Figure 2.

Widespread β-gal expression in the E15 mouse embryo. A, The β-gal reporter is expressed in a variety of neural and non-neural tissues on a cryosection of an E15 embryo. B, C, Higher-magnification images show reporter expression in the ventricular zones of the rhombencephalon (R) and mesencephalon (M) (10×; B), DRG (8×; C, arrow), skeletal muscle (C, asterisk), and cartilage of the vertebrae (C, arrowhead). D, β-Gal activity is prominent in the aortic arch of the heart (7×; arrow). E, F, High levels of the reporter are also present in the lungs (18×; E) and the intestines (9×; F). The sections are counterstained with neutral red.