Antibody:	anti-Eck
Detection system:	Secondary antibody coupled to fluorescein

Structure	Level	Pattern	Image	Note
TS9: primitive streak	Weak			Low level of expression specifically in cells of streak.

Structure	Level	Pattern	Image	Note
TS10: primitive streak	Present		3A	Authors report expression in region of primitive streak.
TS10: embryo	Strong	Regionally restricted	3A	Strong expression in midline.

Structure	Level	Pattern	Image	Note
TS11: notochordal plate	Strong		3B	Strong expression in notochordal plate relative to lateral mesoderm.
TS11: embryo ectoderm	Present	Regionally restricted	3B	Expression in ectodermal cells in midline immediately overlying notochordal plate, relative to more lateral regions of ectoderm.

Structure	Level	Pattern	Image	Note
TS14: notochordal plate	Strong		3C	High levels of expression restricted to progressively more caudal regions containing notochordal plate cells.
TS14: future spinal cord neural plate	Present		3C	Expression in neural plate cells in caudal regions.
TS14: dorsal aorta	Present	Regionally restricted	3C	Uniform distribution of expression in cells lining the dorsal aorta.
TS14: gut	Weak	Regionally restricted	3C	Low level of expression in caudal regions of hindgut.

Structure	Level	Pattern	Image	Note
TS15: notochord	Weak		3D
TS15: dorsal aorta	Present	Regionally restricted	3D	Uniform distribution of expression in cells lining the dorsal aorta.
TS15: migrating neural crest	Strong	Regionally restricted	3D	High levels of expression in presumptive neural crest cells aggregating as dorsal root ganglia between somites and neural tube in the trunk.

Structure	Level	Pattern	Image	Note
TS13: future hindbrain	Present	Regionally restricted	4A	Single lateral band of expression in hindbrain neuroepithelia. Limits to this expression seen cranially at level of preotic sulcus.
TS13: 2nd branchial arch	Present		4A	Expression extended ventrolaterally in cells occupying the second branchial arch.
TS13: trophoblast giant cell	Present		4A

Structure	Level	Pattern	Image	Note
TS13: future hindbrain	Present	Regionally restricted	4B	Single lateral band of expression in hindbrain neuroepithelia. Limits to this expression seen cranially at level of preotic sulcus.
TS13: 2nd branchial arch	Present		4B	Expression extended ventrolaterally in cells occupying the second branchial arch.
TS13: trophoblast giant cell	Present		4B

Structure	Level	Pattern	Image	Note
TS13: 2nd branchial arch	Present		4C	Expression extended ventrolaterally in cells occupying the second branchial arch.

Structure	Level	Pattern	Image	Note
TS13: 2nd branchial arch	Present		4D	Expression extended ventrolaterally in cells occupying the second branchial arch
TS13: future hindbrain	Present	Regionally restricted	4D	Limits to this expression seen caudally at level of otic placode.

Structure	Level	Pattern	Image	Note
TS13: future hindbrain	Present	Regionally restricted	4E	Limits to this expression seen caudally at level of otic placode.

Structure	Level	Pattern	Image	Note
TS13: 1st branchial arch	Absent		4F
TS13: trunk paraxial mesenchyme	Absent		4F

Structure	Level	Pattern	Image	Note
TS15: rhombomere 4	Weak		5A	Low level of expression specifically in cells of rhombomere 4.
TS15: facio-acoustic preganglion complex	Strong		5A	High levels of expression in facio-acoustico (VII-VIII) and glossopharyngeal (IX-X) neural crest cells associated with the otic vesicle.
TS15: glossopharyngeal-vagus preganglion complex	Strong		5A	High levels of expression in facio-acoustico (VII-VIII) and glossopharyngeal (IX-X) neural crest cells associated with the otic vesicle.

Structure	Level	Pattern	Image	Note
TS15: facio-acoustic preganglion complex	Strong		5B	High levels of expression in facio-acoustico (VII-VIII) and glossopharyngeal (IX-X) neural crest cells associated with the otic vesicle.
TS15: glossopharyngeal-vagus preganglion complex	Strong		5B	High levels of expression in facio-acoustico (VII-VIII) and glossopharyngeal (IX-X) neural crest cells associated with the otic vesicle.

Structure	Level	Pattern	Image	Note
TS15: 2nd branchial arch	Present		5C	Expression persisted in second branchial arches.

Structure	Level	Pattern	Image	Note
TS15: 3rd branchial arch	Present			Expression persisted in third branchial arches.
TS15: 1st branchial arch mandibular component	Weak			Relatively low levels of expression first observed in maxillary and mandibular components of first branchial arch and medial nasal process at E9.5 and E10.5.
TS15: 1st branchial arch maxillary component	Weak			Relatively low levels of expression first observed in maxillary and mandibular components of first branchial arch and medial nasal process at E9.5 and E10.5.

Structure	Level	Pattern	Image	Note
TS17: 2nd branchial arch	Weak		5D	Little expression detectable in cells of second branchial arches at
TS17: 1st branchial arch mandibular component	Weak		5D	Little expression detectable in cells of second branchial arches at E9.5 and E10.5.
TS17: 1st branchial arch maxillary component	Weak		5D	Little expression detectable in cells of second branchial arches at E9.5 and E10.5.
TS17: medial-nasal process	Weak		5D	Little expression detectable in cells of second branchial arches at E9.5 and E10.5.

Structure	Level	Pattern	Image	Note
TS17: 3rd branchial arch	Weak			Little expression detectable in cells of third branchial arches or facial ganglia at E10.5.
TS17: lung	Present	Regionally restricted		Expression in epitheium of segmented bronchi as early as E10.5.
TS17: infundibular recess of 3rd ventricle	Present			Expression in infundibular recess emanating from floor of diencephalon as early at E10.5.

Structure	Level	Pattern	Image	Note
TS17: forelimb bud mesenchyme	Present	Regionally restricted	6A	Expression first detected in mesenchyme of forelimb bud at E10.5, localized specifically to distal mesenchyme.

Structure	Level	Pattern	Image	Note
TS17: hindlimb bud mesenchyme	Present	Regionally restricted	6B	Expression first detected in mesenchyme of hindlimb buds at E10.5, localized specifically to distal mesenchyme.

Structure	Level	Pattern	Image	Note
TS19: handplate	Present		6C	Differential expression along the proximal-distal axis persisted at E11.5. Expression localized to hanplate region.

Structure	Level	Pattern	Image	Note
TS19: footplate	Present		6D	Differential expression along the proximal-distal axis persisted at E11.5. Expression localized to footplate region.

Structure	Level	Pattern	Image	Note
TS22: humerus cartilage condensation	Present	Regionally restricted	6E	Expression in perichondria and chondrocytes of developing long bones regardless of their position along the proximal-distal axis.
TS22: radius cartilage condensation	Present	Regionally restricted	6E	Expression in perichondria and chondrocytes of developing long bones regardless of their position along the proximal-distal axis.

Structure	Level	Pattern	Image	Note
TS23: carpal bone	Present	Regionally restricted	6F	Expression in perichondria and chondrocytes of developing long bones regardless of their position along the proximal-distal axis.
TS23: forelimb phalanx	Present	Regionally restricted	6F	Expression in perichondria and chondrocytes of developing long bones regardless of their position along the proximal-distal axis.
TS23: metacarpal bone	Present	Regionally restricted	6F	Expression in perichondria and chondrocytes of developing long bones regardless of their position along the proximal-distal axis.
TS23: ulna	Present	Regionally restricted	6F	Expression in perichondria and chondrocytes of developing long bones regardless of their position along the proximal-distal axis.
TS23: forelimb epidermis	Present		6F	Expression in epithelia of limb.

Structure	Level	Pattern	Image	Note
TS22: Meckel's cartilage	Present		7A	Expression in craniofacial skeletal tissues, including mandible and Meckel's cartilages.
TS22: mandible	Present		7A	Expression in craniofacial skeletal tissues, including mandible and Meckel's cartilages.
TS22: tooth bud	Strong		7A	Strong expression in tooth primordia at E14.5
TS22: submandibular gland primordium epithelium	Present		7A

Structure	Level	Pattern	Image	Note
TS22: Meckel's cartilage	Present		7B	Expression in craniofacial skeletal tissues, including mandible and Meckel's cartilages.
TS22: mandible	Present		7B	Expression in craniofacial skeletal tissues, including mandible and Meckel's cartilages.
TS22: tooth bud	Strong		7B	Strong expression in tooth primordia at E14.5
TS22: palatal shelf epithelium	Present		7B
TS22: submandibular gland primordium epithelium	Present		7B
TS22: tongue epithelium	Present		7B

Structure	Level	Pattern	Image	Note
TS22: rib cartilage condensation	Present	Regionally restricted	7C	Expression in perichondria and chondrocytes of developing ribs.
TS22: lung	Present	Regionally restricted	7C	Expression in epithelia of terminal bronchi and bronchioles.

Structure	Level	Pattern	Image	Note
TS22: rib cartilage condensation	Present	Regionally restricted	7D	Expression in perichondria and chondrocytes of developing ribs.
TS22: facial ganglion	Weak		7D	Low levels of expression in facial ganglia, including the trigeminal ganglion.
TS22: trigeminal ganglion	Weak		7D	Low levels of expression in facial ganglia, including the trigeminal ganglion.
TS22: thymus primordium	Present	Regionally restricted	7D	Expression in epithelia of thymus.

Structure	Level	Pattern	Image	Note
TS22: vertebral cartilage condensation	Present	Regionally restricted	7E	Expression in perichondria and chondrocytes of developing vertebras

Structure	Level	Pattern	Image	Note
TS20: neurohypophysis infundibulum	Present		7F	Expression persisted in infundibular recess of diencephalon.
TS20: remnant of Rathke's pouch	Trace		7F	Little expression associated with Rathke's pouch.