A Cre-reporter transgenic mouse expressing the far-red fluorescent protein Katushka.
Cre/loxP-dependent expression of fluorescent proteins represents a powerful biological tool for cell lineage, fate-mapping, and genetic analysis. Live tissue imaging has significantly improved with the development of far-red fluorescent proteins, with optimized spectral characteristics for in vivo applications. Here, we report the generation of the first transgenic mouse line expressing the far-red fluorescent protein Katushka, driven by the hybrid CAG promoter upon Cre-mediated recombination. After germ line or tissue-specific Cre-driven reporter activation, Katushka expression is strong and ubiquitous, without toxic effects, allowing fluorescence detection in fresh and fixed samples from all tissues examined. Moreover, fluorescence can be detected by in vivo noninvasive whole-body imaging when Katuhska is expressed exclusively in a specific cell population deep within the animal body such as pancreatic beta cells. Thus, this reporter model enables early, widespread, and sensitive in vivo detection of Cre activity and should provide a versatile tool for a wide spectrum of fluorescence and live-imaging applications.
Biotechnology Program, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid, Spain.
Rodrigo
R
Diéguez-Hurtado
Javier
J
Martín
Inés
I
Martínez-Corral
María Dolores
MD
Martínez
Diego
D
Megías
David
D
Olmeda
Sagrario
S
Ortega
D000818:Animals; D005434:Flow Cytometry / Q000379:methods; D017930:Genes, Reporter; D019426:Integrases / Q000235:genetics*; D008164:Luminescent Proteins / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal / Q000379:methods; D011401:Promoter Regions, Genetic; D011995:Recombination, Genetic; D000097573:Red Fluorescent Protein
D019426:Integrases; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein; C045073:Cre recombinase