Karyotype evolution and nuclear organization across the genus Arabidopsis Dissertation zur Erlangung des akademischen Grades doctor rerum naturalium (Dr.rer.nat.) vorgelegt der Mathematisch-Naturwissenschaftlich-Technischen Fakultät (matematisch-naturwissenschaftlicher Bereich) der Martin-Luther-Universität Halle-Wittenberg von Herrn Alexandre Berr geb. am: 13/06/1979 in: Maisons-Alfort (94), Frankreich Gutachter: 1. Prof. Dr. Ingo Schubert, IPK, Gatersleben, Germany. 2. Prof. Dr. Gunter Reuther, Martin-Luther-Universität, Halle-Wittenberg, Germany. 3. Dr. Thomas Schmidt, University of Technology, Dresden, Germany. Verteidigung: Halle (Saale), den 18/12/2006 urn:nbn:de:gbv:3-000011124[http://nbn-resolving.de/urn/resolver.pl?urn=nbn%3Ade%3Agbv%3A3-000011124] à Aurélie et Arthur ACKNOWLEDGEMENTS This work was done from February 2004 till June 2006 at the Leibniz-Institute für Pflanzengenetik und Kulturpflanzenforschung (IPK) in Gatersleben and was in part supported by the Deutsche Forschungsgemeinschaft (Schu 951/10-1). It is difficult to overstate my gratitude to my supervisor Prof. Dr. Ingo Schubert, the head of Cytogenetics Department, for giving me the opportunity to work in his group, for constant guidance, inspiration, continuous support and inestimable encouragement. I would like to give my thanks to Dr. Ales Pecinka, Dr. Jörg Fuchs, Dr. Martin Lysak, Dr.