Figure 2.

Cre recombinase activity in GFAP-Cre, Emx1-Cre, and Neurod6-Cre mouse lines. A, B, Representative td⁺ fluorescence images of mouse brain sections from GFAP-Cre; Ai9, Emx1-Cre; Ai9, and NeuroD6-Cre; Ai9 mice at age of P7. Note that Ai9 is a Cre activity reporter mouse line, whose td fluorescence depends the Cre recombinase activity. Ctx: cortex. In B, the brain slices were costained td (red) with β-catenin (green) and DAPI (blue); the regions within white square indicate choroid plexus. Scale bars, 1000 μm (A) and 100 μm (B). C, Magnification of choroid plexus regions in B. Scale bar, 20 μm. GFAP-Cre and Neurod6-Cre are not expressed in choroid plexus, while Emx1-Cre is expressed in choroid plexus.