Probe:	Fn1 probe5
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS12: neural fold	Absent		1A	Expression not detectable within dorsal neural folds.
TS12: embryo	Strong	Regionally restricted	1A	High expression in region dorsal to heart.

Structure	Level	Pattern	Image	Note
TS12: neural fold	Absent		1B	Expression not detectable within dorsal neural folds.
TS12: dorsal mesocardium	Present		1B
TS12: foregut diverticulum endoderm	Present		1B
TS12: splanchnopleure	Present		1B

Structure	Level	Pattern	Image	Note
TS13: neural fold	Present		1D	Expression at edges of dorsal neural tube.

Structure	Level	Pattern	Image	Note
TS13: neural fold	Present	Regionally restricted	1E	Expression in dorsal neural ectoderm in the top few cells layers.
TS13: surface ectoderm	Present	Regionally restricted	1E	Expression in cells of apposing non-neural surface ectoderm.
TS13: branchial arch ectoderm	Present		1E	Expression in pharyngeal pocket endoderm and pharyngeal ectoderm.
TS13: branchial arch endoderm	Present		1E	Expression in pharyngeal pocket endoderm and pharyngeal ectoderm.

Structure	Level	Pattern	Image	Note
TS14: central nervous system	Present	Regionally restricted	1G	Expression maintained in dorsal neural tube.
TS14: branchial arch	Present	Regionally restricted	1G	Expression within the region of branchial arches 3, 4 and 6.
TS14: blood vessel	Present	Regionally restricted	1G	Expression in microvascular endothelial cells in the head.

Structure	Level	Pattern	Image	Note
TS15: neural crest	Present	Regionally restricted	S2A	Expression in cardiac neural crest progenitors.
TS15: migrating neural crest	Present	Regionally restricted	S2A	Expression in cardiac neural crest cells.

Structure	Level	Pattern	Image	Note
TS15: branchial arch mesenchyme	Weak		S2B	Expression downregulated within arch mesenchyme
TS15: branchial arch ectoderm	Strong		S2B	Expression enriched in pharyngeal ectoderm and pharyngeal pocket endoderm.
TS15: branchial pouch endoderm	Strong		S2B	Expression enriched in pharyngeal ectoderm and pharyngeal pocket endoderm.
TS15: outflow tract endocardial tube	Present		S2B	Within the outflow tract, expression in mesenchymal cells (presumptive cardiac neural crest cells) and endocardial cells.
TS15: outflow tract mesenchyme	Present		S2B	Within the outflow tract, expression in mesenchymal cells (presumptive cardiac neural crest cells) and endocardial cells.

Structure	Level	Pattern	Image	Note
TS15: branchial arch ectoderm	Strong		S2B'	Expression enriched in pharyngeal ectoderm and pharyngeal pocket endoderm.
TS15: branchial pouch endoderm	Strong		S2B'	Expression enriched in pharyngeal ectoderm and pharyngeal pocket endoderm.
TS15: branchial arch mesenchyme	Weak		S2B'	Low levels of expression in mesenchymal cells lateral to the dorsal aorta and in pharyngeal arches.
TS15: trunk mesenchyme	Weak		S2B'	Low levels of expression in mesenchymal cells lateral to the dorsal aorta and in pharyngeal arches.