title: Conditional gene expression systems in the transgenic rat brain.
abstract: BACKGROUND
  Turning gene expression on and off at will is one of the most powerful tools for the study of gene function in vivo. While several conditional systems were successful in invertebrates, in mice the Cre/loxP recombination system and the tet-controlled transcription activation system are predominant. Both expression systems allow for spatial and temporal control of gene activities, and, in the case of tet regulation, even for the reversible activation/inactivation of gene expression. Although the rat is the principal experimental model in biomedical research, in particular in studies of neuroscience, conditional rat transgenic systems are exceptionally rare in this species.
  
  
  RESULTS
  We addressed this lack of technology, and established and thoroughly characterized CreERT2 and tTA transgenic rats with forebrain-specific transgene expression, controlled by the CaMKII alpha promoter. In addition, we developed new universal rat reporter lines for both transcription control systems and established inducible and efficient reporter gene expression in forebrain neurons.
  
  
  CONCLUSIONS
  We demonstrate that conditional genetic manipulations in the rat brain are both feasible and practicable and outline advantages and limitations of the Tet and Cre/loxP system in the rat brain.
authors.affiliation: Department of Molecular Biology, Central Institute of Mental Health and Heidelberg University, Medical Faculty Mannheim, J5, 68159 Mannheim, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Schönig
authors.forename: Tillmann
authors.initials: T
authors.lastname: Weber
authors.forename: Ariana
authors.initials: A
authors.lastname: Frömmig
authors.forename: Lena
authors.initials: L
authors.lastname: Wendler
authors.forename: Brigitte
authors.initials: B
authors.lastname: Pesold
authors.forename: Dominik
authors.initials: D
authors.lastname: Djandji
authors.forename: Hermann
authors.initials: H
authors.lastname: Bujard
authors.forename: Dusan
authors.initials: D
authors.lastname: Bartsch
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D004318:Doxycycline / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D019426:Integrases / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D051381:Rats; D055647:Rats, Transgenic; D011995:Recombination, Genetic / Q000235:genetics; D013629:Tamoxifen / Q000494:pharmacology; D013752:Tetracycline / Q000494:pharmacology; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: C485184:enhanced green fluorescent protein; D013629:Tamoxifen; D049452:Green Fluorescent Proteins; D008156:Luciferases; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; C045073:Cre recombinase; D019426:Integrases; D001616:beta-Galactosidase; D013752:Tetracycline; D004318:Doxycycline