Figure 3. Megsin-Cre expression is in the epithelium of the forestomach and esophagus.

Transgenic expression of Megsin-Cre in whole mouse stomach was detected in the forestomach indicated by YFP signals in whole-mount preparation from a Megsin-Cre/+, ROSA26R^YFP/+ mouse (A) and β-galactosidase activity assays on sections from a Megsin-Cre/+, ROSA26R^lacZ/+ mouse (B–C). It was undetectable in the glandular hindstomach. Expression of Megsin-Cre in the forestomach of transgenic mice (D–I). As indicated by the epithelial marker E-cadherin and the smooth muscle marker αSMA, Megsin-Cre expression was restricted to the epithelium of the forestomach (D–F) and no expression was seen in the smooth muscle layers (G–I). Colocalization of YFP and E-cadherin and mutual exclusion of YFP and α-SMA indicated the specific expression of Megsin-Cre in the esophagus epithelium of transgenic mice (Fig. 3J–O). FS: forestomach, HS: glandular hindstomach. Scale bar: 100 μm.