In the utricle (A–F”) and saccule (G–L”), the lineage (A,D,G,J, blue) and expression (A’,D’,G’,J’, green) domains of Emx2 are both restricted to the LES and IR, respectively. (C,F,I,L) show Emx2 lineage (blue) and anti-spectrin staining (red). (C’,F’,I’,L’) and (C”,F”,I”,L”) are same regions as (C,F,I,L) showing lineage staining (blue) and anti-Emx2 staining (green) at the nucleus level of HCs, respectively. The LPR (C”,F”,I”,L”, yellow line) correlates with the border of Emx2 immunostaining (green line) better than the border of Emx2-lineage domain (C’,F’,I’,L’, cyan line). Asterisks label the Emx2-lineage negative HCs with reversed bundle polarity that are positive for Emx2 staining, whereas arrowheads label Emx2-lineage HCs with default bundle polarity that are negative for Emx2 immunoreactivity.