Molecular identification of filterable bacteria and archaea in the water of acidic lakes of northern Russia

Wetland ecosystems are the natural centers of freshwater formation in northern Russia lowland landscapes. The humic acidic waters formed in bogs feed the numerous lakes of the northern regions. One milliliter of the water in these lakes contains up to 10⁴ ultrasmall microbial cells that pass through “bacterial” filters with a pore size of 0.22 μm. The vast majority of these cells do not grow on nutrient media and cannot be identified by routine cultivation-based approaches. Their identification was performed by analysis of clone libraries obtained by PCR amplification of archaeal and bacterial 16S rRNA genes from the fraction of cells collected from water filtrates of acidic lakes. Most of the obtained bacterial 16S rRNA gene sequences represented the class Betaproteobacteria and exhibited the highest homology of (94–99%) with 16S rRNA genes of representatives of the genera Herbaspirillum, Herminiimonas, Curvibacter, and Burkholderia. The archaeal 16S rRNA gene clone library comprised genes of Euryarchaeota representatives. One-third of these genes exhibited 97–99% homology to the 16S rRNA genes of taxonomically described organisms of the orders Methanobacteriales and Methanosarcinales. The rest of the cloned archaeal 16S rRNA genes were only distantly related (71–74% homology) to those in all earlier characterized archaea.     

The action of an enzymatically stable Leu-enkephalin analog on the prostanoid content in the myocardium under stress- and adrenaline-induced damage

The protective action of enzymatically stable analogue of Leu-enkephalin (D-ala-2-leu5-arg6), injected intraperitoneally, in the course of stress- and epinephrine induced myocardial damage was demonstrated in animal (129 white rats) experiments. Two effect of enkephalin were sufficient for the cardiac protection: enkephalin-stimulated prostacyclin biosynthesis and simultaneous inhibition of thromboxane production.     

Age-related characteristics of postradiation regeneration of the blood system

This study was pursued on hybrid (CBA X C57Bl)F1 mice at the ages of 17 and 27 months irradiated at a dose of 4 Gy. It was shown that the postirradiation recovery of haemopoiesis in old mice was the same as in the young (2-3 month-old), and in some respects (for instance, granulocytic and erythroid cells of the bone marrow, and CFUc) the recovery was even more active exhibiting a period of a pronounced hyperregeneration.     

Production of DON-related trichothecenes byFusarium graminearum Schw from Krasnodarski krai of the USSR

34Fusarium graminearum Schw isolates produced 4-deoxynivalenol to form significant amounts of 4, 7 — dideoxynivalenol and lesser amounts of 4 — deoxynivalenol monoacetates on grain substratesin vitro. This is the first report on the capability a large group of naturally occurring isolates to produce 4,7-dideoxynivalenol. The average levels of 4,7-dideoxynivalenol on rice, corn, barley, and wheat as a substrate were respectively 26.8, 14.0, 12.8, and 10.5% of the level of 4-deoxynivalenol. 4, 7 — dideoxynivalenol was present in all examined naturally contaminated wheat kernel samples at levels of 1.7 to 7.9% of the level of 4-deoxynivalenol. These findings suggest that more attention should be given to the occurrence of 4,7-dideoxynivalenol in cereals.     

Variation in the ribosomal internal transcribed spacers (ITS1 and ITS2) among eight taxa of the Mimulus guttatus species complex

The internal transcribed spacer region (ITS1 and ITS2) of the 18S-25S nuclear ribosomal DNA sequence and the intervening 5.8S region were sequenced from three individuals in each of eight taxa of the Mimulus guttatus species complex. Three discrete variants, or "types," of ITS sequences were found, among which 30%-40% of sites differed, compared with 1%-2% within types. Dot plots indicate that these types were not related by conspicuous rearrangements or inversions. More than one ITS type was often found in the same taxon, and two of three ITS types span species boundaries, indicating their presence prior to speciation. These ITS sequences showed essentially no positional homology with the nearest sequenced relative, tomato. In contrast, the 5.8S region was relatively unvaried, with 8 of 162 sites varied in the sample among all eight taxa. The phylogeny inferred by the most common ITS sequence type, rooted by the two other ITS types, agreed with isozymes in showing the distinctness of M. nudatus, M. laciniatus, and M. tilingii from the other five taxa.      

Effect of exposure to stress on the role of T- and B-lymphocytes in the response of the hematopoietic system

Cellular composition of the bone marrow, spleen and peripheral blood was studied after 6-hour immobilization on the back in experiments on 4 groups of (CBAxC57BL)F1 mice with varying degree of T lymphocyte deficiency (thymectomy, sham thymectomy, administration of antilymphocytic serum, B mice). The evidence obtained shows that the "lymphoid peak" recorded in the bone marrow during stress is likely to be formed at the expense of T and B lymphocyte migration from the peripheral lymphoid organs. The data have been also obtained, indicating that T lymphocytes migrating to the bone marrow during the first 6-9 hours after the exposure to stress may participate in granulocytopoiesis activation.     

中国小菇属十个新记录种

报道了小菇科小菇属真菌10个中国新记录种,香菌组：橙盖小菇Mycena aurantiidisca、黄白小菇Mycena flavoalba、粉黄小菇Mycena floridula;棘刺组：异刺小菇Mycena heteracantha;纤柄组：碱味小菇Mycena amygdalina;脆足组：粉被小菇Mycena zephirus;冬生组：绣线菊小菇Mycena speirea、冬生小菇Mycena hiemalis;小菇组：绒柄小菇Mycena flos-nivium,分别来自吉林等11个省份、自治区。提供了每个物种的形态描述和线条图,以及与相近种的讨论。共计90条自测及下载ITS序列,在采用贝叶斯法和最大似然法构建的小菇属系统发育树中,新记录种均得到分子数据支持。凭证标本存放于吉林农业大学菌物标本馆（HMJAU）。     

A Bacterial Phosphatase-Like Enzyme of the Malaria Parasite Plasmodium falciparum Possesses Tyrosine Phosphatase Activity and Is Implicated in the Regulation of Band 3 Dynamics during Parasite Invasion

Eukaryotic parasites of the genus Plasmodium cause malaria by invading and developing within host erythrocytes. Here, we demonstrate that PfShelph2, a gene product of Plasmodium falciparum that belongs to the Shewanella-like phosphatase (Shelph) subfamily, selectively hydrolyzes phosphotyrosine, as shown for other previously studied Shelph family members. In the extracellular merozoite stage, PfShelph2 localizes to vesicles that appear to be distinct from those of rhoptry, dense granule, or microneme organelles. During invasion, PfShelph2 is released from these vesicles and exported to the host erythrocyte. In vitro, PfShelph2 shows tyrosine phosphatase activity against the host erythrocyte protein Band 3, which is the most abundant tyrosine-phosphorylated species of the erythrocyte. During P. falciparum invasion, Band 3 undergoes dynamic and rapid clearance from the invasion junction within 1 to 2 s of parasite attachment to the erythrocyte. Release of Pfshelph2 occurs after clearance of Band 3 from the parasite-host cell interface and when the parasite is nearly or completely enclosed in the nascent vacuole. We propose a model in which the phosphatase modifies Band 3 in time to restore its interaction with the cytoskeleton and thus reestablishes the erythrocyte cytoskeletal network at the end of the invasion process.     

Filterable microbial forms in the Rybinsk water reservoir

Molecular identification of the filterable forms of microorganisms in the water of the Rybinsk reservoir, one of the largest open water bodies in European Russia, was carried out. The number of ultrasmall microbial cells passing through 0.22 μm filters was 104 cells/mL. These were represented by both bacteria and archaea. Most bacterial 16S rRNA gene sequences retrieved from filtered water affiliated with the Betaproteobacteria and exhibited high similarity (99.0–99.5%) to those of bacteria of the genus Polynucleobacter. The archaeal 16S rRNA gene clone library was composed of the sequences from members of the Euryarchaeota, including the orders Methanobacteriales and Methanomicrobiales, as well as two archaeal groups (LDS and RC-V) with no characterized representatives. The species composition of filterable bacteria from reservoir water was different from that revealed previously in bogs and small lakes at catchment areas. By contrast, the pool of filterable archaea in the reservoir exhibited significant similarity to that at boggy catchment areas and was characterized by predominance of the clade LDS. Available data indicate that this archaeal group is typical of the northern freshwater ecosystems, and the organisms of this group are represented by ultrasmall cells.