Loss of Disabled-1 Reduces Olfactory Adult Neurogenesis

This study examines the role of the Reelin-signaling pathway in the peripheral olfactory system. We found that olfactory sensory neurons (OSNs) express the Disabled-1 (Dab1) protein and Dab1 mutants have reduced olfactory detection compared to controls. We generated a conditional deletion of dab1 in OSNs. We studied differences in OSN neurogenesis by comparing the number of immature neurons marked by GAP43 in our no-cre controls to OMP-cre; Dab1 flox/flox and OMP-cre; Dab1 flox/+ mice. OMP-cre; Dab1 flox/flox mice had fewer GAP 43-labeled cells compared to the no-cre controls. The reduction in immature OSNs prompted us to explore the number of olfactory stem cells and proliferative cells by localizing Sox2 and Ki67, respectively. We found that the OMP-cre; Dab1 flox/flox mice had many fewer Sox2 and Ki67-expressing cells in their olfactory epithelium (OE) than control mice. This work reveals that dab1 is critical for adult neurogenesis within the OE