Fig. 3.

Expression pattern of Tbx2 in X. tropicalis. In situ hybridization results are shown for Tbx2 (embryos uncleared). a– c: Expression at early gastrula (stage 10.5) is shown in lateral (a) and vegetal (b) views of whole-mount embryos and in transverse section (c; ventral to the right). In both a and b, the embryo is oriented with dorsal to the left and the dorsal blastopore lip is indicated by an arrowhead in a. d: A vegetal view of a late gastrula (st12) is shown, ventral side uppermost. e–r: Expression at early neurula (stage 13; e– g) late neurula (stage 19; h,l), and tail bud stages 21/22 (m), 25 (n), 26 (o,p), 29 (q), and 33 (r) are also shown. Expression in the forebrain (telencephalon) at tail bud stages is indicated by an asterisk (o–r). Except for anterior (j) and posterior (d,l) views, all embryos are oriented with anterior to the left. cg, cement gland; crg, cranial ganglia; drg, dorsal root ganglia; fn, frontonasal process; hm, hypaxial muscle; ht, heart tube; lp, lens placode; ov, otic vesicle; pa, placodal area; pd, pronephric duct; pr, proctodeum.