Fig. 3

Different regions of the oral-aboral axis display different patterns of BMP signaling activity in the mesentery. A Sketch of the lateral overviews of mesenteries at different positions along the oral-aboral body axis shown on B–D’. White lines demarcate different mesentery domains, pSMAD1/5 (cyan), and DNA (magenta). B Subpharyngeal region displays pSMAD1/5 activity in the rmr (retractor muscle region) and mm (medial mesentery) (blue solid arrowheads), and few pSMAD1/5-positive nuclei in the cnidoglandular tract of the septal filament (sf; blue, hollow arrowhead), C gonadal region, and D trophic region, display pSMAD1/5 activity in the rmr, pSMAD1/5 activity is mostly absent in the mm (white, hollow arrowhead) and few pSMAD1/5-positive nuclei in the sf (blue, hollow arrowheads). B', C' and D' show regions boxed in B, C and D, respectively. E Summary of BMP signaling domains across different mesentery regions. All stainings were performed at least two times independently with 3 or more animals imaged. Scale bars 50 µm. rmr—retractor muscle region, mm—medial mesentery, sf—septal filament, ct—ciliated tract