Antibody:	anti-osteopontin (AF808)
Detection system:	Secondary antibody coupled to Alexa Fluor

Structure	Level	Pattern	Image	Note
TS28: utricle	Present		5A , 5A'	Expression was detected in a subset of hair cells, co-localized with the pan-hair cell marker Myo7a.

Structure	Level	Pattern	Image	Note
TS28: utricle	Present		5A"	Expression was detected in a subset of hair cells, co-localized with the pan-hair cell marker Myo7a. Based on cell morphology, the cell type was consistent with Type I hair cells.

Structure	Level	Pattern	Image	Note
TS28: utricle	Present		5B	Spp1 expression co-localized with the Type I hair cell marker, Tnc.

Structure	Level	Pattern	Image	Note
TS28: utricle	Present		5B'	In the orthogonal view, Spp1 was localized lumenal to Tnc expression in the neck region of each Type I hair cell.

Structure	Level	Pattern	Image	Note
TS28: utricle	Present		5C	There was no overlap of Spp1 expression with the Type II hair cell marker, Calb2.

Structure	Level	Pattern	Image	Note
TS27: utricle	Present		7_Spp1 Myo7a P0 , 7_Spp1 P0	At P0, Spp1 was expressed in a limited number of hair cells (~60% of the Type I hair cells and 23% of immature hair cells). Hair cells were labeled by the marker Myo7a.

Structure	Level	Pattern	Image	Note
TS27: utricle	Present		7_Spp1 Orthogonal P0	At P0, Spp1 was expressed in a limited number of hair cells (~60% of the Type I hair cells and 23% of immature hair cells). Hair cells were labeled by the marker Myo7a.

Structure	Level	Pattern	Image	Note
TS28: utricle	Present		7_Spp1 P12 , 7_Spp1 Myo7a P12	At P12, Spp1 was expressed in 90% of Type I hair cells. Hair cells were identified with the marker Myo7a. Only 20% of Type II hair cells were Spp1-positive.

Structure	Level	Pattern	Image	Note
TS28: utricle	Present		7_Spp1 Orthogonal P12	At P12, Spp1 was expressed in 90% of Type I hair cells. Hair cells were identified with the marker Myo7a. Only 20% of Type II hair cells were Spp1-positive.

Structure	Level	Pattern	Image	Note
TS28: utricle	Present		7_Spp1 Myo7a P64 , 7_Spp1 P64	At P64, Spp1 was expressed in 90% of Type I hair cells. Hair cells were identified with the marker Myo7a. Spp1 expression in Type II hair cells dropped to 4%.

Structure	Level	Pattern	Image	Note
TS28: utricle	Present		7_Spp1 Orthogonal P64	At P64, Spp1 was expressed in 90% of Type I hair cells. Hair cells were identified with the marker Myo7a. Spp1 expression in Type II hair cells dropped to 4%.

Structure	Level	Pattern	Image	Note
TS22: utricle epithelium	Present	Regionally restricted	8_Spp1 E14	Expression was detected in a small number of hair cells located at the extreme medial edge of the utricular epithelium.

Structure	Level	Pattern	Image	Note
TS23: utricle epithelium	Present	Regionally restricted	8_Spp1 E15	Expression expanded anteriorly and laterally from the medial edge. Immunopositive cells were not present in the striola.

Structure	Level	Pattern	Image	Note
TS24: utricle epithelium	Present	Regionally restricted	8_Spp1 E16	Expression was detected in the entire medial half of the utricle. Immunopositive cells were not present in the striola.

Structure	Level	Pattern	Image	Note
TS27: utricle epithelium	Present	Widespread	8_Spp1 P0	Immunopositive cells were present throughout the utircle with the exception of the striolar hair cells.

Structure	Level	Pattern	Image	Note
TS28: utricle epithelium	Present	Regionally restricted	8_Spp1 P14	Immunopositive Type I hair cells were present in the striola.

Structure	Level	Pattern	Image	Note
TS28: utricle epithelium	Present	Regionally restricted	8_Spp1 P63	Most Type I hair cells in the striola were immunopositive.