Antibody:	anti-Sox9 (AF3075)
Detection system:	Biotinylated secondary antibody/[Strept]avidin coupled to horseradish peroxidase

Structure	Level	Pattern	Image	Note
TS17: mesonephros	Weak		1B
TS17: reproductive system	Weak	Regionally restricted	1B	Weak expression in cells at mesonephric-gonadal border.
TS17: coelomic epithelium of gonad primordium	Absent		1B

Structure	Level	Pattern	Image	Note
TS19: gonadal mesenchyme	Present		2A	Expression in cells in interior of densely cellular testis prior to formation of testicular cords.
TS19: coelomic epithelium of gonad	Absent		2A

Structure	Level	Pattern	Image	Note
TS20: primary sex cord	Strong		2B	Abundant expression in forming testicular cords.
TS20: mesonephric tubule	Present		2B
TS20: mesonephros mesenchyme	Present	Scattered	2B	Expression in scattered cells mesonephric mesenchyme.
TS20: coelomic epithelium of testis	Absent		2B

Structure	Level	Pattern	Image	Note
TS20: testis	Present	Regionally restricted	2C
TS20: mesonephros	Present	Regionally restricted	2C	No expression in juxta-coelomic zone.
TS20: coelomic epithelium of testis	Absent		2C

Structure	Level	Pattern	Image	Note
TS20: primary sex cord	Strong		2D	Abundant expression in forming testicular cords.
TS20: mesonephric tubule	Present		2D
TS20: mesonephros mesenchyme	Present	Scattered	2D	Expression in scattered cells mesonephric mesenchyme.
TS20: mesonephros	Present	Regionally restricted	2D	Expression in cells at mesonephric-gonadal border directly continuous with forming testicular cords.
TS20: coelomic epithelium of testis	Absent		2D

Structure	Cell Type	Level	Pattern	Image	Note
TS21: Sertoli cell	Sertoli cell	Present		3A	Continuous layer of expressing cells along basement membranes of solid testicular cords.

Structure	Cell Type	Level	Pattern	Image	Note
TS22: Sertoli cell	Sertoli cell	Present		3B	Continuous layer of expressing cells along basement membranes of solid testicular cords.

Structure	Cell Type	Level	Pattern	Image	Note
TS24: Sertoli cell	Sertoli cell	Present		3C	Continuous layer of expressing cells along basement membranes of solid testicular cords.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: Sertoli cell	Sertoli cell	Present		3D	Continuous layer of expressing cells along basement membranes of solid testicular cords.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: Sertoli cell	Sertoli cell	Present		3E	Continuous layer of expressing cells along basement membranes of canalized seminiferous tubules.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: Sertoli cell	Sertoli cell	Present		3F	Continuous layer of expressing cells along basement membranes of canalized seminiferous tubules.