Figure 4.

Foxg1^Cre/Cre mice fail to develop olfactory structures. Coronal sections of wild-type (A–D) and Foxg1^Cre/Cre (A′–D′) mice at the indicated embryonic stages were stained with toluidine blue. Foxg1 mutant mice show asymmetrically developing airways rostrally and no stratified olfactory epithelium (A, arrows), vomeronasal organs (C, arrows), or olfactory bulbs (D, arrows). No difference was observed between Foxg1^+/+ and Foxg1^Cre/+ mice. The right nostril of the animal is in the right half of the image. Scale bars: A–B′, 200 μm; C–D′, 400 μm.