Fig. 1.

sox4b is expressed in the pituitary during zebrafish organogenesis. WISH was performed on wt zebrafish embryos using the sox4b antisense probe. A–C, Lateral views (anterior to the left, dorsal to the top) of wt embryos labeled with the sox4b probe (blue) by WISH. The arrowheads indicate the pituitary placode at 24 (A), 26 (B), and 48 (C) hpf, respectively. D–F and H–J, Analysis by double-fluorescent WISH (anterior to the left), with one z-plane of the confocal images shown; D–F, expression of sox4b (red, E) and the pan-adenohypophyseal marker lim3 (green, D) colocalize in the pituitary placode (F); G, fluorescence emission quantification in F; H–J, sox4b (green, H) and tshβ (red, I) are coexpressed in a subtype of pituitary cells (J); K, fluorescence emission quantification in J. In D–F and H–J, the ventral head regions were dissected before confocal microscopy. L and M, sox4b expression does not require pit1 at 24 hpf. Analysis of sox4b expression by WISH in wt and homozygous pit1 mutants. Lateral view, anterior to the left, the arrow indicates the label in the pituitary. Scale bars, 100 μm (A, B, C, L, and M) and 20 μm (D–J). D, Diencephalon; M, mesencephalon; My, myencephalon; Tel, telencephalon.