Expression of the GFP reporter gene in adult R26t1Δ and homozygous R26t1Δ/t1Δ mice. Western blot analysis of muscle extracts from wild-type (WT), R26t1Δ and R26t1Δ/t1Δ mice three to five month of age. Upper part: No GFP-specific signal could be detected in muscle without DOX administration. The very same blot was probed for calnexin (Cal.) and the result is shown below the GFP-specific signal. Lower part: Western blot analysis of GFP (four upper lanes) and calnexin (four lower lanes) expression in spleen, thymus, muscle and testis extracts from DOX-induced wild-type (WT), heterozygous (R26t1Δ) and homozygous (R26t1Δ/t1Δ) mice. The GFP and calnexin signals were obtained from the same blot. For reasons of simplicity the calnexin loading control and the GFP signal are aligned and pictured as one group. Animals were treated with DOX for 3 weeks prior analysis.