Probe:	Rspo1 cDNA2
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS11: embryo	Absent

Structure	Level	Pattern	Image	Note
TS13: head mesenchyme	Present	Regionally restricted	1B	Expression is in the mesenchymal cells of the presumptive diencephalon and mesencephalon region.
TS13: lateral plate mesoderm	Present	Regionally restricted	1B	Expression is in a small patch of lateral plate mesodermal cells proximal to the intermediate mesoderm at the level of the rostral somites.

Structure	Level	Pattern	Image	Note
TS15: diencephalon roof plate	Present		1F
TS15: future forebrain	Present		1F
TS15: future hindbrain roof plate	Present		1F
TS15: future midbrain roof plate	Present		1F
TS15: neural tube roof plate	Present		1F
TS15: telencephalon roof plate	Present		1F
TS15: trunk mesenchyme	Present	Regionally restricted	1F	Expression is in the medial part of lateral plate mesoderm adjacent to the intermediate mesoderm along the body axis.

Structure	Level	Pattern	Image	Note
TS17: diencephalon roof plate	Present		1J
TS17: forebrain	Present		1J
TS17: hindbrain roof plate	Present		1J
TS17: midbrain roof plate	Present		1J
TS17: neural tube roof plate	Present		1J
TS17: trunk mesenchyme	Present	Regionally restricted	1J	Expression is in the medial part of lateral plate mesoderm adjacent to the intermediate mesoderm along the body axis.

Structure	Level	Pattern	Image	Note
TS15: future forebrain	Present		2A
TS15: head mesenchyme	Present	Regionally restricted	2A	Expression is in mesenchymal cells in the forebrain region.

Structure	Level	Pattern	Image	Note
TS15: trunk mesenchyme	Present	Regionally restricted	2E	Expression is in the medial part of lateral plate mesoderm adjacent to the intermediate mesoderm along the body axis.

Structure	Level	Pattern	Image	Note
TS17: head mesenchyme	Present	Regionally restricted	2I	Expression is in mesenchymal cells surrounding the optic placode.

Structure	Level	Pattern	Image	Note
TS17: forelimb bud ectoderm	Weak	Regionally restricted	3A	Expression is at the junction between limb buds and body trunk.
TS17: forelimb bud mesenchyme	Weak	Regionally restricted	3A	Expression is underlying the expressing ectoderm.

Structure	Level	Pattern	Image	Note
TS17: forelimb bud ectoderm	Weak	Regionally restricted	3E	Expression is at the junction between limb buds and body trunk.
TS17: forelimb bud mesenchyme	Weak	Regionally restricted	3E	Expression is underlying the expressing ectoderm.

Structure	Level	Pattern	Image	Note
TS20: hand mesenchyme	Strong	Regionally restricted	3I	Expression is in the condensing mesenchymal cells of the phalanges.

Structure	Level	Pattern	Image	Note
TS22: hindlimb phalanx cartilage condensation	Strong	Regionally restricted	3M	Expression is in the condensing mesenchymal cells of the phalanges.

Structure	Level	Pattern	Image	Note
TS23: vibrissa	Present		4A

Structure	Level	Pattern	Image	Note
TS23: mammary mesenchyme	Present		4E

Structure	Level	Pattern	Image	Note
TS23: metanephros	Strong	Regionally restricted	4I	Expression is in metanephric mesenchymal cells and the developing glomeruli and is absent in the nephric ducts.

Structure	Level	Pattern	Image	Note
TS23: stomach	Present		4M	Expression is in the smooth muscle layer.

Structure	Level	Pattern	Image	Note
TS23: forebrain	Strong	Regionally restricted	4Q	Expression is in the hippocampus.

Structure	Level	Pattern	Image	Note
TS25: humerus	Present	Regionally restricted	4U	Expression is in the prehypertrophic and hypertrophic chondrocytes of long bones.

Structure	Level	Pattern	Image	Note
TS20: metanephros	Strong
TS20: forebrain	Present	Regionally restricted		Expression is in the hippocampus.
TS20: medulla oblongata	Weak
TS20: spinal cord	Weak

Structure	Level	Pattern	Image	Note
TS23: metanephros	Strong
TS23: forebrain	Moderate	Regionally restricted		Expression is in the hippocampus.
TS23: vibrissa	Moderate
TS23: cranium	Weak
TS23: facial bone primordium	Weak
TS23: medulla oblongata	Weak
TS23: spinal cord	Weak
TS23: stomach	Weak
TS23: tongue	Weak
TS23: vertebra	Weak
TS23: skeleton	Weak	Regionally restricted		Expression is in the long bones.

Structure	Level	Pattern	Image	Note
TS25: skeleton	Moderate	Regionally restricted		Expression is in the long bones.
TS25: vertebra	Moderate
TS25: cranium	Weak
TS25: facial bone	Weak
TS25: medulla oblongata	Weak
TS25: metanephros	Weak
TS25: spinal cord	Weak
TS25: vibrissa	Weak