Extended Data Fig. 3: Additional human immunohistochemistry (IHC) of immature and mature olfactory sensory neurons (OSN) populations.

a, Co-staining for LHX2 and OMP demonstrates many LHX2⁺/OMP^- neurons, distributed in deeper layers of the OE, which are immature OSNs; OMP is a marker for fully differentiated OSNs, while LHX2 expression in differentiating OSNs orchestrates OR receptor expression. b, DCX was identified by scRNA-seq here as enriched in immature OSNs (see Fig. 2a). IHC confirms scattered DCX⁺ neuronal somata and dendrites in the OE. c, Similarly, the bHLH transcription factor OLIG2 was identified to be enriched in immature OSNs; IHC confirms nuclear expression in the deeper OSN layers of OE tissue. Dashed line indicates basal lamina. Immunostaining for a–c was conducted in triplicate with similar results. Scale bar, 25 µm.