Time- and dose-dependent differential upregulation of three genes by 17 beta-estradiol in endothelial cells.

The purpose of this study was to identify genetic targets in the vasculature for estrogen by profiling genes expressed in female human aortic endothelial cells exposed to various doses of 17 beta-estradiol at differing concentrations and for differing periods of time. Our approach employed a RT-PCR-based cloning strategy of DNA differential display analysis, with differential expression verified by semiquantitative PCR performed with gene-specific primers. A significant increase in mRNA expression in response to 17 beta-estradiol was observed for the following three genes: aldose reductase (3.4-fold), caspase homologue-alpha protein (4.2-fold), and plasminogen activator inhibitor-1 intron e (2.3-fold). For all three upregulated genes, estradiol-induced upregulation occurred with a similar time course and temporally clustered to the first 24 h after hormone treatment. In addition, the effect of estradiol dose on gene expression was consistent and occurred at physiological concentrations. Our results describe previously uncharacterized estradiol-sensitive time- and dose-dependent regulation of genes with potential importance to vascular function in human endothelial cells.     

Cytogenetic analysis of diploid Avena L. species containing the as genome

Cytogenetic examination showed that three diploid oat species containing the As genome are highly similar in karyotype structure and chromosome C-banding patterns. Avena strigosa is more similar to A. wiestii, while A. hirtula is to an extent separated from the two species, differing in the C-banding pattern of chromosome 6. The karyotypes of all three species harbor a small acrocentric chromosome, which is absent from diploid oat species containing other variants of the A genome. The results made it possible to assume genome specificity of the rearrangement resulting in this chromosome.     

A practical,high-resolution,microcomputer-based method for the analysis of relaxation data exhibiting multicomponent exponential decays

We have developed and tested a practical, rapid, high-resolution, microcomputer-based method for the analysis of multicomponent exponential decays. The analysis utilizes the Fourier deconvolution technique and includes methods to reduce noise both in the input data and in the results. The developed method is particularly well suited for analysing decays consisting of a wide range of decay times. The method resolves two exponential decays differing by a factor of two when the input data are mathematically generated and without noise, and resolves two decays differing by a factor of three when 2% Gaussian noise is present in the same data. The method lends intself to routine analysis of any relaxation process consisting of exponential decays, including biomedical applications such as enzyme kinetics, circulatory transport functions, pharmacokinetics, plasma exchange therapy, and analysis of compartmental models for any process.     

Self-design of fish diets by means of self-feeders: validation of procedures

In this paper, we show the results from four different experiments in which sea bass, maintained under laboratory conditions, could choose between two or three different diets through self-feeders, which gradually increased the complexity and potential range of selection, to design their own diet in accordance with their requirements. At first, sea bass were allowed to select between two complete diets differing in the proportion of protein (52-58%): this showed their capacity to distinguish between two diets made of the same ingredients. Next, two incomplete diets, containing a fixed amount of protein (56%) and lacking either fat or carbohydrate, were made available. Three mixed diets made up of pairs of macronutrients (protein-carbohydrate, protein-fat or fat-carbohydrate) were tested in the next experiment and, finally, three diets containing only one macronutrient (protein fat or carbohydrate) were made available to fish. Taking into account selection made by the fish in the first three experiments, in which macronutrient selection was statistically different, protein was the main macronutrient chosen by fish (278.15 kJ/kgBW/day, on average), followed by fat and carbohydrate (162.85 and 64.56 kJ/kgBW/day, respectively). In conclusion, the results reveal the ability of sea bass to select an appropriate diet from experimental diets containing two or three macronutrients and suggest that the proposed methodology is a powerful tool for studying the differing nutritional needs of different species of fish.     

Climate change, global food supply and risk of hunger

This paper reports the results of a series of research projects which have aimed to evaluate the implications of climate change for food production and risk of hunger. There are three sets of results: (a) for IS92a (previously described as a 'business-as-usual' climate scenario); (b) for stabilization scenarios at 550 and 750 ppm and (c) for Special Report on Emissions Scenarios (SRES). The main conclusions are: (i) the region of greatest risk is Africa; (ii) stabilization at 750 ppm avoids some but not most of the risk, while stabilization at 550 ppm avoids most of the risk and (iii) the impact of climate change on risk of hunger is influenced greatly by pathways of development. For example, a SRES B2 development pathway is characterized by much lower levels of risk than A2; and this is largely explained by differing levels of income and technology not by differing amounts of climate forcing.     

Nomenclature in the dock. Overclassification leads to instability: a case study in the horticulturally important genus Cyclamen (Myrsinaceae)

Nine different classifications have been produced in the last 70 years for the horticulturally valuable genus Cyclamen , a small genus with fewer than 30 species. These classifications, generated by intuitive methods and cladistic analyses, incorporated a total of four infrageneric ranks above that of species and were based on data from morphology, cytology and DNA sequencing. Our results, based on cladistic analyses of three independent data sources − nrDNA ITS, cpDNA trn L intron and morphological data − reveal good resolution only in nrDNA sequence data. However, when these three data sources are combined they provide stronger resolution and support for three major clades, only one of which, subgenus Psilanthum , has been consistently supported in previous classifications. The differing infrageneric classifications produced in Cyclamen result from varying taxon sampling, differing interpretation of morphological data, changes in the sources and analysis of data, and inconsistent application of names. Extensive subdivision of small genera in the absence of adequate data that could provide evidence for consistent patterns of relationship is premature and leads to a proliferation of names.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 339–349.     

Genetic effects on the biomass partitioning and growth of Pisum and Lycopersicon

We examined a series of eight pea genotypes differing in three naturally occurring allelic mutations, i.e., af (afila), st (stipules reduced), and tl (tendril-less) and three species, five cultivars, and one interspecific hybrid of tomato differing in SP (SELF-PRUNING) allele composition to determine whether different phenotypes ontogenetically express different biomass partitioning patterns compared to the isometric partitioning pattern and an interspecific 3/4 scaling "rule" governing annual growth with respect to body mass. The slopes and "elevations" (i.e., α and log β, respectively) of log-log linear regression curves of bivariate plots of leaf, stem, and root dry mass and of annual growth vs. total body mass were used to assess pattern homogeneity. The annual growth of all pea and tomato phenotypes complied with the 3/4 growth rule. The biomass partitioning patterns of all tomato phenotypes were statistically indistinguishable from the isometric pattern as were those of the pea wild type and three single-mutant genotypes. However, significant departures from the isometric (and pea wild type) biomass allocation pattern were observed for three genotypes, all of which were homozygous for the af allele. These results open the door to explore the heritability and genetics underlying the allometry of biomass partitioning patterns and growth.     

The psammic rotifer structure in three Lobelian Polish lakes differing in pH

Thirty five species of rotifers were found in the psammon of three lakes of differing pH in open water. The largest number of rotifer species and their highest abundance was found in lake Rekowskie which had a slightly acid to neutral water pH. The lowest quantity and the number of rotifers species were observed in the lake with lowest pH. The results suggest that pH is one of the most important factors affecting the number and diversity of psammic rotifers in these lakes.     

In vitro cytotoxicity of Haemophilus influenzae lipopolysaccharides for bovine aortal endothelial cells

The cytotoxicity of purified lipopolysaccharide (LPS) from a prototype Haemophilus influenzae type b (Hib) strain (Eagan) and three transformants, differing in their LPS phenotype, for bovine aortal endothelial cells (BAOEC) was investigated. All LPS preparations caused cell disruption and release of lactate dehydrogenase (LDH), an indicator of cytotoxicity, from BAOEC monolayers but to differing extents. There was no correlation between the cytotoxicity of purified Hib LPS to BAOEC monolayers and potential to cause bacteraemia in experimental animals.     

Theoretical and experimental prospects for protein identification based solely on accurate mass measurement

We discuss the theoretical and experimental potential and limitations of protein identification by mass measurement of proteolytic peptides and database searching. For peptides differing in composition by one (or two or three) amino acids, a surprisingly high number turn out to have isomers: 10% (or 29% or 53%), considering the 20 common amino acids with equal relative abundance. Even if isomers differing by leucine/isoleucine are excluded, the latter numbers are 14% and 38%--those isomeric peptides cannot be distinguished based on mass alone, and tandem mass spectrometry and/or other additional constraints are needed. However, for nominally isobaric peptides, the mass accuracy and resolving power of broadband Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry theoretically and experimentally suffice to resolve virtually all peptide doublets differing by up to two amino acids--including the smallest mass difference of 3.4 mDa. We demonstrate experimental resolution of another pair of peptides differing by 11 mDa, even when present in a complex mixture of hundreds of other peptides.     

Neue diterpene und germacranolide aus Mikania-Arten

From three Mikania species, three new labdanic acid and two kaurenic acid derivatives have been isolated together with known compounds and four new germacranolides, differing only in the ester moiety.     

Low genic variation in male-reproductive-tract proteins of Drosophila melanogaster and D. simulans

We report results, using two-dimensional gel electrophoresis (2DE), of natural population surveys of allelic variation in approximately 300 male-reproductive-tract polypeptides in both Drosophila melanogaster and its sibling species, D. simulans. Despite our efforts to maximize operational sensitivity of our 2DE gels to polymorphism, variation estimates in both species were low (proportion of polymorphic loci [P] = 9%, and average heterozygosity [H] = 1%-3%), compared with those by one-dimensional gel electrophoresis (1DE) (P = 29%-55%; H = 8%-19%) in the same populations. However, H of polymorphic loci was very similar for 2DE and 1DE proteins; and for 17 of a total of 54 polymorphic proteins, 2DE detected three or four distinct alleles. The results suggest that the differing levels of variability widely seen with 1DE and 2DE are real and reflect differing intensities of functional constraint between different classes of structural loci. However, the alternative possibility remains that 2DE has a greater between-locus unevenness of variant detection sensitivity than does 1DE.     

The regulation of root growth in response to phosphorus deficiency mediated by phytohormones in a Tibetan wild barley accession

Low phosphorus (LP) causes a dramatic change of root system architecture in plants, which is possibly mediated by signaling pathways of hormones. In order to understand the regulatory mechanisms of the root development under LP, we examined the potential role of phytohormones in response to LP using three barley genotypes, differing in LP tolerance, namely 2 Tibetan wild barley genotypes XZ99 (LP tolerant) and XZ100 (LP sensitive), and a cultivated barley ZD9 (LP moderately tolerant). The results showed that LP stress caused a number of changes in root development, with XZ99 having less primary root growth inhibition, more lateral root and root hair formation than the other two genotypes. Meanwhile, LP stress also resulted in the dramatic changes in plant hormone contents, with changed extent and pattern differing among the three genotypes. The relative expression of genes responsible for indole acetic acid (IAA) and ethylene synthesis in roots also showed a significant difference among genotypes in both control and LP conditions. It can be concluded that the root system of Tibetan wild barley XZ99 adapts to phosphorus deficiency by changing the signal transduction pathway mediated by auxin, ethylene and cytokinins. However, further studies are needed to elucidate the behaviors of the key genes involved in the hormone-related response.     

Functional equivalence of non-lethal effects: generalized fish avoidance determines distribution of gray treefrog, Hyla chrysoscelis, larvae

How patterns of prey abundance are generated determines how predation influences population and community level dynamics. We investigated how a natural population of ovipositing treefrogs, Hyla chrysoscelis , partitioned their eggs amongst experimental ponds differing in the non-lethal presence of five fish predators, each representing a distinct family. Four fish predators were functionally equivalent in terms of the behavioral response they induced in H. chrysoscelis females and hence the distribution of larval H. chrysoscelis . Mean number of H. chrysoscelis eggs deposited was significantly decreased by the mere presence of these predators relative to controls, with three species eliciting a complete avoidance (e.g. no eggs deposited). One fish predator, Aphredoderus sayanus , was statistically indistinguishable from the control treatment. These data mimic patterns of species distribution observed in nature in response to the presence of fish, but suggest an alternative mechanism for generating patterns of prey abundance amongst habitats differing in their predator composition. Furthermore, our results expand the importance of predator induced non-lethal effects as a process that could dramatically affect population and community level dynamics.     

Functional associations of floret and inflorescence traits among grass species

The aerodynamics of wind pollination selects for an intimate relation between form and function in anemophilous plants. Inflorescence architecture and floral morphology vary extensively within the Poaceae, but the functional implication of this variation remains largely unknown. Here we quantify associations between floret, culm, and inflorescence characteristics for 25 grass species in Kananaskis, Alberta, Canada, and consider whether different architectures may implement unique mechanisms to aid pollination. The species cluster into four categories defined by all combinations of floret size (small vs. large) and inflorescence architecture (compact vs. diffuse). Species differed significantly for all 18 traits that we measured, with 12 traits differing only between floret-size classes, three differing only between inflorescence types, and three differing among both (independently or by an interaction). Based on these morphological associations, we discuss the aerodynamic and functional consequences of each category for wind pollination. The independence of inflorescence and floral traits has probably allowed exploration of all possible combinations of inflorescence architecture and floret size during the evolution of the Poaceae.     

The effect of population density of the lime leafminer Phyllonorycter issikii Kumata (Lepidoptera, Gracillariidae) on the ratio of intrapopulation forms

Dependence of the lime moth Phyllonorycter issikii Kumata (Lepidoptera, Gracillariidae) population polymorphism on infestation density of Tilia cordata Mill. was studied for the first time in 2001–2005 at three sites in the city of Izhevsk. The growth of the infestation rate results in an increase in the fraction of the dark morph of the moth significantly differing in the longer wings and higher fecundity.     

Differential expression of manganese superoxide dismutase sequence variants in near isogenic lines of wheat during cold acclimation

Numerous sequence variants of wheat (Triticum aestivum L.) manganese superoxide dismutase (MnSOD) genes have been found. Quantitative real-time PCR was used to measure the expression levels of three MnSOD genes distinguished by a variable amino acid, and three genes distinguished by sequence variation in the 3′ untranslated region (3′ UTR), in wheat plants grown at 20°C and cold-acclimated for 1–4 weeks at 2°C. The amino acid variants did not differ significantly in expression levels, however, differential expression of genes differing in the 3′ UTR was observed. Diploid wheat-related species also carried sequence variants of MnSOD, with differing levels of expression, suggesting diversification of the MnSOD gene family occurred prior to the polyploidization events of hexaploid wheat.     

Structure of the oligosaccharide of human J chain.

The complete structure of the oligosaccharide moiety of J chain isolated from a Waldenstr?ms macroglobulin Wa has been established. The oligosaccharide is present in three forms differing in the amount of sialic acid and designated J-A, J-B, and J-C. The structure and proportion of each of these is: formula : (see text) : Removal of the oligosaccharide moiety with glycosidases results in an increased mobility of J chain in sodium dodecyl sulfate polyacrylamide gel electrophoresis corresponding to a shift in apparent molecular weight from 23,500 to 19,500. The preparation and utilization of iodinated glycopeptides for sequence analysis is presented.     

Kinetics of bromodichloromethane metabolism by cytochrome P450 isoenzymes in human liver microsomes

The kinetic constants for the metabolism of bromodichloromethane (BDCM) by three cytochrome P450 (CYP) isoenzymes have been measured in human liver microsomes. The three CYP isoenzymes, CYP2E1, CYP1A2 and CYP3A4, have been identified previously as important in the metabolism of this compound. To measure the constants for each isoenzyme, enzyme-specific inhibitory antibodies were used to block the activities for two of the three isoenzymes. CYP2E1 was found to have the lowest K(m), 2.9 microM, and the highest catalytic activity, k(cat). The K(m) for the other isoenzymes, CYP1A2 and CYP3A4, were about 60 microM with lower values of k(cat). Apparent kinetic constants obtained from two microsomal samples that were not inhibited were consistent with these results. In addition, 11 human microsome samples characterized for 10 CYP activities were correlated with the metabolism of 9.7 microM BDCM by each sample; statistical analysis showed a correlation with CYP2E1 activity only. This result is consistent with the finding that CYP2E1 is the only isoenzyme with a K(m) lower than the BDCM concentration used. The kinetic constants obtained from the inhibited microsomes were compared to similar results from recombinant human isoenzyme preparations containing only one CYP isoenzyme. The results for CYP2E1 were very similar, while the results for CYP1A2 were somewhat less similar and there was a substantial divergence for CYP3A4 in the two systems. Possible reasons for these differences are differing levels of CYP reductase and/or differing makeup of the membrane lipid environment for the CYPs. Because of the low levels of BDCM exposure from drinking water, it appears likely that CYP2E1 will dominate hepatic CYP-mediated BDCM metabolism in humans.     

Effects of the habitat-soil factor on transgenerational plasticity in a diaspore-polymorphic cold desert annual

Plant and Soil - We determined effects of soil from three habitats differing in physiochemical properties on transgenerational plasticity in diaspore production of the diaspore-polymorphic annual...