A biometric study of some hybridizing Crataegus populations in Denmark

Crataegus curvisepala Lindm., C. laevigata (Poiret) DC. and C. monogyna Jacq. (Rosaceae) form hybrid complexes in Denmark due to introgression. C. palmstruchii Lindm. seems to be variously introgressed individuals of C. laevigata. C. eremitagensis Raunk., C. raavadensis Raunk. and C. schumacheri Raunk. apparently belong to C. curvisepala x laevigata. The delimitation between C. curvisepala x laevigata and C. laevigata x monogyna is discussed.     

On the history of nuclear matrix manifestation

The nonchromatin proteinous residue of the cell nucleus was revealed in our laboratory as early as in 1948 and then identified by light and electron microscopy as residual nucleoli,intranuclear network and nuclear envelope before 1960,This structure termed afterwards as “nuclear residue“,“nuclear skeleton“,“nuclear cage“,“nuclear carcass“etc.,was much later(in 1974) isolated,studied and entitled as “nuclear matrix“ by Berezney and Coffey,to whom the discovery of this residual structure is often wronly ascribed.The real history of nuclear matrix manifestation is reported in this paper.     

Does urbanization affect selective pressures and life‐history strategies in the common blackbird (Turdus merula L.)?

Urbanization, one of the most extreme land‐use alterations, is currently spreading, and the number of species confronting these changes is increasing. However, contradictory results of previous studies impede a clear interpretation of which selective pressure (nest predation or food limitation) is more important in urban habitats compared with natural situations, and whether birds can confront them by adjusting their life‐history strategies. We investigated life‐history syndromes of three common blackbird (Turdus merula) populations differing in their human influence (urban, rural, and woodland). We analysed daily nest predation and nestling starvation rates to assess the relative importance of these selection pressures in each habitat. Simultaneously, several life‐history traits were investigated to determine if T. merula seem adapted to their main source of selection. Food limitation was more important in the city, whereas nest predation was the most important selective force in the forest. The rural habitat was characterized by an intermediate influence of these two factors. Life‐history syndromes, as the covariation of a suite of traits, confirmed these results because T. merula seem well adapted to the main cause of selection in each habitat. Our results are consistent with urbanization imposing new challenges on birds, and that they adaptively respond to them. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 759–766.     

CPEB Regulation of TAK1 Synthesis Mediates Cytokine Production and the Inflammatory Immune Response

The cytoplasmic-element-binding (CPEB) protein is a sequence-specific RNA-binding protein that regulates cytoplasmic polyadenylation-induced translation. In mouse embryo fibroblasts (MEFs) lacking CPEB, many mRNAs encoding proteins involved in inflammation are misregulated. Correlated with this aberrant translation in MEFs, a macrophage cell line depleted of CPEB and treated with lipopolysaccharide (LPS) to stimulate the inflammatory immune response expresses high levels of interleukin-6 (IL-6), which is due to prolonged nuclear retention of NF-κB. Two proteins involved in NF-κB nuclear localization and IL-6 expression, IκBα and transforming growth factor beta-activated kinase 1 (TAK1), are present at excessively low and high steady-state levels, respectively, in LPS-treated CPEB-depleted macrophages. However, only TAK1 has an altered synthesis rate that is CPEB dependent and CPEB/TAK1 double depletion alleviates high IL-6 production. Peritoneal macrophages isolated from CPEB knockout (KO) mice treated with LPS in vitro also have prolonged NF-κB nuclear retention and produce high IL-6 levels. LPS-injected CPEB KO mice secrete prodigious amounts of IL-6 and other proinflammatory cytokines and exhibit hypersensitivity to endotoxic shock; these effects are mitigated when the animals are also injected with (5Z)-7-oxozeaenol, a potent and specific inhibitor of TAK1. These data show that CPEB control of TAK1 mRNA translation mediates the inflammatory immune response.     

Bioconversion of β-Sitosterol and Its Esters by Actinobacteria of the Genus <Emphasis Type="Italic">Rhodococcus</Emphasis>

The ability of pure cultures of Rhodococcus actinobacteria from the Ural Specialized Collection of Alkanotrophic Microorganisms (World Federation for Culture Collections accession number 768; http://www.ecology.psu.ru/iegmcol) to convert β-sitosterol (BSS) and its 3β-acylated derivatives was studied. Rhodococcus strains with pronounced cholesterol oxidase activity, capable of converting BSS to stigmat-4-ene-3-one in the reaction of cooxidation with n-hexadecane, were selected. The dependence of the activity of cholesterol oxidase of rhodococci on the length of the acyl group in BSS esters was studied. Conditions under which Rhodococcus cells convert BSS to 17β-hydroxyandrost-4-ene-3-one (testosterone), commonly used in pharmacology, were determined.     

A novel phosphatidylinositol(3,4,5)P3 pathway in fission yeast

The mammalian tumor suppressor, phosphatase and tensin homologue deleted on chromosome 10 (PTEN), inhibits cell growth and survival by dephosphorylating phosphatidylinositol-(3,4,5)-trisphosphate (PI[3,4,5]P3). We have found a homologue of PTEN in the fission yeast, Schizosaccharomyces pombe (ptn1). This was an unexpected finding because yeast (S. pombe and Saccharomyces cerevisiae) lack the class I phosphoinositide 3-kinases that generate PI(3,4,5)P3 in higher eukaryotes. Indeed, PI(3,4,5)P3 has not been detected in yeast. Surprisingly, upon deletion of ptn1 in S. pombe, PI(3,4,5)P3 became detectable at levels comparable to those in mammalian cells, indicating that a pathway exists for synthesis of this lipid and that the S. pombe ptn1, like mammalian PTEN, suppresses PI(3,4,5)P3 levels. By examining various mutants, we show that synthesis of PI(3,4,5)P3 in S. pombe requires the class III phosphoinositide 3-kinase, vps34p, and the phosphatidylinositol-4-phosphate 5-kinase, its3p, but does not require the phosphatidylinositol-3-phosphate 5-kinase, fab1p. These studies suggest that a pathway for PI(3,4,5)P3 synthesis downstream of a class III phosphoinositide 3-kinase evolved before the appearance of class I phosphoinositide 3-kinases.     

Recovery of Rhodococcus biosurfactants using methyl tertiary-butyl ether extraction.

In the present study, we proposed methyl tertiary-butyl ether (MTBE) as a solvent for extraction of biosurfactants from Rhodococcus bacterial cultures. After comparison with other well known solvent systems used for biosurfactant extraction, it was found that MTBE was able to extract crude surfactant material with high product recovery (10 g/l), efficiency (critical micelle concentration (CMC), 130-170 mg/l) and good functional surfactant characteristics (surface and interfacial tensions, 29 and 0.9 mN/m, respectively). The isolated surfactant complex contained 10% polar lipids, mostly glycolipids possessing maximal surface activity. Ultrasonic treatment of the extraction mixture increased the proportion of polar lipids in crude extract, resulting in increasing surfactant efficiency. Due to certain characteristics of MTBE, such as relatively low toxicity, biodegradability, ease of downstream recovery, low flammability and explosion safety, the use of this solvent as an extraction agent in industrial scale biosurfactant production is feasible.     

A consortium of immobilized rhodococci for oilfield wastewater treatment in a column bioreactor

The possible use of a consortium of actinobacteria from the genus Rhodococcus immobilized on a polymeric carrier has been investigated for oilfield wastewater treatment in a bioreactor. It has been found that Rhodococcus opacus IEGM 263 and Rhodococcus ruber IEGM 231 cells remain viable at high concentrations of mineral salts in water and are able to oxidize oil hydrocarbons up to 62–81%. It has been shown that the consortium of rhodococci was more efficient in the elimination of hydrocarbons from wastewater than monocultures.     

Catalysis of the biodegradation of unusable medicines by Alkanotrophic rhodococci

Experiments on the biodegradation of unusable medicines containing a phenolic hydroxy group by actinobacteria of the genus Rhodococcus were performed. Six species and sixty-four strains were tested. It was found that rhodococci could degrade paracetamol, and some R. ruber strains showed high levels of its degradation. An efficient method for the identification and quantification of paracetamol and the products of its conversion (p-aminophenol, pyrocatechol, and hydroquinone) immediately in the culture liquid was developed. Conditions for the complete biodegradation of paracetamol dosage forms (pills) were optimized. The experimental results can be applied to the development of biotechnological methods for degrading medicines: faked, rejected, or those that are expired.     

Efficient Uptake of Cesium Ions by Rhodococcus Cells

Bacteria of the genus Rhodococcus were found to be able to accumulate cesium by means of active transport and nonspecific sorption on the cell surface structures. The maximum removal (up to 97%) of cesium from a medium supplemented with ammonium acetate was observed at 28°C, pH 7.8–8.6, and an equimolar content (0.2 mM) of potassium and cesium ions in the medium. The most active cesium-accumulating rhodococcal strains may be useful in biological treatment of industrial wastewaters contaminated with radionuclides.