Antibody:

anti-carboxypeptidase A1

Structure	Level	Pattern	Image	Note
TS19: pancreas primordium epithelium	Present	Scattered	3A	At all embryonic stages examined, Cpa1-positive cells do not express mature endocrine hormones.

Structure	Level	Pattern	Image	Note
TS20: pancreas branching epithelium tip	Present	Regionally restricted	3B	By E12.5, there were well-formed primary branches in the pancreas, and Cpa1 expression was largely restricted to the branching tips. At all embryonic stages examined, Cpa1-positive cells do not express mature endocrine hormones.

Structure	Level	Pattern	Image	Note
TS21: pancreas branching epithelium tip	Present	Regionally restricted	3C	The tip-restricted expression pattern of expression persists through successive branching and growth of the pancreatic tree. At all embryonic stages examined, Cpa1-positive cells do not express mature endocrine hormones.

Structure	Level	Pattern	Image	Note
TS22: pancreas branching epithelium tip	Present		3D	The tip-restricted expression pattern of expression persists through successive branching and growth of the pancreatic tree. Expression levels vary among tip cells. At all embryonic stages examined, Cpa1-positive cells do not express mature endocrine hormones.

Structure	Level	Pattern	Image	Note
TS19: pancreas primordium epithelium	Present	Scattered	3E	At all embryonic stages examined, Cpa1-positive cells do not co-express the early endocrine progenitor marker, Neurog3.

Structure	Level	Pattern	Image	Note
TS20: pancreas branching epithelium tip	Present	Regionally restricted	3F	By E12.5, there were well-formed primary branches in the pancreas, and Cpa1 expression was largely restricted to the branching tips. At all embryonic stages examined, Cpa1-positive cells do not co-express the early endocrine progenitor marker, Neurog3.

Structure	Level	Pattern	Image	Note
TS21: pancreas branching epithelium tip	Present		3G	The tip-restricted expression pattern of expression persists through successive branching and growth of the pancreatic tree. At all embryonic stages examined, Cpa1-positive cells do not co-express the early endocrine progenitor marker, Neurog3.

Structure	Level	Pattern	Image	Note
TS22: pancreas branching epithelium tip	Present		3H	The tip-restricted expression pattern of expression persists through successive branching and growth of the pancreatic tree. Expression levels vary among tip cells. At all embryonic stages examined, Cpa1-positive cells do not co-express the early endocrine progenitor marker, Neurog3.

Structure	Level	Pattern	Image	Note
TS19: pancreas primordium epithelium	Present	Scattered	3I	All Cpa1-positive cells co-express Pdx1 and constitute a subset of Pdx1-positive epithelial cells.

Structure	Level	Pattern	Image	Note
TS20: pancreas branching epithelium tip	Present	Regionally restricted	3J	By E12.5, there were well-formed primary branches in the pancreas, and Cpa1 expression was largely restricted to the branching tips. All Cpa1-positive cells co-express Pdx1 and constitute a subset of Pdx1-positive epithelial cells (representing 13.3% of total Pdx1-positive cells at E12.5).

Structure	Level	Pattern	Image	Note
TS21: pancreas branching epithelium tip	Present	Regionally restricted	3K	The tip-restricted expression pattern of expression persists through successive branching and growth of the pancreatic tree. All Cpa1-positive cells co-express Pdx1 and constitute a subset of Pdx1-positive epithelial cells (representing 13.6% of total Pdx1-positive cells at E13.5).

Structure	Level	Pattern	Image	Note
TS22: pancreas branching epithelium tip	Present		3L	The tip-restricted expression pattern of expression persists through successive branching and growth of the pancreatic tree. Expression levels vary among tip cells. All Cpa1-positive cells co-express Pdx1 and constitute a subset of Pdx1-positive epithelial cells (representing 16.8% of total Pdx1-positive cells at E14.5).

Structure	Level	Pattern	Image	Note
TS20: pancreas branching epithelium tip	Present	Regionally restricted	3M	Cpa1-positive tip cells proliferate ~3-5 times faster than trunk epithelial cells, as revealed by co-staining with the mitotic marker phospho-histone H3.