Antibody:	anti-Pax2
Detection system:	Biotinylated secondary antibody/[Strept]avidin coupled to horseradish peroxidase

Structure	Level	Pattern	Image	Note
TS15: otocyst	Present	Non-Uniform	2D	Staining was more pronounced on the medial side adjacent to the hindbrain.
TS15: optic vesicle	Present	Regionally restricted	2D	Label was symmetrical.

Structure	Level	Pattern	Image	Note
TS17: otocyst	Present	Regionally restricted	3E	Expression was distributed throughout the dorsomedial and ventral regions.
TS17: endolymphatic appendage	Present		3E

Structure	Level	Pattern	Image	Note
TS17: otocyst	Present	Regionally restricted	3F	Expression was distributed throughout the dorsomedial and ventral regions.

Structure	Level	Pattern	Image	Note
TS17: otocyst	Present	Regionally restricted	3G	Expression was distributed throughout the dorsomedial and ventral regions.

Structure	Level	Pattern	Image	Note
TS17: otocyst	Present	Regionally restricted	3H	Expression was distributed throughout the dorsomedial and ventral regions.

Structure	Level	Pattern	Image	Note
TS17: otocyst	Present	Regionally restricted	3M	Expression was detected in the vestibular atrium and cochlear pouch.

Structure	Level	Pattern	Image	Note
TS17: otocyst	Present	Regionally restricted	3N	Expression was detected in the vestibular atrium and cochlear pouch. Expression encircled the entire developing cochlear duct.

Structure	Level	Pattern	Image	Note
TS17: otocyst	Present	Regionally restricted	3O	Expression was detected in the vestibular atrium and cochlear pouch. Expression encircled the entire developing cochlear duct.

Structure	Level	Pattern	Image	Note
TS17: otocyst	Present	Regionally restricted	3P	Expression was detected in the vestibular atrium and cochlear pouch. Expression encircled the entire developing cochlear duct.

Structure	Level	Pattern	Image	Note
TS19: endolymphatic appendage	Present	Regionally restricted	5A*	Expression was detected in the endolymphatic sac at the tip of the endolymphatic duct.

Structure	Level	Pattern	Image	Note
TS19: endolymphatic appendage	Present		5B*

Structure	Level	Pattern	Image	Note
TS19: endolymphatic appendage	Present		5C*

Structure	Level	Pattern	Image	Note
TS19: otocyst epithelium	Present	Regionally restricted	5D*	Two small groups of epithelial cells opposite the base of the endolymphatic duct were labeled.

Structure	Level	Pattern	Image	Note
TS19: otocyst epithelium	Present	Regionally restricted	5E*	Two small groups of epithelial cells opposite the base of the endolymphatic duct were labeled.

Structure	Level	Pattern	Image	Note
TS19: vestibular component epithelium	Present	Regionally restricted	5F*	Expression was relatively intense and continuous along the medial posterior and anterior epithelia in the vestibular atrium beneath the base of the endolymphatic duct.

Structure	Level	Pattern	Image	Note
TS19: vestibular component epithelium	Present	Regionally restricted	5G*	Expression was relatively intense and continuous along the medial posterior and anterior epithelia in the vestibular atrium beneath the base of the endolymphatic duct.

Structure	Level	Pattern	Image	Note
TS19: vestibular component epithelium	Present	Regionally restricted	5H*	Expression was relatively intense and continuous along the medial posterior and anterior epithelia in the vestibular atrium beneath the base of the endolymphatic duct.

Structure	Level	Pattern	Image	Note
TS19: vestibular component epithelium	Present	Regionally restricted	5I*	Expression was relatively intense and continuous along the medial posterior and anterior epithelia in the vestibular atrium beneath the base of the endolymphatic duct.

Structure	Level	Pattern	Image	Note
TS19: vestibular component epithelium	Present	Regionally restricted	5J*	Expression was relatively intense and continuous along the medial posterior and anterior epithelia in the vestibular atrium beneath the base of the endolymphatic duct.

Structure	Level	Pattern	Image	Note
TS19: vestibular component epithelium	Present	Regionally restricted	5K*	Expression was relatively intense and continuous along the medial posterior and anterior epithelia in the vestibular atrium beneath the base of the endolymphatic duct.

Structure	Level	Pattern	Image	Note
TS19: vestibular component epithelium	Present	Regionally restricted	5L*	Expression was relatively intense and continuous along the medial posterior and anterior epithelia in the vestibular atrium beneath the base of the endolymphatic duct.

Structure	Level	Pattern	Image	Note
TS19: otocyst	Present		5M*

Structure	Level	Pattern	Image	Note
TS19: otocyst	Present		5N*

Structure	Level	Pattern	Image	Note
TS19: inner ear epithelium	Present	Regionally restricted	5O*	Expression was detected in the thickened sensory epithelium of the cochlea, especially in the more ventral region.

Structure	Level	Pattern	Image	Note
TS19: inner ear epithelium	Present	Regionally restricted	5P*	Expression was detected in the thickened sensory epithelium of the cochlea, especially in the more ventral region.

Structure	Level	Pattern	Image	Note
TS19: inner ear epithelium	Present	Regionally restricted	5Q*	Expression was detected in the thickened sensory epithelium of the cochlea, especially in the more ventral region. The extreme tip of the cochlea epithelium was labeled intensely.

Structure	Level	Pattern	Image	Note
TS19: inner ear epithelium	Present	Regionally restricted	5R*	Expression was detected in the thickened sensory epithelium of the cochlea, especially in the more ventral region.

Structure	Level	Pattern	Image	Note
TS20: endolymphatic appendage	Present	Regionally restricted	6D	Expression was detected in the endolymphatic duct.
TS20: utricle	Present	Regionally restricted	6D	Expression was detected in the common crus.

Structure	Level	Pattern	Image	Note
TS20: vestibular component epithelium	Present	Regionally restricted	6E	In a consecutive section, Pax2 staining was complementary to Gata3.

Structure	Level	Pattern	Image	Note
TS20: vestibular component epithelium	Present	Regionally restricted	6F	In a consecutive section, Pax2 staining was complementary to Gata3.

Structure	Level	Pattern	Image	Note
TS21: crus commune	Present	Regionally restricted	7A	Expression was detected in the lateral epithelium of the crus commune.
TS21: vestibular component epithelium	Present	Non-Uniform	7A	Expression was detected in the the thickened epithelia. A small, weakly labeled patch corresponded to a sensory crista.
TS21: cochlear duct	Present	Regionally restricted	7A	Expression was detected in the distal region.

Structure	Level	Pattern	Image	Note
TS21: cochlear duct	Present	Regionally restricted	7C	Expression was detected in both the floor and roof of the cochlear duct.

Structure	Level	Pattern	Image	Note
TS21: vestibular ganglion	Absent

Structure	Level	Pattern	Image	Note
TS20: vestibular ganglion	Absent		9B
TS20: utricle epithelium	Present	Regionally restricted	9B	Nonsensory regions on each side of the sensory patch were labeled. Selected cells within the sensory patch were also labeled.

Structure	Cell Type	Level	Pattern	Image	Note
TS24: inner ear epithelium		Present	Regionally restricted	10A	Expression was detected in small, nonsensory areas beside sensory patches. Nonsensory areas were labeled adjacent to the anterior and lateral cristae.
TS24: inner ear epithelium	ear hair cell	Present	Widespread	10A
TS24: semicircular canal	vestibular hair cell	Present	Regionally restricted	10A	Hair cell nuclei were labeled in the cristae.

Structure	Cell Type	Level	Pattern	Image	Note
TS24: macula of utricle	macular hair cell	Present		10B

Structure	Cell Type	Level	Pattern	Image	Note
TS24: organ of Corti	ear hair cell	Present		10D