Fig. S4

Fig. S4 Expression pattern of follistatin-like 2 during embryonic development. (A) Expression of fstl2 starts at the onset of gastrulation in the deep cells of the embryonic shield (sh). (B) At 60% epiboly, fstl2 transcripts are observed in notochord (n) as well as in the yolk syncytial layer (ysl). (C–D) At 75% epiboly and bud stage (E–F), expression is restricted to the notochord. (G–I) At the 7-somite stage, fstl2 expression is observed in notochord as well as in segmental plate (sp) with a stronger staining in the adaxial cells (ad) of the formed somites. Expression is also observed in hindbrain (h). (J) At the 18-somite stage, expression is observed in hindbrain rhombomeres (rh) 2, 4 and 6, somites (s) and in tail epidermis (te). (K–L) At 24 hpf, transcripts accumulate in the choroid fissure (cf), at the rhombomeres boundaries (rhb) in axial vasculature (av) and in posterior somites. (M–N) At 36 hpf, additional expression is observed in forebrain ventricular zone (fv) and epiphysis (ep). (O–P) At 48 hpf, expression is also observed in branchial arches (ba), head mesenchyme (hm) and pectoral fin (pf). Embryos in lateral views anterior to the top in A, B, D and F; in dorsal views anterior to the top in C and E; in lateral views anterior to the left in G and J–O and in dorsal views anterior to the left in H, I and P.