Microhabitat preference of sympatric Hydraena Kugelann, 1794 species (Coleoptera: Hydraenidae) in a low-order forest stream

Aim of this study was to investigate the presence and distribution of Hydraenidae in relation to selected abiotic parameters in a single, uniform riffle of the Caramagna Stream (northwestern Italy). Six species belonging to the genus of Hydraena Kugelann, 1794 were found (H. andreinii D'Orchymont, 1934, H. subimpressa Rey, 1885, H. assimilis Rey, 1885, H. heterogyna Bedel, 1898, H. truncata Rey, 1884 and H. devillei Ganglbauer, 1901), with evident niche preferences. Our study provided interesting information about ecological requirements of minute moss beetles at small-scale and evidenced that maintaining elevate habitat diversity is essential to preserve high species abundance at local scale.     

Novel dye for detection of callus embryo by confocal laser scanning fluorescence microscopy

In the present study a new luminescent dye 3‐N‐(2‐pyrrolidinylacetamido)benzanthrone (AZR) was synthesized. Spectroscopic measurements of the novel benzanthrone 3‐aminoderivative were performed in seven organic solvents showing strong fluorescence. The capability of the prepared dye for visualization has been tested on flax, red clover and alfalfa to determinate the embryo in plant callus tissue cultures. Callus cells were stained with AZR and further analysed utilizing confocal laser scanning fluorescence microscopy. Performed experiments show high visualization effectiveness of newly synthesized fluorescent dye AZR that is efficient in fast and relatively inexpensive diagnostics of callus embryos that are problematic due to in vitro culture specificity.     

Identifying molecularly defined antigens for a Histoplasma capsulatum-specific interferon gamma release assay

BackgroundIn a previous work we showed the feasibility of an interferon gamma release assay (IGRA) for detecting latent infection by Histoplasma capsulatum. While in that proof-of-concept study we used crude fungal extracts as antigens, the newest IGRAs developed for other infections are based on molecularly defined antigens, mostly on mixtures of immunogenic peptides.AimsTo identify proteins in H. capsulatum that might serve as molecularly defined antigens for an IGRA test.MethodsWe surveyed the literature looking for known H. capsulatum-immunogenic proteins and assayed two of them as antigens in an IGRA test, in a study that involved 80 volunteers. Furthermore, we used several bioinformatics tools to identify specific H. capsulatum proteins and to analyze possible strategies for the design of H. capsulatum-specific immunogenic peptides.ResultsSeven H. capsulatum-immunogenic proteins were retrieved from the literature. IGRA tests using either the heat shock protein 60 or the M antigen showed high sensitivities but low specificities, most likely due to the high sequence similarity with the corresponding orthologs in other pathogenic microorganisms. We identified around 2000 H. capsulatum-specific proteins, most of which remain unannotated. Class II T-cell epitope predictions for a small number of these proteins showed a great variability among different alleles, prompting for a “brute force” approach for peptide design.ConclusionsThe H. capsulatum genome encodes a large number of distinctive proteins, which represent a valuable source of potential specific antigens for an IGRA test. Among them, the Cfp4 protein stands out as a very attractive candidate.     

Allelopathic effects of volatile organic compounds released from Pinus halepensis needles and roots

The Mediterranean region is recognized as a global biodiversity hotspot. However, over the last decades, the cessation of traditional farming in the north part of the Mediterranean basin has given way to strong afforestation leading to occurrence of abandoned agricultural lands colonized by pioneer expansionist species like Pinus halepensis. This pine species is known to synthesize a wide range of secondary metabolites, and previous studies have demonstrated strong allelopathic potentialities of its needle and root leachates. Pinus halepensis is also recognized to release significant amounts of volatile organic compounds (VOC) with potential allelopathic effects that have never been investigated. In this context, the objectives of the present study were to improve our knowledge about the VOC released from P. halepensis needles and roots, determine if these VOC affect the seed germination and root growth of two herbaceous target species (Lactuca sativa and Linum strictum), and evaluate if soil microorganisms modulate the potential allelopathic effects of these VOC. Thirty terpenes were detected from both, needle and root emissions with β‐caryophyllene as the major volatile. Numerous terpenes, such as β‐caryophyllene, δ‐terpinene, or α‐pinene, showed higher headspace concentrations according to the gradient green needles < senescent needles < needle litter. Seed germination and root growth of the two target species were mainly reduced in presence of P. halepensis VOC. In strong contrast with the trend reported with needle leachates in literature, we observed an increasing inhibitory effect of P. halepensis VOC with the progress of needle physiological stages (i.e., green needle < senescent needle < needle litter). Surprisingly, several inhibitory effects observed on filter paper were also found or even amplified when natural soil was used as a substrate, highlighting that soil microorganisms do not necessarily limit the negative effects of VOC released by P. halepensis on herbaceous target species.     

Proximodistal Organization of the CA2 Hippocampal Area

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A Cross-Species Analysis Reveals a General Role for Piezo2 in Mechanosensory Specialization of Trigeminal Ganglia from Tactile Specialist Birds

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The Drosophila RNA-binding protein ELAV is required for commissural axon midline crossing via control of commissureless mRNA expression in neurons

Drosophila ELAV is the founding member of an evolutionarily conserved family of RNA-binding proteins considered as key inducers of neuronal differentiation. Although several ELAV-specific targets have been identified, little is known about the role of elav during neural development. Here, we report a detailed characterization of the elav mutant commissural phenotype. The reduced number of commissures in elav mutant embryos is not due to loss or misspecification of neural cells but results from defects in commissural axon projections across the midline. We establish a causal relationship between the elav mutant commissural phenotype and a reduction in the expression of commissureless, a key component of the Robo/Slit growth cone repulsive signalling pathway. In the nerve cord of elav mutant embryos, comm mRNA expression is strongly reduced in neurons, but not in midline glial cells. Furthermore, specific expression of an elav transgene in posterior neurons of each segment of an elav mutant nerve cord restores comm mRNA expression in these cells, as well as the formation of posterior commissures. Finally, forced expression of comm in specific commissural neuron subsets rescues the midline crossing defects of these neurons in elav mutant embryos, further indicating that elav acts cell autonomously on comm expression.     

Translation regulation after taxol treatment in NIH3T3 cells involves the elongation factor (eEF)2

Changes to the translational machinery that occur during apoptosis have been described in the last few years. The two principal ways in which translational factors are modified during apoptosis are: (i) changes in protein phosphorylation and (ii) specific proteolytic cleavages. Taxol, a member of a new class of anti-tubulin drugs, is currently used in chemotherapeutic treatments of different types of cancers. We have previously demonstrated that taxol induces calpain-mediated apoptosis in NIH3T3 cells [Pi?eiro et al., Exp. Cell Res., 2007, 313:369-379]. In this study we found that translation was significantly inhibited during taxol-induced apoptosis in these cells. We have studied the phosphorylation status and expression levels of eIF2a, eIF4E, eIF4G and the regulatory protein 4E-BP1, all of which are implicated in translation regulation. We found that taxol treatment did not induce changes in eIF2alpha phosphorylation, but strongly decreased eIF4G, eIF4E and 4E-BP1 expression levels. MDL28170, a specific inhibitor of calpain, prevented reduction of eIF4G, but not of eIF4E or 4E-BP1 levels. Moreover, the calpain inhibitor did not block taxol-induced translation inhibition. All together these findings demonstrated that none of these factors are responsible for the taxol-induced protein synthesis inhibition. On the contrary, taxol treatment increased elongation factor eEF2 phosphorylation in a calpain-independent manner, supporting a role for eEF2 in taxol-induced translation inhibition.