The IRG mouse: A two-color fluorescent reporter for assessing Cre-mediated recombination and imaging complex cellular relationships in situ

• Published in: Genesis (New York, N.Y. : 2000) N.Y. : 2000), 2008-06, Vol.46 (6), p.308-317
• Main Authors: De Gasperi, Rita, Rocher, Anne B., Sosa, Miguel A. Gama, Wearne, Susan L., Perez, Gissel M., Friedrich Jr, Victor L., Hof, Patrick R., Elder, Gregory A.
• Format: Article
• Language: English
• Subjects: Animals; Brain - cytology; Brain - metabolism; Cells, Cultured; conditional gene activation; Cre recombinase; Crosses, Genetic; Diagnostic Imaging; DsRed-express; Embryo, Mammalian - cytology; Embryo, Mammalian - metabolism; enhanced green fluorescent protein; Female; Fluorescent Dyes - metabolism; Genes, Reporter; Genetic Markers - genetics; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Immunohistochemistry; Integrases - genetics; Integrases - metabolism; Intermediate Filament Proteins - genetics; loxP; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Male; Mice; Mice, Transgenic; Microscopy, Confocal; Nerve Tissue Proteins - genetics; Nestin; Promoter Regions, Genetic; Recombination, Genetic; Red Fluorescent Protein; Tissue Distribution; Transgenes; transgenic mice
• ISSN: 1526-954X; 1526-968X
• DOI: 10.1002/dvg.20400

The Cre‐loxP system is widely used for making conditional alterations to the mouse genome. Cre‐mediated recombination is frequently monitored using reporter lines in which Cre expression activates a reporter gene driven by a ubiquitous promoter. Given the distinct advantages of fluorescent reporters, we developed a transgenic reporter line, termed IRG, in which DsRed‐Express, a red fluorescent protein (RFP) is expressed ubiquitously prior to Cre‐mediated recombination and an enhanced green fluorescent protein (EGFP) following recombination. Besides their utility for monitoring Cre‐mediated recombination, we show that in IRG mice red and green native fluorescence can be imaged simultaneously in thick tissue sections by confocal microscopy allowing for complex reconstructions to be created that are suitable for analysis of neuronal morphologies as well as neurovascular interactions in brain. IRG mice should provide a versatile tool for analyzing complex cellular relationships in both neural and nonneural tissues. genesis 46:308–317, 2008. Published 2008 Wiley‐Liss, Inc.