Development of microsatellite markers and evaluation of genetic diversity of the Amazonian ornamental fish Pterophyllum scalare

The objective of the present work was to develop species-specific microsatellite markers for P. scalare and to analyze the diversity and genetic structure of a wild population, from the Amazon River, and three commercial stocks (common, marble, and clown morphological variants), from farmers in Vieras-Minas Gerais. Through microsatellite-enriched genetic libraries, 11 microsatellite markers with adequate amplification patterns were characterized. Population genetic analysis identified eight polymorphic loci that generated 66 alleles ranging from two alleles (PSCA1B3) to nine (PSCA2H1). The polymorphic information content ranged from 0.031 to 0.827. High genetic differentiation was observed between the wild population and the stocks, and moderate differentiation between the three stocks. Deviation in the Hardy-Weinberg equilibrium was observed in one locus in the wild population, in five loci in the common morphological variant, in two in the marble, and in two in the clown morphological variant. Bayesian analysis of genetic structure revealed the existence of two clusters, one represented by the natural population and the other by the stocks. The developed microsatellite markers serve as a tool for the analysis of diversity and genetic structure and conservation studies of P. scalare.

     

Effects of municipal solid waste compost,farmyard manure and chemical fertilizers on wheat growth,soil composition and soil bacterial characteristics under Tunisian arid climate

The use of municipal solid waste compost (MSWC) as soil organic amendment is of an economic and environmental interest. However, little is known about the effectiveness of MSWC application on agricultural soil in northern Africa arid climate. We assessed the impact of five years' applications of different organic and mineral fertilizers on wheat grain yields and soil chemical and microbial characteristics. Soils were treated with MSWC at rates of 40 (C1) and 80 (C2) Mg ha^?1, farmyard manure at a rate of 40 Mg ha^?1 (M), chemical fertilizers (Cf) and the combinations (C1Cf, C2Cf, MCf). Wheat grain yield was enhanced with all amendments. Parallel increases of heavy metal levels and faecal coliform were also recorded except for Cf treatments. Based on wheat grain yield, heavy metal and faecal coliform data, we determined the treatment effectiveness index (E_xx), calculated by dividing the pollutant increase ratio by the grain yield increase ratio. The treatment effectiveness index E_C1 indicated lower faecal and heavy metal pollution with positive gains in wheat yields. Despite polluting effects on soil determined by the different treatments, no significant differences between treatments were observed in total bacterial count and soil bacterial community structure, as shown by 16S rRNA gene PCR-denaturing gradient gel electrophoresis banding patterns and 16S rRNA gene Length Heterogeneity-PCR analysis. According to the collected data, the use of MSWC at a rate of 40 Mg ha^?1 might be recommended.     

Testing the equi-resistance principle of the xylem transport system in a small ash tree: empirical support from anatomical analyses

In plants, water flows from roots to leaves through a complex network of xylem conduits. The xylem architecture is characterized by the conduit enlargement towards the stem base and the multiplication of conduits near the apices of lateral branches. The xylem architecture of a small ash tree was analysed by measuring the vessel hydraulic diameter (Dh) and number (N) at different heights along the stem and branches. Along the stem, Dh and N increased from the apex to the point of crown insertion. Below, Dh and N decreased and remained constant, respectively. In branches, the Dh and N of apices increased with distance from the ground (PL) (P < 0.001 and P < 0.0001, respectively), indicating that apical resistance (R(APEX)) becomes lower in the most peripheral branches (P < 0.0001). At the level of branch nodes along the stem, the total conductive area (AC) of the stem and branches just above the node was 11% higher than that of the stem just below the node (P = 0.024), whereas the conductivity (Kh) remained invariant above and below (P = 0.76). The difference in AC (ΔAC) between the branches and stem above each node increased with the distance of the node position from the stem apex (L). The xylem architecture of the analysed tree was characterized by anatomical modifications likely aimed at equilibrating the different path length effects on the hydraulic resistance of the different branches. Conduit tapering and multiplication seem to play a crucial role for the achievement of equal hydraulic resistance of all the leaves in the crown.     

Changes in fertilization medium viscosity using hyaluronic acid impact bull sperm motility and acrosome status

The female reproductive tract, in particular the composition of the uterine and oviduct fluids, is responsible, at least in part, for triggering sperm cell modifications, essential for the acquisition of fertilization ability. Hyaluronic acid (HA) is a glycosaminoglycan present in these fluids, and its role in the fertilization process and sperm functionality is still barely understood. This work was designed to (a) determine the rheological characteristics of the fertilization medium by the addition of HA and (b) determine the HA influence on sperm motility and functional status. To that end, the in vitro fertilization medium was supplemented with 4 doses of HA (6, 60, 600 and 6,000 µg/ml) and analysed for viscosity and adhesion strength characteristics. Then, thawed semen from 6 bulls were incubated in these media and assessed at 4 different moments for morphological and functional parameters (plasma and acrosomal membrane integrities, mitochondrial membrane potential, capacitation, acrosomal reaction, and motility). The rheological evaluation showed that the addition of HA was able to increase both the viscosity and the adhesion strength of the fertilization medium, especially in the 6,000 µg/ml group in which the effect was more pronounced. No influence of HA could be observed on mitochondrial potential, and acrosomal and plasma membrane integrities. However, HA supplementation, at lower doses, led to an increase in the number of reacted sperm, as well as changes in motility parameters, with increase in the number of motile, rapid and progressive spermatozoa. In conclusion, the addition of HA alters the rheological properties of the fertilization medium and leads to the improvement of the properties related to sperm motility and capacitation, without compromising other functional aspects of the cell.     

Application of the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation assay to a flow injection system for the evaluation of antioxidant activity of some pure compounds and beverages

The 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(*)(+)) assay was adapted to a flow injection (FI) system to obtain a sensitive and rapid technique for the monitoring of antioxidant activity of pure compounds and complex matrixes, such as beverages and food extracts. The FI system includes a HPLC pump that flows the mobile phase (a solution of ABTS(*)(+) in ethanol) through a 20 microL loop injector, a single bead string reactor filled with acid-washed silanized beads, a delay coil and a photodiode array UV-visible detector. The technique was very sensitive, with limits of detection and of quantification of 4.14 and 9.29 micromol of Trolox/L, respectively, and demonstrated high repeatability and reproducibility. The proposed technique was then applied to the evaluation of the antioxidant activity of some pure compounds, demonstrating good agreement with published data obtained by the original spectrophotometric ABTS(*)(+) assay. Finally, the total antioxidant activity of 10 beverages was determined by both the proposed and the original method. The values ranged from 0.09 mmol L(-)(1) for cola to 49.24 mmol L(-)(1) for espresso coffee and did not result significantly different from those obtained by the original spectrophotometric ABTS(*)(+) assay (Student's paired t-test: t = 1.4074, p = 0.1929). In conclusion, the proposed FI technique seems suitable for the direct, rapid and reliable monitoring of total antioxidant activity of pure compounds and beverages and, due to the ability to operate in continuous, it allows the analysis of about 30 samples h(-)(1) making the assay particularly suitable for large screening of total antioxidant activity in food samples.     

Draft genome sequence of the sexually transmitted pathogen Trichomonas vaginalis

We describe the genome sequence of the protist Trichomonas vaginalis, a sexually transmitted human pathogen. Repeats and transposable elements comprise about two-thirds of the approximately 160-megabase genome, reflecting a recent massive expansion of genetic material. This expansion, in conjunction with the shaping of metabolic pathways that likely transpired through lateral gene transfer from bacteria, and amplification of specific gene families implicated in pathogenesis and phagocytosis of host proteins may exemplify adaptations of the parasite during its transition to a urogenital environment. The genome sequence predicts previously unknown functions for the hydrogenosome, which support a common evolutionary origin of this unusual organelle with mitochondria.     

The enigma of prokaryotic life in deep hypersaline anoxic basins

Deep hypersaline anoxic basins in the Mediterranean Sea are a legacy of dissolution of ancient subterranean salt deposits from the Miocene period. Our study revealed that these hypersaline basins are not biogeochemical dead ends, but support in situ sulfate reduction, methanogenesis, and heterotrophic activity. A wide diversity of prokaryotes was observed, including a new, abundant, deeply branching order within the Euryarchaeota. Furthermore, we demonstrated the presence of a unique, metabolically active microbial community in the Discovery basin, which is one of the most extreme terrestrial saline environments known, as it is almost saturated with MgCl2 (5 M).     

Immunological parameters in goats experimentally infected with SRLV genotype E, strain Roccaverano

Genotype E of small ruminant lentivirus has been recently described in goats from different breeds in Italy. Genotype E infection may differ from known genotypes since deletions of dUTPase and VPR proteins have been confirmed in different independent areas and goat breed, and play a key role on virus replication and pathogenesis. In particular, genotype E Roccaverano strain has been described as low pathogenic since does not lead to clinical symptoms in goats. In contrast, classical CAEV infected goats of the same area and breed presented arthritis. In this study, we have used intratracheal and intra-bone marrow routes to establish genotype E persistent infections. Humoral and cellular immune responses elicited in the host against genotype E and genotype B derived antigens were evaluated until 200 days post-inoculation. Compared to genotype B antigen, seroconversion against genotype E GAG P16-25 antigen was detected at 2-3 weeks after inoculation, significantly earlier and at higher titres. Interestingly, antibody avidity did not increase in the course of the experiment neither against P16-25 nor against SU5, both derived from genotype E. T cell proliferation against P25-GST fusion protein antigens derived from genotype E was firstly detected at 15 days post-inoculation and was maintained throughout time until week 20 post-infection, while T cell proliferation against the genotype B P25 was not produced by the end of the experiment at 20 weeks post-inoculation. The strength of reaction was also higher when using P25 E as stimulator antigen. In contrast with antibody and T cell proliferation, cytotoxic-T-lymphocyte (CTL) activity in the circulating lymphocytes (effector cells) using blood-derived macrophages (BDM) as target cells, was not strain specific being surprisingly higher against genotype B infected antigen presenting cells (APCs). This is the first study reporting experimentally induced immunological changes in SRLV genotype E infection and indicates that CTL activity may be the adaptive immune response able to induce protection against heterologous infection.     

A comparative study on the interference of two herbicides in wheat and italian ryegrass and on their antioxidant activities and detoxification rates

A study was carried out to compare the effects of treating wheat (Triticum aestivum) and Italian ryegrass (Lolium multiflorum) with atrazine and fluorodifen. The herbicides interfered with photosynthesis and dark respiration, depending on the species. Atrazine decreased photosynthesis in both species and dark respiration in wheat, while fluorodifen caused decrements of photosynthetic activity of wheat. Antioxidant enzymes, such as ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), and glutathione reductase (GR), were generally more active in untreated and treated wheat with respect to Italian ryegrass, which explains why oxidative damage, expressed as malondialdehyde (MDA) content, was only found in ryegrass. Investigations on the activity of herbicide-detoxifying enzyme, glutathione S-transferase (GST), and on the accumulation and persistence of the herbicides in the plants showed higher detoxification rates in wheat than in the grass.     

Polyphenolic composition of hazelnut skin

Skins from different hazelnut samples were characterized for total polyphenol content, total antioxidant capacity (TAC), and their content in specific polyphenolic compounds. The main polyphenolic subclass, identified and quantified by means of HPLC-MS/MS, comprised monomeric and oligomeric flavan-3-ols, which accounted for more than 95% of total polyphenols. Flavonols and dihydrochalcones were 3.5% while phenolic acids were less than 1% of the total identified phenolics. The TAC values of the skin samples ranged between 0.6 and 2.2 mol of reduced iron/kg of sample, which is about 3 times the TAC of whole walnuts, 7-8 times that of dark chocolate, 10 times that of espresso coffee, and 25 times that of blackberries. By describing the profile of polyphenols present in hazelnut skins, this study provides the basis to further investigate the potential health effects of hazelnut byproduct.