Thermoproteus uzoniensis sp. nov., a new extremely thermophilic archaebacterium from Kamchatka continental hot springs

A new extremely thermophilic rod-shaped archaebacterium was found in the samples from hot springs and soil of the Uzon caldera (SW of Kamchatka pen.). Cells are rods from 1 to 20 m in length and 0.3 to 0.4 m in width, sometimes branching or with spherical protrusions on the ends. The cell wall consists of two layers: an internal one with distinct hexagonal structure and the outer one with less clear structure and variable thickness. Cells are non-motile and have no flagella. The new organism grows anaerobically by fermenting peptides, concurrently reducing elemental sulfur to H₂S. Fermentation products are acetate, isobutyrate, isovalerate. The G+C content of the DNA is 56.5 mol. %. A new species Thermoproteus uzoniensis is described. Type strain is isolate Z-605, DSM 5262.     

Determining the effects of habitat management and climate on the population trends of a declining steppe bird

The Little Bustard Tetrax tetrax is one of the most threatened steppe bird species in Europe, due mainly to agricultural intensification. Despite the relative importance of the Iberian population (approximately 50% of the global population) little is known about its dynamics and trends, especially in core distribution areas. This study evaluates the influences of meteorological factors and land management on the oscillations and medium-term trends of two Little Bustard populations in Central Spain. During 2001–2007, surveys of breeding male and female Little Bustards were carried out in two central Spanish locations: Valdetorres, in Special Protection Area (SPA) no. 139 (1600 ha), and Campo Real, in Important Bird Area (IBA) no. 075 (1150 ha). Densities were 3.3–4.0 and 1.1–2.1 males/km² in Campo Real, and 1.8–2.2 and 0.6–1.3 females/km² in Valdetorres. The sex ratio was biased towards males in both cases. Both populations declined during 2001–2007, especially in Valdetorres (60%). Variation in habitat composition did not explain variation in the numbers of males. Both populations were influenced by total precipitation in the preceding October–May period. Results suggest that the Little Bustard may be sensitive to future climate trends in Europe. Finally, different simulated demographic scenarios suggest that low female survival and productivity may be the immediate cause of the decline in Little Bustard populations, which is consistent with their sensitivity to climatic conditions.     

Compositional similarity among urban floras within and across continents: biogeographical consequences of human-mediated biotic interchange

Anthropogenic activities have weakened biogeographical barriers to dispersal resulting in the global spread and establishment of an increasing number of non‐native species. We examine the broad‐scale consequences of this phenomenon based on an analysis of compositional similarity across urban floras in the northeastern United States and Europe. We test the prediction that homogenization of species composition is uniquely defined within vs. between continents based on the time and place of origin of non‐native species. In this case, for archaeophytes and neophytes in Europe (introduced before and after ad 1500, respectively) and non‐native species originating from within and outside the United States. More species in urban floras were shared within than between continents. Within Europe, archaeophytes shared more species across urban floras compared with neophytes; strong associations were not observed for non‐native species across US urban floras. Between the two continents, non‐native species in the United States that originated from outside the United States shared species primarily with archaeophytes but also with European natives and neophytes. These results suggest that the direction of biotic interchange was unidirectional with species moving primarily from Europe to the United States with archaeophytes playing a primary and non‐native species originating from outside the two continents a secondary role as a homogenizing source. Archaeophytes, based on combination of biogeographical, evolutionary, and ecological factors in association with a long history of anthropogenic influence, appear to have played a prominent role in the continental and intercontinental homogenization of species composition. This suggests that the uniform homogenization of the Earth's biota is not imminent and is presently directed by a combination of biogeographically defined anthropogenic and historical factors.     

原发性肝癌:CT血液供应、P53抗体和血管内皮生长因子

目的:分析原发性肝癌(primary hepatic carcinoma,简称肝癌)血液供应(blood supply,简称血供)CT类型与患者血清P53抗体、血管内皮生长因子(vascular endothelial growth factor,VEGF)的关系,以及血清P53抗体与VEGF的相关性.方法:用酶联免疫吸附法定量检测首诊肝癌患者血清P53抗体和VEGF,与CT诊断的血供类型结果进行对比,分析不同血供类型的肝癌是否存在血清P53抗体差异(单因素分析),并分析不同血供类型的肝癌血清VEGF是否存在差异(单因素分析),然后分析血清P53抗体和VEGF之间的相关性.结果:四种不同血供类型的肝癌之间血清P53抗体滴度有差异(P<0.05).值得注意的是,富血供型与混合型之间、动-静脉漏型(AVS)与混合型之间血清P53抗体有显著差异(P<0.05),富血供型与AVS型之间血清P53抗体没有显著差异(P>0.05).不同血供类型的肝癌中,富血供型和混合型血清P53抗体与VEGF呈正相关(P<0.05),而AVS型和乏血供型中,血清P53抗体与VEGF不呈直线相关(P>0.05).结论:血清P53抗体和血清VEGF滴度在血供不同肝癌中滴度有差异,在富血供型和混合型中血清P53抗体与VEGF滴度呈正相关.     

Divergence patterns of banding sequences in different polytene chromosome arms reflect relatively independent evolution of different genome components

Divergence patterns of the banding sequences of the chromosomal arms A, C, D, E, and F were compared in 63 species of the genus Chironomus. Evaluation of the number of breakpoints between the pairs of inverted banding sequences and the analysis of the lengths of the conserved segments in the chromosomal arms in the chironomid species examined showed that different arms evolved relatively independently and at different rates. No direct correlation between the arm length and the breakpoints number was observed. The length of the conservative segment was not fixed, but was arm-specific. Robustness and reliability of the estimates of phylogenetic relationships between the species examined increased with the arm number, i.e., with the genome proportion included in the analysis.__________Translated from Genetika, Vol. 41, No. 4, 2005, pp. 549–558.Original Russian Text Copyright © 2005 by Gunderina, Kiknadze, Istomina, Gusev, Miroshnichenko.     

Population structure,diversity, and phylogeography in the near‐threatened Eurasian black vultures Aegypius monachus (Falconiformes; Accipitridae) in Europe: insights from microsatellite and mitochondrial DNA variation

The Eurasian black vulture (Aegypius monachus) has experienced a severe decline during the last two centuries and is globally classified as near‐threatened. This has led to the extinction of many traditional breeding areas in Europe and resulted in the present patchy distribution (Iberian and Balkan peninsulas) in the Western Palearctic. In the present study, we describe the current genetic status of the European populations using both mitochondrial cytochrome b sequences and nuclear microsatellite markers, comparing with those found in Asia (Mongolia and Caucasus region). Although, mitochondrial (mt)DNA revealed a relatively low genetic variability (haplotype diversity), no evidence of genome‐wide genetic erosion exists because nuclear diversity exhibits normal levels and strong differentiation. A highly philopatric dispersal behaviour must be invoked to explain the existence of a clear pattern that revealed by the phylogeographic analysis, which indicates a sharp East–West clinal distribution and an allopatric differentiation. The distribution of mtDNA haplotypes one in the Iberian population and two in Balkan population and the significance divergence at nuclear loci fulfill the definitions of those populations as evolutionary significant units. We discuss how management strategies should aim at the maintenance (or increase) of current genetic variability levels, suggesting that independent conservation plans are urgently required to protect these two breeding European populations from extinction. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 859–872.     

Assessing the taxonomic status of tropical frogs through bioacoustics: geographical variation in the advertisement calls in the Eleutherodactylus discoidalis species group (Anura)

The taxonomic status of a very poorly known group of Andean frogs (the Eleutherodactylus discoidalis group) is assessed through acoustic and statistical analyses of differences in temporal parameters of advertisement calls, such as the number of pulses and the call duration, and also in a spectral parameter, dominant frequency. As these species are usually misidentified or ignored because of their taxonomic complexity in both ecological and biodiversity studies, we provide a bioacoustical diagnosis for each species in order to facilitate identification in the field. Differences in acoustic parameters support the specific status of Eleutherodactylus cruralis , E. discoidalis , Eleutherodactylus ibischi , and Eleutherodactylus madidi . The name E. cruralis is probably applied to three different species: the nominal form from Amazonian forests of the Andean slopes and adjacent lowlands, and two cryptic species restricted to inter-Andean dry valleys and cloud forests from central Bolivia. Moreover, the distribution of energy through the call and the aggregation of pulses seem to be useful meristic characters for detecting interspecific differences. Populations from each macrohabitat can be recognized by distinctive advertisement calls, usually corresponding to a recognized species. For the whole group, pulse rate is significantly correlated to latitude, which could indicate a speciation process along the Andes in relation to habitat changes and isolation. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 353–365.     

Metabolism of the thermophilic bacterium <Emphasis Type="Italic">Oceanithermus profundus</Emphasis>

The metabolism of the novel facultatively anaerobic thermophilic bacterium Oceanithermus profundus was studied during growth on maltose, acetate, pyruvate, and hydrogen. The utilization of carbohydrates was shown to proceed via the glycolytic pathway. Under microaerobic growth conditions, the metabolism of O. profundus grown on maltose depended on the substrate concentration. At an initial maltose concentration of 1.4 mM, O. profundus carried out oxygen respiration, and in the presence of 3.5 mM maltose, facilitated fermentation occurred, with the formation of acetate and ethanol and limited involvement of oxygen. The use of pyruvate and acetate occurred via the TCA cycle. In cells grown on acetate, the activity of glyoxylate pathway enzymes was revealed. Depending on the energy-yielding process providing for growth (oxygen respiration or nitrate reduction), cells contained cytochromes a and c or b, respectively. The results obtained demonstrate the plasticity of the metabolism of O. profundus, which thus appears to be well-adjusted to the rapidly changing conditions in deep-sea hydrothermal vents.     

The thermophilic bacteria hydrolyzing agar: Characterization of thermostable agarase

Three strains of anaerobic thermophilic bacteria capable of growing on agarose as a source of energy and carbon were isolated from hot springs near Lake Baikal (Barguzin National Park) and the caldera Uzon (Kamchatka). Cells of all the three strains were spore bacilli with peritrichous flagellation. These isolates grew at a temperature of 55–60°C and pH 6.5–7.0 and fermented a wide range of organic substrates. Analysis of the 16S rRNA sequences allowed us to ascribe the strains B5 and K14 to the genus Thermoanaerobacter and the strain K67 to the genus Caldoanaerobacter. According to the results of DNA-DNA hybridization, B5 was determined as belonging to the species Thermoanaerobacter wiegelii. Agarase was isolated by preparative PAGE and subsequent gel chromatography from the culture liquid of strain B5 grown on the medium containing 0.5% agarose and 0.3% galactose. The molecular weight of this enzyme amounted to 67 kDa and pI, to 4.2. The T. wiegelii B5 agarase was active in the pH range of 3.5 to 7.0 (optimum, 5.2) and temperature range of 50 to 80°C (optimum, 70°C). The preincubation of this enzyme at 90° C for 60 min did not reduce the agarase activity. This activity increased in the presence of metal ions; the maximal effect was observed in the presence of 5 mM Mg²⁺ and 25 mM Co²⁺.