Designing a standardised sampling method for invertebrate monitoringa : pilot experiment in a motorway retention pond

The implementation of the European Water Framework Directive revealed the necessity to develop new tools designed for freshwater ecosystems monitoring. As a new assessment approach employing invertebrate monitoring, three artificial substra­tes (two benthic and one pelagic) were tested for 7, 14,21 and 35 days of exposure in a motorway retention pond located in Southern France. Two of these artificial substrates appeared to sample too narrow a range of taxa, which was confirmed by two-way ANOVA tests and diversity and evenness indices. Samples taken by the remaining artificial substrate, composed of six plastic plant stems fixed on a 15 x 15 cm square tile, were representative of the species assemblage found in the stormwa­ter retention ponds. The use of an artificial substrate as a standardised method for long terro invertebrate monitoring in ponds holds much potential.La puesta en marcha de la Directiva Marco Europea del Agua requiere el desarrollo de nuevos protocolos de muestreo para el seguimiento de los ecosistemas acuáticos continentales. Como nuevas aproximaciones al seguimiento de invertebrados acuáticos se probaron tres sustratos artificiales (dos bénticos y uno pelágico) con un tiempo de exposición de 7, 14, 21 Y 35 días en una balsa de retención en una autopista del Sur de Francia. Dos de estos sustratos capturaron se1ectivamente un reducido número de taxones específicos, lo que fue confirmado con un análisis ANOVA de dos factores y los índices de diversidad y equitabilidad. Las muestras obtenidas con el sustrato artificial compuesto por seis pies de plantas de plástico fijadas en una baldosa cuadrada de 15 X 15 si que resultaron representativas de la asociación de especies característica de las balsas de retención de aguas en las autopistas. El uso de sustratos artificiales como método estandardizado para el seguimiento a largo plazo de los invertebrados acuáticos en balsas y charcas es de un gran potencial

Fluorescent T7 display phages obtained by translational frameshift

Lytic phages form a powerful platform for the display of large cDNA libraries and offer the possibility to screen for interactions with almost any substrate. To visualize these interactions directly by fluorescence microscopy, we constructed fluorescent T7 phages by exploiting the flexibility of phages to incorporate modified versions of its capsid protein. By applying translational frameshift sequences, helper plasmids were constructed that expressed a fixed ratio of both wild-type capsid protein (gp10) and capsid protein fused to enhanced yellow fluorescent protein (EYFP). The frameshift sequences were inserted between the 3′ end of the capsid gene and the sequence encoding EYFP. Fluorescent fusion proteins are only formed when the ribosome makes a −1 shift in reading frame during translation. Using standard fluorescence microscopy, we could sensitively monitor the enrichment of specific binders in a cDNA library displayed on fluorescent T7 phages. The perspectives of fluorescent display phages in the fast emerging field of single molecule detection and sorting technologies are discussed

Intertwined αβ Spectrin Meeting Helical Actin Protofilament in the Erythrocyte Membrane Skeleton: Wrap-Around vs. Point-Attachment

Our 3-D model for a junctional complex (JC) in the erythrocyte membrane skeleton proposed that the helical actin protofilament functions as a mechanical axis for three pairs of αβ spectrin (Sp), and each pair wraps around the protofilament in a back-to-back fashion. The distal end of each Sp is further associated with the lipid bilayer by a suspension complex (SC). Here, we detail how splitting and rejoining of αβ Sp around a protofilament may form a loop that sustains and equilibrates tension. Sequential association of β and α Sp solves the challenge of constructing multiple loops along the protofilament, and topological connection facilitates their re-association. The wrap-around model minimizes the strain of the actin binding site on β Sp due to tension, redirection, or sliding of intertwined Sp. Pairing Sp balances the opposing forces and provides a mechanism for elastic recovery. The wrap-around junction thus provides mechanical advantages over a point-attachment junction in maintaining the integrity and functionality of the network. Severing α or β Sp may convert a wrapping-around junction to a point-attachment junction. In that case, a “bow up” motion of JC during deformation may disturb or flip the overlaid lipid bilayer, and mark stressed erythrocytes for phagocytosis

Chemical genetics strategies for identification of molecular targets

Chemical genetics is an emerging field that can be used to study the interactions of chemical compounds, including natural products, with proteins. Usually, the identification of molecular targets is the starting point for studying a drug’s mechanism of action and this has been a crucial step in understanding many biological processes. While a great variety of target identification methods have been developed over the last several years, there are still many bioactive compounds whose target proteins have not yet been revealed because no routine protocols can be adopted. This review contains information concerning the most relevant principles of chemical genetics with special emphasis on the different genomic and proteomic approaches used in forward chemical genetics to identify the molecular targets of the bioactive compounds, the advantages and disadvantages of each and a detailed list of successful examples of molecular targets identified with these approaches

Simvastatin Sodium Salt and Fluvastatin Interact with Human Gap Junction Gamma-3 Protein

Finding pleiomorphic targets for drugs allows new indications or warnings for treatment to be identified. As test of concept, we applied a new chemical genomics approach to uncover additional targets for the widely prescribed lipid-lowering pro-drug simvastatin. We used mRNA extracted from internal mammary artery from patients undergoing coronary artery surgery to prepare a viral cardiovascular protein library, using T7 bacteriophage. We then studied interactions of clones of the bacteriophage, each expressing a different cardiovascular polypeptide, with surface-bound simvastatin in 96-well plates. To maximise likelihood of identifying meaningful interactions between simvastatin and vascular peptides, we used a validated photo-immobilisation method to apply a series of different chemical linkers to bind simvastatin so as to present multiple orientations of its constituent components to potential targets. Three rounds of biopanning identified consistent interaction with the clone expressing part of the gene GJC3, which maps to Homo sapiens chromosome 7, and codes for gap junction gamma-3 protein, also known as connexin 30.2/31.3 (mouse connexin Cx29). Further analysis indicated the binding site to be for the N-terminal domain putatively ‘regulating’ connexin hemichannel and gap junction pores. Using immunohistochemistry we found connexin 30.2/31.3 to be present in samples of artery similar to those used to prepare the bacteriophage library. Surface plasmon resonance revealed that a 25 amino acid synthetic peptide representing the discovered N-terminus did not interact with simvastatin lactone, but did bind to the hydrolysed HMG CoA inhibitor, simvastatin acid. This interaction was also seen for fluvastatin. The gap junction blockers carbenoxolone and flufenamic acid also interacted with the same peptide providing insight into potential site of binding. These findings raise key questions about the functional significance of GJC3 transcripts in the vasculature and other tissues, and this connexin’s role in therapeutic and adverse effects of statins in a range of disease states

SCHEV-OVAC Webinar: Open Education: Student Success and Faculty Autonomy.

The 2020-2021 Open Education: Student Success and Faculty Autonomy webinar series hosted by SCHEV-OVAC provides a space for learning and sharing to spark innovation and expand open education in Virginia. The virtual conversations will consist of short lightning talks, which will allow institutions to share their open education efforts and learn from similar efforts happening around Virginia. Provided by the University Libraries at Virginia Tech. Register her

Die Rezeption Eugen Finks in der Republik China

Der Aufsatz befasst sich mit der Rezeptionsgeschichte westlicher Geisteswissenschaften in China, insbesondere der Philosophie Eugen Finks