Antibody:	anti-cleaved Notch1 (Val1744) antibody (anti-NICD) (#2421)
Assay notes:	The antibody recognized the active form: Notch intracellular domain.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present	Regionally restricted	1B , 1C	Expressed in the prospective somite S-1 and the posterior region during phase I.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present	Regionally restricted	1I , 1H	Expression in the posterior region and S-1 also moved anteriorly during phase II.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present	Regionally restricted	1O , 1N	Expression moved to the prospective somites S0 and S-2 region during phase III.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present		1T , 1U	Expressed steadily in all three phases.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present	Regionally restricted	2C , 2A , 2B' , 2B	Expressions of Notch1 and Hes7 were clearly separated in the middle to anterior. In the posterior end, expressions of Notch1 and Hes7 were intermingled, and subsets of cells even coexpressed Notch1 and Hes7.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present	Regionally restricted	2D , 2F , 2E , 2E'	Expressions of Notch1 and Hes7 were clearly separated in the middle to anterior. In the posterior end, expressions of Notch1 and Hes7 were intermingled, and subsets of cells even coexpressed Notch1 and Hes7.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present	Regionally restricted	2G , 2I , 2H , 2H'	Expressions of Notch1 and Hes7 were clearly separated in the middle to anterior. In the posterior end, expressions of Notch1 and Hes7 were intermingled, and subsets of cells even coexpressed Notch1 and Hes7.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present	Scattered	2K' , 2J , 2L , 2K	In the posterior end, expressions of Notch1 and Hes7 were intermingled. Expression domains were not clearly segregated in either the S0 or S-1 region. Some cells even coexpressed Hes7 and Notch1.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present	Regionally restricted	3A , 3B	Expression moved from the middle to S-2 region during phase II, covered by the pMapk1/3 domain.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present	Regionally restricted	3D , 3C	Expression moved from the middle to S-2 region during phase III, covered by the pMapk1/3 domain.

Structure	Level	Pattern	Image	Note
TS17: tail unsegmented mesenchyme	Present		3F , 3E	During phase I, when S-2 became S-1 after segmentation, pMapk1/3 expression was down-regulated and the whole Notch1 domain in S-1 was freed from pMapk1/3.