Fig. 1. Spatial expression pattern of Spfoxa. (A-L) WMISH was performed at seven different developmental stages, as indicated in the upper right corner of each panel. Note that starting at 21 hours postfertilization, asymmetric expression of foxa is observed across the endoderm (C,H,L). This is not as apparent in D, which is purposely overdeveloped to reveal that only endoderm expresses foxa. The asterisks in E-G,K,L indicate the stomodeal region of the oral ectoderm. Arrows (I,J) indicate higher expression levels in foregut and hindgut relative to the midgut. LV, lateral view; VV, view from the vegetal plate; OV, view from the oral ectoderm.