Probe:	probe 1
Probe preparation:	Antisense labelled with S35 RNA
Visualized with:	Autoradiography

Structure	Level	Pattern	Image	Note
TS18: neural tube	Present	Regionally restricted	4A/B	Anterior boundary is at the level of the third thoracic prevertebra; clearly restricted to the ventral part of the neural tube.
TS18: axial skeleton	Weak		4A/B	Expression in prevertebra and spinal ganglia is very weak.
TS18: spinal ganglion	Weak		4A/B	Expression in prevertebra and spinal ganglia is very weak.

Structure	Level	Pattern	Image	Note
TS21: spinal ganglion	Weak		4C/D	Much lower expression than in the neural tube.
TS21: axial skeleton	Present	Regionally restricted	4C/D	Anterior boundary of expression in prevertebra was difficult to define; approximately at the ninth thoracic vertebra (T9).

Structure	Level	Pattern	Image	Note
TS21: spinal cord	Present	Regionally restricted	4E/F	Restricted to posterior regions; sharp anterior boundary at the level of the third thoracic prevertebra (T3)

Structure	Level	Pattern	Image	Note
TS14: allantois	Present	Regionally restricted	5A/B	Expression at the base of the allantois.
TS14: future spinal cord neural plate	Ambiguous		5A/B	Little, if any, expression in cells of the neural plate.

Structure	Level	Pattern	Image	Note
TS18: neural tube	Present	Regionally restricted	5C/D	Anterior boundary is at the level of the third thoracic prevertebra; clearly restricted to the ventral part of the neural tube.
TS18: neural tube ventricular layer	Absent		5C/D	No expression in the ependymal layer.

Structure	Level	Pattern	Image	Note
TS21: basal columns	Present		5E/F	Only in postmitotic cells, including the mantle layer, marginal layer and the ventral horns.
TS21: spinal cord mantle layer	Present		5E/F	Only in postmitotic cells, including the mantle layer, marginal layer and the ventral horns.
TS21: spinal cord marginal layer	Present		5E/F	Only in postmitotic cells, including the mantle layer, marginal layer and the ventral horns.
TS21: spinal cord ventricular layer	Absent		5E/F	No expression in the ependymal layer.

Structure	Level	Pattern	Image	Note
TS21: hindlimb	Present	Regionally restricted		Expression in the proximal part of the hindlimb bud
TS21: metanephros	Weak	Regionally restricted		Weak expression in the area where the metanephric tubules and metanephric ducts develop

Structure	Level	Pattern	Image	Note
TS23: spinal cord	Present	Regionally restricted		Anterior boundary of expression at the level of the third thoracic prevertebra.

Structure	Level	Pattern	Image	Note
TS23: intermediate grey horn	Strong		5G/H
TS23: spinal cord marginal layer	Strong		5G/H
TS23: spinal cord mantle layer	Present		5G/H	Expression in ventral horns was considerably reduced compared to the mantle layer.
TS23: ventral grey horn	Present		5G/H	Expression in ventral horns was considerably reduced compared to the mantle layer.
TS23: dorsal grey horn	Absent		5G/H	No expression in the ependymal layer or in dorsal horns
TS23: spinal cord ventricular layer	Absent		5G/H	No expression in the ependymal layer or in dorsal horns

Structure	Level	Pattern	Image	Note
TS23: renal cortex	Present		6A/B	Expression mainly in the cortex.
TS23: metanephros	Present	Regionally restricted	6A/B	Expression in mesenchyme is considerably reduced.
TS23: extraembryonic component	Ambiguous		6A/B	Strong expression, close to the kidney, could not be located unequivocally; appears to be either the ureter, part of the genital ridge, or the umbilical cord.
TS23: reproductive system	Ambiguous		6A/B	Strong expression, close to the kidney, could not be located unequivocally; appears to be either the ureter, part of the genital ridge, or the umbilical cord.
TS23: ureter	Ambiguous		6A/B	Strong expression, close to the kidney, could not be located unequivocally; appears to be either the ureter, part of the genital ridge, or the umbilical cord.

Structure	Level	Pattern	Image	Note
TS25: renal cortex	Present		6C/D	Expression mainly in the cortex.
TS25: metanephros	Present	Regionally restricted	6C/D	Expression in mesenchyme is considerably reduced.