Reporter:	lacZ
Antibody:	anti-B-galactosidase (ab9361)
Detection system:	Secondary antibody coupled to Alexa Fluor 488

Structure	Cell Type	Level	Pattern	Image	Note
TS23: lesser epithelial ridge		Strong		1A' , 1A	Expressed in each turn.
TS23: cochlear duct		Present	Regionally restricted	1A' , 1A	Expressed in outer sulcus in the lateral cochlear ductal floor.
TS23: bony labyrinth	spiral ganglion neuron	Present	Regionally restricted	1A , 1A'	Expressed in the modiolus.

Structure	Level	Pattern	Image	Note
TS23: lesser epithelial ridge	Present		1E' , 1E	Relatively less robust relative to the middle and base turn.
TS23: cochlear duct	Present	Regionally restricted	1E , 1E'	Relatively weaker expression in the outer sulcus extending to the lower half of the lateral cochlear wall.

Structure	Level	Pattern	Image	Note
TS23: lesser epithelial ridge	Strong		1F , 1F'
TS23: cochlear duct	Present	Regionally restricted	1F' , 1F	Relatively weaker expression in the outer sulcus extending to the lower half of the lateral cochlear wall.

Structure	Level	Pattern	Image	Note
TS23: lesser epithelial ridge	Strong		1G' , 1G	Expression overlapped with Cd44 expression.
TS23: cochlear duct	Present	Regionally restricted	1G' , 1G	Relatively weaker expression in the outer sulcus extending to the lower half of the lateral cochlear wall.

Structure	Cell Type	Level	Pattern	Image	Note
TS26: lesser epithelial ridge		Strong		2A' , 2A	Broader and more intense than that of E15.5. Coexpressed with Cd44. No apical-basal gradient was seen.
TS26: external spiral sulcus		Strong	Regionally restricted	2A' , 2A	Expressed in the lateral cochlear wall, broader and more intense than that of E15.5.
TS26: bony labyrinth	spiral ganglion neuron	Weak	Regionally restricted	2A , 2A'	Expressed in the modiolus.
TS26: cochlear duct epithelium	cochlear outer hair cell	Weak	Regionally restricted	2A , 2A'	Only in the apical turn.

Structure	Cell Type	Level	Pattern	Image	Note
TS26: lesser epithelial ridge		Strong	Regionally restricted	2D , 2D'	Expressed in cells located in the lateral two-thirds, whereas the two rows of cells residing in the medial portion showed weaker but detectable expression. Coexpressed with Cd44.
TS26: cochlear duct epithelium	cochlear outer hair cell	Weak	Regionally restricted	2D , 2D'	Only in the apical turn.
TS26: external spiral sulcus		Present	Regionally restricted	2D' , 2D	Expressed in the lateral cochlear wall.

Structure	Cell Type	Level	Pattern	Image	Note
TS26: lesser epithelial ridge		Strong	Regionally restricted	2E' , 2E	Expressed in cells located in the lateral two-thirds, whereas the two rows of cells residing in the medial portion showed weaker but detectable expression. Coexpressed with Cd44.
TS26: cochlear duct epithelium	cochlear outer hair cell	Weak	Regionally restricted	2E' , 2E	Only in this apical turn and Cd44-.
TS26: cochlear duct epithelium	Hensen cell	Weak	Regionally restricted	2E' , 2E	Only in this apical turn and Cd44-.

Structure	Level	Pattern	Image	Note
TS26: lesser epithelial ridge	Strong	Regionally restricted	2H , 2H'	Expressed in cells located in the lateral two-thirds, whereas the two rows of cells residing in the medial portion showed weaker but detectable expression. Coexpressed with Cd44.
TS26: external spiral sulcus	Present	Regionally restricted	2H' , 2H	Expressed in the lateral cochlear wall.

Structure	Level	Pattern	Image	Note
TS26: lesser epithelial ridge	Strong	Regionally restricted	2I , 2I'	Expressed in cells located in the lateral two-thirds, whereas the two rows of cells residing in the medial portion showed weaker but detectable expression. Coexpressed with Cd44.

Structure	Level	Pattern	Image	Note
TS26: lesser epithelial ridge	Strong	Regionally restricted	2L' , 2L	Expressed in cells located in the lateral two-thirds, whereas the two rows of cells residing in the medial portion showed weaker but detectable expression. Coexpressed with Cd44.
TS26: external spiral sulcus	Present	Regionally restricted	2L' , 2L	Expressed in the lateral cochlear wall.

Structure	Level	Pattern	Image	Note
TS26: lesser epithelial ridge	Strong	Regionally restricted	2M , 2M'	Expressed in cells located in the lateral two-thirds, whereas the two rows of cells residing in the medial portion showed weaker but detectable expression. Coexpressed with Cd44.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: cochlea epithelium		Present	Regionally restricted	3A , 3A'	Expressed in the lesser epithelial ridge and lateral cochlear wall.
TS27: stria vascularis		Present		3A , 3A'	Highest expression in the epithelial layer.
TS27: modiolus	spiral ganglion neuron	Present		3A , 3A'
TS27: spiral limbus	interdental cell of cochlea	Absent		3A' , 3A
TS27: cochlear duct epithelium	cochlear inner hair cell	Absent		3A' , 3A
TS27: cochlear duct epithelium	cochlear outer hair cell	Absent		3A' , 3A
TS27: external spiral sulcus		Present		3A' , 3A

Structure	Cell Type	Level	Pattern	Image	Note
TS28: spiral limbus	interdental cell of cochlea	Present		3B , 3B' , 3B"
TS28: cochlea epithelium	Claudius cell	Present	Regionally restricted	3B" , 3B' , 3B	Expressed in the lesser epithelial ridge and lateral cochlear wall. More intense compared to P0.
TS28: external spiral sulcus		Present		3B' , 3B" , 3B	More intense compared to P0.
TS28: stria vascularis		Present		3B" , 3B , 3B'	Highest expression in the epithelial layer. Expression was markedly lower than in P0.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: cochlea epithelium	Claudius cell	Present		3C" , 3C' , 3C	Expression was more robust in the Cd44-positive (Claudius cells) lateral and Cd44-negative (Hensen's cells) medial lesser epithelial ridge than in E18.5.
TS27: cochlea epithelium	Hensen cell	Present		3C" , 3C' , 3C	Expression was more robust in the Cd44-positive (Claudius cells) lateral and Cd44-negative (Hensen's cells) medial lesser epithelial ridge than in E18.5.
TS27: cochlear duct epithelium	cochlear inner hair cell	Absent		3C , 3C" , 3C'
TS27: cochlear duct epithelium	cochlear outer hair cell	Absent		3C , 3C" , 3C'
TS27: external spiral sulcus		Present		3C' , 3C" , 3C	More robust than at E18.5.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: cochlea epithelium	Claudius cell	Present	Regionally restricted	3D" , 3D' , 3D	Expression was more robust in the Cd44-positive (Claudius cells) lateral and Cd44-negative (Hensen's cells) medial lesser epithelial ridge than in P0.
TS28: cochlea epithelium	Hensen cell	Present	Regionally restricted	3D" , 3D' , 3D	Expression was more robust in the Cd44-positive (Claudius cells) lateral and Cd44-negative (Hensen's cells) medial lesser epithelial ridge than in P0.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: external spiral sulcus		Strong		3E , 3E'
TS28: cochlea epithelium	Claudius cell	Strong		3E' , 3E
TS28: cochlea epithelium	Hensen cell	Strong		3E' , 3E
TS28: stria vascularis		Absent		3E' , 3E
TS28: spiral limbus	interdental cell of cochlea	Present		3E , 3E'	More intense compared to P4.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: cochlea epithelium	Claudius cell	Strong		3F , 3F'	There was no difference in the expression from the apical to basal turns.
TS28: cochlea epithelium	Hensen cell	Strong		3F , 3F'	There was no difference in the expression from the apical to basal turns.
TS28: external spiral sulcus		Strong		3F , 3F'
TS28: stria vascularis		Absent		3F' , 3F

Structure	Level	Pattern	Image	Note
TS27: cochlear duct epithelium	Present	Regionally restricted	4C	Expressed in the lateral cochlear wall and the lesser epithelial ridge.

Structure	Level	Pattern	Image	Note
TS27: cochlear duct epithelium	Present	Regionally restricted	4E" , 4E , 4E'	Expressed in the lateral cochlear wall and the lesser epithelial ridge.

Structure	Level	Pattern	Image	Note
TS27: cochlear duct epithelium	Present	Regionally restricted	4F , 4F' , 4F"	Expressed in the lateral cochlear wall and the lesser epithelial ridge.

Structure	Level	Pattern	Image	Note
TS27: cochlear duct epithelium	Present	Regionally restricted	4G" , 4G' , 4G	Expressed in the lateral cochlear wall and the lesser epithelial ridge.

Structure	Cell Type	Level	Pattern	Image	Note
TS23: bony labyrinth	spiral ganglion neuron	Present	Regionally restricted	5B	Relatively low expression in the modiolus.

Structure	Cell Type	Level	Pattern	Image	Note
TS23: bony labyrinth	spiral ganglion neuron	Present	Regionally restricted	5C	Relatively low expression in the modiolus.

Structure	Cell Type	Level	Pattern	Image	Note
TS26: bony labyrinth	spiral ganglion neuron	Present	Regionally restricted	5E	Relatively low expression in the modiolus.

Structure	Cell Type	Level	Pattern	Image	Note
TS26: bony labyrinth	spiral ganglion neuron	Present	Regionally restricted	5F	Relatively low expression in the modiolus.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: modiolus	spiral ganglion neuron	Present		5H

Structure	Cell Type	Level	Pattern	Image	Note
TS27: modiolus	spiral ganglion neuron	Present		5I

Structure	Cell Type	Level	Pattern	Image	Note
TS28: modiolus	spiral ganglion neuron	Present		5K	Higher expression.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: modiolus	spiral ganglion neuron	Present		5L	Higher expression.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: modiolus	spiral ganglion neuron	Absent		5N	Undetectable in Tubb3-positive spiral ganglion neurons.
TS28: modiolus		Present	Single cells	5N	Expressed in a few Tubb3-negative cells surrounding the spiral ganglion neurons.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: modiolus	spiral ganglion neuron	Absent		5O	Undetectable in Tubb3-positive spiral ganglion neurons.
TS28: modiolus		Present	Regionally restricted	5O	Expressed in a few Tubb3-negative cells surrounding the spiral ganglion neurons.

Structure	Level	Pattern	Image	Note
TS23: lesser epithelial ridge	Strong		6R	Relatively normal cochlear morphology.
TS23: cochlear duct	Present	Regionally restricted	6R	Relatively normal cochlear morphology. Relatively weaker expression in the outer sulcus extending to the lower half of the lateral cochlear wall.

Structure	Level	Pattern	Image	Note
TS26: lesser epithelial ridge	Strong		6T	Relatively normal cochlear morphology.
TS26: stria vascularis	Strong		6T	Relatively normal cochlear morphology.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: cochlea epithelium	Claudius cell	Strong		6V	Relatively normal cochlear morphology.
TS27: stria vascularis		Strong		6V	Relatively normal cochlear morphology.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: cochlea epithelium	Claudius cell	Strong		6X	Relatively normal cochlear morphology.
TS28: stria vascularis		Strong		6X	Relatively normal cochlear morphology.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: cochlea epithelium	Claudius cell	Strong		6Z	Relatively normal cochlear morphology.
TS28: stria vascularis		Strong		6Z	Relatively normal cochlear morphology.

Structure	Cell Type	Level	Pattern	Image	Note
TS23: lesser epithelial ridge		Strong		S1A' , S1A	Expressed in each turn.
TS23: cochlear duct		Strong	Regionally restricted	S1A , S1A'	Expressed in outer sulcus in the lateral cochlear ductal floor.
TS23: bony labyrinth	spiral ganglion neuron	Present	Regionally restricted	S1A' , S1A	Expressed in the modiolus.

Structure	Cell Type	Level	Pattern	Image	Note
TS23: bony labyrinth	spiral ganglion neuron	Present		S1B	Relatively less robust relative to the middle and base turn.

Structure	Cell Type	Level	Pattern	Image	Note
TS23: bony labyrinth	spiral ganglion neuron	Present		S1C

Structure	Cell Type	Level	Pattern	Image	Note
TS23: bony labyrinth	spiral ganglion neuron	Present		S1D