Deep sequencing-based transcriptome analysis of Plutella xylostella larvae parasitized by Diadegma semiclausum

Background: Parasitoid insects manipulate their hosts' physiology by injecting various factors into their host upon parasitization. Transcriptomic approaches provide a powerful approach to study insect host-parasitoid interactions at the molecular level. In order to investigate the effects of parasitization by an ichneumonid wasp (Diadegma semiclausum) on the host (Plutella xylostella), the larval transcriptome profile was analyzed using a short-read deep sequencing method (Illumina). Symbiotic polydnaviruses (PDVs) associated with ichneumonid parasitoids, known as ichnoviruses, play significant roles in host immune suppression and developmental regulation. In the current study, D. semiclausum ichnovirus (DsIV) genes expressed in P. xylostella were identified and their sequences compared with other reported PDVs. Five of these genes encode proteins of unknown identity, that have not previously been reported

Upon impact: the fate of adhering <i>Pseudomonas fluorescens</i> cells during Nanofiltration

Nanofiltration (NF) is a high-pressure membrane filtration process increasingly applied in drinking water treatment and water reuse processes. NF typically rejects divalent salts, organic matter, and micropollutants. However, the efficiency of NF is adversely affected by membrane biofouling, during which microorganisms adhere to the membrane and proliferate to create a biofilm. Here we show that adhered Pseudomonas fluorescens cells under high permeate flux conditions are met with high fluid shear and convective fluxes at the membrane-liquid interface, resulting in their structural damage and collapse. These results were confirmed by fluorescent staining, flow cytometry, and scanning electron microscopy. This present study offers a 'first-glimpse' of cell damage and death during the initial phases of bacterial adhesion to NF membranes and raises a key question about the role of this observed phenomena during early-stage biofilm formation under permeate flux and cross-flow conditions.European Research Council (ERC

Essential roles of zebrafish rtn4/Nogo paralogues in embryonic development

BACKGROUNDAs a consequence of gene/genome duplication, the RTN4/Nogo gene has two counterparts in zebrafish: rtn4a and rtn4b. The shared presence of four specific amino acid motifs--M1 to M4--in the N-terminal region of mammalian RTN4, and zebrafish Rtn4b suggests that Rtn4b is the closest homologue of mammalian Nogo-A.RESULTSTo explore their combined roles in zebrafish development, we characterized the expression patterns of rtn4a and rtn4b in a comparative manner and performed morpholino-mediated knockdowns. Although both genes were coexpressed in the neural tube and developing brain at early stages, they progressively acquired distinct expression domains such as the spinal cord (rtn4b) and somites (rtn4a). Downregulation of rtn4a and rtn4b caused severe brain abnormalities, with rtn4b knockdown severely affecting the spinal cord and leading to immobility. In addition, the retinotectal projection was severely affected in both morphants, as the retina and optic tectum appeared smaller and only few retinal axons reached the abnormally reduced tectal neuropil. The neuronal defects were more persistent in rtn4b morphants. Moreover, the latter often lacked pectoral fins and lower jaws and had malformed branchial arches. Notably, these defects led to larval death in rtn4b, but not in rtn4a morphants.CONCLUSIONSIn contrast to mammalian Nogo-A, its zebrafish homologues, rtn4a and particularly rtn4b, are essential for embryonic development and patterning of the nervous system

Adsorption and corrosion inhibition properties of 5-amino 1,3,4-thiadiazole-2-thiol on the mild steel in hydrochloric acid medium: Thermodynamic, surface and electrochemical studies

International audienceThe inhibition effect of 5-amino 1,3,4-thiadiazole-2-thiol (5-ATT) on the corrosion of mild steel in 1 M HCl solution at 303 K was studied practicing weight loss, electrochemical electrochemical (AC and DC) studies and Xray photoelectron spectroscopy (XPS) methods. The obtained results showed that 5-ATT was an effective inhibitor in HCl medium. The inhibition efficiency, eta(%), increased with the increase in concentration inhibitor but the temperature has almost no effect on the inhibition efficiency of 5-ATT. The activation dissolution thermodynamic parameters were calculated and discussed. Thermodynamic data and XPS analysis clearly show that the adsorption mechanism of 5-ATT on the mild steel surface in 1 M HCl solution is mainly electrostatic-adsorption. Tafel curves reveal that 5-ATT behaves as a mixed-type inhibitor with cathodic predominance and obeyed Langmuir adsorption isotherm. With the aim of extracting the parameters of the electrochemical impedance spectroscopy an appropriate equivalent circuit model was offered

Semiconducting (half-metallic) ferromagnetism in Mn(Fe) substituted Pt and Pd nitrides

Using first-principles calculations as based on density-functional theory, we propose a class of so far unexplored diluted ferromagnetic semiconductors and half metals. Here, we study the electronic properties of recently synthesized 4d and 5d transition-metal dinitrides. In particular, we address Mn and Fe substitution in PtN2 and PdN2. Structural relaxation shows that the resulting ordered compounds, Pt0.75(Mn,Fe)0.25N2 and Pd0.75(Mn,Fe)0.25N2, maintain the cubic crystal symmetry of the parent compounds. On substitution, all compounds exhibit long-range ferromagnetic order. While both Pt0.75Mn0.25N2 and Pd0.75Mn0.25N2 are semiconducting, Fe substitution causes half-metallic behavior for both parent materials