SPATIAL DETERMINATION OF NEURONAL DIVERSIFICATION IN THE OLFACTORY EPITHELIUM.

Neurons in the murine olfactory epithelium (0E) differ by the olfactory receptor they express as well as other molecular phenotypes that are regionally restricted. These patterns can be precisely regenerated following epithelial injury, suggesting that spatial cues within the tissue can direct neuronal diversification. Nonetheless, the permanency and mechanism of this spatial patterning remain subject to debate. Via transplantation of stem and progenitor cells from dorsal 0E into ventral 0E, we demonstrate that, in mice of both sexes, nonautonomous spatial cues can direct the spatially circumscribed differentiation of olfactory sensory neurons. The vast majority of dorsal transplant- derived neurons express the ventral marker 0CAM(NCAM2) and lose expression of NQ01 to match their new location. Single-cell analysis also demonstrates that 0SNs adopt a fate defined by their new position following progenitor cell transplant, such that a ventral olfactory receptor is expressed after stem and progenitor cell engraftment. Thus, spatially constrained differentiation of olfactory sensory neurons is plastic, and any bias toward an epigenetic memory of place can be overcome.