The Slit/Robo pathway is altered in the pharyngeal region of
Tbx1 and Gbx2 mutant embryos. (A-I) ISH for
Slit2 in wt (A,C,E,G) and mutant (B,D,F,H,I) E8.75 mouse embryos.
Yellow and white arrows indicate downregulation or normal expression of
Slit2, respectively. (J-N) A decreased number of migrating
Robo1-positive cNCCs was detected in E9.5 Gbx2-/-
embryos (J) and in the caudal PAs of E10.5 Gbx2-PSE, Tbx1-PSE
(Tbx1flox/-;AP2αCre/+) and
Tbx1-/- embryos (yellow arrow and bracketed region in
L,M,N) as compared with wt (K).