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21.
Adrianna Nowicka Magdalena Kanabus Ewa Sledziewska-Gójska Zygmunt Ciesla 《Molecular genetics and genomics : MGG》1994,243(5):584-592
An Escherichia coli strain bearing the dnaQ49 mutation, which results in a defective s subunit of DNA polymerase III, and carrying the lexA71 mutation, which causes derepression of the SOS regulon, is totally unable to maintain high-copy-number plasmids containing the umuDC operon. The strain is also unable to maintain the pAN4 plasmid containing a partial deletion of the umuD gene but retaining the wild-type umuC gene. These results suggest that a high cellular level of UmuC is exceptionally harmful to the defective DNA polymerase III of the dnaQ49 mutant. We have used this finding as a basis for selection of new plasmid umuC mutants. The properties of two such mutants, bearing the umuC61 or umuC95 mutation, are described in detail. In the umuC122:: Tn 5 strain harbouring the mutant plasmids, UV-induced mutagenesis is severely decreased compared to that observed with the parental umuDC + plasmid. Interestingly, while the frequency of UV-induced GC → AT transitions is greatly reduced, the frequency of AT → TA transversions is not affected. Both mutant plasmids bear frameshift mutations within the same run of seven A residues present in umuC +; in umuC61 the run is shortened to six A whereas in umuC95 is lengthened to eight A. We have found in both umuC61 and umuC95 that translation is partially restored to the proper reading frame. We propose that under conditions of limiting amounts of UmuC, the protein preferentially facilitates processing of only some kinds of UV-induced lesions. 相似文献
22.
Andrew F. Feldman Daniel J. Short Gianotti Jianzhi Dong Isabel F. Trigo Guido D. Salvucci Dara Entekhabi 《Global Change Biology》2023,29(1):110-125
Vegetation cover creates competing effects on land surface temperature: it typically cools through enhancing energy dissipation and warms via decreasing surface albedo. Global vegetation has been previously found to overall net cool land surfaces with cooling contributions from temperate and tropical vegetation and warming contributions from boreal vegetation. Recent studies suggest that dryland vegetation across the tropics strongly contributes to this global net cooling feedback. However, observation-based vegetation-temperature interaction studies have been limited in the tropics, especially in their widespread drylands. Theoretical considerations also call into question the ability of dryland vegetation to strongly cool the surface under low water availability. Here, we use satellite observations to investigate how tropical vegetation cover influences the surface energy balance. We find that while increased vegetation cover would impart net cooling feedbacks across the tropics, net vegetal cooling effects are subdued in drylands. Using observations, we determine that dryland plants have less ability to cool the surface due to their cooling pathways being reduced by aridity, overall less efficient dissipation of turbulent energy, and their tendency to strongly increase solar radiation absorption. As a result, while proportional greening across the tropics would create an overall biophysical cooling feedback, dryland tropical vegetation reduces the overall tropical surface cooling magnitude by at least 14%, instead of enhancing cooling as suggested by previous global studies. 相似文献
23.
Maja Wiprächtiger Melanie Haupt Andreas Froemelt Magdalena Klotz Claudio Beretta Dominik Osterwalder Vanessa Burg Stefanie Hellweg 《Journal of Industrial Ecology》2023,27(1):254-271
Industrial ecology (IE) methodologies, such as input/output or material flow analysis and life cycle assessment (LCA), are often used for the environmental evaluation of circular economy strategies. Up to now, an approach that utilizes these methods in a systematic, integrated framework for a holistic assessment of a geographic region's sustainable circular economy potential has been lacking. The approach developed in this study (IE4CE approach) combines IE methodologies to determine the environmental impact mitigation potential of circular economy strategies for a defined geographic region. The approach foresees five steps. First, input/output analysis helps identify sectors with high environmental impacts. Second, a refined analysis is conducted using material flow and LCA. In step 3, circular strategies are used for scenario design and evaluated in step 4. In step 5, the assessment results are compiled and compared across sectors. The approach was applied to a case study of Switzerland, analyzing 8 sectors and more than 30 scenarios in depth. Carbon capture and storage (CCS) from waste incineration, biogas and cement production, food waste prevention in households, hospitality and production, and the increased recycling of plastics had the highest mitigation potential. Most of the scenarios do not influence each other. One exception is the CCS scenarios: waste avoidance scenarios decrease the reduction potential of CCS. A combination of scenarios from different sectors, including their impact on the CCS scenario potential, led to an environmental impact mitigation potential of 11.9 Mt CO2-eq for 2050, which equals 14% of Switzerland's current consumption-based impacts. 相似文献
24.
25.
Rizky Pasthika Kirana Kumar Gaurav Sanu Arora Gerlinde Wiesenberger Maria Doppler Sebastian Michel Simone Zimmerl Magdalena Matic Chinedu E. Eze Mukesh Kumar Ajla Topuz Marc Lemmens Rainer Schuhmacher Gerhard Adam Brande B. H. Wulff Hermann Buerstmayr Barbara Steiner 《Plant biotechnology journal》2023,21(1):109-121
Aegilops tauschii is the diploid progenitor of the wheat D subgenome and a valuable resource for wheat breeding, yet, genetic analysis of resistance against Fusarium head blight (FHB) and the major Fusarium mycotoxin deoxynivalenol (DON) is lacking. We treated a panel of 147 Ae. tauschii accessions with either Fusarium graminearum spores or DON solution and recorded the associated disease spread or toxin-induced bleaching. A k-mer-based association mapping pipeline dissected the genetic basis of resistance and identified candidate genes. After DON infiltration nine accessions revealed severe bleaching symptoms concomitant with lower conversion rates of DON into the non-toxic DON-3-O-glucoside. We identified the gene AET5Gv20385300 on chromosome 5D encoding a uridine diphosphate (UDP)-glucosyltransferase (UGT) as the causal variant and the mutant allele resulting in a truncated protein was only found in the nine susceptible accessions. This UGT is also polymorphic in hexaploid wheat and when expressed in Saccharomyces cerevisiae only the full-length gene conferred resistance against DON. Analysing the D subgenome helped to elucidate the genetic control of FHB resistance and identified a UGT involved in DON detoxification in Ae. tauschii and hexaploid wheat. This resistance mechanism is highly conserved since the UGT is orthologous to the barley UGT HvUGT13248 indicating descent from a common ancestor of wheat and barley. 相似文献
26.
Magdalena J. Rossowska Parvaneh Ghanel Tetsuo Nakamoto 《Biological trace element research》1995,50(3):229-236
The purpose of this study was to determine the relationship between concentrations of Zn and Cu and the activities of superoxide
dismutase and glutathione peroxidase in the heart and liver of young rat pups whose dams were fed a diet supplemented with
caffeine and/or Zn. Four groups of dams with their newborn pups were fed one of the following diets for 22 d: 20% protein
basal diet; the basal diet supplemented with caffeine (2 mg/100 body wt); the basal diet supplemented with Zn (300 mg/kg diet);
or the basal diet supplemented with caffeine plus Zn. The Cu levels in the livers of the pups were decreased by maternal intake
of the caffeine and Zn diet. The maternal intake of the caffeine diet increased Mn-superoxide dismutase (MnSOD) activity and
Cu, Zn-superoxide dismutase (CUZnSOD) in the heart of the pups. On the other hand, the activity of Cu,ZnSOD was significantly
reduced in the liver of pups whose dams consumed a caffeine, Zn, or caffeine plus Zn diet. Cu, ZnSOD activity in the liver
of the pups seems to be correlated with Cu levels in the tissue. Selenium-dependent glutathione peroxidase (GSH-Px) activities
in the heart and liver showed no difference among the groups. The effect of dietary caffeine and/or Zn on the activity of
antioxidant enzymes in the heart and liver were different in young rats. The activities of these enzymes in the heart were
lower than in the liver of 22-d-old rats. Our experiments indicate that the heart has limited defenses against the toxic effects
of peroxides when compared to the liver. 相似文献
27.
Magdalena Kanabus Adrianna Nowicka Ewa Sledziewska-Gójska Piotr Jonczyk Zygmunt Ciesla 《Molecular & general genetics : MGG》1995,247(2):216-221
It has previously been suggested that inhibition of the proofreading 3-5 exonuclease activity of DNA polymerase may play an important role in generation of UV-induced mutations inEscherichia coli. Our previous work showing that overproduction of , the proofreading subunit of DNA polymerase III, counteracts the SOS mutagenic response ofE. coli seemed to be consistent with this hypothesis. To explore further the nature of the antimutagenic effect of we constructed plasmid pMK17, which encodes only two of the three highly conserved segments of — Exol and ExoII; the third segment, ExoIII, which is essential for 3–5 exonuclease activity, is deleted. We show that at 40°C, over-production of the truncated e subunit significantly delays production of M13 phage, suggesting that the protein retains its capacity to bind to DNA. On the other hand, the presence of pMK17 in atrpE65 strain growing at 40°C causes a 10-fold decrease in the frequency of UV-induced Trp+ mutations. This antimutagenic effect of the truncated s is effectively relieved by excess UmuD,C proteins. We also show that the presence of plasmid pIP21, which contains thednaQ49 allele encoding an subunit that is defective in proofreading activity, almost completely prevents generation of UV-induced mutations in thetrpE65 strain. We propose that the DNA binding ability of free , rather than its 3–5 exonuclease activity, affects processing of premutagenic UV-induced lesions, possibly by interfering with the interaction between the UmuC-UmuD-RecA complex and Pol III holoenzyme. This interaction is probably a necessary condition for translesion synthesis. 相似文献
28.
An autosomal dominant retinitis pigmentosa family with close linkage to D7S480 on 7q 总被引:7,自引:0,他引:7
José M. Millán Francisco Martínez Concha Vilela Magdalena Beneyto Félix Prieto Carmen Nájera 《Human genetics》1995,96(2):216-218
Retinitis pigmentosa is the most prevalent inherited disorder of the retina. It can be autosomal dominant (adRP), autosomal recessive (arRP) or X-linked (XLRP). A form of adRP mapping to chromosome 7q was reported in a large Spanish pedigree. We have typed DNA from the members of another Spanish family for polymorphic markers from the known candidate genes. Positive lod scores were obtained only for the markers located on 7q31-35, giving a maximum lod score of 2.98 (3.01 by multipoint analysis) at = 0.00 for D7S480. A brief clinical evaluation is given. 相似文献
29.
Both the pineal nonapeptide hormone arginine vasotocin (AVT) (2.5 μg) administered intra-nasally and the pineal indole melatonin (50 mg) administered intravenously to three male narcoleptics (two with auxiliary symptoms and one with sleep attacks only), dramatically increased the amount of REM sleep and decreased REM sleep latency. The duration of the sleep onset REM periods in the two narcoleptics with auxiliary symptoms increased by more than 100 percent after AVT and melatonin administration. In the narcoleptic with sleep attacks only both AVT and melatonin induced REM periods at sleep onset. The hypothesis is advanced that narcolepsy represents an impairment of the melatonin-AVT control in the induction and circadian organization of REM sleep associated with an immaturity of REM triggering centers. 相似文献
30.
Manfred Brockhaus John L. Magnani Meenhard Herlyn Magdalena Blaszczyk Zenon Steplewski Hilary Koprowski Victor Ginsburg 《Archives of biochemistry and biophysics》1982,217(2):647-651
Four hybridomas obtained from mice immunized with human adenocarcinomas of colon or stomach produce antibodies that bind specifically in solid-phase radioimmunoassay to the ceramide pentasaccharide that contains the lacto-N-fucopentaose III sequence of sugars. Binding of the antibodies to the glycolipid is inhibited by lacto-N-fucopentaose III, but not by structurally related oligosaccharides. The antibodies bind to glycolipids of erythrocytes, granulocytes, and certain normal and malignant tissues. 相似文献