Antibody:	P13
Detection system:	Secondary antibody coupled to horseradish peroxidase

Structure	Level	Pattern	Image	Note
TS23: embryo mesenchyme	Present	Regionally restricted	2A	Expression predominantly in mesenchymal stromal fibroblasts.
TS23: blood vessel	Present	Regionally restricted	2A	Also located in a component of the developing vasculature.

Structure	Level	Pattern	Image	Note
TS23: dermis	Present	Regionally restricted	2B	Expression in the dorsal skin; particularly high in the dermal component, with concentrations of expression on dermal condensates surrounding developing hair.
TS23: epidermis	Absent		2B	Negative expression in epithelial structures.

Structure	Level	Pattern	Image	Note
TS23: upper lip	Present	Regionally restricted	2C	Expression in the upper lip.
TS23: vibrissa dermal component	Present	Regionally restricted	2C	Concentration of expression on dermal condensates surrounding the developing whisker follicles.
TS23: vibrissa epidermal component	Absent		2C	Negative expression in epithelial structures.

Structure	Level	Pattern	Image	Note
TS23: submandibular gland primordium mesenchyme	Present	Regionally restricted	2D	Expression was strongest on stromal fibroblasts associated with epithelial structures.
TS23: submandibular gland primordium epithelium	Absent		2D	Negative expression in epithelial structures.

Structure	Level	Pattern	Image	Note
TS23: lung mesenchyme	Present	Regionally restricted	2E	Expression was strongest on stromal fibroblasts associated with epithelial structures.
TS23: lung epithelium	Absent		2E	Negative expression in epithelial structures.

Structure	Level	Pattern	Image	Note
TS23: rib	Absent		2F	Negative expression in cartilage primoridum of a developing rib.

Structure	Level	Pattern	Image	Note
TS23: heart	Present	Regionally restricted	2G	Infrequent expression in fibroblasts; expression on vasculature apparent.
TS23: cardiac muscle tissue	Absent		2G	Negative expression in cardiac myocytes.

Structure	Level	Pattern	Image	Note
TS23: liver	Present	Regionally restricted	2H	Infrequent expression in fibroblasts; expression on vasculature apparent. Negative expression in liver hepatocytes.

Structure	Level	Pattern	Image	Note
TS23: diencephalon	Present	Regionally restricted	2I	Infrequent expression in fibroblasts; expression on vasculature apparent. Negative expression in neuronal cells in the brain.

Structure	Level	Pattern	Image	Note
TS23: cerebral cortex	Present	Regionally restricted	2J	Infrequent expression in fibroblasts; expression on vasculature apparent. Negative expression in neuronal cells in the brain.

Structure	Level	Pattern	Image	Note
TS27: lung	Present	Regionally restricted	3A P1 Lung	Expression decreased from level seen in the embryo, although expression in stromal fibroblasts was detected around the alveoli and larger blood vessels.

Structure	Level	Pattern	Image	Note
TS27: metanephros	Present	Regionally restricted	3A P1 Kidney	Expression predominantly on stromal fibroblasts and cells surrounding developing blood vessels.
TS27: glomerular tuft	Strong	Regionally restricted	3A P1 Kidney	Strong staining also identified on glomerular mesangial cells.

Structure	Level	Pattern	Image	Note
TS27: spleen	Strong	Regionally restricted	3A P1 Spleen	Strong expression in the stroma, widespread throughout the tissue.

Structure	Level	Pattern	Image	Note
TS27: thymus	Present	Regionally restricted	3A P1 Thymus	Expression limited to vascular structures.

Structure	Level	Pattern	Image	Note
TS27: liver	Present	Regionally restricted	3A P1 Liver	Expression limited to vascular structures.

Structure	Level	Pattern	Image	Note
TS27: heart	Present	Regionally restricted	3A P1 Heart	Expression limited to vascular structures.

Structure	Level	Pattern	Image	Note
TS28: lung	Weak	Regionally restricted	3A P70 Lung	Expression decreased from level seen in the embryo, although expression in stromal fibroblasts was detected around the alveoli and larger blood vessels.

Structure	Level	Pattern	Image	Note
TS28: glomerular tuft	Weak	Regionally restricted	3A P70 Kidney	Expression decreased compared with embryonic and newborn mice, restricted to mesangial cells in some of the glomeruli.

Structure	Level	Pattern	Image	Note
TS28: spleen red pulp	Weak	Regionally restricted	3A P70 Spleen	Expression decreased compared with embryonic and newborn mice; only a very low level of expression in the red pulp.

Structure	Level	Pattern	Image	Note
TS28: thymus	Absent		3A P70 Thymus	Expression in the vasculature was undetectable.

Structure	Level	Pattern	Image	Note
TS28: liver	Weak	Regionally restricted	3A P70 Liver	Expression in the vasculature was substantially reduced compared with embryonic and newborn mice.

Structure	Level	Pattern	Image	Note
TS28: heart	Weak		3A P70 Heart	Expression decreased compared with embryonic and newborn mice.

Structure	Level	Pattern	Image	Note
TS28: dermis	Present		3B P9	Extensive expression.
TS28: epidermis	Absent		3B P9
TS28: hair follicle	Absent		3B P9	No expression in epithelial cells within the hair follicle.
TS28: skin	Present	Regionally restricted	3B P9	No expression in adipose layers.

Structure	Level	Pattern	Image	Note
TS28: dermis	Weak		3B P16	Dramatic downregulation on expression in the dermal layer.
TS28: epidermis	Absent		3B P16
TS28: hair follicle	Absent		3B P16	No expression in epithelial cells within the hair follicle.
TS28: skin	Present	Regionally restricted	3B P16	No expression in adipose layers.

Structure	Level	Pattern	Image	Note
TS28: dermis	Weak	Regionally restricted	3B P23	Low level of expression maintained into adulthood in a restricted population of scattered dermal fibroblasts, particularly in the deeper layers and on cells surrounding hair follicles.
TS28: epidermis	Absent		3B P23
TS28: hair follicle	Absent		3B P23	No expression in epithelial cells within the hair follicle.
TS28: skin	Present	Regionally restricted	3B P23

Structure	Level	Pattern	Image	Note
TS28: dermis	Weak	Regionally restricted	3B P37	Low level of expression maintained into adulthood in a restricted population of scattered dermal fibroblasts, particularly in the deeper layers and on cells surrounding hair follicles
TS28: epidermis	Absent		3B P37
TS28: hair follicle	Absent		3B P37	No expression in epithelial cells within the hair follicle.
TS28: skin	Present	Regionally restricted	3B P37	No expression in adipose layers.

Structure	Level	Pattern	Image	Note
TS23: blood vessel	Strong	Regionally restricted	3C E15 embryonic brain	Strong expression in developing vasculature in the brain
TS23: brain	Strong	Regionally restricted	3C E15 embryonic brain	Strong expression in developing vasculature in the brain

Structure	Level	Pattern	Image	Note
TS28: blood vessel	Trace	Regionally restricted	3C P70 adult brain	Little or no expression in blood vessels in the brain.
TS28: brain	Trace	Regionally restricted	3C P70 adult brain	Little or no expression in blood vessels in the brain.