Antibody:	anti-KCNQ4
Detection system:	Secondary antibody coupled to Alexa Fluor
Assay notes:	There were no differences observed when using either antiserum alone or in combination.

Structure	Level	Pattern	Image	Note
TS27: organ of Corti	Present	Regionally restricted	4A1	No expression in the apical region.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: organ of Corti	cochlear inner hair cell	Present		4A2	Expressed in the basal hook region.
TS27: organ of Corti	cochlear outer hair cell	Present		4A2	Expressed in the basal hook region.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear inner hair cell	Present	Regionally restricted	4A3	The developmental upregulation had reached the apical turn.
TS28: organ of Corti	cochlear outer hair cell	Present	Regionally restricted	4A3	The developmental upregulation had reached the apical turn.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear inner hair cell	Present		4A4	The basal hook region showed the adult expression pattern.
TS28: organ of Corti	cochlear outer hair cell	Present		4A4	The basal hook region showed the adult expression pattern.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear inner hair cell	Present	Regionally restricted	4A5	All hair cells, except those in the apical tip, had acquired the adult pattern.
TS28: organ of Corti	cochlear outer hair cell	Present	Regionally restricted	4A5	All hair cells, except those in the apical tip, had acquired the adult pattern.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear inner hair cell	Present		4A6	All hair cells, except those in the apical tip, had acquired the adult pattern.
TS28: organ of Corti	cochlear outer hair cell	Present		4A6	All hair cells, except those in the apical tip, had acquired the adult pattern.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear inner hair cell	Present	Graded	5A inset , 5A	A basal to apical longitudinal gradients were seen. The inset showed the last vestiges of developmental upregulation of expression in IHCs at the very apical tip.
TS28: organ of Corti	cochlear outer hair cell	Present	Graded	5A inset , 5A	A apical to basal longitudinal gradients were seen.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear outer hair cell	Strong		5B
TS28: organ of Corti	cochlear inner hair cell	Weak		5B

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear inner hair cell	Present		5C
TS28: organ of Corti	cochlear outer hair cell	Present		5C

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear outer hair cell	Present		5E , 5F
TS28: organ of Corti	cochlear inner hair cell	Strong		5E , 5F

Structure	Level	Pattern	Image	Note
TS28: cochlear ganglion	Strong		5I

Structure	Level	Pattern	Image	Note
TS28: cochlear ganglion	Strong		5L

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear outer hair cell	Present		6C upper left
TS28: organ of Corti	cochlear inner hair cell	Present	Regionally restricted	6C upper left	No expression in the apical region.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear inner hair cell	Present		6C upper middle
TS28: organ of Corti	cochlear outer hair cell	Present		6C upper middle

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear outer hair cell	Weak		6C upper right
TS28: organ of Corti	cochlear inner hair cell	Strong		6C upper right

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear inner hair cell	Strong		6C lower left
TS28: organ of Corti	cochlear outer hair cell	Strong		6C lower left

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear outer hair cell	Present		6C lower middle
TS28: organ of Corti	cochlear inner hair cell	Strong		6C lower middle

Structure	Cell Type	Level	Pattern	Image	Note
TS28: organ of Corti	cochlear outer hair cell	Present		6C lower right
TS28: organ of Corti	cochlear inner hair cell	Strong		6C lower right

Structure	Level	Pattern	Image	Note
TS26: cochlea	Weak	Regionally restricted		Expressed in the cochlear base, but it was just above background level thresholds.