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.     

A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

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.     

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.     

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.     

First gall midges (Diptera,Cecidomyioidea) from Late Cretaceous amber of the Taimyr Peninsula

Gall midges from Santonian amber of Yantardakh (Taimyr Peninsula) are investigated for the first time. Eight new genera and eight new species belonging to five tribes of the subfamily Micromyinae (Lestremiidae) are described. These are Caputmunda yantardakhica gen. et sp. nov. (Catochini), Cretoperomyia taimyrica gen. et sp. nov. (Peromyiini), Palaeostrobliella dmitrii gen. et sp. nov., Yantardakhiella pusilla gen. et sp. nov., and Zherikhiniella pedicellata gen. et sp. nov. (Strobliellini), Menssana norilsk gen. et sp. nov. (Micromyini), and Cretomycophila ekaterinae gen. et sp. nov., and Corporesana khatanga gen. et sp. nov. (Aprionini). A representative of Porricondylinae (Cecidomyiidae, Porricondylinae, Holoneurini) is recorded. The diagnoses based on morphometric parameters of tribes and previously established genera are emended. The species composition of gall midges from three Cretaceous amber faunas of different ages are analyzed.     

Protective action of reactivating factor of <Emphasis Type="Italic">Luteococcus japonicus</Emphasis> subsp. <Emphasis Type="Italic">casei</Emphasis> toward cells of <Emphasis Type="Italic">Escherichia coli</Emphasis> reparation mutants inactivated with UV-light

Reactivating factor (RF) from Luteococcus japonicus subsp. casei had a protective action on UV-irradiated cells of Escherichia coli AB1157 with a native reparation system and on cells of isogenic reparation mutants of E. coli UvrA⁻, RecA⁻, and PolA⁻: the effect resulted in multifold increase of survivability. Defense action of L. casei exometabolite is not connected with stimulating reparation systems in E. coli, and, probably, it is mediated by involvement of the exometabolite in the mechanism of cell division. RF did not provoke the reactivation of E. coli cells inactivated by UV-light.