Figure 2. Hmga1 is expressed in the neural plate, neural plate border, and premigratory and migratory neural crest cells.

(A) HCR against Hmga1 at HH5 reveals expression in the neural plate and neural plate border. (B–B’) A wild-type HH6 chick embryo double-labeled with Hmga1 (B) and Pax7 (B’) probes. Hmga1 expression overlaps with Pax7 in the neural plate border. (B’’–B’’’) Transverse section through embryo in (B) shows Hmga1 and Pax7 transcripts in the neural plate and neural plate border, respectively, but not the non-neural ectoderm. (C–D’) As the neural folds elevate, Hmga1 expression is retained in the dorsal neural tube. (D’’–D’’’) Transverse section through embryo in (D) shows Hmga1 transcripts in the neural tube. (E–F) As neural crest cells delaminate (E’’’) and migrate laterally from the neural tube (F’’’), Hmga1 is expressed in emigrating (E’’) and migrating neural crest cells (F’’), along with Pax7 (E’ and F’). Arrow points towards delaminating (E’’) and migrating (F’’) cranial neural crest cells. hn, Hensen’s node; npb, neural plate border; np, neural plate; nne, non-neural ectoderm; ect, ectoderm; dNF, dorsal neural folds; nc, notochord; nt, neural tube. See also Figure 2—figure supplement 1.

Figure 2—figure supplement 1. Overlapping expression of Hmga1 and Pax7 in the neural crest visualized in individual channels.

(A-H) Transverse sections shown in Figure 2 stained with DAPI (A,C,E,G). The expression of Hmga1 and Pax7 overlapped in the neural plate border (B,B’; arrows), dorsal neural folds (D,D’; arrows), premigratory (F,F’; arrows), and migratory neural crest cells (H,H’; arrows).