EST-based identification of genes expressed in the liver of adult seabass (Dicentrarchus labrax, L.)

The scarcity of the genomic resources for some fish species, in spite of their commercial interest, could retard the positive effects that modern biotechnology can offer to aquaculture industry. Then an effort should be made to reduce, as far as it concerns genomic resources, the gap that separates farming species from "model organisms". In this paper, we present an EST project in which we performed single pass sequencing on 1229 randomly selected clones from a sea bass cDNA library. The sequences are deposited in the NCBI database with the following accession numbers: from , from , from and from . EST cataloguing and profiling of seabass will set the basis for functional genomic research in this species, but will also serve for comparative and environmental genomics, for the identification of polymorphic markers useful, for example, to survey the disease resistance of fish, for the discovery of new molecular markers of exposure and for the production of micro- and macro-arrays.     

Protective effect of Hypericum calabricum Sprengel on oxidative damage and its inhibition of nitric oxide in lipopolysaccharide-stimulated RAW 264.7 macrophages

The present study shows for the first time the phenolic composition and the in vitro properties (antioxidant and inhibition of nitric oxide production) of Hypericum calabricum Sprengel collected in Italy. The content of hypericins (hypericin and pseudohypericin), hyperforin, flavonoids (rutin, hyperoside, isoquercetrin, quercitrin, quercetin and biapigenin) and chlorogenic acid of H. calabricum, have been determined. The ethyl acetate fraction from the aerial parts of H. calabricum exhibited activity against the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC50 value of 1.6 jig/ml. The test for inhibition of nitric oxide (NO) production was performed using the murine monocytic macrophage cell line RAW 264.7. The ethyl acetate fraction had significant activity with an IC50 value of 102 jig/ml and this might indicate that it would have an anti-inflammatory effect in vivo.     

Implicit, predictive timing draws upon the same scalar representation of time as explicit timing

It is not yet known whether the scalar properties of explicit timing are also displayed by more implicit, predictive forms of timing. We investigated whether performance in both explicit and predictive timing tasks conformed to the two psychophysical properties of scalar timing: the Psychophysical law and Weber's law. Our explicit temporal generalization task required overt estimation of the duration of an empty interval bounded by visual markers, whereas our temporal expectancy task presented visual stimuli at temporally predictable intervals, which facilitated motor preparation thus speeding target detection. The Psychophysical Law and Weber's Law were modeled, respectively, by (1) the functional dependence between mean subjective time and real time (2) the linearity of the relationship between timing variability and duration. Results showed that performance for predictive, as well as explicit, timing conformed to both psychophysical properties of interval timing. Both tasks showed the same linear relationship between subjective and real time, demonstrating that the same representational mechanism is engaged whether it is transferred into an overt estimate of duration or used to optimise sensorimotor behavior. Moreover, variability increased with increasing duration during both tasks, consistent with a scalar representation of time in both predictive and explicit timing. However, timing variability was greater during predictive timing, at least for durations greater than 200 msec, and ascribable to temporal, rather than non-temporal, mechanisms engaged by the task. These results suggest that although the same internal representation of time was used in both tasks, its external manifestation varied as a function of temporal task goals.     

Protein immobilization strategies for protein biochips

In the past few years, protein biochips have emerged as promising proteomic and diagnostic tools for obtaining information about protein functions and interactions. Important technological innovations have been made. However, considerable development is still required, especially regarding protein immobilization, in order to fully realize the potential of protein biochips. In fact, protein immobilization is the key to the success of microarray technology. Proteins need to be immobilized onto surfaces with high density in order to allow the usage of small amount of sample solution. Nonspecific protein adsorption needs to be avoided or at least minimized in order to improve detection performances. Moreover, full retention of protein conformation and activity is a challenging task to be accomplished. Although a large number of review papers on protein biochips have been published in recent years, few have focused on protein immobilization technology. In this review, current protein immobilization strategies, including physical, covalent, and bioaffinity immobilization for the fabrication of protein biochips, are described. Particular consideration has been given to oriented immobilization, also referred to as site-specific immobilization, which is believed will improve homogeneous surface covering and accessibility of the active site.     

Characterization of two Arabidopsis thaliana glutathione S-transferases

Glutathione S-transferases (GST) are multifunctional proteins encoded by a large gene family, divided on the basis of sequence identity into phi, tau, theta, zeta and lambda classes. The phi and tau classes are present only in plants. GSTs appear to be ubiquitous in plants and are involved in herbicide detoxification and stress response, but little is known about the precise role of GSTs in normal plant physiology and during biotic and abiotic stress response. Two cDNAs representing the two plant classes tau and phi, AtGSTF9 and AtGSTU26, were expressed in vitro and the corresponding proteins were analysed. Both GSTs were able to catalyse a glutathione conjugation to 1-chloro-2,4-dinitrobenzene (CDNB), but they were inactive as transferases towards p-nitrobenzylchloride (pNBC). AtGSTF9 showed activity towards benzyl isothiocyanate (BITC) and an activity as glutathione peroxidase with cumene hydroperoxide (CumHPO). AtGSTU26 was not active as glutathione peroxidase and towards BITC. RT-PCR analysis was used to evaluate the expression of the two genes in response to treatment with herbicides and safeners, chemicals, low and high temperature. Our results reveal that AtGSTU26 is induced by the chloroacetanilide herbicides alachlor and metolachlor and the safener benoxacor, and after exposure to low temperatures. In contrast, AtGSTF9 seems not to be influenced by the treatments employed.     

Different effects of SNP and GSNO on mitochondrial O<Stack><Subscript>2</Subscript><Superscript>.−</Superscript></Stack>/H<Subscript>2</Subscript>O<Subscript>2</Subscript> production

Sodium Nitroprusside (SNP) and S-Nitrosoglutathione (GSNO) differently affect mitochondrial H₂O₂ release at Complex-I. mM SNP increases while GSNO decreases the release induced by succinate alone or added on top of NAD-linked substrates. Stimulation likely depends on Nitric Oxide ( ^. NO) (released by SNP but not by GSNO) inhibiting cytochrome oxidase and mitochondrial respiration. Preincubations with SNP or high GSNO (10 mM plus DTE to increases its ^. NO release) induces an inhibition of the succinate dependent H₂O₂ production consistent with a ^. NO dependent covalent modification. However maximal inhibition of the succinate dependent H₂O₂ release is obtained in the presence of low GSNO (20–100 μM), but not with SNP. This inhibition appears independent of ^. NO release since μM GSNO does not affect mitochondrial respiration, or the H₂O₂ detection systems and its effect is very rapid. Inhibition may be partly due to an increased removal of O₂^.− since GSNO chemically competes with NBT and cytochrome C in O₂^.− detection.     

Longevity mutation in SCH9 prevents recombination errors and premature genomic instability in a Werner/Bloom model system

Werner and Bloom syndromes are human diseases characterized by premature age-related defects including elevated cancer incidence. Using a novel Saccharomyces cerevisiae model system for aging and cancer, we show that cells lacking the RecQ helicase SGS1 (WRN and BLM homologue) undergo premature age-related changes, including reduced life span under stress and calorie restriction (CR), G1 arrest defects, dedifferentiation, elevated recombination errors, and age-dependent increase in DNA mutations. Lack of SGS1 results in a 110-fold increase in gross chromosomal rearrangement frequency during aging of nondividing cells compared with that generated during the initial population expansion. This underscores the central role of aging in genomic instability. The deletion of SCH9 (homologous to AKT and S6K), but not CR, protects against the age-dependent defects in sgs1Δ by inhibiting error-prone recombination and preventing DNA damage and dedifferentiation. The conserved function of Akt/S6k homologues in lifespan regulation raises the possibility that modulation of the IGF-I–Akt–56K pathway can protect against premature aging syndromes in mammals.     

Wide divergence of fungal communities inhabiting rocks and soils in a hyper-arid Antarctic desert

Highly simplified microbial communities colonise rocks and soils of continental Antarctica ice-free deserts. These two habitats impose different selection pressures on organisms, yet the possible filtering effects on the diversity and composition of microbial communities have not hitherto been fully characterised. We hence compared fungal communities in rocks and soils in three localities of inner Victoria Land. We found low fungal diversity in both substrates, with a mean species richness of 28 across all samples, and significantly lower diversity in rocks than in soils. Rock and soil communities were strongly differentiated, with a multinomial species classification method identifying just three out of 328 taxa as generalists with no affinity for either substrate. Rocks were characterised by a higher abundance of lichen-forming fungi (typically Buellia, Carbonea, Pleopsidium, Lecanora, and Lecidea), possibly owing to the more protected environment and the porosity of rocks permitting photosynthetic activity. In contrast, soils were dominated by obligate yeasts (typically Naganishia and Meyerozyma), the abundances of which were correlated with edaphic factors, and the black yeast Cryomyces. Our study suggests that strong differences in selection pressures may account for the wide divergences of fungal communities in rocks and soils of inner Victoria Land.