing monounsaturated fatty acids (FA) decreased during passaging. Additionally, in the total FA pool of the cells, 20:4n-6 increased, which happened at the expense of n-3 polyunsaturated FAs, especially 22:6n-3. The GPL and FA correlated with the decreased immunosuppressive capacity of hBMSCs during expansion. Our observations were further supported by alterations in the gene expression levels of several enzymes involved in lipid metabolism and immunomodulation. The results show that extensive expansion of hBMSCs harmfully modulates membrane GPLs, affecting lipid signaling and eventually impairing functionality.     

4D modeling in a gimbaled linear accelerator by using gold anchor markers

Purpose

The purpose of this study was to verify whether the dynamic tumor tracking (DTT) feature of a Vero4DRT system performs with 10-mm-long and 0.28 mm diameter gold anchor markers.

A time course study on dose-response relationship between alcohol exposure and its effects on lipid profile and biomarkers of tissue damage

This present research investigated variations in lipid profiles and important biomarkers of tissue damage in response to graded concentrations of alcohol administration in male Wistar rats. Group A (control) received distilled water while group B, C and D received 30%, 40% and 50% (v/v) alcohol respectively. Five rats each from groups A-D were sacrificed after day(s) 1, 7, 14, 21 and 28 of administration. A significant increase was observed at day 28 for serum cholesterol by 79% (group B), 78% (group C) and 47% (group D) together with serum phospholipid 58% (group B), 50% (group C) and 92% (group D). Serum triacylglycerol increased by 71% (group B), 43% (group C) and 16% (group D) at day 21, while concentration of serum albumin decreased at day 28 by 40.9% (group B), 50.2% (group C), 53.3% (group D) respectively when compared with control (group A). Serum aminotransferases and alkaline phosphatase specific activities, as well as creatinine and uric acid concentration increased in a concentration-dependent manner, following alcohol administration. Though most of these effects induced by alcohol were time- and concentration-dependent, 40% alcohol appear to be more stable, giving results consistent with alcohol-induced damages, with minimal mortality. This study therefore further validated dyslipidemia and imbalance in clinical biomarkers as hallmarks of tissue damage induced by excessive alcohol consumption with an insight on the time- and concentration-response relationship between alcohol consumption and its toxicity.     

Species traits and channel architecture mediate flow disturbance impacts on invertebrate drift

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东方蜜蜂微孢子虫侵染过程中nce-miR-34537和靶基因PIP5KI的表达谱

【目的】本研究旨在对前期鉴定到的nce-miR-34537进行表达和序列验证,预测nce-miR-34537的靶基因并明确其分子特性,进而检测nce-miR-34537及其靶基因在东方蜜蜂微孢子虫(Nosema ceranae)侵染意大利蜜蜂(Apis mellifera ligustica)工蜂过程的表达谱,为进一步探究nce-miR-34537调控东方蜜蜂微孢子虫侵染的功能和作用机制提供基础。【方法】通过Stem-loop-RT-PCR和Sanger测序验证nce-miR-34537的表达和序列。通过生物信息学软件预测nce-miR-34537的靶基因PIP5KI(I型磷脂酰肌醇4-磷酸-5-激酶基因)的理化性质等分子特性和保守基序,并构建基于氨基酸序列的系统进化树。采用RT-qPCR检测nce-miR-34537及其靶基因的表达谱。【结果】nce-miR-34537在东方蜜蜂微孢子虫孢子中真实存在和表达。nce-miR-34537共靶向PIP5KI等151个基因。PIP5KI蛋白的分子式为C₈₈₂H_{1 364}N₂₂₆     

mem-iLID,a fast and economic protein purification method

Protein purification is the vital basis to study the function, structure and interaction of proteins. Widely used methods are affinity chromatography-based purifications, which require different chromatography columns and harsh conditions, such as acidic pH and/or adding imidazole or high salt concentration, to elute and collect the purified proteins. Here we established an easy and fast purification method for soluble proteins under mild conditions, based on the light-induced protein dimerization system improved light-induced dimer (iLID), which regulates protein binding and release with light. We utilize the biological membrane, which can be easily separated by centrifugation, as the port to anchor the target proteins. In Xenopus laevis oocyte and Escherichia coli, the blue light-sensitive part of iLID, AsLOV2-SsrA, was targeted to the plasma membrane by different membrane anchors. The other part of iLID, SspB, was fused with the protein of interest (POI) and expressed in the cytosol. The SspB-POI can be captured to the membrane fraction through light-induced binding to AsLOV2-SsrA and then released purely to fresh buffer in the dark after simple centrifugation and washing. This method, named mem-iLID, is very flexible in scale and economic. We demonstrate the quickly obtained yield of two pure and fully functional enzymes: a DNA polymerase and a light-activated adenylyl cyclase. Furthermore, we also designed a new SspB mutant for better dissociation and less interference with the POI, which could potentially facilitate other optogenetic manipulations of protein–protein interaction.