Probe:	Alk6 cDNA1
Probe preparation:	Antisense labelled with S35 RNA

Structure	Level	Pattern	Image	Note
TS9: embryo	Absent

Structure	Level	Pattern	Image	Note
TS13: embryo	Absent

Structure	Level	Pattern	Image	Note
TS15: branchial arch	Present		4A
TS15: limb	Present		4A
TS15: sclerotome	Present		4A
TS15: future hindbrain	Present	Regionally restricted	4A	Expression was abundant in the neuroepithelial wall of the fourth ventricle.
TS15: nasal process	Present		4A
TS15: neural tube	Present		4A
TS15: olfactory placode	Present		4A
TS15: optic cup inner layer	Present	Regionally restricted	4A	Expression was detected in the caudal part of the inner neural layer of the optic cup.
TS15: somite	Present		4A
TS15: foregut	Present	Regionally restricted	4A	Expression was detected in the region of the future stomach.

Structure	Level	Pattern	Image	Note
TS17: branchial arch	Present	Regionally restricted	4B	Expression was detected in the branchial arches, especially in the most lateral parts.
TS17: telencephalon	Present	Regionally restricted	4B	Expression was abundant in the neuroepithelial wall of the telencephalic ventricle.
TS17: blood vessel	Present		4B
TS17: neural tube	Present		4B
TS17: foregut	Present	Regionally restricted	4B	Expression was detected around the pharyngeal region of the foregut.

Structure	Level	Pattern	Image	Note
TS20: Meckel's cartilage	Present		5A
TS20: hip	Present		5A
TS20: otic capsule	Present		5A
TS20: sclerotome	Present		5A
TS20: shoulder	Present		5A
TS20: genital tubercle	Weak	Regionally restricted	5A	Weak expression was detected in the genital tubercle mesenchyme.
TS20: epidermis	Present		5A
TS20: lung epithelium	Present		5A
TS20: mesonephric tubule	Present		5A
TS20: pleura	Present		5A
TS20: primitive collecting duct	Present	Regionally restricted	5A	Expression was detected in the lining of the collecting tubules in the inner medullary region of the metanephros.
TS20: urogenital sinus	Present	Regionally restricted	5A	Expression was detected in the pelvic part of the urogenital sinus.
TS20: midgut epithelium	Present		5A
TS20: optic stalk	Present		5A
TS20: foregut epithelium	Present	Regionally restricted	5A	Expression was detected in the lining of the oropharyngeal region of the foregut.
TS20: brain	Present	Regionally restricted	5A	Expression was detected in the ependymal layers of the ventricles.
TS20: metencephalon ventricular layer	Present		5A
TS20: midbrain roof plate	Present		5A
TS20: midbrain ventricular layer	Present		5A
TS20: pons	Present		5A
TS20: telencephalon ventricular layer	Present		5A
TS20: cerebral cortex	Present	Regionally restricted	5A	Expression was detected in the roof of the neopallial cortex, predominantly in the region of the future olfactory lobe.

Structure	Level	Pattern	Image	Note
TS20: Meckel's cartilage	Present		5B
TS20: sclerotome	Present		5B
TS20: genital tubercle	Weak	Regionally restricted	5B	Weak expression was detected in the genital tubercle mesenchyme.
TS20: tongue	Present	Regionally restricted	5B	Expression was detected in the intrinsic muscle of the tongue.
TS20: epidermis	Present		5B
TS20: mesonephric tubule	Present		5B
TS20: urogenital sinus	Present	Regionally restricted	5B	Expression was detected in the pelvic part of the urogenital sinus.
TS20: primitive collecting duct	Present	Regionally restricted	5B	Expression was detected in the lining of the collecting tubules in the inner medullary region of the metanephros.
TS20: midgut epithelium	Present		5B
TS20: optic stalk	Present		5B
TS20: foregut epithelium	Present	Regionally restricted	5B	Expression was detected in the lining of the oropharyngeal region of the foregut.
TS20: brain	Present	Regionally restricted	5B	Expression was detected in the ependymal layers of the ventricles.
TS20: metencephalon ventricular layer	Present		5B
TS20: midbrain roof plate	Present		5B
TS20: midbrain ventricular layer	Present		5B
TS20: pons	Present		5B
TS20: diencephalon	Present	Regionally restricted	5B	Expression was detected in the optic recess.
TS20: spinal cord	Present	Regionally restricted	5B	Expression was mainly in the ependymal layers around the lumen.
TS20: cardinal vein	Present		5B

Structure	Level	Pattern	Image	Note
TS20: Meckel's cartilage	Present		5C
TS20: otic capsule	Present		5C
TS20: sclerotome	Present		5C
TS20: genital tubercle	Weak	Regionally restricted	5C	Weak expression was detected in the genital tubercle mesenchyme.
TS20: epidermis	Present		5C
TS20: mesonephric tubule	Present		5C
TS20: primitive collecting duct	Present	Regionally restricted	5C	Expression was detected in the lining of the collecting tubules in the inner medullary region of the metanephros.
TS20: urogenital sinus	Present	Regionally restricted	5C	Expression was detected in the pelvic part of the urogenital sinus.
TS20: nephric duct	Strong		5C
TS20: paramesonephric duct	Strong		5C
TS20: midgut epithelium	Present		5C
TS20: optic stalk	Present		5C
TS20: foregut epithelium	Present	Regionally restricted	5C	Expression was detected in the lining of the oropharyngeal region of the foregut.
TS20: brain	Present	Regionally restricted	5C	Expression was detected in the ependymal layers of the ventricles.
TS20: metencephalon ventricular layer	Present		5C
TS20: midbrain roof plate	Present		5C
TS20: midbrain ventricular layer	Present		5C
TS20: pons	Present		5C
TS20: spinal cord mantle layer	Present		5C
TS20: epithalamus	Strong		5C

Structure	Level	Pattern	Image	Note
TS20: olfactory epithelium	Present	Regionally restricted	5D	Expression was abundant in the olfactory epithelium in the roof of the primitive nasal cavity.
TS20: brain	Present	Regionally restricted	5D	Expression was detected in the ependymal layers of the ventricles.
TS20: ganglionic eminence	Present		5D
TS20: 4th ventricle choroid plexus	Absent		5D
TS20: choroid invagination	Absent		5D	Staining was negative in the choroid plexus of the lateral ventricle.
TS20: neurohypophysis infundibulum	Absent		5D

Structure	Level	Pattern	Image	Note
TS20: brain	Present	Regionally restricted	5E	Expression was detected in the ependymal layers of the ventricles.
TS20: epithalamus	Strong		5E
TS20: thalamus	Present	Non-Uniform	5E	Expression was weak in the ventral thalamus and more pronounced in the ependymal layer of the dorsal thalamus. There was a sharp border of signal at the sulcus limitans.

Structure	Level	Pattern	Image	Note
TS20: nasal septum	Present		5F
TS20: head mesenchyme	Present	Regionally restricted	5F	Expression was detected in the mesenchyme surrounding the nasal cavity.
TS20: saccule	Strong	Regionally restricted	5F	Expression was detected in cells lining the saccule.
TS20: cochlea	Present		5F
TS20: semicircular canal	Weak		5F
TS20: medulla oblongata	Absent		5F
TS20: remnant of Rathke's pouch	Absent		5F
TS20: cochlear ganglion	Present		5F

Structure	Level	Pattern	Image	Note
TS20: limb pre-cartilage condensation	Present		5G
TS20: pre-cartilage condensation	Present		5G
TS20: cranium	Present	Regionally restricted	5G	Expression was detected in the precartilage primordia of the basosphenoid bone.
TS20: hip	Present		5G
TS20: shoulder	Present		5G
TS20: skeletal muscle	Present	Regionally restricted	5G	Expression was detected in the body wall musculature.
TS20: perioptic mesenchyme	Present	Regionally restricted	5G	Expression was detected in the extrinsic ocular muscle.
TS20: stomach pyloric region	Strong		5G
TS20: neural retinal epithelium	Present	Regionally restricted	5G	Expression was detected in the inferior part.
TS20: brain	Present	Regionally restricted	5G	Expression was detected in the ependymal layers of the ventricles.

Structure	Level	Pattern	Image	Note
TS20: rib pre-cartilage condensation	Present	Regionally restricted		Expression was detected in the primordia of the rib shafts.
TS20: cranium	Present	Regionally restricted		Expression was detected in the precartilage primordia of the basioccipital bone.
TS20: mandible primordium	Present
TS20: maxilla	Present
TS20: pinna	Present
TS20: head mesenchyme	Present	Regionally restricted		Expression was detected in the condensation of mesenchyme forming the outer table of the primitive ectomeninx and the tentorium cerebelli.
TS20: cartilage	Present	Regionally restricted		Expression was detected in the precartilage primordium of laryngeal cartilage and the two main bronchii.
TS20: skeletal muscle	Present	Regionally restricted		Expression was detected in the myotome-derived and prevertebral premuscle masses.
TS20: cranial nerve	Present	Regionally restricted		Expression was detected in the rootlets of the facial nerve.
TS20: midbrain	Weak	Regionally restricted		Expression was weak in the ventricular zone of the tectum.
TS20: cerebellum primordium	Present	Regionally restricted		Expression was detected in the ventricular zone of the cerebellum.
TS20: spinal cord mantle layer	Present
TS20: gonad	Absent
TS20: heart	Absent
TS20: hindgut	Absent
TS20: liver	Absent
TS20: notochord	Absent
TS20: pancreas	Absent
TS20: cervical ganglion	Present
TS20: umbilical artery	Present
TS20: umbilical vein	Present
TS20: venous system	Present
TS20: arterial system	Present	Regionally restricted		Expression was generally detected in arteries, but not the descending abdominal aorta. The throacic aorta was strongly expressing.

Structure	Level	Pattern	Image	Note
TS20: paramesonephric duct	Strong		6

Structure	Level	Pattern	Image	Note
TS23: sternum	Present	Regionally restricted	10A	Expression was detected in sternum cartilage.
TS23: cricoid cartilage	Present		10A
TS23: nasal capsule	Present		10A
TS23: thyroid cartilage	Present		10A
TS23: tail vertebral cartilage condensation	Present		10A	Expression was high in the perichondrium.
TS23: basioccipital bone	Weak	Regionally restricted	10A	Weak expression was associated with the periosteum.
TS23: ilium	Weak	Regionally restricted	10A	Weak expression was associated with the periosteum.
TS23: rib	Weak	Regionally restricted	10A	Weak expression was detected in the dorsal rib shafts.
TS23: thyroid gland	Present		10A
TS23: thymus primordium	Weak		10A
TS23: vibrissa follicle	Weak		10A

Structure	Level	Pattern	Image	Note
TS23: digit mesenchyme	Strong	Regionally restricted		Expression was very strong in the cartilage of the digits.
TS23: gland	Present	Regionally restricted		Expression was detected in the lacrimal gland.