Distribution of the ticks <Emphasis Type="Italic">Ixodes persulcatus</Emphasis> and <Emphasis Type="Italic">Ixodes pavlovskyi</Emphasis> on the boundary of the forest and forest-steppe zones in the Ob region

Surveys of ixodoid ticks were performed in Novosibirsk Province (Novosibirsk and Toguchin Districts) and in the vicinity of Akademgorodok (Novosibirsk) in 2009–2010. The abundance and distribution of ticks were assessed in 8 types of habitats. Ixodes persulcatus (Schulze, 1930) was collected by flagging in Novosibirsk and Toguchin Districts, with the highest densities of 19 ind./km being observed in habitats with small-leaved trees. Three species of ticks: Ixodes persulcatus, I. pavlovskyi (subspecies I. pavlovskyi occidentalis Filip. et Pan., 1998), and Dermacentor reticulatus (Fabricius, 1794) were recorded in a recreational forest of Akademgorodok. A high abundance (22 ind./km) of I. pavlovskyi was observed in pine forests subjected to considerable recreational load. The abundance of I. persulcatus was the highest in aspen-birch and birch-aspen forests. D. reticulatus was captured in pine forests and fallow lands, its abundance varying from 0.2 to 2 ind./km.     

Gating-Related Molecular Motions in the Extracellular Domain of the I<Subscript>Ks</Subscript> Channel: Implications for I<Subscript>Ks</Subscript> Channelopathy

Cardiac slow delayed rectifier (I_Ks) channel complex consists of KCNQ1 channel and KCNE1 auxiliary subunits. The extracellular juxtamembranous region of KCNE1 is an unstructured loop that contacts multiple KCNQ1 positions in a gating-state-dependent manner. Congenital arrhythmia-related mutations have been identified in the extracellular S1–S2 linker of KCNQ1. These mutations manifest abnormal phenotypes only when coexpressed with KCNE1, pointing to the importance of proper KCNQ1/KCNE1 interactions here in I_Ks channel function. We investigate the interactions between the KCNE1 loop (positions 36–47) and KCNQ1 S1–S2 linker (positions 140–148) by means of disulfide trapping and voltage clamp techniques. During transitions among the resting-state conformations, KCNE1 positions 36–43 make contacts with KCNQ1 positions 144, 145, and 147 in a parallel fashion. During conformational changes in the activated state, KCNE1 position 40 can make contacts with all three KCNQ1 positions, while the neighboring KCNE1 positions (36, 38, 39, and 41) can make contact with KCNQ1 position 147. Furthermore, KCNQ1 positions 143 and 146 are high-impact positions that cannot tolerate cysteine substitution. To maintain the proper I_Ks channel function, position 143 requires a small side chain with a hydroxyl group, and position 146 requires a negatively charged side chain. These data and the proposed molecular motions provide insights into the mechanisms by which mutations in the extracellular juxtamembranous region of the I_Ks channel impair its function.     

Interspecific differences in drift behaviour between the native <Emphasis Type="Italic">Gammarus pulex</Emphasis> and the exotic <Emphasis Type="Italic">Gammarus roeseli</Emphasis> and possible implications for the invader’s success

“Drifting” is known to subject aquatic invertebrates to intense predation by drift feeding fish. Consequently, interspecific variations in drifting behaviour could lead to differences in predation pressure between coexisting prey species. Predation being an important factor determining the success of invaders, differences in drift patterns could advantage either native or exotic invertebrates through differential predation by native fish predators. The exotic freshwater amphipod (Gammarus roeseli) has now largely colonized Western Europe where it is often found in sympatry with a native species (Gammarus pulex). Here we documented interspecific differences in drifting behaviour that might have favored the invader’s success through differential predation. Benthic and drifting amphipods were sampled three times at the same site to compare the proportion of each species within and between sample types (benthos or drift) across time. Compared with the benthos, where the invader (G. roeseli) was significantly less abundant than the native (G. pulex), G. roeseli was proportionally overrepresented in the drift but displayed a very different drifting pattern. While G. pulex drift rates remained roughly constant over a 24 h period, G. roeseli showed a marked diel periodicity with low diurnal and high nocturnal drift rates. Such drifting behaviour could procure this species with a competitive advantage regarding predation as most drift feeding fish are diurnal. As a result, the native appears more disadvantaged with respect to drift. This may partly explain the ability of G. roeseli to coexist with G. pulex in a habitat more suitable to the native.     

Novel Mutation of the <Emphasis Type="Italic">GPIIIa</Emphasis> Gene in the Russian Population, <Emphasis Type="Italic">Leu40Arg</Emphasis>, Linked to the <Emphasis Type="Italic">Leu33Pro</Emphasis>

Glycoprotein IIb/IIIa complex, a platelet surface fibrinogen receptor, plays a key role in producing primary hemostasis. At present, only a single mutation in the GPIIIa gene, Leu33Pro, and a single mutation in the GPIIb gene, Ile843Ser, has been described. The mutations are known to enhance signaling functions of the receptor and are associated with the development of arterial thromboses. In the present study, we describe a novel GPIIIa mutation, which is T to G nucleotide substitution in position 1585, resulting in the replacement of Leu for Arg in position 40 of the amino acid sequence of the protein.__________Translated from Genetika, Vol. 41, No. 6, 2005, pp. 838–843.Original Russian Text Copyright © 2005 by Sirotkina, Shaydina, Vavilova, Schwartz.     

Visual detection of diminutive floral guides in the bumblebee <Emphasis Type="Italic">Bombus terrestris</Emphasis> and in the honeybee <Emphasis Type="Italic">Apis mellifera</Emphasis>

Many flowers display colour patterns comprising a large peripheral colour area that serves to attract flower visitors from some distance, and a small central, contrastingly coloured area made up by stamens or floral guides. In this study, we scaled down the size of floral guides to detect the minimal size bumblebees (Bombus terrestris) and honeybees (Apis mellifera) require for guidance. We analyzed the approach and the precise contact of the antennal tips with the floral guide of artificial flowers which precedes landing and inspection. Both bumblebees and honeybees were able to make antennal contact with circular floral guides which were 2 mm in diameter; bumblebees performed better than honeybees and antennated also at floral guides smaller than 2 mm. In discrimination experiments with bumblebees, a minimum floral guide size of 2 mm was required for discrimination between artificial flowers with and without floral guides. With increasing experience bumblebees targeted close to the site of reward instead of making antennal contact with the floral guide, whereas honeybees did not alter their initial behaviour with growing experience. Bumblebees and honeybees spontaneously target diminutive floral guides to achieve physical contact with flowers by means of their antennae which helps them to inspect flowers.     

Decreased competiveness of the foodborne pathogen <Emphasis Type="Italic">Campylobacter jejuni</Emphasis> during Co-culture with the hyper-ammonia producing anaerobe <Emphasis Type="Italic">Clostridium aminophilum</Emphasis>

Campylobacter spp. are a leading bacterial cause of human foodborne illness. When cocultured in anaerobic Bolton broth with the hyper-ammonia producing bacterium, Clostridium aminophilum, ammonia accumulation was greater and final growth of Campylobacter jejuni was reduced (CFU ≥ 1.4 log₁₀/mL) compared to that obtained by pure culture controls. Co-culture with the less active ammonia-producing saccharolytic Prevotella albensis had no effect on final C. jejuni concentrations. When co-cultured similarly except with the addition of 10 μmol/L monensin, monensin-susceptible Cl. aminophilum was reduced by 2 to 4 log₁₀ CFU/mL and concentrations of C. jejuni, which is insensitive to monensin, did not differ from its pure culture control. These results suggest that in the absence of added monensin, the hyper ammonia-producing Cl. aminophilum may be able to outcompete asaccharolytic C. jejuni for amino acid substrates and that this competitive ability was eliminated by addition on monensin.     

Duration of the cell cycle phases in mutants for the tumor suppressor <Emphasis Type="Italic">Merlin</Emphasis> in <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

The cell cycle duration was estimated in Drosophila melanogaster mutants for the tumor suppressor Merlin with the use of different approaches. Experiments on induction of mosaic clones in tissues of the larval wing imaginal disc showed that the cell cycle in mutant discs is shorter than that in control. Flow fluorescence cytometry revealed no differences between mutant and normal animals in the relative duration of the cell cycle phases, which suggests proportional shortening of the cell cycle phases. The study with pulselabeled mitoses confirmed these results and showed that the length of the cell cycle is 7 h (S phase duration 3 h) in control individuals and 5 h (S phase duration 2 h) in Merlin gene mutants.     

Genetic diversity of the genus <Emphasis Type="Italic">Lactobacillus</Emphasis> bacteria from the human gastrointestinal microbiome

The species and strain genetic diversity of bacterial cultures belonging to the genus Lactobacillus, which were isolated from the gastrointestinal microbiome of the human population living in the former Soviet Union in the years 1960–1980, was studied. The bacteria demonstrated probiotic characteristics. Phylogenetic analysis of sequences of the gene coding for 16S rRNA detected earlier by us, showed that the gene found in bacteria isolated from the intestinal content of healthy adultsand represented by species L. plantarum, L. helveticus, L. casei/paracasei, L. rhamnosus, and L. fermentum has high homology (97–100%) with this gene in type representatives of the species. The genotypic and strain diversity of cultures was studied using RAPD-PCR and nonspecific primers. This method with the use of the ERIC-1 primer gave reliable and reproducible results as compared that using with M13 and MSP primers and allowed the identification of examined bacteria belonging to the genus Lactobacillus at the level of species and certification at the strain level.     

Vegetation of the aquatic and marshland habitats in the Orava region,including the first records of <Emphasis Type="Italic">Potametum alpini,Potametum zizii</Emphasis> and <Emphasis Type="Italic">Ranunculo-Juncetum bulbosi</Emphasis> in the territory of Slovakia

The vegetation of the aquatic and marshland habitats of the Orava region (north of Slovakia) was studied in 2009, using traditional phytosociological methods. Sixteen aquatic and eighteen marsh plant communities were described within 96 phytosociological relevés by using TWINSPAN with the application of the dominance principle. Three associations, Potametum alpini, Potametum zizii and Ranunculo-Juncetum bulbosi, were found as new communities for Slovakia. Myriophylletum verticillati, Potametum nodosi, Potametum graminei and Alisma gramineum community were recorded in the northernmost localities in Slovakia. Among marsh communities, Calletum palustris is very rare, both in the Orava region and in Slovakia as a whole. According to Ellenberg’s indicator values (EIV), moisture was evaluated as the main ecological gradient. Plant communities are ordered along the first Detrended Correspodence Analysis (DCA) axis in a typical hydroseries (Potametea → Lemnetea → Phragmition communis → Phalaridion arundinaceae, Oenanthion aquaticae and Sparganio-Glycerion → Magnocaricion elatae). The second DCA axis was most correlated with EIV for nutrients. Among the five directly measured ecological characteristics (temperature, pH and conductivity of water, water depth, and substrate type), conductivity of water (0.44, P < 0.01) and substrate type (0.32, P < 0.05) were the statistically significant variables explaining the variability along the first DCA axis.     

Inhibition of biofilm formation by the antisense peptide nucleic acids targeted at the <Emphasis Type="Italic">motA</Emphasis> gene in <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> PAO1 strain

Pseudomonas aeruginosa is a ubiquitous bacterium which is able to attach to many abiotic and biotic surfaces and form biofilms resulting in infections. The motA gene was an essential gene in the early phase of biofilm formation of P. aeruginosa PAO1. In this study, antisense peptide nucleic acids (PNAs) and PNAs conjugated with the peptide (KFF)₃K were used to investigate whether they could mediate gene-specific antisense effects in P. aeruginosa PAO1. We found that antisense (KFF)₃K-PNA targeted at motA gene could inhibit biofilm formation in P. aeruginosa PAO1 in a dose-dependent manner. The minimal effective concentration of this antisense agent was 1 μmol l⁻¹, and the inhibited effect could last for at least 8 h. When compared with the control group, the value of OD570 of P. aeruginosa PAO1 reduced apparently when treated with (KFF)₃K-PNA. The expression of motA was sharply reduced when treated with (KFF)₃K-PNA, but reduced slightly when treated with PNA, and had no reduction when treated with (KFF)₃K. Our results demonstrated that the cell-penetrating peptide of (KFF)₃K improved significantly the antisense inhibition effect of PNA. The (KFF)₃K-PNA conjugates might be used as antisense agent for inhibition of the biofilm formation. This provides exciting possibility for developing new tool for microbial genetic treatment.     

Origin of the Genus <Emphasis Type="Italic">Homo</Emphasis>

The origin of the genus Homo in Africa signals the beginning of the shift from increasingly bipedal apes to primitive, large-brained, stone tool-making, meat-eaters that traveled far and wide. This early part of the human genus is represented by three species: Homo habilis, Homo rudolfensis, and Homo erectus. H. habilis is known for retaining primitive features that link it to australopiths and for being the first stone tool makers. Little is known about H. rudolfensis except that it had a relatively large brain and large teeth compared to H. habilis and that it overlapped in time and space with other early Homo. Our understanding of the paleobiology and evolution of the larger-brained H. erectus is enhanced due to its rich fossil record. H. erectus was the first obligate, fully committed biped, and with a body adapted for modern striding locomotion, it was also the first in the human lineage to disperse outside of Africa. The early members of the genus Homo are the first to tip the scale from the more apish side of our evolutionary history toward the more human one.     

Cell lines from the soft tick <Emphasis Type="Italic">Ornithodoros moubata</Emphasis>

Primary cell cultures (n = 16) were initiated from tissues of embryonic and neonatal larval Ornithodoros moubata following methods developed for hard ticks. After maintenance for 20–25 months in vitro, cell multiplication commenced in surviving cultures, leading to the establishment of six cell lines designated OME/CTVM21, 22, 24, 25, 26 and 27. All lines are maintained at 28°C, with subculture at 2–8 week intervals. The cultures comprise heterogeneous populations of large cells of 15–100 μm in diameter, often with finger-like protrusions and/or intracellular crystals, rarely attached, predominantly floating and forming clumps or hollow multicellular vesicles up to 1 mm in diameter. Attempts to cryopreserve the cells are described. Tick-borne encephalitis virus has been serially passaged ten times in OME/CTVM21 cells without significant decrease in virus production and with no change in its biological properties as shown by the size and morphology of plaques produced in porcine kidney cells.     

Genetic variation within <Emphasis Type="Italic">Symbiodinium</Emphasis> clade B from the coral genus <Emphasis Type="Italic">Madracis</Emphasis> in the Caribbean (Netherlands Antilles)

The internal transcribed spacer (ITS) region was sequenced in symbiotic dinoflagellates (zooxanthellae) from five morphospecies in the genus Madracis. The phylogeny of the symbionts is congruent with a companion phylogeny of the coral host. Comparison with known clade B symbiont ITS types reveals that M. mirabilis contains the B13 symbiont and that the other morphospecies contain the B7 symbiont. Madracis formosa also contains a previously undescribed type. The B7 and B13 symbionts appear to be highly specific to morphospecies in the genus Madracis. The host specificity between the B13 symbionts and its coral host may be the result of co-evolution of the coral-symbiont association and suggests that the brooding species, M. mirabilis, is reproductively isolated. Microhabitat differentiation associated with light utilization independent of depth is discussed.     

Maturation of a eukaryotic cytochrome <Emphasis Type="Italic">c</Emphasis> in the cytoplasm of <Emphasis Type="Italic">Escherichia coli</Emphasis> without the assistance by a dedicated biogenesis apparatus

Maturation of c-type cytochromes involves the covalent and stereospecific enzymatic attachment of a heme b via thioether linkages to two conserved cysteines within apocytochromes. Horse cytochrome c is readily matured into its native holoform in the cytoplasm of E. coli when co-expressed with yeast cytochrome c heme lyase. Here we report the low yield formation of holocytochrome with covalently attached heme also in the absence of heme lyase. This is the first demonstration of in vivo maturation of a eukaryotic cytochrome c in a prokaryotic cytoplasm without the assistance by a dedicated enzymatic maturation system. The assembled cytochrome c can be oxidized by cytochrome c oxidase, indicating the formation of a functional protein. The absorption spectrum is typical of a low spin, six coordinated c-type heme. Nevertheless, minor spectral differences relative to the native cytochrome c, deviation of the midpoint reduction potential and slightly altered kinetic parameters of the interaction with cytochrome c oxidase emphasize the importance of cytochrome c heme lyase in folding cytochrome c into its native conformation.     

Lactobacilli-Host mutualism: &quot;learning on the fly&quot;

Metazoans establish with microorganisms complex interactions for their mutual benefits. Drosophila, which has already proven useful host model to study several aspects of innate immunity and host-bacteria pathogenic associations has become a powerful model to dissect the mechanisms behind mutualistic host-microbe interactions. Drosophila microbiota is composed of simple and aerotolerant bacterial communities mostly composed of Lactobacillaceae and Acetobactereaceae. Drosophila mono- or poly-associated with lactobacilli strains constitutes a powerful model to dissect the complex interplay between lactobacilli and host biologic traits. Thanks to the genetic tractability of both Drosophila and lactobacilli this association model offers a great opportunity to reveal the underlying molecular mechanisms. Here, we review our current knowledge about how the Drosophila model is helping our understanding of how lactobacilli shapes host biology.     

Antioxidant activity in the leaves of <Emphasis Type="Italic">Melilotus albus</Emphasis> and <Emphasis Type="Italic">Trifolium medium</Emphasis> from man-made disturbed habitats in the Middle Urals under the influence of copper

Physiological mechanisms of adaptation to copper-induced stress in two widespread legume plants, white sweet clover (Melilotus albus Merik.) and zigzag clover (Trifolium medium L.), growing in habitats differing in the man-made pollution. An antioxidant plant defense system was activated in response to 10 mM CuSO₄, which is a stress factor. Specific biochemical features related to adaptation to soil contamination with copper were observed in tested plant species. Superoxide dismutase was activated in response to stress in both species from various habitats. M. albus from the impact zone manifested the better capacity of proline accumulation as compared with plants from less polluted habitats. T. medium plants from the impact zone contained more active peroxidase. It was suggested that plants growing for a long time under stressful conditions manifest the greater tolerance to copper ions than plants, which did not experience stress or were subjected to the milder stress.     

Ontogenetic changes in the ecological function of the association behavior between jack mackerel <Emphasis Type="Italic">Trachurus japonicus</Emphasis> and jellyfish

Commensal behavior of jack mackerel Trachurus japonicus (Temminck & Schlegel) with jellyfishes has been widely observed but its ecological function is still unclear. The goal of the present research is to examine the function of association behavior with jellyfish in the laboratory and in field observations with an emphasis on ontogenetic changes. In the laboratory, jack mackerel juveniles (mean standard length (SL) = 11, 19, 38, and 55 mm) were placed in 500-l polycarbonate tanks with two live moon jellyfish, Aurelia aurita (Linné), and one artificial jellyfish made of silicon. Association behavior with either live or artificial jellyfish was visually observed under the following conditions: control, presence of a predator model, before and after feeding live Artemia, 1 h and 3 h after feeding, and at night. Jack mackerel at 11 mm SL associated with both the moon jellyfish and artificial jellyfish, unrelated to the presence of a predator model or feeding. Juveniles at 19 mm associated with moon jellyfish only in the presence of a predator model. Larger juveniles associated with moon jellyfish at 1 h and 3 h after feeding. Thus the ecological function of association was proposed to develop first from school formation, next as a hiding place from predators, and then as a food source. Underwater observations of jack mackerel associating with giant jellyfish Nemopilema nomurai (Kishinouye) in two different areas in the Sea of Japan supported this hypothesis. High predation pressure from benthic piscivorous fishes in the southern area (Tsushima) may encourage association with jellyfish, whereas pressure from pelagic predators in the northern area (Maizuru) may encourage settlement to rocky reef habitats in temperate waters. Thus the jellyfish may also function as a vehicle for the northward migration of this species. Guest editors: K. A. Pitt & J. E. Purcell Jellyfish Blooms: Causes, Consequences, and Recent Advances     

Study of the enhancer-blocking activities of new boundaries in the <Emphasis Type="Italic">bithorax</Emphasis> complex of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

It was shown earlier that the Mcp, Fab-7, and Fab-8 boundaries of the bithorax complex contain insulators that effectively block the enhancers of the yellow and white genes. Other boundaries have not been studied so far. The recent mapping of binding sites for the insulator protein dCTCF in the regulatory regions of the bithorax complex genes permitted the Fab-3, Fab-4, and Fab-6 boundaries to be localized. Here, we showed that, despite the presence of dCTCF-binding sites, fragments of the Fab-3, Fab-4, and Fab-6 boundaries do not exhibit the properties of insulators in the model system with the yellow and white genes. Moreover, in some regions of the genome the Fab-4 and Fab-6 boundaries display the properties of silencers.