Antibody:	Anti-Brn2
Detection system:	Secondary antibody coupled to Alexa Fluor

Structure	Level	Pattern	Image	Note
TS24: cortical plate	Present	Regionally restricted	1A Brn2 Cux1 , 1A Brn2	Expression was uniform in the upper cortical plate. A number of neurons in the lower cortical plate were also labeled; many of these neurons coexpressed Cux1 (indicated by arrows in image). Arrowheads indicate neurons that do no coexpress Cux1.
TS24: cerebral cortex intermediate zone	Present		1A Brn2 , 1A Brn2 Cux1	A number of neurons in the intermediate zone were labeled. Many of these neurons co-expressed Cux1.

Structure	Level	Pattern	Image	Note
TS27: cortical plate	Present	Regionally restricted	1C Brn2 , 1C Brn2 Cux1	Expression was strong in the upper half of the upper cortical plate, and only weak or no expression was observed in the lower half of the upper cortical plate.

Structure	Level	Pattern	Image	Note
TS26: cortical plate	Present	Regionally restricted	S1A Brn2 , S1A Brn2 Cux1	Expression was uniform in the upper cortical plate.

Structure	Level	Pattern	Image	Note
TS27: cortical layer II	Strong		S1C Brn2 Cux1 , S1C Brn2
TS27: cortical layer III	Strong		S1C Brn2 Cux1 , S1C Brn2
TS27: cortical layer V	Present		S1C Brn2 , S1C Brn2 Cux1	Expression was detected in some L5 neurons.
TS27: cortical layer IV	Ambiguous		S1C Brn2 , S1C Brn2 Cux1	Only weak or no expression was observed in the developing L4.