Fig. 2

The Wnt/β-Catenin Pathway Is Ectopically Activated in extl3/ext2 Mutants

(A-M′) In extl3/ext2 mutants Wnt/β-catenin target genes expand progressively between 34 and 48 hpf.

(F, H, J, and L) Sibling prim migration has finished by 48 hpf.

(G, I, K, and M) In extl3/ext2 mutants, the prim stalls and lef1, axin2, sef, and fgf10 are upregulated.

(G′, I′, K′, and M′) Magnified views of extl3/ext2 mutant prim. Black arrows: Wnt/β-catenin target expression in interneuromast cells.

(N-U′) Time course of the Wnt/β-catenin target wnt10a and inhibitor dkk1b. Upregulation of wnt10a correlates with the downregulation of dkk1b.

(O, O′, S, and S′) Mild downregulation of dkk1b corresponds with the expansion of wnt10a at 40-42 hpf.

(P, P′, T, and T′) By 44-46 hpf, wnt10a expands along the prim and dkk1b expression is almost lost.

(Q, Q′, U, and U′) By 48-50 hpf, dkk1b expression is entirely reduced, resulting in complete expansion of wnt10a.

(V-Y′′) The Fgf target pea3 is gradually lost in the prim (V-Y′) but is progressively activated in surrounding cells (V′′-Y′′).

(Z and Z′) Lower-magnification images of the 44-46 hpf embryos in X, X′, and X′′.

See also Figures S2 and S3.