Fig. 4. Gata3 in mandibular arch development. E10.5 wild-type (Gata3^+/+, A,C,E,G; Ednra^+/+, I,K), Gata3^–/– (B,D,F,H) and Ednra^–/– (J,L) embryos following whole-mount in situ hybridization analysis using DIG-labeled riboprobes against Hand2 (A-D), Dlx5 (E-H) and Gata3 (I-L). Embryos are shown in both lateral (A,B,E,F,I,J) and ventral (C,D,G,H,K,L) views. (A-D) Unlike wild-type embryos (A,C), Hand2 expression in Gata3^–/– embryos is observed only in the rostral mandibular arch (B,D); expression is also decreased in the second arch. There is an overall decrease in arch size in Gata3^–/– embryos. (E-H) Dlx5 expression is observed only along the rostral half of the mandibular arch of Gata3^–/– embryos (F,H). (I-L) Mandibular arch expression of Gata3, observed in the distal arch mesenchyme of wild-type embryos (I,K), appears unchanged in Ednra^–/– embryos (J,L). 1, mandibular region of the first pharyngeal arch; 2, second pharyngeal arch; h, heart; lb, limb bud; np, nasal prominence.