Fig. 3.

Regenerating mesenchymal cells express skeletogenic gene markers and appear to detach from the ACC epithelium. a Semi-thin sections of whole mount ISH for skeletal genes: Afi-c-lectin (embedded in resin), Afi-alx1 and Afi-msp130L (embedded in wax). Red arrows point at areas where gene expression (dark blue/purple staining) is present, as schematized on the right. Yellow, aboral coelomic cavity; blue, radial water canal; pink, radial nerve cord; CR, cross section; SAG, sagittal section. Crossed arrows further indicate the orientation of the section: A, aboral; O, oral; R, right; L, left; P, proximal; D, distal. Scale bars = 10 μm. b TEM micrographs of cells likely detaching from the ACC epithelium. (1’) and (2’) are details of (1) and (2), respectively. Yellow, ACC; pink, RNC. Scale bars = 2 μm