Generation of inducible Cre systems for conditional gene inactivation in mice Inauguraldissertation zur Erlangung des Doktorgrades der Mathematisch-Naturwissenschaftlichen Fakultät der Universität zu Köln vorgelegt von Frank Thomas Wunderlich aus Freiburg i. Br. Berichterstatter: Prof. Dr. Klaus Rajewsky Prof. Dr. Jens Brüning Tag der mündlichen Prüfung: ____________________________ TABLE OF CONTENTS I TABLE OF CONTENTS I ABBREVIATIONS IV 1. INTRODUCTION 11.1 Genetic engineering by site specific recombinases 11.2 Conditional gene targeting 51.3 Inducible gene targeting 101.3.1 Transcriptional control of Cre activity 111.3.2 Posttranslational control of Cre activity 141.4 Objectives 21 2. MATERIALS AND METODS 222.1 Chemicals and antibodies 222.2 Molecular biology 222.2.1 Competent E. coli and isolation of plasmid DNA 222.2.2 Constructions of expression plasmids and targeting vectors 232.2.2.1 CrePR expression plasmids 252.2.2.2 ROSA26 Cre indicator targeting vector 272.2.2.3 ROSA26 Cre*PR targeting vector 282.2.2.4 HPRT CAGGS Cre*PR targeting vector 282.2.2.5 HPRT EF1 α Cre*PR targeting vector 302.2.2.6 HPRT CAGGS tet-on targeting vector 302.2.2.