%0 Journal Article
%T A pink mouse reports the switch from red to green fluorescence upon Cre-mediated recombination
%A Heiner Hartwich
%A Somisetty V Satheesh
%A Hans Nothwang
%J BMC Research Notes
%D 2012
%I BioMed Central
%R 10.1186/1756-0500-5-296
%X Here, we report a dual fluorescence reporter mouse line, which switches expression from the red fluorescent protein mCherry to eGFP after Cre-mediated recombination. Both fluorescent proteins are expressed from the ubiquitously active and strong CAGGS promoter. Among the founders, we noticed a pink mouse line, expressing high levels of the red fluorescent protein mCherry throughout the entire body. Presence of mCherry in the living animal as well as in almost all organs was clearly visible without optical equipment. Upon Cre-activity, mCherry expression was switched to eGFP, demonstrating functionality of this reporter mouse line.The pink mouse presented here is an attractive novel reporter line for fluorescence-based monitoring of Cre-activity. The high expression of mCherry, which is visible to the naked eye, facilitates breeding and crossing, as no genotyping is required to identify mice carrying the reporter allele. The presence of two fluorescent proteins allows in vivo monitoring of recombined and non-recombined cells. Finally, the pink mouse is an eye-catching animal model to demonstrate the power of transgenic techniques in teaching courses.Spatiotemporally restricted genetic modification in the mouse is becoming an indispensable tool in biological research [1]. Applications include analysis of essential genes, whose constitutive ablation results in embryonic/perinatal lethality, discrimination between primary and secondary effects, or mapping cell connectivity and cell fate [2-4]. The importance of targeted genetic modification is underlined by a recent global initiative to generate conditional alleles for all murine genes [5-7]. Most targeted genetic modifications make use of the Cre/loxP system. In this approach, a Cre-driver mouse line, expressing Cre recombinase of the phage P1 under a tissue or cell-type specific promoter, is crossed to mice with a loxP flanked (¡°floxed¡±) allele, which is recognized by Cre [8].Several Cre-driver lines have been generat
%U http://www.biomedcentral.com/1756-0500/5/296