Alpha-N-acetylgalactosaminidase from marine bacterium Arenibacter latericius KMM 426T removing blood type specificity of A-erythrocytes

An -N-acetylgalactosaminidase IV able to remove blood type specificity of human A(II)-erythrocytes and not effecting B(III)-erythrocytes was isolated from the marine bacterium Arenibacter latericius KMM 426^T. The -N-acetylgalactosaminidase IV preparation exhibits high activity during inhibition of hemagglutination with blood group substance A containing determinants analogous to A-erythrocytes. The enzyme has a pH optimum from 7.0 to 8.0 and completely retains its activity during 30-min heating at 50°C and for a week at 20°C. The enzyme can be stored under the sterile conditions for any length of time at 4°C, but it does not withstand freezing. The -N-acetylgalactosaminidase is resistant to NaCl; for p-nitrophenyl--N-acetyl-D-galactosaminide, the K _m is 0.38 mM. The molecular mass of the enzyme determined by gel filtration is 84 kD.     

The mutant gene "wal" is active in cells of mouse hair follicles

In order to determine the place of action of the mutant gene waved alopecia (wal), we have obtained chimeric wal/wal c/c Gpi-1aa<-->+/+ C/C Gpi-1bb animals by aggregation of eight-cellular embryos of BALB/c-wal/wal mice and CBA (+/+) mice. The presence or absence of the chimeric structure was determined from the mosaic nature of fur color and hair structure, as well as on the basis of the presence of electrophoretically distinct variants of glucosephosphate isomerase in blood. Chimeras had alternating transverse patches of different lengths and widths consisting of curly (genotype wal/wal) or straight (genotype +/+) hairs. The percentage of cells with wal/wal mutant genotype in chimeras established on the basis of glucosephosphate isomerase isozymes varied from 10 to 80%. A higher percentage of the parental wal/wal component in chimeras correlated with the number of patches having wavy hairs. Analysis of the fur pattern represented by the alternation of transverse patches of wavy or straight hairs in chimeric wal/wal (+/+ mice has shown that mutant gene wal acts in ectodermal cells of hair follicles.     

Molecular characteristics of diverse populations are consistent with the hypothesis of a recent invasion of Drosophila melanogaster by mobile P elements

Approximately 100 strains derived from natural populations of Drosophila melanogaster were tested for the presence or absence of P- element sequences by using two molecular probes derived from internal regions of a full-sized P element. Strains that had been collected from several continents at varying times during the past 60 years were examined. The oldest available strains, representing most major geographical regions of the world, exhibited no detectable hybridization to the P-element probes. In contrast, all recently collected natural populations that were tested carried P-element sequences. The earliest appearance of P elements occurred in collections made during the 1950s and early 1960s in the Americas and during the late 1960s on other continents. The youngest strains that were completely devoid of P elements originated in populations sampled during the mid-1960s in America, but as late as 1974 in populations from the USSR. There are differences in the patterns of hybridization to the two P-element probes between populations from different geographical regions. These differences are consistent with the varying P-M phenotypic properties of these populations. Taken together with the results of phenotypic tests reported in earlier studies, the available evidence is consistent with the hypothesis of a worldwide P-element invasion of D. melanogaster during the past 30 years and suggests that the putative invasion of the Americas possibly preceded by approximately a decade that in Europe, Africa, and the rest of the world.      

Leptofibrils in rat ventricular cardiomyocytes in vitro

The presence of leptofibrils in ventricular myocytes of the heart of the 2- and 14-day old rats in 8-day old cultures was shown and their structure was investigated. Leptofibrils are seen only in myocytes on a definite stage of differentiation. Leptofibrils are attached to Z-bands running parallel or perpendicular to myofibrils. The period of their cross striation varies from 135 to 215 nm. Possible functions of the leptofibrils are discussed.     

The interaction of secreted proteins Noggin4 and Wnt8 from <Emphasis Type="Italic">Xenopus laevis</Emphasis> embryos

We demonstrated that the secreted protein Noggin4 from Xenopus laevis was capable of the in vitro binding to the secreted factor Wnt8, one of the ligands of the Wnt/betaCatenin signaling pathway. It was also shown that posttranslational modifications occurring during secretion of these proteins from the embryonic cells were necessary for their effective interaction. Also, we proposed a method for the preparation of physiologically active secreted morphogenic proteins from the intercellular space of the Xenopus laevis embryos.     

Microdialysis study in vivo of the release of adenine nucleotide degradation products into intercellular space of canine myocardium during regional ischemia and reperfusion

Intercellular concentrations of adenine nucleotide degradation products (ANDP)--adenosine inosine and hypoxanthine--in ischemic and control regions of the canine myocardium were measured by microdialysis technique during 20- and 40-min coronary artery occlusion and reperfusion. In hearts that fibrillated on reperfusion during the ischemic 40-min period catabolism of adenine nucleotides was more intensive, which could be the min cause of the reperfusion ventricular fibrillation. Reperfusion ventricular fibrillation was accompanied by an increase in the intercellular ANDP level in the control region, that indicated the development of the total myocardial ischemia. During the initial period of reperfusion after 20-min, a sharp increase in the interstitial ANDP level was observed in the ischemic region as compared with the end of the ischemia which could be explained as a result of demasking of reperfusion damage in such a case. The 40-min reperfusion induced slow reduction of the intercellular ANDP level in the ischemic region, while the regional blood flow already 5 min after the reperfusion did not differ from the blood flow in the control region. It is supposed that a slow washout of ANDP could be caused by the "no-reflow" phenomenon.     

Methods of In Vivo Gene-Specific Knockdown Using Morpholino and Vivo-Morpholino Oligonucleotides

The functioning of the small GTPase gene, Ras-dva1, has been studied during regeneration processes of the tadpole tails of the clawed frog Xenopus laevis. For this purpose, we have developed two approaches for the gene knockdown using injections of sequence-specific antisense morpholino oligonucleotides (MO) or vivo-morpholino oligonucleotides (vivo-MO). It has been shown for the first time that intracellular Ras-dva-specific MO injected into Xenopus 4–16 of blastomere embryos or vivo-MO injected directly into the distal part of the tadpole tail at stages 40–41 efficiently inhibit the Ras-dva1 gene functioning and leads to the same morphological malformations of the tail regeneration. Using qRT-PCR, we detected the inhibition of expression of the regeneration marker genes (Fgf20a and Msx1b) on the first day after amputation in the tail tissues of tadpoles with the Ras-dva1 knockdown.     

Use of prodigiozan for preventing acute respiratory viral diseases in a children's collective]

The epidemiological efficacy of 0.02 per cent solution of prodigiosan, a bacterial polysaccharide was used for the treatment of children in an area with acute respiratory infections, such as influenza and parainfluenza. The drug was administered intranasally by means of a dosing sprayer in the amounts of 0.2 ml once in 4 days for 4 months. Among the children treated with prodigiosan the rate of the acute respiratory viral infections was 2 times lower and the average duration of the disease was 2.4 times lower as compared to the control group. After 4 months of the drug use the average value of the "skin autoflora" test was much lower than that in the control group which testified to an increase in the non-specific immunobiological reactivity of the children under the effect of prodigiosan.     

Mitochondrial control-region sequences in two shorebird species, the turnstone and the dunlin, and their utility in population genetic studies

We determined the mitochondrial control-region sequences of five turnstones (Arenaria interpres) and three dunlins (Calidris alpina). Comparisons revealed that the central part (part II) is conserved relative to much more variable parts at the beginning (part I) and the end (part III). This pattern of sequence conservation is also found in the control regions of other vertebrates. The average sequence divergence between turnstone and dunlin was 21.8% for part I, 7.5% for part II, and 29.5% for part III. Within-species sequence divergence over the entire control region was much lower, at 0.9% for turnstones and 2.0% for dunlins. In both shorebird species, part III contains a repetitive sequence composed only of A and C nucleotides, which has not been found in the control regions of other birds. A survey of the part I sequences of 25 turnstones and 25 dunlins sampled around the world revealed that these species have very different population genetic structures. Dunlins are not only much more differentiated in their sequences but also have a strongly subdivided population genetic structure. Pleistocene vicariant events combined with strong natal philopatry and high mutation rates of the sequences are likely responsible for this population genetic subdivision. Conversely, part I sequences of turnstones are weakly differentiated and are geographically unstructured. We argue that this is not the result of global gene flow but that, instead turnstones have recently expanded from a refugial population that was bottlenecked.      

Vizualizing the morphogen adsorption gradient in the <Emphasis Type="Italic">Xenopus laevis</Emphasis> embryo using fluorescently labeled heparin-binding motif of BMP4 morphogen

Spatial distribution of heparan sulfates in the embryonic extracellular matrix at midgastrula stage has been demonstrated in the Xenopus laevis embryo model. Towards this end, fluorescently labeled fusion protein EGFP-hbmBMP4 made up by green fluorescent protein (EGFP) and heparin-binding motif of Bone Morphogenetic Protein 4 (BMP4) was produced in the E. coli expression system. Xenopus laevis embryos at midgastrula stage (stage 11) were fixed and cut along the anteroposterior axis and then incubated with EGFP-hbmBMP4. The fluorescently labeled samples were analyzed in fluorescence microscope. The spatial distribution of fluorescence intensity reflecting BMP4 adsorption on the embryonic extracellular matrix proved to be similar to the corresponding distribution pattern for the Noggin1 heparin-binding motif obtained previously. The highest intensity zone was detected around the dorsal blastopore lip; another high intensity zone, although slightly less prominent, was observed in the ventral blastopore lip region. Since on one hand, heparin-binding sites significantly differ in their organization in BMP4 and Noggin1 proteins and, on the other hand, spatial adsorption distribution patterns for these proteins coincide in the embryo, it appears that all secreted morphogens containing a heparin-binding site share a single adsorption gradient in the embryonic extracellular space.