Fig. 6

Notch signalling is active in neural crest cells at the earliest stages of migration. a Transverse sections through the forelimb region of wildtype embryos at E9.25 (20 somite pairs) co-immunostained for N1ICD and the neural crest cell marker AP2α. Inset images in lower panels show higher magnification of the boxed region in upper panel. Solid arrowheads highlight neural crest cells undergoing active Notch signalling (AP2α and N1ICD positive). Open arrowheads highlight non-neural crest cell types within the migrating neural crest stream that are undergoing active Notch signalling (AP2α-negative, N1ICD-positive). nt, neural tube; da, dorsal aorta. b Sections of Wnt1-Cre; Mib1^fl/fl embryos at E9.25 co-immunostained and labelled for N1ICD and AP2α. Scale bar = 50 μm. c, d Sections of wildtype and Wnt1-Cre; Mib1^fl/fl embryos at E9.5 (23 somite pairs) co-immunostained for N1ICD and AP2α. n = 3 embryos/genotype. Scale bar = 50 μm