The effect of genetic environment on locus-specific instability of the <Emphasis Type="Italic">yellow</Emphasis> gene in the Uman’ population of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

The effects of genotype of the laboratory strains, C(1)DX, ywf/Y, 23.5 MRF/CyL ⁴, and C(1)DX,yf; π₂, on locus-specific instability in the yellow gene of the strains y ^2-217, y ^2-715, and y ^2-700 from Uman’ population of Drosophila melanogaster was studied. Crosses of the males from Uman’-derived lines with the C(1)DX,ywf/Y females yielded a cascade of derivatives, mostly consisting of y ⁺ and y ² alleles, while their crosses with the 23.5 MRF/CyL ⁴ and C(1)DX,yf; π₂ females mostly resulted in the appearance of y ⁺ and y ¹ derivatives. The genomes of laboratory strains used in the study contained the full-sized hobo elements, which could differ from one another relative to the structure of variable region and affinity to different DNA sequences.     

Effective Inhibitors of Tyrosyl-DNA Phosphodiesterase 1 Based on Monoterpenoids as Potential Agents for Antitumor Therapy

Russian Journal of Bioorganic Chemistry - Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is one of the important DNA repair enzymes responsible for the repair of DNA damage caused by anticancer drugs, such...     

Glycosidases of marine organisms

This review discusses the catalytic properties, activity regulation, structure, and functions of O-glycoside hydrolases from marine organisms exemplified by endo-1→3-β-D-glucanases of marine invertebrates.     

Effect of Methanol and Mineral Nitrogen Compounds on the Composition of Methanotrophic Enrichments from the Sediments of a Lake Baikal Methane Seep

Microbiology - Diversity of methano- and methylotrophic bacteria in enrichments from the oxidized sediment layer maintained at 10°C in mineral media with nitrogen compounds (...     

Pten deletion causes mTorc1-dependent ectopic neuroblast differentiation without causing uniform migration defects

Neuronal precursors, generated throughout life in the subventricular zone, migrate through the rostral migratory stream to the olfactory bulb where they differentiate into interneurons. We found that the PI3K-Akt-mTorc1 pathway is selectively inactivated in migrating neuroblasts in the subventricular zone and rostral migratory stream, and activated when these cells reach the olfactory bulb. Postnatal deletion of Pten caused aberrant activation of the PI3K-Akt-mTorc1 pathway and an enlarged subventricular zone and rostral migratory stream. This expansion was caused by premature termination of migration and differentiation of neuroblasts and was rescued by inhibition of mTorc1. This phenotype is reminiscent of lamination defects caused by Pten deletion in developing brain that were previously described as defective migration. However, live imaging in acute slices showed that Pten deletion did not cause a uniform defect in the mechanics of directional neuroblast migration. Instead, a subpopulation of Pten-null neuroblasts showed minimal movement and altered morphology associated with differentiation, whereas the remainder showed unimpeded directional migration towards the olfactory bulb. Therefore, migration defects of Pten-null neurons might be secondary to ectopic differentiation.     

Level and correlation of metabolites of NAD(P)+-dependent dehydrogenase systems in newborn calf tissues in acute diarrhea]

Substantial disorders of redox and energetic processes are observed in the newborn calf tissues which is evidenced by changes in glucose, lactate oxalo-acetate, malate, citrate, alpha-ketoglytarate and glutamate concentrations, as well as in activity of lactate dehydrogenase and gamma-glutamyltransferase, succinate dehydrogenase and alkaline phosphatase and correlations of (NAD(p)/NAD(P)H) in blood cytoplasm and liver and kidney mitochondria.     

Patterns of transposable elements distribution on the Drosophila melanogaster polytene chromosomes before and after selection for a quantitative trait

The effect of selection for radius vein length on the distribution of hybridization sites of the P and hobo transposons and the mdgl and mdg2 retrotransposons on polytene chromosomes of Drosophila melanogaster salivary glands was studied. The patterns of these transposable elements (TEs) distribution were polymorphic in both the parental strain and selected strains. The similarity in mdg1 and mdg2 patterns between strains selected in one direction was closer than between strains selected in opposite directions, but the selected strains were closer to each other than to the parental strain regardless of selection direction. No mdg2 hybridization sites that would be absent in the control were found in the selected strains. There were more mdg2 and hobo hybridization sites in the strains selected in the (+) direction than in the (-) direction. The mobility of hobo copies in the strains studied correlated with the presence of its full-sized copy in the genome. The polymorphism of all TEs studied except for mdgl was greater for strains selected in the (+) direction that in the (-) direction. These facts suggest that some TEs migrate over the genome independently of selection, and others are markers of evolutionary events rather than their causes.     

Disaccharide Pyrimidine Nucleosides and Their Derivatives: A Novel Group of Cell-Penetrating Inhibitors of Poly(ADP-Ribose) Polymerase 1

Nearly 30 synthetic nucleosides were tested with human recombinant poly(ADP-ribose) polymerase 1 as potential inhibitors of this enzyme. The most active compounds were some disaccharide analogues of thymidine: 3′-O-β-D-ribofuranosyl-5-iodo-dUrd (2d; IC₅₀ = 45 μM), 3′-O-β-D-ribofuranosyl-2′-deoxythymidine (2e; IC₅₀ = 38 μM), and 3′-O-β-D-ribofuranosyl-2′-deoxythymidine oxidized (4; IC₅₀ = 25 μM). These compounds also reduced H₂O₂-induced synthesis of poly(ADP-ribose) in cultured human ovarian carcinoma (SKOV-3) cells in a dose-dependent manner. Furthermore, compounds 2d or 2e until a concentration of 1 mM did not affect growth of SKOV-3 cells, whereas dialdehyde compound 4, as well as thymidine, exhibited a significant cytotoxicity.     

Pattern of transposable elements distribution on <Emphasis Type=Italic>Drosophila melanogaster</Emphasis> polytene chromosomes before and after quantitative trait selection

The effect of selecting the length of a radial vein on the distribution of hybridization sites for P and hobo transposons and mdg1 and mdg2 retrotransposons on polytene chromosomes of Drosophila melanogaster salivary glands was studied. The pattern of the transposable element (TEs) distribution was polymorphic in both parental and selected strains. The similarity in mdg1 and mdg2 distribution between strains selected in one direction was closer than between strains selected in the opposite direction, but the selected strains were closer to each other than to the parental strain, regardless of direction of selection. No new mdg2 hybridization sites that would be absent from the control were found in the selected strains compared to the control. The number of mdg1 and hobo hybridization sites was more selected in strains in the (+) direction than in the (−) direction. The mobility of hobo copies in the strains correlated with the presence of its full-sized copy in the genome. The polymorphism of all TEs studied except for mdg1 was higher in strains selected in the (+) direction than in the (−) direction. These results suggest that some TEs migrate over the genome independently of selection, whereas the other are markers of evolutionary events rather than their causes.