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Ranunculus oblitus, a new species of Ranunculus section Batrachium, is described from South America. The species is significantly different from the European laminar-leaved species R. aquatilis, and the Holarctic submerged species R. trichophyllus. It resembles the North Asian-North American species R. mongolicus differing by narrower petals, larger and fewer achenes. Available molecular data indicate affiliation to North American taxa of the R. trichophyllus group, especially R. porteri. The species occurs along the west coast of the continent from southern Peru to southern Chile, extending from sea level to an elevation of 4500 m a.s.l. in the Andes. There is some evidence that a second native Batrachium species occurs in South America.

Seagrasses comprise the only submerged marine angiosperms, a feat of adaptation from three independent freshwater lineages within the Alismatales. These three parallel lineages offer the unique opportunity to study convergent versus lineage-specific adaptation to a fully marine lifestyle. Here, we present chromosome-level genome assemblies from a representative species of each of the seagrass lineages -Posidonia oceanica(Posidoniaceae),Cymodocea nodosa(Cymodoceaceae), andThalassia testudinum(Hydrocharitaceae)-along with an improved assembly forZostera marina(Zosteraceae). We also include a draft genome ofPotamogeton acutifolius, a representative of Potamogetonaceae, the freshwater sister lineage to the Zosteraceae. Genome analysis reveals that all seagrasses share an ancient whole genome triplication (WGT) event, dating to the early evolution of the Alismatales. An additional whole genome duplication (WGD) event was uncovered forC. nodosaandP. acutifolius. Dating of ancient WGDs and more recent bursts of transposable elements correlate well with major geological and recent climatic events, supporting their role as rapid generators of genetic variation. Comparative analysis of selected gene families suggests that the transition from the submerged-freshwater to submerged-marine environment did not require revolutionary changes. Major gene losses related to, e.g., stomata, volatiles, defense, and lignification, are likely a consequence of the submerged lifestyle rather than the cause (‘use it or lose it’). Likewise, genes, often retained from the WGD and WGT, were co-opted for functions requiring the alignment of many small adaptations (‘tweaking’), e.g., osmoregulation, salinity, light capture, carbon acquisition, and temperature. Our ability to manage and conserve seagrass ecosystems depends on our understanding of the fundamental processes underpinning their resilience. These new genomes will accelerate functional studies and are expected to contribute to transformative solutions — as continuing worldwide losses of the ‘savannas of the sea’ are of major concern in times of climate change and loss of biodiversity.

The central part of the Kuril Archipelago (the Russian Far East) remains the least studied due to its poor accessibility. Such insufficient floristic data lead to uncertainties in the floristic subdivision of the Kuril Islands. We aimed to explore the vascular flora of the Simushir island, the largest one among the Middle Kurils. We revealed 24 new species for the flora of Simushir or Middle Kurils in general, including three species (Callitriche anceps, Carex meyeriana, and Ribes nigrum) that are new for the whole Kuril Archipelago. One-third of species new for Simushir are alien. Almost all the rest of the new species are associated with special types of habitats and can be found only after a detailed study of the island. We reported six new aquatic species for the Middle Kurils, refuting the earlier idea of extreme poverty of the Middle Kurils’ aquatic flora. We found no grounds for drawing a floristic border within the Northern and Middle Kurils, as the floristic similarity between Onekotan (oceanic Northern Kurils), continental Northern Kurils, and Simushir has the same magnitude.

Cefazolin is a first-line antibiotic to treat infection related to deployment-associated blast injuries. Prior literature demonstrated a 331% increase cefazolin liver area under the curve (AUC) in mice exposed to a survivable blast compared with controls. We repeated the experiment, validated the findings, and established a semimechanistic two-compartment pharmacokinetic (PK) model with effect compartments representing the liver and skin. We found that blast statistically significantly increased the pseudo–partition coefficient to the liver by 326% (95% confidence interval: 76–737%), which corresponds to the observed 331% increase in cefazolin liver AUC described previously. To a lesser extent, plasma AUC in blasted mice increased 14–45% compared with controls. Nevertheless, the effects of blast on cefazolin PK were transient, normalizing by 10 hours after the dose. It is unclear as to how this blast effect t emporally translates to humans; however, given the short-lived effect on PK, there is insufficient evidence to recommend cefazolin dosing changes based on blast overpressure injury alone. Clinicians should be aware that cefazolin may cause drug-induced liver injury with a single dose and the risk may be higher in patients with blast overpressure injury based on our findings. SIGNIFICANCE STATEMENT Blast exposure significantly, but transiently, alters cefazolin pharmacokinetics in mice. The questions of whether other medications or potential long-term consequences in humans need further exploration.

Flora of the southern Kuril continental islands is extremely diverse due to the complex history of geology and climate, fluctuating connections with other territories in the past, and the habitat diversity of the archipelago. It is likely well-investigated due to the long history of botanical studies, and floristic findings are expected only in taxonomically difficult plant groups. To test this assumption, we carried out a special investigation of the aquatic vascular plants on the Lesser Kuril Ridge (isl. Shikotan, Polonskogo, Yurii, Tanfilieva, Zelyonyi) and isl. Kunashir. In line with our expectations, we revealed nine taxa that have never been reported for the whole Kuril archipelago (including six new for Sakhalin floristic province of Russia: Potamogeton manchuriensis, P. × sparganiifolius, P. × variifolius, P. × vepsicus, Sagittaria aginashi, Sparganium subglobosum); all of them are aquatic ones. We found 24 species that are new for the Lesser Kuril Ridge or the whole Southern Kurils from which only about a half were aquatic. Unexpectedly, we found 53 mainly terrestrial species that are new for the Little Kurils (the Lesser Kuril Ridge with exception of isl. Shikotan), and substantially supplemented floristic lists of each island.

Floristic subdivision of the northern part of the Kuril archipelago (Russian Far East) remains controversial. Such uncertainty in biogeographical subdivision could be caused by insufficient floristic data due to poor accessibility of mainly uninhabited northern Kuril islands. We aimed to explore the flora of the largest uninhabited northern Kuril island Onekotan to clarify its position in floristic subdivision. All the 19 species that we added to the known flora of Onekotan island grow on Paramushir and often on some other northern Kurils. Additionally, we revealed two species (Minuartia rubella and Poa lanata) that are new for the whole Kuril archipelago. Our findings demonstrated that floristic similarity between Onekotan and the both large northern continental Kuril islands (Shumshu and Paramushir) is higher than it was demonstrated before. However, discussion of floristic subdivision of the Northern Kurils is premature unless all the islands are sufficiently studied. Keywords: Biogeographic subdivision, Cluster analysis, Field survey, Kuril islands, Vascular plants

We present current information on the conservation of aquatic vascular plants in West and East Siberia and the Russian Far East. This includes the region from the Ural Mountains in the west to the eastern seaboard of Russia from Kamchatka and Chukotka in the north to Vladivostok in the south, including Sakhalin, the Kuril and Commander Islands. A list of aquatic vascular plant species protected in the region is presented with an indication of their conservation status derived from regional Red Data Books, combined with population trend data from the literature, as well as field observations made by the authors. The region as a whole supports a total of 246 aquatic plant species, of which 96 are listed as threatened in regional Red Lists. The main threats to these species are habitat degradation, eutrophication and pollution of water bodies as a consequence of human activity and climate change. Many species which are specialized, relict or endemic, and others occurring here on the edge of their range, are vulnerable because of these factors. The main conservation action needed includes protection of natural habitats, establishment of monitoring protocols for the most severely threatened species and research into the autecology of threatened species. There is also a need to resolve taxonomic questions obstructing conservation.

Most of Utricularia taxa in temperate Eurasia are poorly distinguished by vegetative characters, while flowering is rare in some of them. Thus, we aimed to clarify the taxonomy and distribution of temperate Eurasian Utricularia. We supplemented the existing results of intensive morphological and genetic studies of Utricularia mainly from West and Central Europe with our data from East Europe and North Asia. We combined molecular barcoding (nuclear ITS and plastid rps16 regions) and fingerprinting (ISSR) techniques (74 collection localities) with morphological analysis of herbarium collections (more than 1800 specimens from 16 herbaria) and numerous natural populations with a special focus on hardly accessible Siberian and Far Eastern regions of Russia. We demonstrated that temperate Eurasian Utricularia taxa could be easily discriminated with barcoding approach if the hybridization is taken into account. Genetic and morphological variation of U. macrorhiza in comparison with U. vulgaris supported the treatment of the former as a separate species. We have revealed U. tenuicaulis previously treated as fertile lineage of U. australis and its sterile hybrid with U. macrorhiza (U. × japonica) in the Russian Far East and the latter additionally in southwestern East Siberia, outside their known distribution. For the first time we evidenced hybridization between U. tenuicaulis and U. vulgaris. The sterile hybrid (U. × neglecta) is widely distributed in Europe and West Siberia. In the Northern Hemisphere, plants initially referred to as sterile U. australis represent in fact U. × japonica and U. × neglecta, and the name U. australis should not be applied to any of them. Utricularia ochroleuca and U. stygia represent a complex of sterile forms with continuous morphological variation (U. × ochroleuca) originated from hybridization between U. intermedia and U. minor. Almost forgotten Japanese species U. multispinosa appeared to be sister to all temperate Eurasian species, and it was revealed for the first time in the southern Russian Far East.We have refined the distributions of Utricularia species in East Europe and North Asia and have shown that extant areas of U. macrorhiza and U. vulgaris are explained by the temperature regime – an important insight in context of global climate change.

Introduction: Sepsis is one of the leading causes of death in military and civilian hospitals. Rapid identification of involved pathogens is a key step for appropriate diagnosis, treatment and ultimately survival. Current diagnostics tools are either very bulky and not deployment ready, or require a long time to provide results. Given these obstacles, new solutions are urgently needed. Optomagnetic Imaging Spectroscopy (OMIS) is novel technology successfully used for the detection of cancer cells and viruses. OMIS has high sensitivity due to recording the unpaired and paired electrons of sample material. Furthermore, machine learning that uses the algorithms random forest (RF) classifier and artificial neural network (ANN) is integrated into the technology to enhance detection. Here we evaluated the feasibility of OMIS for the detection of bacteria in blood. Methods: We used commercially available human blood spiked with a defined concentration multidrug resistant Staphylococcus aureus derived from a clinical isolate. Final concentrations of bacteria of 1 × 106, 1 × 105 and 1 × 104 CFU/mL corresponding to High (H), Medium (M) and Low (L) concentrations respectively. A total of 240 samples (60 samples per concentration as well as 60 samples of sterile blood (N)) was imaged, and the data were analyzed using random forest classifier and artificial neural network. Images for the training set and validation sets were separately obtained and used for comparison against true positive values (confirmatory plating on the nutrient agar). Results: The average score of classification samples in the correct category (N, L, M, H) one-by-one was 94% for the ANN algorithm, while for the RF algorithm accuracy was 93% (average means that three times different 40 samples (of 240 samples) were chosen, and each prediction test had different sample mixtures). The closeness of the two values of accuracy strongly indicates that the input data (interaction of light with paired and unpaired electrons) and output data (classification N, L, M, H concentration of bacteria) are correlated.

High morphological variation of Typha L. species (Typhaceae) inspires some authors to describe new taxa. We aim to test genetic distinctiveness of some taxa reported in East Europe on morphological basis to verify their taxonomical status. We use sequences of intergenic spacer rpl32-trnL of cpDNA that was shown to be a reliable molecular marker in non-hybrid Typha species. We found that T. caspica Pobed., T. elata Boreau, T. incana Kapit. et Dyukina, T. krasnovae Doweld, T. rossica Krasnova are genetically identical to T. latifolia L., as well as T. foveolata Pobed., T. austro-orientalis Mavrodiev, T. elatior Boenn., T. angustata Bory et Chaub., T. linnaei Mavrodiev et Kapit. to T. angustifolia L. Thus, until some additional evidence of their distinctiveness is not found, we suggest to treat T. caspica, T. elata, T. krasnovae, T. rossica as synonyms of T. latifolia, while T. foveolata, T. austro-orientalis, T. elatior, T. angustata should be synonymized with T. angustifolia. Consequently, T. linnaei is a superfluous name (coined in attempts of neotypification T. angustifolia) and should be also considered synonymous to the latter. The hypothesis of hybrid origin of T. incana should be tested further with microsatellite DNA repeats – if correct, this would indicate T. latifolia as plastid donor.

Modern combat-related injuries are often associated with acute polytrauma. As a consequence of severe combat-related injuries, a dysregulated immune response results in serious infectious complications. The gram-negative bacterium Pseudomonas aeruginosa is an opportunistic pathogen that often causes life-threatening bloodstream, lung, bone, urinary tract, and wound infections following combat-related injuries. The rise in the number of multidrug-resistant P. aeruginosa strains has elevated its importance to civilian clinicians and military medicine. Development of novel therapeutics and treatment options for P. aeruginosa infections is urgently needed. During the process of drug discovery and therapeutic testing, in vivo testing in animal models is a critical step in the bench-to-bedside approach, and required for Food and Drug Administration approval. Here, we review current and past literature with a focus on combat injury-relevant animal models often used to understand infection development, the interplay between P. aeruginosa and the host, and evaluation of novel treatments. Specifically, this review focuses on the following animal infection models: wound, burn, bone, lung, urinary tract, foreign body, and sepsis.

Aims: To create a comprehensive, consistent and unequivocal phytosociological classification of European marsh vegetation of the class Phragmito-Magnocaricetea. Location: Europe. Methods: We applied the Cocktail method to a European data set of 249, 800 vegetation plots. We identified the main purposes and attributes on which to base the classification, defined assignment rules for vegetation plots, and prepared formal definitions for all the associations, alliances and orders of the class Phragmito-Magnocaricetea using formal logic. Each formula consists of the combination of “functional species groups”, cover values of individual species, and in the case of high-rank syntaxa also of “discriminating species groups” created using the Group Improvement (GRIMP) method. Results: The European Phragmito-Magnocaricetea vegetation was classified into 92 associations grouped in 11 alliances and six orders. New syntaxa (previously invalidly published according to the International Code of Phytosociological Nomenclature) were introduced: Bolboschoeno maritimi-Schoenoplection tabernaemontani, Glycerio maximae-Sietum latifolii, Glycerio notatae-Veronicetum beccabungae, Schoenoplectetum corymbosi and Thelypterido palustris-Caricetum elongatae. Based on a critical revision, some other syntaxa were rejected or excluded from the class Phragmito-Magnocaricetea. Conclusions: This work provides the first consistent classification of the class Phragmito-Magnocaricetea at the European scale, which is an important tool for nature conservation. Our classification largely respects previously existing concepts of syntaxa, but it also proposes modifications to the recently published EuroVegChecklist. This work also provides a protocol that can be used for extending the current classification to new syntaxa and geographical regions.

Possible routes in which aquatic plants have spreaded across their vast ranges from ancestral areas and refugia still remain poorly known. We have chosen Eurasian yellow water-lilies (Nuphar Sm. sect. Nuphar, Nymphaeaceae) as a model group for a wide-scale phylogeographical study as they represent a common component of the continental freshwater flora. To elucidate the history of diversification of the section Nuphar, we sequenced nuclear ribosomal ITS and chloroplast intergenic spacers (trnH-psbA, trnL–trnF) from 117 localities from almost all the section area. Sequence data were analysed with a statistical parsimony approach using the network algorithm. We also incorporated data on morphological variation and pollen viability. The section Nuphar originated and diversified into several evolutionary lineages in Eastern Asia. Two lineages, represented by N. pumila and N. lutea, spread from the Russian Far East westwards to Siberia and further to Europe. Nuphar pumila also migrated from the Far East to North America (where it is referred to as N. microphylla). Nuphar lutea colonized deglaciated north-eastern Europe not only from the south, but also from the Siberian refugia. Nuphar lutea and N. pumila hybridize rarely in Eastern Europe and Asia and warrant species status. We provide the first evidence, based on a phylogeographical approach, for the origin and diversification of aquatic flowering plants in Eastern Asia. Our results indicate that phylogeographic analysis on the area-wide scale is one of the most efficient ways to deduce possible routes in which aquatic plants have spread across their total range from ancestral areas and refugia.

Although aquatic plants usually are less taxonomically diverse than related terrestrial groups, genetic studies could reveal groups of sibling species and thus increase taxonomic resolution. We hypothesised that different age and environmental diversity of water bodies in southern Siberia caused diversification within Stuckenia pectinata s.l. (Potamogetonaceae). To test this hypothesis we studied nuclear (ITS) and plastid (rpl32-trnL) genetic variation of 37 populations of S. pectinata from eastern Europe, the Russian Far East and southern Siberia with special emphasis on the latter. Plastid DNA variability within S. pectinata s.l. was found to be structured neither geographically nor taxonomically. We revealed strong ITS differentiation within S. pectinata s.l. in southern Siberian water bodies with different combinations of age and salinity. We discuss possible causes of such differentiation. We found a striking contrast between the absence of ITS variability across almost all of Europe colonized by the only ribotype, and relatively high ITS variability in southern Siberia. This contrast could be explained by the different history of young European populations that could have appeared as a result of recent northwards expansion following the Last Glacial Maximum, and the relatively old ones of southern Siberia. The absence of clear correspondence between genetic variation and morphological variability does not sufficiently support delimitation of species within Siberian S. pectinata s.l. (such as S. chakassiensis and S. macrocarpa).

Isoetes L. is a cosmopolitan genus comprising about 200 species, almost half of them being allo- or autopolyploids. We investigated the origin of decaploid I. lacustris using next generation sequencing (NGS). We sequenced the second intron of LEAFY (LFYint2) and analysed the morphology of seven samples of I. lacustris from five localities from East Europe and West Siberia. We have shown that I. lacustris is an allopolyploid having in its genome the subgenomes of the North American diploid I. prototypus, tetraploid I. tuckermanii (which contains subgenomes of diploid I. viridimontana and unknown species), and one more unknown diploid progenitor. NGS showed high reproducibility, demonstrating the same sets of LFYint2 copies in all the samples. The potential fifth subgenome has not been found, most likely due to a loss of the LEAFY gene as a result of subgenome reduction, as is characteristic of polyploids. These data imply that the ancestor of I. lacustris most likely originated in the north-east of North America (New England and Acadian region) where I. prototypus, I. tuckermanii and I. viridimontana co-occur, and that I. lacustris then spread to Eurasia via the North Atlantic Land Bridge. NGS-based amplicon sequencing has the potential to evaluate the ratio of frequency of different copies and to distinguish allopolyploidy and autopolyploidy (if the PCR efficiency of each of the copies is taken into account). This is especially useful, given that both play a prominent role in Isoetes evolution. We also demonstrate that widely adopted cloning of LFYint2 in Isoetes leads to biased results due to the amplification errors.

Potamogeton is a cosmopolitan genus of aquatic plants comprising ca. 72 species and 99 hybrids. Hybridization and polyploidization events are characteristic of its evolutionary history, thus molecular approach is desirable for confirmation of species and hybrids determinations. In this study, we tested the suitability of low-copy nuclear gene PHYB as a barcoding marker, as this gene was shown to have sufficient level of variability in Potamogeton in preceding studies. We cloned and sequenced part of gene PHYB exon 1 for 19 samples of 8 Potamogeton species. Our sampling took place in East Europe, Siberia, Russian Far East and NE North America. The obtained sequences were used to construct a genetic network. We report some features of PHYB which hamper its application as a barcode in Potamogeton. Most of the tetraploid species provided two sets of dissimilar PHYB sequences, which probably stand for two paralogs. PCR-derived errors, such as recombination and random substitutions, shifted the position of some sequences in the network. In addition, one haplotype was shared between two closely related species, breaking the species-specificity of PHYB barcode. Even though it may provide higher resolution for hybrid identification than ITS or 5S-NTS, using it as a marker for standard barcoding in this genus is not the best option.

Eight species of charophytes have been found in the vast area of the ubiquitous permafrost in Far North-East Asia (i.e. the Republic of Sakha (Yakutia), the Magadan Region, and the Chukotka Autonomous Area, Russia): Chara contraria, C. globularis, C. strigosa, C. virgata, Nitella flexilis, N. opaca, N. wahlbergiana and Tolypella canadensis. Charophytes are found in a variety of water bodies and watercourses in areas with various thicknesses of permafrost, within the boreal and subarctic climate zones. Charophyte habitats are mostly associated with the distribution of carbonate rocks. The number of species and their records decrease towards north and east mainly due to shortening of the vegetation period. The highest density of records of charophytes and their most northern records are in river valleys, where the topography and heating effect of the river mitigate the influence of climate and permafrost. This association can be used to model and predict charophyte distribution in periglacial areas during glaciation. Widespread eurytopic species with a flexible life cycle, Chara contraria and C. globularis, are found in valley water bodies due to their ability to withstand environmental variation associated with marked changes in water temperature and flood disturbance. Rare perennial species such as C. strigosa and Tolypella canadensis are represented in deep lakes with less variation in environmental conditions. This paper discusses the distribution, habitat and life history strategies of charophytes that exist in the severe conditions of the permafrost area in Far North-East Asia based on previously published and new data.

Two species of Isoetes (Isoetaceae) occur in the Kamchatka Peninsula, northern Russian Far East — I. asiatica (Makino) Makino and I. maritima Underw. The distribution and ecology of these species are discussed. A hybrid of these species was found alongside its parental species in south Kamchatka in the shallows of a lake impacted by humans, and it is formally described here as I.×paratunica D. F. Brunton, Mochalova & A. A. Bobrov. It is the first Isoёtes hybrid discovered in Russia.

A number of bacterial pathogens require the ZnuABC Zinc (Zn2+) transporter and/or a second Zn2+ transport system to overcome Zn2+ sequestration by mammalian hosts. Previously we have shown that in addition to ZnuABC, Yersinia pestis possesses a second Zn2+ transporter that involves components of the yersiniabactin (Ybt), siderophore-dependent iron transport system. Synthesis of the Ybt siderophore and YbtX, a member of the major facilitator superfamily, are both critical components of the second Zn2+ transport system. Here we demonstrate that a ybtX znu double mutant is essentially avirulent in mouse models of bubonic and pneumonic plague while a ybtX mutant retains high virulence in both plague models. While sequestration of host Zn is a key nutritional immunity factor, excess Zn appears to have a significant antimicrobial role in controlling intracellular bacterial survival. Here, we demonstrate that ZntA, a Zn2+ exporter, plays a role in resistance to Zn toxicity in vitro, but that a zntA zur double mutant retains high virulence in both pneumonic and bubonic plague models and survival in macrophages. We also confirm that Ybt does not directly bind Zn2+in vitro under the conditions tested. However, we detect a significant increase in Zn2+-binding ability of filtered supernatants from a Ybt+ strain compared to those from a strain unable to produce the siderophore, supporting our previously published data that Ybt biosynthetic genes are involved in the production of a secreted Zn-binding molecule (zincophore). Our data suggest that Ybt or a modified Ybt participate in or promote Zn-binding activity in culture supernatants and is involved in Zn acquisition in Y. pestis.

Bacterial pathogens must overcome host sequestration of zinc (Zn(2+) ), an essential micronutrient, during the infectious disease process. While the mechanisms to acquire chelated Zn(2+) by bacteria are largely undefined, many pathogens rely upon the ZnuABC family of ABC transporters. Here we show that in Yersinia pestis, irp2, a gene encoding the synthetase (HMWP2) for the siderophore yersiniabactin (Ybt) is required for growth under Zn(2+) -deficient conditions in a strain lacking ZnuABC. Moreover, growth stimulation with exogenous, purified apo-Ybt provides evidence that Ybt may serve as a zincophore for Zn(2+) acquisition. Studies with the Zn(2+) -dependent transcriptional reporter znuA::lacZ indicate that the ability to synthesize Ybt affects the levels of intracellular Zn(2+) . However, the outer membrane receptor Psn and TonB as well as the inner membrane (IM) ABC transporter YbtPQ, which are required for Fe(3+) acquisition by Ybt, are not needed for Ybt-dependent Zn(2+) uptake. In contrast, the predicted IM protein YbtX, a member of the Major Facilitator Superfamily, was essential for Ybt-dependent Zn(2+) uptake. Finally, we show that the ZnuABC system and the Ybt synthetase HMWP2, presumably by Ybt synthesis, both contribute to the development of a lethal infection in a septicaemic plague mouse model.

The second messenger molecule cyclic diguanylate (c-di-GMP) is essential for Y. pestis biofilm formation that is important for blockage-dependent plague transmission from fleas to mammals. Two diguanylate cyclases (DGCs) HmsT and Y3730 (HmsD) are responsible for biofilm formation in vitro and biofilm-dependent blockage in the oriental rat flea Xenopsylla cheopis, respectively. Here, we have identified a tripartite signaling system encoded by the y3729-y3731 operon that is responsible for regulation of biofilm formation in different environments. We present genetic evidence that a putative inner membrane-anchored protein with a large periplasmic domain Y3729 (HmsC) inhibits HmsD DGC activity in vitro while an outer membrane Pal-like putative lipoprotein Y3731 (HmsE) counteracts HmsC to activate HmsD in the gut of X. cheopis. We propose that HmsE is a critical element in transduction of environmental signal(s) required for HmsD-dependent biofilm formation.

Based on the current study, the clinical characteristics of unipolar depression in the clinical picture of schizophrenia with the paroxysmal type of disease course are presented. Given the concomitant depression with phobic symptoms, the following clinical variants are marked: depression with generalized social phobia and/or anthropophobia and depression with generalized pathological body sensations and hypochondriacal phobias. In other words, we are talking about a necessity to allocate a special type of schizophrenia with affective structure episodes and comorbid neurosis-like symptoms. Information on the basic treatment strategy of schizophrenia with depressive structure episodes and comorbid neurosis-like symptoms in everyday psychiatric practice is also provided.

Cyclic di-GMP (c-di-GMP) is a signalling molecule that governs the transition between planktonic and biofilm states. Previously, we showed that the diguanylate cyclase HmsT and the putative c-di-GMP phosphodiesterase HmsP inversely regulate biofilm formation through control of HmsHFRS-dependent poly-β-1,6-N-acetylglucosamine synthesis. Here, we systematically examine the functionality of the genes encoding putative c-di-GMP metabolic enzymes in Yersinia pestis. We determine that, in addition to hmsT and hmsP, only the gene y3730 encodes a functional enzyme capable of synthesizing c-di-GMP. The seven remaining genes are pseudogenes or encode proteins that do not function catalytically or are not expressed. Furthermore, we show that HmsP has c-di-GMP-specific phosphodiesterase activity. We report that a mutant incapable of c-di-GMP synthesis is unaffected in virulence in plague mouse models. Conversely, an hmsP mutant, unable to degrade c-di-GMP, is defective in virulence by a subcutaneous route of infection due to poly-β-1,6-N-acetylglucosamine overproduction. This suggests that c-di-GMP signalling is not only dispensable but deleterious for Y. pestis virulence. Our results show that a key event in the evolution of Y. pestis from the ancestral Yersinia pseudotuberculosis was a significant reduction in the complexity of its c-di-GMP signalling network likely resulting from the different disease cycles of these human pathogens.

Iron acquisition from the host is an important step in the pathogenic process. While Yersinia pestis has multiple iron transporters, the yersiniabactin (Ybt) siderophore-dependent system plays a major role in iron acquisition in vitro and in vivo . In this study, we determined that the Ybt system is required for the use of iron bound by transferrin and lactoferrin and examined the importance of the Ybt system for virulence in mouse models of bubonic and pneumonic plague. Y. pestis mutants unable to either transport Ybt or synthesize the siderophore were both essentially avirulent via subcutaneous injection (bubonic plague model). Surprisingly, via intranasal instillation (pneumonic plague model), we saw a difference in the virulence of Ybt biosynthetic and transport mutants. Ybt biosynthetic mutants displayed an ∼24-fold-higher 50% lethal dose (LD 50 ) than transport mutants. In contrast, under iron-restricted conditions in vitro , a Ybt transport mutant had a more severe growth defect than the Ybt biosynthetic mutant. Finally, a Δ pgm mutant had a greater loss of virulence than the Ybt biosynthetic mutant, indicating that the 102-kb pgm locus encodes a virulence factor, in addition to Ybt, that plays a role in the pathogenesis of pneumonic plague.

We have found a taxonomically unclear linear-leaved Potamogeton (section Graminifolii , Potamogetonaceae) in Central Yakutia (Asian Russia). This form resembles P . friesii and P . pusillus , two common species in the republic, and the mainly European species P . rutilus and North American P . strictifolius . These species, except P . strictifolius , did not differ by variation of the nuclear ITS region. The chloroplast markers petL-psbE and rpl32-trnL clearly separated the unclear Yakutian plants from P . friesii and P . pusillus , and the latter marker revealed similarity between the European P . rutilus and the Yakutian samples. The latter fit well within the morphological circumscription of P . rutilus . We confirmed the presence of P . rutilus in five localities in Central Yakutia and 13 more in other regions of North Asia. These records greatly extends to the east the distribution range of this species known before mainly west of the Middle Volga. Potamogeton rutilus prefers clean, mainly mesotrophic lakes with alkaline waters, and occurs in coastal areas or in limestone and sandstone catchments. The species usually grow in deep waters on silt-sandy bottom, in species-rich communities. It is sensitive to pollution and competition with more robust aquatic plants. Due to local distribution and specific habitat requerments P . rutilus can be regarded as threatened species and deserve the category Vulnerable in regional and global Red Lists.

Primarily, three operons, hmsHFRS, hmsT and hmsP, are responsible for the development of a Yersinia pestis biofilm, which is essential for blockage-dependent transmission of plague from fleas to mammals. Here, using specific antibodies, a polymeric beta-1,6-N-acetyl-d-glucosamine-like polysaccharide was detected in the extracellular matrix of hmsHFRS-dependent Y. pestis biofilm. The production of this exopolysaccharide (EPS) was controlled by diguanylate cyclase HmsT and EAL domain phosphodiesterase HmsP, acting as positive and negative regulators respectively. Cellular compartmentalization of soluble segments of Hms inner membrane proteins, including the putative glycosyltransferase domain of HmsR, the diguanylate cyclase/GGDEF domain of HmsT and the phosphodiesterase/EAL domain of HmsP, was determined by a combination of topology prediction algorithms and construction of C-terminal translational fusions with beta-galactosidase and alkaline phosphatase. Multiple interactions of Hms inner membrane proteins were detected using bacterial cAMP based two-hybrid system. Biochemical analyses confirmed some of these protein-protein interactions. Our results indicate that synthesis and regulation of the Y. pestis biofilm EPS occurs in the cytoplasm by a proposed Hms enzymatic complex.

Yersinia pestis, the causative agent of bubonic, septicemic and pneumonic plague, encodes a multitude of Fe transport systems. Some of these are defective due to frameshift or IS element insertions, while others are functional in vitro but have no established role in causing infections. Indeed only 3 Fe transporters (Ybt, Yfe and Feo) have been shown to be important in at least one form of plague. The yersiniabactin (Ybt) system is essential in the early dermal/lymphatic stages of bubonic plague, irrelevant in the septicemic stage, and critical in pneumonic plague. Two Mn transporters have been characterized (Yfe and MntH). These two systems play a role in bubonic plague but the double yfe mntH mutant is fully virulent in a mouse model of pneumonic plague. The same in vivo phenotype occurs with a mutant lacking two (Yfe and Feo) of four ferrous transporters. A role for the Ybt siderophore in Zn acquisition has been revealed. Ybt-dependent Zn acquisition uses a transport system completely independent of the Fe-Ybt uptake system. Together Ybt components and ZnuABC play a critical role in Zn acquisition in vivo. Single mutants in either system retain high virulence in a mouse model of septicemic plague while the double mutant is completely avirulent.

The taxa of Ranunculus section Batrachium (Ranunculaceae) have been variably and unsatisfactorily treated in North Europe. Since the description of Ranunculus schmalhausenii ( Batrachium dichotomum ), probably the most common species in the area, its taxonomic status and identity have been unclear and differently implied. In the majority of treatments, individuals of R . schmalhausenii were ascribed to R . peltatus but sometimes also to the other morphologically similar, heterophyllous taxa. Based on detailed morphological study combined with geographical, ecological and biological evaluation the separate species status of this taxon was finally evidenced. The additive ITS polymorphism pattern of R . schmalhausenii confirmed its hybridogenous origin, however identification of the parental species was impeded by the heterogeneous character of the polymorphism detected. Genetic variation expressed by R . schmalhausenii samples may provide evidence of its multiple origin and suggests sexual reproduction of the taxon. Analysis of a sequence variation of two noncoding cp DNA regions, namely psb E- pet L and rpl 32 -trn L, showed that individuals of R . schmalhausenii inherited cp DNA from two lineages of Batrachium , indicating that this taxon was created at least in two separate hybridization events. Ranunculus schmalhausenii may have originated from sexual ancestral species as multiple created hybrids which have been stabilized by polyploidisation. Genetic structure of R. schmalhausenii is somehow similar to also hybridogenous R. penicillatus . In this study, a detailed morphological, geographical, ecological, and biological description of R . schmalhausenii was presented and the differences between this species and similar taxa were outlined. The name was lectotypified and its synonymy was provided. In contrast to many other heterophyllous species of Ranunculus section Batrachium , R . schmalhausenii occurs mainly in young, postglacial landscapes of Fennoscandia, prefering deep and clear waters with current or wave action and a hard bottom, which perfectly corresponds with a relict, postglacial nature of the species. The species probably presents an example of rapid hybrid speciation (less than 10 000 years) in postglacial environment of North Europe and may be considered as endemic to Fennoscandia. Moreover, R . schmalhausenii , as a weak competitor and pollution sensitive taxon, can be regarded as an indicator of clean waters. Phylogenetic relations within section Batrachium indicates convergent evolution of some species and two cases of possible cp DNA capture.

The paper presents new records for 20 vascular plant species from 13 Eurasian countries. Four taxa (Calamagrostis sichuanensis, Klasea dissecta, Ptilagrostis milleri and Stipa klimesii) are reported from China, four (Aconogonon valerii, Carex siderosticta, Poa tanfiljewii and Potamogeton × subobtusus) from Russia, three (Amorpha fruticosa, Carduus acanthoides and Plantago minuta) from Tajikistan, two (Achillea sergievskiana and Delphinium barlykense) from Kazakhstan, one (Calamagrostis effusiflora) from Bhutan and India, one (Campanula wolgensis) from Mongolia, one (Orobanche coerulescens) from Georgia, two (Dysphania geoffreyi and Ptilagrostis milleri) from Nepal, one (Stipa × alaica) from Afghanistan, one (Stipa × manrakica) from Kyrgyzstan, one (Ranunculus × gluckii) from Poland and one (Sporobolus cryptandrus) from Italy. Four of the taxa presented (Amorpha fruticosa, Carduus acanthoides, Carex siderosticta and Sporolobus cryptandrus) are regarded as alien to the studied areas, whereas the remaining 16 are native elements to the flora of the countries. For each species synonyms, general distribution, habitat preferences, taxonomy with remarks on recognition and differentiation of the species from the most similar taxa occurring in a given country, as well as a list of recorded localities (often far from the previously known areas) are presented. Based on the spikelet morphology, we have proposed in Ptilagrostis a new section Barkworthia M. Nobis, A. Nobis & A. Nowak, which comprises two species Ptilagrostis yadongensis and Ptilagrostris milleri, with distinctly unequal glumes, lemmas and paleas.

The paper presents new records for 18 vascular plant species from six Eurasian countries. Three taxa (Lepidium densiflorum, Stipa czerepanovii, Xanthium albinum) are reported from Kazakhstan, one (Ranunculus schmakovii) from Mongolia, three (Dianthus campestris, Ranunculus kauffmannii, Viola suavis) from Poland, five (Eragrostis amurensis, Linum catharticum, Ludwigia peploides subsp. stipulacea, Pyrethrum mikeschinii, Solidago canadensis) from Tajikistan, five (Clinopodium menthifolium, Juncus effusus, Mollugo cerviana, Poa sphondylodes, Vulpia myuros) from Russia, and one (Orobanche alba subsp. xanthostigma) from Georgia. Ten of the taxa presented (Clinopodium menthifolium, Dianthus campestris, Eragrostis amurensis, Juncus effusus, Lepidium densiflorum, Mollugo cerviana, Solidago canadensis, Viola suavis, Vulpia myuros and Xanthium albinum) are regarded as alien to the studied areas, whereas the remaining eight are native elements to the flora of the countries. For each species, synonyms, general distribution, habitat preferences, taxonomy with remarks on recognition and differentiation of the species from the most similar occurring in a given country, as well as a list of localities recorded (often far from the previously known areas), are presented.

In addition to the yersiniabactin (Ybt) siderophore-dependent system, two inorganic iron ABC transport systems of Yersinia pestis , Yfe and Yfu, have been characterized. Here we show that the Yfu system functions in Y. pestis : a Ybt − Yfe − Yfu − mutant exhibited a greater growth defect under iron-deficient conditions than its Ybt − Yfe − parental strain. We also demonstrate that another putative Y. pestis iron uptake system, Yiu, which potentially encodes an outer membrane receptor, YiuR, and an ABC iron transport cassette, YiuABC, is functional. The cloned yiuABC operon restored growth of an enterobactin-deficient mutant Escherichia coli strain, 1017, under iron-chelated conditions. Iron uptake by the Yiu system in Y. pestis was demonstrated only when the Ybt, Yfe, and Yfu systems were mutated. Using a yiuA :: lacZ fusion, we show that the yiuABC promoter is repressed by iron through Fur. A mouse model of bubonic plague failed to show a significant role for the Yiu system in the disease process. These results demonstrate that two additional iron transporters are functional in Y. pestis and indicate that there is a hierarchy of iron transporters, with Ybt being most effective and Yiu being the least effective of those systems which have been characterized.

In Yersinia pestis, biofilm formation is stimulated by HmsT, a GGDEF-domain containing protein that synthesizes cyclic-di-GMP (c-di-GMP), and inhibited by HmsP, an EAL-domain protein. Only the EAL-domain portion of HmsP is required to inhibit biofilm formation. The EAL domain of HmsP was purified as a 6XHis-tag fusion protein and demonstrated to have phosphodiesterase activity using bis(p-nitrophenyl) phosphate (bis-pNPP) as a substrate. This enzymatic activity was strictly manganese dependent. A critical residue (E506) of HmsP within the EAL domain, that is required for inhibition of biofilm formation, is also essential for this phosphodiesterase activity. While the proposed function of EAL-domain proteins is to linearize c-di-GMP, this is a direct demonstration of the required phosphodiesterase activity of a purified EAL-domain protein.

The Hms(+) phenotype of Yersinia pestis promotes the binding of haemin or Congo red (CR) to the cell surface at temperatures below 34 degrees C. We previously demonstrated that temperature regulation of the Hms(+) phenotype is not controlled at the level of transcription. Instead, HmsH, HmsR and HmsT are degraded upon a temperature shift from 26 degrees C to 37 degrees C. We used random transposon mutagenesis to identify new genes involved in the temperature-regulated expression of the Hms phenotype. One of these genes, which we designated hmsP, encodes a putative phosphodiesterase with a conserved EAL motif. Mutations in hmsP caused formation of red colonies on CR plates at 26 degrees C and 37 degrees C. Strains complemented with hmsP(+) on a plasmid form white colonies at both temperatures. We used a crystal violet assay and confocal laser scanning microscopy to demonstrate Hms-dependent biofilm formation by Y. pestis cells. Y. pestis Hms(+) strains grown at 26 degrees C but not at 37 degrees C form a biofilm on borosilicate glass surfaces. Strains that either overexpress HmsT (a GGDEF domain protein) or have a mutation in hmsP produced an extremely thick biofilm. Alanine substitutions for each of the GGEE residues (amino acids 296-299) of HmsT as well as the E506 and L508 residues of HmsP caused a loss of function. We propose that HmsT and HmsP together control the amount of biofilm produced in Y. pestis. Degradation of HmsT at 37 degrees C may be a critical factor in controlling the temperature-dependent expression of the Hms biofilm.

In Yersinia pestis , the Congo red (and hemin) binding that is characteristic of the Hms + phenotype occurs at temperatures up to 34°C but not at higher temperatures. Manifestation of the Hms + phenotype requires at least five proteins (HmsH, -F, -R, -S, and -T) that are organized into two separate operons: hmsHFRS and hmsT. HmsH and HmsF are outer membrane proteins, while HmsR, HmsS, and HmsT are predicted to be inner membrane proteins. We have used transcriptional reporter constructs, RNA dot blots, and Western blots to examine the expression of hms operons and proteins. Our studies indicate that transcription from the hmsHFRS and hmsT promoters is not regulated by the iron status of the cells, growth temperature, or any of the Hms proteins. In addition, the level of mRNA for both operons is not significantly affected by growth temperature. However, protein levels of HmsH, HmsR, and HmsT in cells grown at 37°C are very low compared to those in cells grown at 26°C, while the amounts of HmsF and HmsS show only a moderate reduction at the higher growth temperature. Neither the Pla protease nor a putative endopeptidase (Y2360) encoded upstream of hmsH is essential for temperature regulation of the Hms + phenotype. However, HmsT at 37°C is sensitive to degradation by Lon and/or ClpPX. Thus, the stability of HmsH, HmsR, and HmsT proteins likely plays a role in temperature regulation of the Hms + phenotype of Y. pestis .