@misc{PajoroMadrigalMuinoetal.2014, author = {Pajoro, Alice and Madrigal, Pedro and Mui{\~n}o, Jose M. and Matus, Jos{\´e} Tom{\´a}s and Jin, Jian and Mecchia, Martin A. and Debernardi, Juan M. and Palatnik, Javier F. and Balazadeh, Salma and Arif, Muhammad and {\´O}'Maoil{\´e}idigh, Diarmuid S. and Wellmer, Frank and Krajewski, Pawel and Riechmann, Jos{\´e}-Luis and Angenent, Gerco C. and Kaufmann, Kerstin}, title = {Dynamics of chromatin accessibility and gene regulation by MADS-domain transcription factors in flower development}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, volume = {15}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, issn = {1866-8372}, doi = {10.25932/publishup-43113}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431139}, pages = {19}, year = {2014}, abstract = {Background: Development of eukaryotic organisms is controlled by transcription factors that trigger specific and global changes in gene expression programs. In plants, MADS-domain transcription factors act as master regulators of developmental switches and organ specification. However, the mechanisms by which these factors dynamically regulate the expression of their target genes at different developmental stages are still poorly understood. Results: We characterized the relationship of chromatin accessibility, gene expression, and DNA binding of two MADS-domain proteins at different stages of Arabidopsis flower development. Dynamic changes in APETALA1 and SEPALLATA3 DNA binding correlated with changes in gene expression, and many of the target genes could be associated with the developmental stage in which they are transcriptionally controlled. We also observe dynamic changes in chromatin accessibility during flower development. Remarkably, DNA binding of APETALA1 and SEPALLATA3 is largely independent of the accessibility status of their binding regions and it can precede increases in DNA accessibility. These results suggest that APETALA1 and SEPALLATA3 may modulate chromatin accessibility, thereby facilitating access of other transcriptional regulators to their target genes. Conclusions: Our findings indicate that different homeotic factors regulate partly overlapping, yet also distinctive sets of target genes in a partly stage-specific fashion. By combining the information from DNA-binding and gene expression data, we are able to propose models of stage-specific regulatory interactions, thereby addressing dynamics of regulatory networks throughout flower development. Furthermore, MADS-domain TFs may regulate gene expression by alternative strategies, one of which is modulation of chromatin accessibility.}, language = {en} } @misc{MorelCastroFossatietal.2014, author = {Morel, T. and Castro, Norberto and Fossati, Luca and Hubrig, Swetlana and Langer, N. and Przybilla, Norbert and Sch{\"o}ller, Markus and Carroll, Thorsten Anthony and Ilyin, Ilya and Irrgang, Andreas and Oskinova, Lida and Schneider, Fabian R. N. and Simon D{\´i}az, Sergio and Briquet, Maryline and Gonz{\´a}lez, Jean-Francois and Kharchenko, Nina and Nieva, M.-F. and Scholz, Ralf-Dieter and de Koter, Alexander and Hamann, Wolf-Rainer and Herrero, Artemio and Ma{\´i}z Apell{\´a}niz, Jesus and Sana, Hugues and Arlt, Rainer and Barb{\´a}, Rodolfo H. and Dufton, Polly and Kholtygin, Alexander and Mathys, Gautier and Piskunov, Anatoly E. and Reisenegger, Andreas and Spruit, H. and Yoon, S.-C.}, title = {The B fields in OB stars (BOB) survey}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {821}, issn = {1866-8372}, doi = {10.25932/publishup-41523}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415238}, pages = {8}, year = {2014}, abstract = {The B fields in OB stars (BOB) survey is an ESO large programme collecting spectropolarimetric observations for a large number of early-type stars in order to study the occurrence rate, properties, and ultimately the origin of magnetic fields in massive stars. As of July 2014, a total of 98 objects were observed over 20 nights with FORS2 and HARPSpol. Our preliminary results indicate that the fraction of magnetic OB stars with an organised, detectable field is low. This conclusion, now independently reached by two different surveys, has profound implications for any theoretical model attempting to explain the field formation in these objects. We discuss in this contribution some important issues addressed by our observations (e.g., the lower bound of the field strength) and the discovery of some remarkable objects.}, language = {en} }