Fig. S3
Pharmacological inhibition of HS recapitulates extl3/ext2 mutants. Related to Figures 2-4.
(A-C′) The ectopic pea3 expression surrounding the primordium is Fgf dependent in extl3/ext2 mutants (B-B′) and NaClO3-treated embryos (C-C′). (D-F′′) The ectopic pea3 expression is restricted to cells immediately surrounding the primordium in extl3/ext2 mutants (E-E′′) and NaClO3-treated embryos (F-F′′) as demonstrated by double labeling with ClaudinB:GFP and pea3. (G-H′′) 3G10 labels HS chains and its persistence in NaClO3 treated embryos shows that only HS chain modifications are lost (See Table S1). (I-W′) Time course of the Fgf targets pea3 and dkk1b and the Wnt/β-catenin target lef1 in DMSO controls compared to NaClO3-treated embryos. Similar to extl3/ext2 mutants, lef1 expands only as pea3 and dkk1b are gradually downregulated after NaClO3- treatment.