Fig. 2: Characterization of auditory receptors in the macaque cochlea.

a Uniform Manifold Approximation and Projection (UMAP) visualization of hair cells in the macaque cochlea, including inner hair cells (IHCs) and outer hair cells (OHCs). A total of 259 hair cells were extracted from the whole cellular map (left panel) and subsequentially re-integrated by scVI (single-cell variational inference) method. The middle panel showed the distribution of macaque samples in a UMAP plot as same in extensive plot displaying two distinct hair cell subtypes (right panel). b Top panel: Expression profile of canonical marker genes for IHCs, as previously identified in mouse models. These genes include SLC17A8 (vesicular glutamate transporter 3), TBX2 (T-box transcription factor TBX2), CALB2 (calretinin), and ATP2A3 (sarcoplasmic/endoplasmic reticulum calcium ATPase 3). Bottom panel: Expression profile of canonical marker genes for OHCs, as previously identified in mouse models. These genes include SLC26A5(solute carrier family 26 member 5, Prestin), IKZF2 (Ikaros family zinc finger protein 2), KCNQ4 (potassium voltage-gated channel subfamily KQT member 4), and PCP4 (calmodulin regulator protein PCP4). Gene expression was calculated with log-transformed normalization. c Confocal microscopy images demonstrating the localization of PRESTIN protein encoded by SLC26A5 in the 5-year-old macaque OHCs and the 3-week-old mouse OHCs, respectively. n = 3 independent experiments with similar results. d Patch-clamp recordings were used for testing the electromotility of OHCs in response to current injection.