Probe:	Erg cDNA1
Probe preparation:	Antisense labelled with S35 RNA

Structure	Level	Pattern	Image	Note
TS13: cardiovascular system	Present	Regionally restricted	1A	Expression is in the endothelia.
TS13: dorsal aorta	Present	Regionally restricted	1A	Expression is in the endothelia.
TS13: extraembryonic vascular system	Present	Regionally restricted	1A	Expression is in the endothelia.
TS13: migrating neural crest	Present	Regionally restricted	1A	Expression is in neural crest cells migrating from the hindbrain.
TS13: neural tube	Absent		1A
TS13: trunk somite	Absent		1A	No expression in the caudal somites.

Structure	Level	Pattern	Image	Note
TS13: extraembryonic component	Present	Regionally restricted	1C	Expression is in endothelial cells lining the placental sinusoids.
TS28: placenta	Present	Regionally restricted	1C	Expression is in endothelial cells lining the placental sinusoids.

Structure	Level	Pattern	Image	Note
TS13: yolk sac	Present	Regionally restricted	1D	Expression is scattered in the blood islands of the yolk sac.

Structure	Level	Pattern	Image	Note
TS17: extraembryonic component	Present	Regionally restricted	2A	Endothelial expression in the placental labyrinthine trophoblast and maternal sinusoids, but not in the non-endothelial spongiotrophoblast layer.
TS28: placenta	Present	Regionally restricted	2A	Endothelial expression in the placental labyrinthine trophoblast and maternal sinusoids, but not in the non-endothelial spongiotrophoblast layer.

Structure	Level	Pattern	Image	Note
TS17: dorsal aorta	Present	Regionally restricted	3B	Expression is in the aortic endothelium.
TS17: intraembryonic coelom	Absent		3B	Expression is absent in the coelomic epithelium.

Structure	Level	Pattern	Image	Note
TS17: 2nd branchial arch mesenchyme	Present		3D
TS17: 2nd branchial arch	Present	Regionally restricted	3D	Expression is in the vascular endothelium.

Structure	Level	Pattern	Image	Note
TS15: branchial arch	Present	Regionally restricted	4B	Expression is in the mesodermal components.
TS15: neural tube	Absent		4B
TS15: optic vesicle	Absent		4B

Structure	Level	Pattern	Image	Note
TS17: forelimb bud	Strong	Graded	5B	Expression in the mesenchymal component decreased from proximal precartilaginous areas to the distal progress zone.
TS17: embryo mesenchyme	Present		5B

Structure	Level	Pattern	Image	Note
TS21: axial skeleton	Present	Regionally restricted	6	Expression in intervertebral spaces.
TS21: Meckel's cartilage	Present		6
TS21: nose	Present	Regionally restricted	6	Expression is in the nasal cartilage.
TS21: chondrocranium	Present		6	Expression in the neurocranium basis.
TS21: vault of skull	Present		6	Expression in the neurocranium basis.
TS21: urogenital sinus	Present		6
TS21: genital tubercle	Present		6	Expression is in the tubercle ridge, specific sex of this specimen was not given.
TS21: dermis	Present		6
TS21: gut	Present	Regionally restricted	6	Expression is in the mesenchymal cells surrounding the digestive tract and is absent in non-mesoderm-derived digestive tract.
TS21: mesenchyme of metanephros	Present		6
TS21: reproductive system	Present	Regionally restricted	6	Expression is in the urogenital tract.
TS21: urinary system	Present	Regionally restricted	6	Expression is in the urogenital tract.
TS21: brain	Absent		6
TS21: nephric duct	Absent		6

Structure	Level	Pattern	Image	Note
TS21: limb	Present	Regionally restricted	8A	Expression is in pre-cartilagenous structures; expression in distal mesenchyme of limbs.

Structure	Level	Pattern	Image	Note
TS23: forelimb interdigital region	Present	Regionally restricted	8B	Expression is in the mesenchyme.
TS23: hand	Present		8B

Structure	Level	Pattern	Image	Note
TS25: cardiovascular system	Present	Regionally restricted		Expression is in endothelial cells of the forming capillaries.

Structure	Level	Pattern	Image	Note
TS17: gonad primordium mesenchyme	Weak

Structure	Level	Pattern	Image	Note
TS13: yolk sac	Strong	Regionally restricted		Expression is in the blood islands of the yolk sac.
TS28: placenta	Strong
TS13: cardiovascular system	Present	Regionally restricted		Expression is in the endothelial tissue.
TS13: dorsal aorta	Present	Regionally restricted		Expression is in the endothelial tissue.

Structure	Level	Pattern	Image	Note
TS15: yolk sac	Strong	Regionally restricted		Expression is in the blood islands of the yolk sac.
TS28: placenta	Strong
TS15: cardiovascular system	Present	Regionally restricted		Expression is in the endothelial tissue.

Structure	Level	Pattern	Image	Note
TS17: yolk sac	Present	Regionally restricted		Expression is in the blood islands of the yolk sac.
TS28: placenta	Present
TS17: cardiovascular system	Present	Regionally restricted		Expression is in the endothelial tissue.
TS17: forelimb bud	Present	Regionally restricted		Expression is in the precartilagenous tissue.
TS17: gonad primordium mesenchyme	Present

Structure	Level	Pattern	Image	Note
TS21: cardiovascular system	Present			Expression in all vascular structures.
TS21: axial skeleton	Present	Regionally restricted		Expression is in intervertebral spaces.
TS21: Meckel's cartilage	Present
TS21: nose	Present	Regionally restricted		Expression is in the cartilage.
TS21: chondrocranium	Present			Expression is in the neurocranium basis.
TS21: vault of skull	Present			Expression is in the neurocranium basis.
TS21: mesenchyme of metanephros	Present
TS21: genital tubercle	Present
TS21: reproductive system	Present	Regionally restricted		Expression is in the urogenital tract.
TS21: urinary system	Present	Regionally restricted		Expression is in the urogenital tract.
TS21: lung mesenchyme	Present
TS21: dermis	Present
TS21: gut	Present	Regionally restricted		Expression is in the mesodermal tissue surrounding the digestive tract.

Structure	Level	Pattern	Image	Note
TS23: cardiovascular system	Present			Expression is in all vascular structures.
TS23: axial skeleton	Present	Regionally restricted		Expression is in precartilagenous tissue.
TS23: mesenchyme of metanephros	Present
TS23: genital tubercle	Present
TS23: reproductive system	Present	Regionally restricted		Expression is in the urogenital tract.
TS23: urinary system	Present	Regionally restricted		Expression is in the urogenital tract.
TS23: lung mesenchyme	Present
TS23: dermis	Present
TS23: gut	Present	Regionally restricted		Expression is in the mesodermal tissue surrounding the digestive tract.

Structure	Level	Pattern	Image	Note
TS25: cardiovascular system	Present			Expression is in all vascular structures.
TS25: axial skeleton	Present	Regionally restricted		Expression is in the joints.
TS25: mesenchyme of metanephros	Present
TS25: genital tubercle	Present
TS25: reproductive system	Present	Regionally restricted		Expression is in the urogenital tract.
TS25: urinary system	Present	Regionally restricted		Expression is in the urogenital tract.
TS25: lung mesenchyme	Present
TS25: dermis	Present
TS25: gut	Present	Regionally restricted		Expression is in the mesodermal tissue surrounding the digestive tract.