Antibody:	2A7
Detection system:	Secondary antibody coupled to horseradish peroxidase

Structure	Level	Pattern	Image	Note
TS11: extraembryonic component	Present		2A
TS11: embryo	Absent		2A	The authors use the term epiblast.

Structure	Level	Pattern	Image	Note
TS13: notochord	Present	Regionally restricted	2B	Expression is throughout most of the length.
TS13: 1st branchial arch	Present		2B
TS13: gut	Present	Regionally restricted	2B	Expression is in the closing gut, continuous with the visceral endoderm.

Structure	Level	Pattern	Image	Note
TS14: Rathke's pouch	Present		2C
TS14: branchial arch	Present		2C
TS14: eye	Present		2C
TS14: otic placode	Present		2C
TS14: notochord	Very strong	Uniform	2C

Structure	Level	Pattern	Image	Note
TS16: lens pit	Strong		2D
TS16: Rathke's pouch	Present		2D
TS16: branchial arch	Present		2D
TS16: gut	Present		2D
TS16: nasal pit	Present		2D
TS16: otocyst	Present		2D
TS16: notochord	Strong	Uniform	2D

Structure	Level	Pattern	Image	Note
TS18: notochord	Present	Uniform	2E
TS18: esophagus epithelium	Present	Regionally restricted	2E	Expression is in the oropharyngeal epithelium.
TS18: pharynx epithelium	Present	Regionally restricted	2E	Expression is in the oropharyngeal epithelium.
TS18: Rathke's pouch	Present		2E
TS18: branchial arch	Present		2E
TS18: nose	Present		2E
TS18: otocyst	Present		2E
TS18: lens vesicle	Strong		2E
TS18: eye	Present	Regionally restricted	2E	Expression is in the overlying ectoderm of the eye.

Structure	Level	Pattern	Image	Note
TS20: cornea epithelium	Present		2F
TS20: notochord	Present		2F
TS20: remnant of Rathke's pouch	Present		2F
TS20: tongue	Present		2F
TS20: esophagus epithelium	Present	Regionally restricted	2F	Expression is in the oropharyngeal epithelium.
TS20: pharynx epithelium	Present	Regionally restricted	2F	Expression is in the oropharyngeal epithelium.
TS20: lens vesicle	Absent		2F
TS20: epidermis	Present	Regionally restricted	2F	Expression is in the area of the epidermis that will give rise to the mammary gland.

Structure	Level	Pattern	Image	Note
TS12: extraembryonic visceral endoderm	Present	Regionally restricted	3A	The staining looks like a thin but discrete belt extending around the distal part of the egg cylinder along the anterior posterior direction. The stained area extending caudally from the belt is widely branched.
TS12: notochord	Present		3A

Structure	Level	Pattern	Image	Note
TS13: branchial arch	Present		3B
TS13: gut	Present		3B
TS13: notochord	Present	Regionally restricted	3B	Expression is in the bottle-shaped cells at the rostral extremity of the notochord.

Structure	Level	Pattern	Image	Note
TS15: notochord	Present		3C

Structure	Level	Pattern	Image	Note
TS15: notochord	Strong		3D
TS15: gut	Present	Regionally restricted	3D	Expression is in the gut epithelium.

Structure	Level	Pattern	Image	Note
TS11: embryo ectoderm	Absent		4A
TS11: extraembryonic component	Present		4A
TS11: extraembryonic visceral endoderm	Present	Uniform	4A

Structure	Level	Pattern	Image	Note
TS16: Rathke's pouch	Present	Uniform	4B	Expression is at the apical cell surface.

Structure	Level	Pattern	Image	Note
TS23: remnant of Rathke's pouch	Present	Uniform	4C

Structure	Level	Pattern	Image	Note
TS17: 1st branchial arch	Present	Regionally restricted	4D	Expression is in the surface epithelial cells.
TS17: 2nd branchial arch	Present	Regionally restricted	4D	Expression is in the surface epithelial cells.

Structure	Level	Pattern	Image	Note
TS23: tongue epithelium	Present		4E
TS23: esophagus epithelium	Present		4E	Expression is in the oropharyngeal epithelium.
TS23: pharynx epithelium	Present		4E	Expression is in the oropharyngeal epithelium.

Structure	Level	Pattern	Image	Note
TS19: surface ectoderm	Present	Regionally restricted	4F	Expression is in the mammary gland primordia.

Structure	Level	Pattern	Image	Note
TS20: epidermis	Absent			The expression in the mammary gland primordia is no longer apparent.