title: Conditional Knockout of the L-Type Voltage-gated Calcium Channel CaV1.3 via the FLEX Switch
creator: Bartels, Katrin
subject: ddc-570
subject: 570 Life sciences
description: L-type voltage-gated calcium channels (VGCCs) play a central role in regulating intracellular calcium (Ca2+) concentrations, thereby contributing to signal transduction in many electrically excitable cells. The L-type channel CaV1.3 is expressed in neurons, in hair cells of the inner ear, in heart tissue and in pancreatic ß-cells. Mice with a ubiquitous deletion of the pore-forming alpha1-subunit (CaV1.3-/-) showed that CaV1.3 has cardiac pace maker activity and controls the neurotransmitter release in the cochlea. Furthermore, Ca2+ influx through this channel was proposed to be involved in anxiety-related behaviour and in consolidation of contextually conditioned fear. Aim of my work was to gain more insight into the physiological role of CaV1.3 in different cell types and tissues, especially in neurons. To circumvent the phenotypes of the conventional knockout mice like deafness and heart insufficiency which may interfere with behavioural analysis, we decided to generate a conditional CaV1.3alpha1 knockout mouse using the Cre/loxP-based FLEX switch system. By a Cre-mediated inversion of the targeted locus, this strategy coupled the ablation of the CaV1.3alpha1 gene to the expression of the reporter gene eGFP, thereby mirroring the exact expression pattern of the endogenous CaV1.3 gene in all tissues. Heterozygous CaV1.3-GFPflex mice were bred with “Cre-deleter” mice in which the Cre recombinase is ubiquitously expressed. We could show that, after Cre expression, the FLEX switch occurred efficiently in vitro and in vivo and that the reporter gene was driven by the endogenous CaV1.3alpha1 promoter. Immunohistochemical analysis revealed eGFP expression in heart tissue as well as in many brain areas like the olfactory bulb, the cerebellum, superior colliculus, brain regions associated with emotional behaviour and sensory processing. In contrast to previously reported CaV1.3 expression, only moderate eGFP staining was found in hippocampal regions. An unexpected observation was the intense eGFP expression in the peri- and subventricular zone, suggesting a role of CaV1.3alpha1 in adult neurogenesis and neural stem cell proliferation. In parallel, we crossed CaV1.3-GFPflex mice to CaMKIIa-mice, thereby obtaining specific eGFP expression in the forebrain according to the expression of the CaMKIIa promoter.  This mouse model offers a great potential to further investigate the distribution and function of the L-type Ca2+ channel CaV1.3 in various tissues. 
date: 2009
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/10021/1/KatrinBartels_Diss_Endversion.pdf
identifier: DOI:10.11588/heidok.00010021
identifier: urn:nbn:de:bsz:16-opus-100216
identifier:   Bartels, Katrin  (2009) Conditional Knockout of the L-Type Voltage-gated Calcium Channel CaV1.3 via the FLEX Switch.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/10021/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng