Fig. 4. Isotopic/isochronic grafts and naïve epiblast grafts to presumptive olfactory placode ectoderm contribute to endogenous olfactory epithelium. (a-A'') After grafting anterior neural folds from HH8 quail, Pax6+ quail cells are in olfactory epithelium (A-A'', arrowheads) and telencephalon (A-A'', arrows). (b-B'') HH8 ectoderm grafted adjacent to anterior neural folds contributes to nasal pit and adjacent ectoderm (boxes in B,B', arrowhead indicates Dlx3+/QPCN+ cell). (c-D'') HH5 quail epiblast grafted to presumptive olfactory territory integrated into ectoderm adjacent to placode, thickened and expressed Dlx3 (box in C,C'; arrow indicates Dlx3+ host nasal pit; arrowhead indicates Dlx3+/QCPN+ cell). Hu staining (D-D'') shows extensive neuronal differentiation. In D,D', large box indicates neurons in grafted epithelium and small box indicates quail cells contributing to the olfactory nerve. Arrowhead indicates Hu+/QCPN+ cell (D''). Inset in D'' shows high magnification of neurons migrating from donor-derived olfactory placode. la, lateral; m, medial; op, olfactory placode; fb, forebrain.