Characterization of Saccharomyces cerevisiae dna2 Mutants Suggests a Role for the Helicase Late in S Phase

The TOR proteins, originally identified as targets of the immunosuppressant rapamycin, contain an ATM-like “lipid kinase” domain and are required for early G1 progression in eukaryotes. Using a screen to identify Saccharomyces cerevisiae mutants requiring overexpression of Tor1p for viability, we have isolated mutations in a gene we call ROT1 (requires overexpression of Tor1p). This gene is identical to DNA2, encoding a helicase required for DNA replication. As with its role in cell cycle progression, both the N-terminal and C-terminal regions, as well as the kinase domain of Tor1p, are required for rescue of dna2 mutants. Dna2 mutants are also rescued by Tor2p and show synthetic lethality with tor1 deletion mutants under specific conditions. Temperature-sensitive (Ts) dna2 mutants arrest irreversibly at G2/M in a RAD9- and MEC1-dependent manner, suggesting that Dna2p has a role in S phase. Frequencies of mitotic recombination and chromosome loss are elevated in dna2 mutants, also supporting a role for the protein in DNA synthesis. Temperature-shift experiments indicate that Dna2p functions during late S phase, although dna2 mutants are not deficient in bulk DNA synthesis. These data suggest that Dna2p is not required for replication fork progression but may be needed for a later event such as Okazaki fragment maturation.     

Spatio-temporal distribution of recruits (0 group) of Merluccius merluccius and Phycis blennoides (Pisces, Gadiformes) in the Strait of Sicily (Central Mediterranean)

Aspects of the recruitment of hake (Merluccius merluccius L., 1758) and greater fork beard (Phycis blennoides Brunnich, 1768) in the Strait of Sicily (Central Mediterranean) are presented. Data were collected from 1994 to 1999 during the international bottom trawl survey program MEDITS. In view of the available literature on juvenile growth of these two species in the Mediterranean area, a length-based criterion was adopted to separate fish belonging to the 0 group (recruits). Recruit density indices (R/km²) by haul were calculated based upon the likely variability of recruit growth among years and used to study abundance variability and spatial pattern of recruitment and to identify the main nursery areas. Although there was inter-annual variability, two stable areas for M. merluccius were identified on the eastern side of the Adventure Bank and the Malta Bank at depths ranging between 100 and 200 m. The main nursery areas for P. blennoides were deeper (from 200 to 400 m) and two stable nursery areas were identified on the western and eastern side of the Adventure Bank; other nurseries were found in the easternmost part of the Strait in 1998 and 1999. Recruitments of the two species were significantly correlated, with the strongest recruitment occurring in 1998 and 1999 for each species.     

Isolation of monoclonal antibodies specific for IL-4, IL-5, IL-6, and a new Th2-specific cytokine (IL-10), cytokine synthesis inhibitory factor, by using a solid phase radioimmunoadsorbent assay

Hybridomas were produced from a rat that was immunized with partially purified proteins from supernatants of induced Th2 cells. These preparations were enriched for cytokine synthesis inhibitory factor (CSIF, IL-10). The mAb in the supernatants were screened by a solid phase radioimmunoadsorbent assay using 35S-methionine-labeled secreted proteins from a lectin-stimulated Th2 clone. A total of 18 anticytokine mAb were isolated, comprising 6 anti-CSIF, 1 anti-IL-4, 1 anti-IL-5, and 10 anti-IL-6 mAb. The anti-CSIF mAb were separable into three groups. mAb in groups A and B neutralized and depleted bioactivity, and bound to overlapping but nonidentical subpopulations of CSIF molecules. The 2 mAb in group C did not neutralize CSIF activity, and bound to CSIF molecules not recognized by mAb from groups A or B. A two-site sandwich ELISA for CSIF could be established with the group A antibody, SXC1, combined with any of the three group B antibodies. The sensitivity of this assay was equivalent to that of the CSIF bioassay. These antibodies have been used to show that CSIF is responsible for most or all of the ability of Th2 supernatants to inhibit cytokine synthesis by Th1 cells. In addition, the ELISA has been used to confirm that CSIF is produced by Th2 but not Th1 clones.     

Biology of red mullet,Mullus barbatus (L. 1758), in the Gulf of Castellammare (NW Sicily,Mediterranean Sea) subject to a trawling ban

Under‐or non‐exploited areas are useful to aid in evaluating the potential productivity of fish stocks for sustainable fisheries. The Gulf of Castellammare (NW Sicily), where trawling has been banned since 1990, is a good site to study the biology and dynamics of low impacted fish populations. A total of 661 (595 female and 66 male) specimens of red mullet Mullus barbatus (95–245 mm total length, TL) obtained by monthly sampling from trammel net artisanal fishery, was collected in the Gulf of Castellammare from April 2006 to June 2007. Mature females occurred from April to September, with a peak in May. The mean Gonado‐somatic index (GSI) also showed a May peak for both sexes. From Sagittae (642) readings the age structure ranged from age class I to VII in females and I to V in males. Female growth parameters, estimated according to the classic von Bertalanffy model, were: L_∞ = 221.2 ± 11.51 mm standard error (SE), k_y^?1 = 0.38 ± 0.09 SE, t₀y = ?0.94 ± 0.38 SE. The growth performance index (ø’ = 2.27) was included in the range of values obtained by hard structure readings in the Central Mediterranean. Natural mortality (M_y^?1) of females estimated by different methods ranged between 0.62 and 0.87 (mean value = 0.71 ± 0.06 SE).     

In vitro saprotrophic basidiomycetes tolerance to pendimethalin

Pendimethalin is a dinitroaniline herbicide classified among the persistent-bioaccumulative toxics. In this paper, the tolerance to this herbicide has been studied in isolates of basidiomycetes (10 species including 9 wood-rotting and 1 litter fungi), collected in different areas of the Campania region (South Italy). The isolates were grown on two different agar media, rich and poor for the presence/absence of dextrose and NH₄NO₃, and amended with 0, 100 and 500 ppm herbicide. The mycelial growth was recorded daily, and statistical analysis of fungal growth rates, determined via linear regression, allowed us to compare the hyphal extension of various macrofungi in presence of herbicide. These data represent the adaptation capacity of the fungal organisms to the peculiar environmental situation. In amended agar, all fungi exhibited a certain tolerance to pendimethalin and, normally, the fungal growth decreased with the increasing of pollutant concentration. Nevertheless, in some cases, the difference of ground reflected the different agar media. In fact, the growth of Agrocybe aegerita, in rich agar decreased with the increase of herbicide dose, while in poor agar it increased with the pollutant. Among the examined fungi, A. aegerita was the species which resulted the most tolerant to herbicide, showing growth to about 70% of the control to the highest concentrations of pollutant and for the two different agar media.Scientific relevance of the paperNo published report is available regarding pendimethalin herbicide biodegradation with basidiomycetes; therefore this work represented the first and preliminary investigation as regards. It's directed to determine the fungal tolerance to the pollutant.     

Antioxidant efficacy of iridoid and phenylethanoid glycosides from the medicinal plant Teucrium chamaedris in cell-free systems

Twelve glycosides, seven iridoids and five phenylethanoids, have been isolated from leaf and root methanolic extracts of Wall Germander (Teucrium chamaedrys), a Mediterranean species historically used as a medicinal plant. Among them, three iridoid and one phenylethanoid glycosides have been isolated and characterized for the first time. All of the structures have been elucidated on the basis of their spectral data, especially 1D and 2D NMR experiments.The antioxidative properties of pure metabolites, as well as of crude organic extracts of the plant, have been analyzed on the basis of their DPPH radical scavenging capability. The antioxidant capacity in cell-free systems of the isolated metabolites was carried out by measuring their capabilities to inhibit the synthesis of thiobarbituric acid reactive species in assay media using as oxidable substrates a vegetable fat and the pentose sugar 2-deoxyribose and to prevent oxidative damage of the hydrosoluble bovine serum albumin (BSA) protein. Phenylethanoid glycosides resulted efficacious DPPH radical, while iridoid glycosides prevent massively the 2-deoxyribose and BSA oxidations in assay media.