Fig. 6

Fig. 6 PGE₂ Interacts with the bmp2b Pathway to Regulate Liver versus Pancreas Specification

(A) Modulation of PGE₂ levels from 12 to 20 hpf impacts expression of bmp2b in the lateral plate mesoderm as shown by in situ hybridization at 20 hpf. dmPGE₂ increases bmp2b expression (n = 15/19 embryos), whereas Indo decreases bmp2b expression (n = 14/21 embryos). Lower: magnified view of the area in the dashed square. bmp2b is also expressed in the otic vesicles (arrow).

(B and C) Size of pancreas-specified population marked by pdx1 is impacted by modulation of the PGE₂ or bmp2b pathways. Representative views are shown in (B), and quantification is shown in (C). dmPGE₂ or heat-shock activation of bmp2b diminishes whereas Indo, dorsomorphin (Dorso), or heat-shock activation of dnBmpR promotes the pancreas progenitor population. The impact of dmPGE₂ is blunted by Dorso or dnBmpR, and the impact of Indo is blunted by heat-shock activation of bmp2b. (Data are represented as mean ± SEM; n e 10 per condition; t test comparisons: p < 0.05 comparing treatment versus control; ^#no significant difference comparing with versus without dmPGE₂; ^##no significant difference comparing with versus without Indo.)