Characterization of proteome alterations in <Emphasis Type=Italic>Phanerochaete chrysosporium</Emphasis> in response to lead exposure

Background  

Total soluble proteome alterations of white rot fungus Phanerochaete chrysosporium in response to different doses (25, 50 and 100 μM) of Pb (II) were characterized by 2DE in combination with MALDI-TOF-MS.     

Linked activation of cell division and oxidative stress defense in alfalfa leaf protoplast-derived cells is dependent on exogenous auxin

The activation of cell division and oxidative stress responses has been investigated in the case of leaf protoplast-derived cells. Initiation of protoplast culture was found to be associated with oxidative stress as indicated by the rate of H₂O₂ release into the medium and/or by catalase and ascorbate peroxidase activities. Both cell division frequency and the above stress-related parameters were dependent on the exogenous auxin (2,4-dichlorophenoxyacetic acid, 2,4-D) concentrations used. In addition, the well known oxidative stress-inducing agent paraquat (1 μM) could promote cell division at suboptimal auxin concentration but not in the absence of exogenous auxin. The H₂O₂ scavenger dimethylthiourea and the NADPH oxidase inhibitor diphenyleneiodonium inhibited not only the activation of cellular defense reactions but cell division as well. Based on the above experimental observations, it is suggested that exogenous auxin (2,4-D) enhances cellular defense reactions in parallel with cell division activation.     

A computational screen for site selective A-to-I editing detects novel sites in neuron specific Hu proteins

Background  

Several bioinformatic approaches have previously been used to find novel sites of ADAR mediated A-to-I RNA editing in human. These studies have discovered thousands of genes that are hyper-edited in their non-coding intronic regions, especially in alu retrotransposable elements, but very few substrates that are site-selectively edited in coding regions. Known RNA edited substrates suggest, however, that site selective A-to-I editing is particularly important for normal brain development in mammals.     

<Emphasis Type=Italic>Sperchon (Scutosperchon) akdagensis</Emphasis> sp. n. (Acari: Hydrachnidia: Sperchontidae) from Turkey

The structural characteristics, unique features, various organ measurements of males and females of the Sperchon (Scutosperchon) akdagensis sp. n. water mite from Turkey are described. In addition, morphological characteristics of the new species are compared with related species.     

Morphological,anatomical and cytological investigation on endemic <Emphasis Type="Italic">Lamium moschatum</Emphasis> var. <Emphasis Type="Italic">rhodium</Emphasis>

In this study, the morphological and anatomical features of endemic Lamium moschatum Miller var. rhodium (Gand.) R. Mill (Lamiaceae) are described in detail. Lamium moschatum var. rhodium has an annual taproot. The stem is erect and clearly quadrangular. The leaves are broadly ovate to cordate-ovate or nearly suborbicular in shape. Inflorescense is verticillate cyme. The corolla is white and the tube is curved and bears an annulus inside, near the base. Cross-sections of the root, stem, petiole, leaf, calyx, corolla and generative organs were examined and the anatomical features of the taxon are discussed. Furthermore, glandular hairs distributed on the plant taxon are shown. In karyological research, chromosome numbers were determined as 2n = 18. The results are presented with photographs and tables.     

Evaluation of the cytogenetic damage induced by the organophosphorous insecticide acephate

The organophosphorous insecticide acephate was tested for its ability to induce in vitro cytogenetic effect in human peripheral lymphocytes by using the chromosomal aberrations (CAs), sister chromatid exchange (SCE) and micronuclei (MN) assay. The level of nuclear DNA damage of acephate was evaluated by using the comet assay. Concentrations of 12.5, 25, 50, 100 and 200 μg mL⁻¹ of acephate were used. All concentrations of acephate induced significant increase in the frequency of CAs and in the formation of MN dose dependently (r = 0.92 at 24 h, r = 0.95 at 48 h for CAs, r = 0.87 for MN). A significant increase was observed in induction of SCE at 50, 100 and 200 μg mL⁻¹ concentrations during 24 h treatment and at all concentrations (except 12.5 μg mL⁻¹) during 48 h treatment period in a dose-dependent manner (r = 0.84 at 24 h, r = 0.88 at 48 h). Acephate did not affect the replicative index and cytokinesis-block proliferation index (CBPI). However, it significantly decreased the mitotic index at all three highest concentrations (50, 100, 200 μg mL⁻¹) for 24 h treatment and at all concentrations (except 12.5 μg mL⁻¹) for 48 h treatment, dose-dependently (r = 0.94 at 24 h, r = 0.92 at 48 h). A significant increase in mean comet tail length was observed at 100 and 200 μg mL⁻¹ concentrations compared with negative control in a concentration-dependent manner (r = 0.94). The mean comet tail intensity was significantly increased at only 200 μg mL⁻¹ concentration. The present results indicate that acephate is a clastogenic, cytotoxic agent and it causes DNA damage at high concentrations in human lymphocytes in culture.     

Comparative analysis of the effects of chitosan and common plant growth regulators on <Emphasis Type="Italic">in vitro</Emphasis> propagation of <Emphasis Type="Italic">Ipomoea purpurea</Emphasis> (L.) Roth from nodal explants

This study aimed to evaluate the effects of partially N-acetylated chitosans with a degree of acetylation (DA) of 10% on in vitro propagation of an ornamental plant, Ipomoea purpurea, by emphasizing the importance of the degree of polymerization (DP) on in vitro plant development. The effects of either a chitosan oligomer mixture with a DP between 2 and 15 (5.0, 10.0, and 20.0 mg L^?1) or chitosan polymer with a DP of 70 were compared with commonly used cytokinins [6-benzylaminopurine (BAP) and kinetin (KIN) at 0.5, 1.0, 2.0, and 4.0 mg L^?1] and auxins [indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) at 0.25, 0.5, 1.0, and 2.0 mg L^?1]. The nodal explants used in this study were taken from donor plants obtained by germination of the seeds. The results indicated that all chitosan treatments had positive effects on the shoot induction, but only the oligomer mixture at 5 mg L^?1 gave the best results for mean shoot number, shoot length, and leaf number, compared to the other treatments and control. Also, all chitosan treatments increased mean number of roots and triggered adventitious root induction. However, root elongation was decreased in the presence of chitosan in the medium. The root elongation-inhibitory effects of chitosan become clearer in the presence of oligomer mixture. In general, chitosan had similar effects with tested cytokinins rather than auxins. The results of this study suggested that the application of chitosan oligomers—rather than polymers—can be an eco-friendly and effective alternative to synthetic cytokinins in horticulture.     

Investigation of Ternary Complex Formations of Polyacrylic Acid with Bovine Serum Albumin in the Presence of Metal Ions by Fluorescence and Dynamic Light Scattering Measurements

In this paper, the complex formation of bovine serum albumin (BSA) and polyacrylic acid (PAA) in the presence metal ions at pH = 7 has been examined by using fluorescence and dynamic light scattering measurements. It has been observed that the most stable complexes of polyacrylic acid and bovine serum albumin have occurred in the presence of copper(II) ions. The other ions have the ability to form weak complexes between polyions and bovine serum albumin. To prior characterizing the interaction between bovine serum albumin and polyacrylic acid, the dynamic light scattering technique have been applied to determine the intensity-size distributions of the solutions of bovine serum albumin, polyacrylic acid, and ternary mixtures containing various molar ratios of bovine serum albumin to polyacrylic acid (the molar ratios of bovine serum albumin to polyacrylic acid has been taken equal to 0.5, 1.0, 1.5, 2.0 and 2.5) prepared at different molar ratios of copper(II) ions/acrylic acid unit. When the molar ratio of copper(II) ions to acrylic acid in the ternary mixtures has been lower than and equals to 0.3, two peaks have been observed in the curves of the intensity-size distributions due to contents of free bovine serum albumin and ternary complexes of polyacrylic acid-copper(II)-bovine serum albumin whereas when the molar ratio of copper(II) ions to acrylic acid equals to 0.4, the hydrodynamic diameter has pointed out only one peak. This result indicates that soluble and stable ternary complexes has occurred when the molar ratio of copper(II) ions to acrylic acid has been taken equal to 0.4.     

Identification of <Emphasis Type="Italic">Lactobacillus</Emphasis> strains from breast-fed infant and investigation of their cholesterol-reducing effects

Hypercholesterolemia has been reported to be the main cause of cardiovascular diseases and the leading cause of death. Therefore, decreasing serum cholesterol level is very important for preventing the cardiovascular diseases. It has been supposed that probiotics in human gastrointestinal tract have the ability to decrease serum cholesterol level by reducing the absorption of cholesterol from the intestinal tract and the bile salt deconjugation. In this study, 28 strains of Lactobacillus spp., isolated from breast-fed infant’s feces, were identified and investigated for their bile salt deconjugation ability. The deconjugation ability of the strains was determined by the release of cholic acid resulting from the deconjugation of conjugated bile salts. Research results showed that four of the strains had bile salt deconjugation ability. The strains with deconjugation ability have been identified in species level by using biochemical test, and molecular techniques, API 50CHL test and 16S rRNA gene sequence analysis respectively. LP1, E3, and E9 strains with deconjugation activity were identified as Lactobacillus rhamnosus and GD2 strain as Lactobacillus plantarum. Even if oxgall decreases the viability of bacteria, the highest amount of cholesterol precipitation (42%) was performed by GD2 strain in the presence of 0.3% (w/v) bile. This study demonstrated that the identified Lactobacillus strains had an excellent ability to survive at low pH, a high bile deconjugation ability, and hypocholesterolemic effect in in vitro conditions.     

The cnidarian nematocyst: a miniature extracellular matrix within a secretory vesicle

Nematocysts are the taxon-defining features of all cnidarians including jellyfish, sea anemones, and corals. They are highly sophisticated organelles used for the capture of prey and defense. The nematocyst capsule is produced within a giant post-Golgi vesicle, which is continuously fed by proteins from the secretory pathway. Mature nematocysts consist of a hollow capsule body in which a long tubule is coiled up that, upon discharge, is expelled in a harpoon-like fashion. This is accompanied by the release of a toxin cocktail stored in the capsule matrix. Nematocyst discharge, which is one of the fastest processes in biology, is driven by an extreme osmotic pressure of about 150 bar. The molecular analysis of the nematocyst has from the beginning indicated a collagenous nature of the capsule structure. In particular, a large family of unusual minicollagens has been demonstrated to form the highly resistant scaffold of the capsule. Recent findings on the molecular composition of Hydra nematocysts have confirmed the notion of a specialized extracellular matrix, which is assembled during an intracellular secretion process to form the most complex predatory apparatus at the cellular level.