Antibody:	Anti-Prox1 (102-PA32)
Detection system:	Secondary antibody coupled to Alexa Fluor 594

Structure	Level	Pattern	Image	Note
TS22: jugular lymph sac	Present		1C	Lymphatic endothelial cells in the jugular lymph sacs co-express Prox1 and Lyve1.

Structure	Level	Pattern	Image	Note
TS20: lymph sac	Present	Regionally restricted	1D	Lymphatic endothelial cells in the jugular lymph sacs were double positive for Prox1 and LA102.

Structure	Level	Pattern	Image	Note
TS17: dermatome	Present		2A , 2B	A small number of Prox1+/Pecam1+ mesenchymal cells were in the dermatomes.

Structure	Level	Pattern	Image	Note
TS21: embryo mesenchyme	Present	Regionally restricted	2C	Double positive Prox1+/LA102+ cells were observed in the scattered cells in the mesenchyme.

Structure	Level	Pattern	Image	Note
TS20: embryo mesenchyme	Present		2E	A small number of Prox1+/Itgam+ cells were detected in the mesenchyme.

Structure	Level	Pattern	Image	Note
TS19: lymph sac	Present		4A	Cells in the lymph sac expressed Adgre1 only or co-expressed Adgre1 and Prox1.

Structure	Level	Pattern	Image	Note
TS22: jugular lymph sac	Present		4D , 4B , 4C	Cells were found in the developing lymph sacs that were positive for all three markers.

Structure	Level	Pattern	Image	Note
TS22: lymphatic vessel	Present		5A	In developing lymph vessels, a small number of cells were identified that were positive for all three markers. In very rare cases, various marker combinations were observed in adjacent cells of lymph vessels. e.g. 3 adjacent cells: one positive for Adgre1 only, one positive for Adgre1 and Lyve1, and a third positive for all three markers.

Structure	Level	Pattern	Image	Note
TS22: lymphatic vessel	Present		5B	In developing lymph vessels, a small number of cells were identified that were positive for all three markers.