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Fig. 2 | EvoDevo

Fig. 2

From: Genomic analysis of the tryptome reveals molecular mechanisms of gland cell evolution

Fig. 2

Fine structure of the pharyngeal ectoderm and ectodermal mesenteries. a Diagrammatic representation of regions where thin sections were examined through the pharynx (I) and at two positions in the mesenteries (II, III). Top—sagittal view of a polyp, middle—cross section at position I, bottom—partial cross sections at positions II (left) and III (right). bf TEMs of a region of the pharyngeal ectoderm (I) indicated by the box in A. b Two zymogen gland cells are false colored for emphasis. c Cross sections of cilia emerging from the pharyngeal ectoderm into the pharyngeal canal. d Mucus-secreting cell, false colored. e Ten zymogen-type gland cells and two cnidocytes. f Electron-dense vesicles (black arrowheads in e, f, n, o) in the apex of non-glandular ectodermal cells. g SEM of a mesentery from position II in panel a. The ectodermal (EC) portion has two parts: the ciliated tract (black line) and cnidoglandular tract (white line); the endodermal (EN) portion is false colored. hj TEMs of the cnidoglandular tract of a mesentery from position II in A. Sections correspond to the position of the dotted line in g. i Two zymogen-type gland cells are false colored. J Some zymogen vesicles have heterogeneous contents (black arrow). k 3D reconstruction of a confocal z-stack through the ciliated tract of a mesentery from position II in A; pink—nuclei of proliferating cells (EdU), blue—quiescent nuclei (DAPI). l TEM section through the ciliated tract at the position indicated by the dotted line in K and by the box in H. Nuclei corresponding to panel K are false colored pink. mo TEMs of a mesentery lacking a ciliated tract, position III in panel A. m Endoderm is false colored. n Zymogen gland cells are false colored. o Ciliary rootlet (black arrow) in the apex of a zymogen gland cell. Scale bars: white line—10 um, black line—500 nm, gray line (panels g, k)—50 um. Panels b and h are composites of multiple micrographs. White arrowheads indicate cnidocytes throughout

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