Probe:	Tbx4 probe12
Probe preparation:	Antisense RNA

Structure	Level	Pattern	Image	Note
TS15: hindlimb ridge mesenchyme	Present		1A

Structure	Level	Pattern	Image	Note
TS17: hindlimb bud	Present	Widespread	1B	Expression was observed throughout the extending hindlimb, with the proximal boundary of expression at the body wall.

Structure	Level	Pattern	Image	Note
TS19: hindlimb bud	Present	Widespread	1C	Expression was observed throughout the extending hindlimb, with the proximal boundary of expression at the body wall.

Structure	Level	Pattern	Image	Note
TS20: hindlimb	Present	Widespread	1D	Expression shifted distally but remained widespread.

Structure	Level	Pattern	Image	Note
TS21: hindlimb	Present	Widespread	1E	Expression shifted distally but remained widespread.

Structure	Level	Pattern	Image	Note
TS22: hindlimb	Present	Widespread	1F	Expression shifted distally but remained widespread.

Structure	Level	Pattern	Image	Note
TS17: forelimb bud	Present	Regionally restricted	2A	Expressed in a small domain in the proximal core at lower levels than in the hindlimb.

Structure	Level	Pattern	Image	Note
TS19: forelimb bud	Present	Regionally restricted	2B	Expressed in a small domain in the proximal core at lower levels than in the hindlimb.

Structure	Level	Pattern	Image	Note
TS20: hand	Weak		2C

Structure	Level	Pattern	Image	Note
TS21: hand	Present		2D	More intense expression, disappearing gradually thereafter.

Structure	Level	Pattern	Image	Note
TS15: genitourinary system mesenchyme	Present	Regionally restricted	3A	Expressed in the mesenchyme surrounding the cloacal slit, in the region that will form the genital folds and the genital tubercle. Expression was contiguous between the allantois/umbilicus, hindlimbs, and nascent proctodeum.
TS15: allantois	Present		3A	Expression was contiguous between the allantois/umbilicus, hindlimbs, and nascent proctodeum.
TS15: hindlimb ridge mesenchyme	Present		3A	Expression was contiguous between the allantois/umbilicus, hindlimbs, and nascent proctodeum.
TS15: umbilical cord	Present		3A	Expression was contiguous between the allantois/umbilicus, hindlimbs, and nascent proctodeum.
TS15: surface ectoderm	Present	Regionally restricted	3A	Expressed in the nascent proctodeum. Expression was contiguous between the allantois/umbilicus, hindlimbs, and nascent proctodeum.

Structure	Level	Pattern	Image	Note
TS17: genital swelling	Present		3B	Expression was contiguous between the allantois/umbilicus, hindlimbs, and nascent proctodeum.
TS17: hindlimb bud	Present		3B	Expression was contiguous between the allantois/umbilicus, hindlimbs, and nascent proctodeum.
TS17: umbilical cord	Present		3B	Expression was contiguous between the allantois/umbilicus, hindlimbs, and nascent proctodeum.

Structure	Level	Pattern	Image	Note
TS19: genital tubercle	Present		3C	Expression became more distal, and a region with no expression was seen between the genital tubercle and the hindlimb.
TS19: hindlimb bud	Present		3C	Expression became more distal, and a region with no expression was seen between the genital tubercle and the hindlimb.

Structure	Level	Pattern	Image	Note
TS20: genital tubercle	Present	Regionally restricted	3D	Progressively more distally expressed.
TS20: hindlimb	Present		3D

Structure	Level	Pattern	Image	Note
TS22: genital tubercle	Present	Regionally restricted	3E	Progressively more distally expressed.

Structure	Level	Pattern	Image	Note
TS24: genital tubercle	Present	Regionally restricted	3F	Progressively more distally expressed.

Structure	Level	Pattern	Image	Note
TS17: lung mesenchyme	Present	Uniform	4A

Structure	Level	Pattern	Image	Note
TS19: lung mesenchyme	Present	Uniform	4B

Structure	Level	Pattern	Image	Note
TS22: lung mesenchyme	Present	Uniform	4C

Structure	Level	Pattern	Image	Note
TS10: extraembryonic mesoderm	Weak		5A , 5A'

Structure	Level	Pattern	Image	Note
TS11: allantois	Strong		5B

Structure	Level	Pattern	Image	Note
TS11: allantois	Present		5C

Structure	Level	Pattern	Image	Note
TS11: allantois	Present		5C'

Structure	Level	Pattern	Image	Note
TS12: allantois	Present		5D

Structure	Level	Pattern	Image	Note
TS12: allantois	Present		5E

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		5F

Structure	Level	Pattern	Image	Note
TS15: chorioallantoic placenta	Present		5G
TS15: umbilical blood vessel	Present		5G

Structure	Level	Pattern	Image	Note
TS15: chorioallantoic placenta	Present		5H
TS15: umbilical blood vessel	Present		5H

Structure	Level	Pattern	Image	Note
TS17: chorioallantoic placenta	Present		5I
TS17: umbilical blood vessel	Present		5I

Structure	Level	Pattern	Image	Note
TS13: allantois	Present	Regionally restricted	5J	Expressed in all cells of the mesothelial (outer) layer. Most cells were positive and only a few scattered negative cells were observed.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present	Regionally restricted	5K	Expressed in all cells of the mesothelial (outer) layer. Positive cells was interspersed with negative cells, which appeared in small clusters frequently located immediately subjacent to the mesothelium.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present	Regionally restricted	5L	Expressed in all cells of the mesothelial (outer) layer. Negative cells were clearly localized to large clusters subjacent to the mesothelium and to the central umbilical vessel.

Structure	Level	Pattern	Image	Note
TS15: umbilical blood vessel	Present	Regionally restricted	5M	Expression surrounded both umbilical vessels, but the endothelium was negative.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		S1A	Most cells were positive and only a few scattered negative cells were observed.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		S1B	Positive cells was interspersed with negative cells, which appeared in small clusters frequently located immediately subjacent to the mesothelium.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		S1C	Negative cells were clearly localized to large clusters subjacent to the mesothelium and to the central umbilical vessel.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		S1D	Most cells were positive and only a few scattered negative cells were observed.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		S1E	Positive cells was interspersed with negative cells, which appeared in small clusters frequently located immediately subjacent to the mesothelium.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		S1F	Negative cells were clearly localized to large clusters subjacent to the mesothelium and to the central umbilical vessel.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		S1G	Most cells were positive and only a few scattered negative cells were observed.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		S1H	Positive cells was interspersed with negative cells, which appeared in small clusters frequently located immediately subjacent to the mesothelium.

Structure	Level	Pattern	Image	Note
TS13: allantois	Present		S1I	Negative cells were clearly localized to large clusters subjacent to the mesothelium and to the central umbilical vessel.

Structure	Level	Pattern	Image	Note
TS19: chorioallantoic placenta	Present
TS19: umbilical blood vessel	Present