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F Pröls

Publications and source records attributed to F Pröls.

22 records · Page 2Linked to original sources

The methylation patterns of chromosomal integration regions influence gene activity of transferred DNA in Petunia hybrida.

The regions of integration of a transferred DNA-fragment from three transgenic Petunia hybrida plants were analysed for their influence on the expression of the foreign DNA. Each of the three transformants, lines 16, 17 and 24, contained a fragment of a plasmid on which two genes were located, an npt-II gene which renders the plants resistant to kanamycin and the A1 gene from Zea mays, a visible marker gene that leads to the production of a brick red anthocyanin pigment in the flowers. Inactivation of both genes in line 16 is associated with integration into a region of highly repetitive DNA, while the integration sites of the other two lines were essentially unique. The integration regions of lines 17 and 24, both of which show expression of the foreign genes at characteristically different intensities, showed a distinct methylation pattern that was stably conserved for these regions in both transgenic and wild-type plants. The characteristic methylation pattern of the two integration regions was also imposed on the border region of the integrated fragments and might thus be responsible for the differences in the intensity of gene expression observed among the two lines.

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Mesangial cells and their adhesive properties.

Glomerular mesangial cells play a central role in maintaining structure and function of the glomerular capillary ultrafiltration apparatus. Under physiological and pathological conditions, mesangial cells regulate amount and composition of the surrounding extracellular matrix. Conversely, components of the embedding matrix affect the mesangial cell phenotype. These interactions are mediated via specific cell surface receptors, the best studied group of which is the beta1 integrin family. The beta1 integrins play a role in mesangial cell adhesion, migration, survival and proliferation. Expression and abundance of integrins in healthy and diseased glomeruli and their functions and mediation of signals are discussed in this review. Other factors modulating mesangial cell-matrix interactions, such as antiadhesive proteins, cytokines, disintegrins and nitric oxide, are also considered. The available evidence from in vitro and in vivo studies indicates that receptor-mediated interactions between mesangial cells and the normal or abnormal extracellular matrix regulate the mesangial cell phenotype and thus contribute to normal maintenance of the glomerulus and to remodeling and repair of the glomerular capillary tuft in response to injury.

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