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101.
Differences in AM fungal root colonization between populations of perennial Aster species have genetic reasons 总被引:1,自引:1,他引:0
We tested the hypothesis whether differences between plant populations in root colonization by arbuscular mycorrhizal (AM) fungi could be caused by genetic differentiation between populations. In addition, we investigated whether the response to AM fungi differs between plants from different populations and if it is affected by the soil in which the plants are cultivated. We used Aster amellus, which occurs in fragmented dry grasslands, as a model species and we studied six different populations from two regions, which varied in soil nutrient concentration.We found significant differences in the degree of mycorrhizal colonization of plant roots between regions in the field. To test if these differences were due to phenotypic plasticity or had a genetic basis, we performed a greenhouse experiment. The results suggested that Aster amellus is an obligate mycotrophic plant species with a high dependency upon mycorrhiza. Plant biomass was affected only by soil, and not by population or the interaction between the population and the soil. Mycorrhizal colonization was significantly affected by all three factors (soil, population, interaction of soil and population). Plants from the population originating from the soil with lower nutrient availability developed more mycorrhiza even when grown in soil with higher nutrient availability. The correspondence between mycorrhizal colonization of plants in the field and in both soils in the pot experiment suggests that the observed differences in root colonization have a genetic basis. 相似文献
102.
103.
Demianova Z Pöysä E Ihalainen S Saura S Shimmo M Franssila S Baumann M 《Molecular bioSystems》2008,4(3):260-265
The present article describes a miniaturized polyacrylamide slab gel electrophoresis-chip (PASGE-Chip) that can rapidly separate a set of predefined samples as well as cell lysate samples for clinical diagnosis. The chip consists of a polymethyl methacrylate (PMMA) upper unit (25 x 30 x 10 mm, width x length x depth) with integrated buffer chambers, running electrodes and loading wells and a bottom unit comprising a silicon dioxide-coated silicon plate with embossed gel chamber (11 x 15 x 0.37 mm). This miniaturized device was designed to be fast, easy to use and cheap to produce. The polyacrylamide slab gel electrophoresis can be performed in less than 10 min with low voltage. The gel-to-gel repeatability is around 3.8%. The limit of detection is approx. 10 ng as determined by Coomassie staining of selected standard proteins, and corresponds to a 10-fold increase in sensitivity as compared with a common size PAGE analysis device (e.g. 10 x 7 cm). The device was successfully applied to peptide mass fingerprint analysis, protein sequencing and ultra-sensitive immunodetection, and the performance was compared to a commonly used regular PAGE device. 相似文献
104.
The aim of this study was to investigate the effect of a high-fat (HF)/energy diet on the intestinal microbiota, the alkaline phosphatase (AP) activity, and related parameters of growth and obesity during the suckling and weaning periods in male Sprague-Dawley rats. From birth, nutrition in suckling pups was manipulated by feeding rat dams either HF or a standard diet, and then after weaning, by exposure of experimental pups to the HF, and control rats to normal diet. On days 15, 20, 40 the numbers of 2 microbial groups, i.e., Bacteroides/Prevotella (BAC) and the Lactobacillus/Enterococcus (LAB) in the jejunum, were determined by fluorescent in situ hybridization technique, and the AP activity was assayed histochemically. During all investigated periods HF pups gained body fat more rapidly than control animals, but from weaning they displayed significantly stunted growth resulting in final body weight loss. Obesity in HF rats was also accompanied by higher LAB and lower numbers of BAC and with permanently higher AP activity. Correlation of these data showed significant negative correlation between LAB, AP, and weight gain and energy efficiency, and significant positive correlation of BAC and AP activity with body fat. These data support the concept that postnatal nutritional experience represents an important factor affecting the ontogeny of intestinal microbial communities and intestinal function. These acquired changes could be a component of regulatory mechanisms involved in adverse and/or positive consequences of HF diet for adiposity, body weight, and energy-balance control in later life. 相似文献
105.
Laura J. Marinelli Mariana Piuri Zuzana Swigoňová Amrita Balachandran Lauren M. Oldfield Julia C. van Kessel Graham F. Hatfull 《PloS one》2008,3(12)
Advances in DNA sequencing technology have facilitated the determination of hundreds of complete genome sequences both for bacteria and their bacteriophages. Some of these bacteria have well-developed and facile genetic systems for constructing mutants to determine gene function, and recombineering is a particularly effective tool. However, generally applicable methods for constructing defined mutants of bacteriophages are poorly developed, in part because of the inability to use selectable markers such as drug resistance genes during viral lytic growth. Here we describe a method for simple and effective directed mutagenesis of bacteriophage genomes using Bacteriophage Recombineering of Electroporated DNA (BRED), in which a highly efficient recombineering system is utilized directly on electroporated phage DNA; no selection is required and mutants can be readily detected by PCR. We describe the use of BRED to construct unmarked gene deletions, in-frame internal deletions, base substitutions, precise gene replacements, and the addition of gene tags. 相似文献
106.
Gazova Z Bellova A Daxnerova Z Imrich J Kristian P Tomascikova J Bagelova J Fedunova D Antalik M 《European biophysics journal : EBJ》2008,37(7):1261-1270
We have screened a library of structurally distinct acridine derivatives (19 compounds) for their ability to inhibit lysozyme amyloid aggregation in vitro. Studied acridines were divided into three structurally different groups depending on the molecule planarity and type of the side chain-planar acridines, spiroacridines and tetrahydroacridines. Thioflavine T fluorescence assay and transmission electron microscopy were used for monitoring the inhibiting activity of acridines. We have found that both the structure of the acridine side chains and molecule planarity influence their antiamyloidogenic activity. The planar acridines inhibited lysozyme aggregation effectively. Spiroacridines and tetrahydroacridines had no significant effect on the prevention of lysozyme fibrillization, probably resulting from the presence of the heterocyclic 5-membered ring and non-planarity of molecule. Moreover, in the presence of some tetrahydroacridines the enhanced extent of aggregation was detected. We identified the most active acridine derivates from studied compound library characterized by low micromolar IC(50) values, which indicate their possible application for therapeutic purpose. 相似文献
107.
Brumovská E Sychrovský V Vokácová Z Sponer J Schneider B Trantírek L 《Journal of biomolecular NMR》2008,42(3):209-223
Density functional theory was employed to study the dependence of 13C and 15N magnetic shielding tensors on the glycosidic torsion angle (chi) and conformation of the sugar ring in 2'-deoxyadenosine, 2'-deoxyguanosine, 2'-deoxycytidine, and 2'-deoxythymidine. In general, the magnetic shielding of the glycosidic nitrogens and the sugar carbons was found to depend on both the conformation of the sugar ring and chi. Our calculations indicate that the magnetic shielding anisotropy of the C6 atom in pyrimidine and the C8 atom in purine bases depends strongly on chi. The remaining base carbons were found to be insensitive to both sugar pucker and chi re-orientation. These results call into question the underlying assumptions of currently established methods for interpreting residual chemical shift anisotropies and 13C and 15N auto- and cross-correlated relaxation rates and highlight possible limitations of DNA applications of these methods. 相似文献
108.
Katarína Dercov Milan
ertík Anna Mal'ov Zuzana Sejkov 《International biodeterioration & biodegradation》2004,54(4):251-254
Chlorophenols, widespread soil and water contaminants and often degradation products of some pesticides, are a potential stress factor for survival of environmental bacteria. The effect of pentachlorophenol (PCP) and 2,4-chlorophenol (2,4-CP) on the growth, amount of lipid, and fatty acid composition in the membrane lipids was examined in a strain of the bacterium Kocuria varians, able to degrade chlorophenols. The index of fatty acid unsaturation in two main membrane lipids, phosphatidylcholine (PC) and phosphatidylethanolamine (PE) decreased in the presence of chlorophenols. Transformation of stearic acid into oleic acid was significantly increased by PCP addition only in PE, but conversion of oleic acid into linoleic acid was blocked by PCP and 2,4-CP in both PC and PE. This observation may indicate that while Δ9 desaturase was sensitive mainly to 2,4-CP, activity of Δ12 desaturase was inhibited by both PCP and 2,4-CP. 相似文献
109.
Siváková D Lajdová A Basistová Z Cvícelová M Karabová P Blazícek P 《Anthropologischer Anzeiger; Bericht über die biologisch-anthropologische Literatur》2008,66(2):199-209
Epidemiological studies have demonstrated that several specific environmental factors and candidate genes influence the human variation in blood pressure. The aim of this study was to investigate variables associated with blood pressure; with a particular emphasis on the differences in insertion/deletion (I/D) polymorphism of the human angiotensin-converting enzyme (ACE), the body composition and the recognized risk factors for atherosclerosis among elderly males and females. A total of 374 participants (174 males and 200 females) aged from 60 to 90 years were recruited from different parts of Slovakia. The elderly were not bed-ridden, nor mentally impaired, they were able to manage their daily activities by themselves. The ACE I/D polymorphism was determined by PCR amplification of the ACE gene sequence. Body composition variables were obtained by bioelectrical impedance analysis, using the BIA 101 soft tissue-body impedance analyzer (Akern, S.r.l.). The subjects were determined to be hypertensive (blood pressure > or = 140/90 mm Hg) or normotensive (blood pressure < or = 140/90 mm Hg ). These two subgroups of males and females did not differ significantly in their mean ages. As expected, the hypertensive subjects of both sexes showed significantly higher mean values in systolic (SBP) and diastolic blood pressure (DBP), in body mass index (BMI), and in the mean values of their plasma glucose and extracellular water (ECW). The genotype distribution and allele frequencies in the whole sample (D = 0.5474, I = 0.4526) fell within the Hardy-Weinberg equilibrium. The frequency of the deleterious D allele in the normotensive (0.5532) and hypertensive (0.5516) subjects was not significantly different. The ACE I/D genotypes did not associate either with the systolic (p = 0.836) or diastolic BP (p = 0.629). From the other variables that may induce differences in blood pressure, a statistical effect was detected for glucose, Na/K, and Apo A1/ApoB ratios and physical activity on SBP, and for ApoA1, physical activity, BMI and total cholesterol on DBP. 相似文献
110.
Zuzana Tomaskova 《生物化学与生物物理学报:生物膜》2008,1778(11):2564-2572
Anomalies in the permeation properties of the cardiac RyR channel reconstituted into bilayer lipid membranes were investigated systematically. We tested the presence of the anomalous mole fraction effect (AMFE) for the ion conductance and the reversal potential with varying mole fractions of two permeant ions, while the total ion concentration was lower, as in previous studies, to avoid the masking effect of the channel pore saturation with ions. Mixtures of Ba2+ with other divalents (Ca2+, Sr2+), of Ca2+ with monovalents (Li+, Cs+), and of Na+ with other monovalents (Cs+, Li+) were used. We revealed a clear anomaly only for the ion conductance measured in the Na+-Cs+ and Ca2+-Li+ mixtures as computed by a Poisson-Nernst-Planck/density functional theory (PNP/DFT) model. Furthermore, we found a significant minimum in the concentration dependence of the reversal potential determined under Li+/Ca2+ bi-ionic conditions. Our study led to new observations that may have important implications for understanding the mechanisms involved in ion handling in the RyR channel pore; furthermore our results could be useful for further validation of ion permeation models developed for the RyR channel. 相似文献