Probe:	Cd34 cDNA4
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS12: left dorsal aorta	Present	Diffuse	1A	Expressed in the pre-endothelial cells.
TS12: right dorsal aorta	Present	Diffuse	1A	Expressed in the pre-endothelial cells.

Structure	Level	Pattern	Image	Note
TS12: left dorsal aorta	Present	Diffuse	1B	Expressed in the presumably pre-endothelial cells, extending along the entire length of the embryo.
TS12: right dorsal aorta	Present	Diffuse	1B	Expressed in the presumably pre-endothelial cells, extending along the entire length of the embryo.
TS12: allantois	Present	Diffuse	1B
TS12: yolk sac	Present	Diffuse	1B

Structure	Level	Pattern	Image	Note
TS12: left dorsal aorta	Present		1C
TS12: primitive ventricle endocardial tube	Present		1C
TS12: right dorsal aorta	Present		1C
TS12: truncus arteriosus	Present		1C
TS12: vitelline artery	Present		1C

Structure	Level	Pattern	Image	Note
TS13: head mesenchyme	Present	Regionally restricted	1D	Expressed in cranial mesenchyme, cranial pre-endothelial cells that later coalesced to form a network of vessels.
TS13: primitive ventricle endocardial tube	Present		1D
TS13: truncus arteriosus	Present		1D
TS13: yolk sac	Present	Patchy	1D

Structure	Level	Pattern	Image	Note
TS14: allantois mesenchyme	Strong		1E
TS14: truncus arteriosus	Strong		1E
TS14: umbilical artery	Strong		1E
TS14: umbilical vein	Strong		1E
TS14: vitelline artery	Strong	Regionally restricted	1E	Expressed in the proximal segment.
TS14: head mesenchyme	Present	Regionally restricted	1E	Expressed in pre-endothelial cells forming a capillary network around brain and the developing eye close to the internal carotid artery.
TS14: 1st arch artery	Present	Regionally restricted	1E	Expressed in the endothelium.
TS14: 2nd arch artery	Weak		1E
TS14: common atrial chamber	Weak		1E
TS14: primitive ventricle	Weak		1E
TS14: sinus venosus	Weak		1E
TS14: aortic sac	Absent		1E
TS14: anterior cardinal vein	Present		1E	Lower than in dorsal aorta and umbilical vein.
TS14: common cardinal vein	Present		1E	Lower than in dorsal aorta and umbilical vein.
TS14: dorsal aorta	Present		1E
TS14: vitelline vein	Present		1E

Structure	Level	Pattern	Image	Note
TS14: 1st arch artery	Present		1F
TS14: 2nd arch artery	Present		1F
TS14: aortic sac	Present		1F
TS14: blood vessel	Present		1F	More abundant in capillary networks around the developing sense organs (otic and nasal pits) than in the larger vessels.

Structure	Level	Pattern	Image	Note
TS16: head blood vessel	Present		1G	Expression was decreased in the head, being confined to capillary networks around the eye and brain, and hyaloid artery. Not detectable in larger vessels in the cranial region.
TS16: head mesenchyme	Present	Regionally restricted	1G	Expressed within the facial mesenchyme.

Structure	Level	Pattern	Image	Note
TS12: blood island	Present	Regionally restricted	3A	Expressed in endothelial cells lying around the periphery of the blood islands.

Structure	Level	Pattern	Image	Note
TS13: blood island	Present	Regionally restricted	3B	Expression in endothelium was weaker. Also expressed in the rounded haematopoietic cells.

Structure	Level	Pattern	Image	Note
TS14: vitelline artery	Present	Regionally restricted	3C	Expressed at the point that it emerges from the embryo.

Structure	Level	Pattern	Image	Note
TS14: vitelline artery	Present	Regionally restricted	3D	Expressed in the endothelial cells discontinuously.

Structure	Level	Pattern	Image	Note
TS16: umbilical artery	Present	Regionally restricted	3E	Expressed in foci of cells close to the embryo.
TS16: vitelline artery	Present	Regionally restricted	3E	Expressed in foci of cells close to the embryo.

Structure	Level	Pattern	Image	Note
TS16: chorioallantoic placenta	Strong	Regionally restricted	3F	Expressed in the allantoic capillaries.
TS16: umbilical artery	Present		3F

Structure	Level	Pattern	Image	Note
TS16: vitelline artery	Present	Clusters	3G	Expressed in the proximal segment.

Structure	Level	Pattern	Image	Note
TS16: vitelline artery	Present	Clusters	3H	Expressed in the proximal segment.

Structure	Level	Pattern	Image	Note
TS12: primitive heart tube endocardial tube	Present
TS12: truncus arteriosus	Present
TS12: trunk mesenchyme	Present	Regionally restricted		Expressed in intersomitic vessels that branched from the dorsal aortae.

Structure	Level	Pattern	Image	Note
TS16: dorsal aorta	Strong
TS16: tail	Strong

Structure	Level	Pattern	Image	Note
TS11: yolk sac	Present