Chromosomal localization of a gamete-killing gene in a wheat line

Monosomic analysis revealed that a gametocidal gene in a common wheat line derivative from Aegilops speltoides is located on chromosome 2B. This gene induces semisterility, low level of chromosome breaks, shriveled seeds, and endosperm degeneration. The obtained data indicate that the localized gene is allelic to well known gametocidal genes Gc1a and Gc1b.     

The dopamine system stress reaction in adults of Drosophila virilis is controlled by genes of Chromosome 6

A linkage group of the gene responsible for changes of DA titer under stress in adults of D. virilis was determined. Line 160 of D. virilis, all autosomes of which bear visible recessive mutations, was used as an analyzer. Flies of lines 160 and 147 were shown to differ in DA content under normal conditions and in the way DA metabolic system reacts to stress. Among the offspring of the analyzing cross, groups of flies were found with one testable autosome from line 147 and all other chromosomes from line 160. Results of the DA titer measurements in flies of these groups under stress conditions have proved that the gene in question is linked to chromosome 6.     

Mercury-resistant bacteria from permafrost sediments and prospects for their use in comparative studies of mercury resistance determinants

Mercury-resistant bacteria were isolated from permafrost sediments of Kolyma lowland and Canada existing over five thousand to two million years. Their content was shown to vary within the range 0.001-2.9% and to depend on the amount of mercury in sampling sites (coefficient of correlation 0.75). A collection of mercury-resistant bacterial strains was created. In this collection, various representatives of both Gram-positive bacteria (Bacillus, Exiguobacterium, Micrococcus, Arthrobacter) and Gram-negative bacteria (Pseudomonas, Acinetobacter, Plesiomonas, Myxobacteriales) were identified. Most resistant bacteria were found to contain determinants homologous to mer-operons of contemporary bacteria. The isolated strains of paleobacteria are proposed to be used for a comparative structural study of contemporary and ancient plasmids and transposons carrying mercury resistance determinants.     

Resistance of Penicillium piceum F-648 to hydrogen peroxide under short term and prolonged oxidative stress

Resistance of Penicillium piceum F-648 to hydrogen peroxide under short-term and prolonged oxidative stress was studied. An increase in the activity of intracellular catalase in fungal cells after short-term exposure to hydrogen peroxide was shown. Activation of fungal cells induced by H2O2 depends on H2O2 concentration, time of exposure, and the growth phase of the fungus. Variants of P. piceum F-648 that produced two forms of extracellular catalase with different catalytic properties were obtained due to prolonged adaptation to H2O2. Catalase with low affinity for substrate was produced predominantly by the parent culture and variant 3; however, a high substrate affinity of catalase was observed in variant 5. Variant 5 of P. peniceum F-648 displayed a high catalytic activity and operational stability of catalase in the presence of phosphate ions and the concentration of substrate less than 30 mM at pH more than 7.     

Monoclonal antibodies for studying antigens of protein origin in serotyping of Yersinia pseudotuberculosis

Hybridomas producing monoclonal antibodies (MAb) to Yersinia pseudotuberculosis, serovars I-IV, responsible for serovar appurtenance, were obtained. Virtually all MAbs reacted with protein antigens in immunoblotting. The only exclusion was MAb 3A2 presumably reacting with a glycoprotein epitope of complex structure. Variability of Y. pseudotuberculosis antigenic structure, depending on culturing temperature, was confirmed. Polypeptides with mono- or polydetermined antigenic specificity were determined using MAbs.     

Shifts in phospholipid composition of the nuclear matrix in rat liver cells exposed to insulin

It was shown that the total content of phospholipids of rat liver nuclear matrix increased after in vivo action of insulin (2 units per 100 g of animal weight). At the same time the sphyngomyelin content was increased and the content of phosphatydilcholine and phoshpatydilinositol was decreased significantly under the hormone action. The decreasing of monophosphoinositides amount was accompanied by the increasing of triphosphoinositides content which indicates the redistribution among the phosphoinositides fractions under the hormone action and may be the result of insulin initiation of phosphoinositide pathway in nuclear membrances.     

Dependence of the ion energy on the parameters of the laser pulse and target in the radiation-pressure-dominated regime of acceleration

When the dominant mechanism for ion acceleration is the laser radiation pressure, the conversion efficiency of the laser energy into the energy of relativistic ions may be very high. Stability analysis of a thin plasma layer accelerated by the radiation pressure shows that Raleigh-Taylor instability may enhance plasma inhomogeneity. In the linear stage of instability, the plasma layer decays into separate bunches, which are accelerated by the radiation pressure similarly to clusters accelerated under the action of an electromagnetic wave. The energy and luminosity of an ion beam accelerated in the radiation-pressure-dominated regime are calculated.