Mapping of chromosome loci determined manifestation of morphological and biochemical traits of quality in <Emphasis Type="Italic">Brassica rapa</Emphasis> L. crops

Mapping chromosomal loci responsible for seven morphological and five biochemical traits of quality in populations of doubled haploid lines of leafy, rooted, and oilseed crops of Brassica rapa L. species was performed for the first time. In total, 140 quantitative trait loci (QTLs) were mapped determining manifestation of the studied morphological and biochemical economically important traits of quality under field and greenhouse conditions; the control of the same traits under different growth conditions or simultaneous control of several traits by one locus were noted. Molecular markers genetically linked with the selected QTLs were detected. The block genomic structure of the genetic components (chromosomal loci and linkage groups) determining manifestation of morphological and biochemical traits of quality that make B. rapa plants nutritionally valuable is discussed for the first time. The conclusion is drawn that the revealed QTLs and identified molecular markers may be of interest for the forthcoming study of genetic control by them of economically important characters and for the marker assisted selection in B. rapa.     

Functional Match between Influenza Virus Hemagglutinin and Neuraminidase Is Restored after Gene Reassortment

Influenza virus A (FluA) reassortants with low-functional neuraminidase (NA) of subtype N1 and hemagglutinin (HA) of subtypes H2, H3, H4, and H13 display virion aggregation and accumulate to a lower titer because sialyl residues are not completely removed from virion components. Nonaggregating variants of FluA (H13N1) were shown to result from a mutation that reduces the HA affinity for sialyl substrates. Amino acid substitution K156E, which increases a negative charge at the edge of the receptor-binding pocket of HA large subunit (HA1), was revealed in two independent variants. This substitution was the only difference between HA1 of the original reassortant and one of its variants and, therefore, accounted for restoration of the functional match between HA and NA.     

Active and passive properties of carotid arteries]

A mathematical model of carotid arteries is constructed from the known experimental data. Passive properties of the vascular wall are characterized by an alternating module of elasticity, the active ones by the specific power of muscle contraction. Its maximum value (0,023 n/m-3) is shown to be reached with intravascular pressure 190 mm Hg. The dependence of inner radius on the power of muscle contraction is studied at different values of intravascular pressure. It is shown that theactive properties of carotid arteries are essentially determined by their passive properties and depend on the stretching of the vessel wall.     

Age composition and antioxidant enzyme activities in blood of Black Sea teleosts

Age composition and age-related trends of antioxidant enzyme activities superoxide dismutase (SOD), catalase (CAT), peroxidase (PER), glutathione reductase (GR) and glutathione-S-transferase (GST) in the blood of seven Black Sea teleosts (Carangidae, Centracanthidae, Gadidae, Mullidae, Gobiidae and Scorpaenidae) collected in marine coastal area of Sevastopol (Ukraine) were studied. In the catches the animals of 1 – 2 years of age dominated while in the Scorpaena porcus population the number of relatively elder individuals belonging to classes of 3–4 years was the highest. The trends of antioxidant enzyme activities in blood were not uniform. Three types of age-dependent responses were indicated in fish blood: 1. enzymatic activity did not change with age; 2. enzymatic activity decreased with age and 3. enzyme activity increased with age or varied unclearly. The interspecies differences of age-related enzymatic activities associated with the specificity of fish biology and ecology were indicated. Despite no clear evidence of age-related differences between fish species belonging to different ecological groups both benthic forms exhibited similar age-dependent trends of SOD and PER. The correlations between blood antioxidant enzyme activities in fish belonging to suprabenthic and benthic/pelagic groups demonstrated the intermediate values as compared to the benthic and pelagic forms. The results suggest the importance of age trends for biomarkers in fish monitoring studies.     

Effect of T-cell mitogens and T-lymphocyte deficiency on splenic colony formation

A study was made of the influence of T-cell mitogens (Con A and PHA) on the colony formation and differentiation of hemopoietic stem cells from normal and thymectomized mice, as well as of the relationship between the colony formation and the dose of injected thymocytes. The incubation of bone marrow cells with Con A and PHA was shown to inhibit the growth of spleen colonies. This inhibition is reduced by thymocytes within the dose intervals of 0.25-2.0 X 10(7) cells/mouse. Administration of these agents serially has led to the potentiation of inhibition effect and to the inability of thymocytes to reverse it. Con A and PHA exert no effect on the differentiation of stem cells. Incubation of the bone marrow cells from thymectomized mice with Con A is much less effective in the depression of colony formation, if compared with the treatment by intact bone marrow preparations. A reversed picture was observed using antiserum to mouse brain (RAMBS). It is proposed that regulation of stem cells is governed by different subpopulations of thymocytes.     

Reduction of the functional match of influenza virus hemagglutinin and neuraminidase after reassortation of genes]

Influenza virus A (FluA) reassortants with low-functional neuraminidase (NA) of subtype N1 and hemagglutinin (HA) of subtypes H2, H3, H4, and H13 display virion aggregation and accumulate to a lower titer because sialyl residues are not completely removed from virion components. Nonaggregating variants of FluA (H13N1) were shown to result from a mutation that reduces the HA affinity for sialyl substrates. Amino acid substitution K156E, which increases a negative charge at the edge of the receptor-binding pocket of HA large subunit (HA1), was revealed in two independent variants. This substitution was the only difference between HA1 of the original reassortant and one of its variants and, therefore, accounted for restoration of the functional match between HA and NA.