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1.
Hairless (H) is the major antagonist within the Notch signalling pathway of Drosophila melanogaster. By binding to Suppressor of Hairless [Su(H)] and two co-repressors, H induces silencing of Notch target genes in the absence of Notch signals. We have applied genomic engineering to create several new H alleles. To this end the endogenous H locus was replaced with an attP site by homologous recombination, serving as a landing platform for subsequent site directed integration of different H constructs. This way we generated a complete H knock out allele H
attP, reintroduced a wild type H genomic and a cDNA-construct (H
gwt, H
cwt) as well as two constructs encoding H proteins defective of Su(H) binding (H
LD, H
iD). Phenotypes regarding viability, bristle and wing development were recorded, and the expression of Notch target genes wingless and cut was analysed in mutant wing discs or in mutant cell clones. Moreover, genetic interactions with Notch (N
5419) and Delta (Dl
B2) mutants were addressed. Overall, phenotypes were largely as expected: both H
LD and H
iD were similar to the H
attP null allele, indicating that most of H activity requires the binding of Su(H). Both rescue constructs H
gwt and H
cwt were homozygous viable without phenotype. Unexpectedly, the hemizygous condition uncovered that they were not identical to the wild type allele: notably H
cwt showed a markedly reduced activity, suggesting the presence of as yet unidentified regulatory or stabilizing elements in untranslated regions of the H gene. Interestingly, H
gwt homozygous cells expressed higher levels of H protein, perhaps unravelling gene-by-environment interactions. 相似文献
2.
Maximilian Schmid Bianca Dufner Julius Dürk Konstanze Bedal Kristina Stricker Lukas Ali Prokoph Christoph Koch Anja K. Wege Henner Zirpel Ger van Zandbergen Rupert Ecker Bogdan Boghiu Uwe Ritter 《PloS one》2015,10(10)
Characterization of host-pathogen interactions is a fundamental approach in microbiological and immunological oriented disciplines. It is commonly accepted that host cells start to change their phenotype after engulfing pathogens. Techniques such as real time PCR or ELISA were used to characterize the genes encoding proteins that are associated either with pathogen elimination or immune escape mechanisms. Most of such studies were performed in vitro using primary host cells or cell lines. Consequently, the data generated with such approaches reflect the global RNA expression or protein amount recovered from all cells in culture. This is justified when all host cells harbor an equal amount of pathogens under experimental conditions. However, the uptake of pathogens by phagocytic cells is not synchronized. Consequently, there are host cells incorporating different amounts of pathogens that might result in distinct pathogen-induced protein biosynthesis. Therefore, we established a technique able to detect and quantify the number of pathogens in the corresponding host cells using immunofluorescence-based high throughput analysis. Paired with multicolor staining of molecules of interest it is now possible to analyze the infection profile of host cell populations and the corresponding phenotype of the host cells as a result of parasite load. 相似文献
3.
Ektoras Hadjipanayi Peer-Hendrik Kuhn Philipp Moog Anna-Theresa Bauer Haydar Kuekrek Lilit Mirzoyan Anja Hummel Katharina Kirchhoff Burak Salgin Sarah Isenburg Ulf Dornseifer Milomir Ninkovic Hans-Günther Machens Arndt F. Schilling 《PloS one》2015,10(8)
Conceptually, premature initiation of post-wound angiogenesis could interfere with hemostasis, as it relies on fibrinolysis. The mechanisms facilitating orchestration of these events remain poorly understood, however, likely due to limitations in discerning the individual contribution of cells and extracellular matrix. Here, we designed an in vitro Hemostatic-Components-Model (HCM) to investigate the role of the fibrin matrix as protein factor-carrier, independent of its cell-scaffold function. After characterizing the proteomic profile of HCM-harvested matrix releasates, we demonstrate that the key pro-/anti-angiogenic factors, VEGF and PF4, are differentially bound by the matrix. Changing matrix fibrin mass consequently alters the balance of releasate factor concentrations, with differential effects on basic endothelial cell (EC) behaviors. While increasing mass, and releasate VEGF levels, promoted EC chemotactic migration, it progressively inhibited tube formation, a response that was dependent on PF4. These results indicate that the clot’s matrix component initially serves as biochemical anti-angiogenic barrier, suggesting that post-hemostatic angiogenesis follows fibrinolysis-mediated angiogenic disinhibition. Beyond their significance towards understanding the spatiotemporal regulation of wound healing, our findings could inform the study of other pathophysiological processes in which coagulation and angiogenesis are prominent features, such as cardiovascular and malignant disease. 相似文献
4.
Hydrobiologia - To observe effects on the phosphorus retention mechanisms of a lake after re-colonisation by macrophytes, Potamogeton crispus L. and Elodea canadensis Michx. were planted in lab... 相似文献
5.
Mechanics and modeling of plant cell growth 总被引:1,自引:0,他引:1
6.
Sashko Spassov Dietmar Pfeifer Karl Strosing Stefan Ryter Matthias Hummel Simone Faller Alexander Hoetzel 《PloS one》2014,9(7)
Recently, we have shown that inhalation of hydrogen sulfide (H2S) protects against ventilator-induced lung injury (VILI). In the present study, we aimed to determine the underlying molecular mechanisms of H2S-dependent lung protection by analyzing gene expression profiles in mice. C57BL/6 mice were subjected to spontaneous breathing or mechanical ventilation in the absence or presence of H2S (80 parts per million). Gene expression profiles were determined by microarray, sqRT-PCR and Western Blot analyses. The association of Atf3 in protection against VILI was confirmed with a Vivo-Morpholino knockout model. Mechanical ventilation caused a significant lung inflammation and damage that was prevented in the presence of H2S. Mechanical ventilation favoured the expression of genes involved in inflammation, leukocyte activation and chemotaxis. In contrast, ventilation with H2S activated genes involved in extracellular matrix remodelling, angiogenesis, inhibition of apoptosis, and inflammation. Amongst others, H2S administration induced Atf3, an anti-inflammatory and anti-apoptotic regulator. Morpholino mediated reduction of Atf3 resulted in elevated lung injury despite the presence of H2S. In conclusion, lung protection by H2S during mechanical ventilation is associated with down-regulation of genes related to oxidative stress and inflammation and up-regulation of anti-apoptotic and anti-inflammatory genes. Here we show that Atf3 is clearly involved in H2S mediated protection. 相似文献
7.
8.
S. Pfeifer und E. Stresemann 《Journal of Ornithology》1952,93(3-4):363-364
Ohne Zusammenfassung 相似文献
9.
Isolation of cadmium sensitive mutants in Chlamydomonas reinhardtii by transformation/insertional mutagenesis 总被引:1,自引:0,他引:1
Abstract An arg7, cw15, mt+ strain of Chlamydomonas reinhardtii (CC1618) was transformed with pARG7.8, a plasmid containing the wild-type ARG7 gene. Over 2300 arg+ transformants were selected on TAP media. Upon subsequent analysis on TAP plus cadmium plates, five of the transformants failed to grow at a level of 400 μM cadmium and were designated as cadmium sensitive (Cds ) mutants. Hybridization data indicated that vector (pBR329) sequences were present in these five mutants, but not in the untransformed parental strain. Two of the mutants have been back crossed to an arg7, cw15, Cd+ , mt− strain (CC425) and found to have progeny which always cosegregate the arg+ and Cds phenotypesin these two mutants results from the insertion of the plasmid pARG7.8 into a gene involving cadmium detoxification, and it provides a method by which to clone the interrupted gene(s). 相似文献
10.
Subgenomic mRNA in OK10 Defective Leukemia Virus-Transformed Cells 总被引:16,自引:6,他引:10
S. Saule A. Sergeant G. Torpier M. B. Raes S. Pfeifer D. Stehelin 《Journal of virology》1982,42(1):71-82