Probe:	Lef1 probe6
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS19: surface ectoderm	Present	Regionally restricted	1A	No expression between the forelimb and the hindlimb.

Structure	Level	Pattern	Image	Note
TS20: mammary placode	Present	Regionally restricted	1B	Expression in the forming mammary placode (P3) as a discrete line.

Structure	Level	Pattern	Image	Note
TS20: mammary placode	Present	Regionally restricted	1C	Expression in a comet-like shape (emerging mammary placode) in an area betwen the fore- and hindlimb.

Structure	Level	Pattern	Image	Note
TS20: mammary placode	Present	Regionally restricted	1D	Expression in a round-like structure (emerging mammary placode) in an area between the fore-and hindlimb.

Structure	Level	Pattern	Image	Note
TS20: mammary placode	Present	Regionally restricted	2A	Expression in mammary placodes 3 and 4.

Structure	Level	Pattern	Image	Note
TS20: mammary placode	Present	Regionally restricted	2B	Expression in the hindlimb area in mammary placode 4 (dot-like structure) and in mammary placode 5 (line).

Structure	Level	Pattern	Image	Note
TS20: mammary placode	Present	Regionally restricted	2C	Expression in the forelimb area in mammary placode 1 as a line, placode 2 as a diffuse line, and in placode 3 as a dot-like structure.

Structure	Level	Pattern	Image	Note
TS20: mammary bud	Present	Regionally restricted	4A , 4B	Expression in the epithelium of the mammary bud (boxed area is mammary bud 4).

Structure	Level	Pattern	Image	Note
TS20: mammary bud	Present	Regionally restricted	4C , 4D	Expression in only a single mammary bud located in the inguinal region.

Structure	Level	Pattern	Image	Note
TS21: mammary bud	Present		4F , 4E	Mammary bud 4.

Structure	Level	Pattern	Image	Note
TS21: mammary bud	Absent		4H , 4G	Mammary bud 4.

Structure	Level	Pattern	Image	Note
TS19: mammary placode	Present	Regionally restricted	5A , 5B	Expression in the mammary placodes (boxed area is mammary placode 4).

Structure	Level	Pattern	Image	Note
TS19: mammary placode	Present	Regionally restricted	5C	Absent in the mammary placodes 1, 2, 3, and 5.

Structure	Level	Pattern	Image	Note
TS19: mammary placode	Present	Regionally restricted	5D	Expression as a line in the area corresponding to mammary placode 4 (dotted box).

Structure	Level	Pattern	Image	Note
TS20: mammary bud	Present	Regionally restricted	5F , 5E	Expression in the epithelium of the mammary bud (boxed area is mammary bud 4).

Structure	Level	Pattern	Image	Note
TS20: mammary bud	Present	Regionally restricted	5I , 5H	Expression is only in mammary bud 4 (dotted box).

Structure	Level	Pattern	Image	Note
TS21: integumental system	Present	Regionally restricted	6B , 6A	Expression in the hair follicles (small dots).
TS21: mammary bud	Present	Regionally restricted	6B , 6A	Expression in the mammary buds (dilated dots).

Structure	Level	Pattern	Image	Note
TS21: integumental system	Present	Regionally restricted	6D , 6C	Expression in the hair follicles.
TS21: mammary bud	Present	Regionally restricted	6C , 6D	Expression in the mammary buds. One pair of inguinal mammary placodes (bud 4) is induced in the mutants and is maintained at E13.5.

Structure	Level	Pattern	Image	Note
TS19: mammary placode	Present	Regionally restricted		Expression in mammary placode 3.

Structure	Level	Pattern	Image	Note
TS19: mammary placode	Present	Regionally restricted		Expression in mammary placode 3.

Structure	Level	Pattern	Image	Note
TS19: surface ectoderm	Absent			Absent in mammary placode 3.