Fig. 4

House-producing cells in post-larval stages of Fritillaria. A Maximum intensity projection of the anterior trunk of fluorescence-stained specimens of F. borealis and F. haplostoma, showing the viscera and house-producing epithelium (dashed areas). The white arc outlines the dorsal projection of the anterior trunk over the esophagus. Optical sections (A’) with bright field illumination show, from the dorsal to the ventral side: a chamber of the house, the dorsal oikoplastic row, and the spiracle opening. B Optical sections of the anterior trunk of F. borealis. Left and bottom panels show orthogonal projections of the Z-stack. Yellow arrowheads indicate fields of house-producing cells, green arrowheads show cellulose fibrils secreted from the surface of the epithelium. C House-producing cells in the anterior trunk of F. haplostoma. Like F. borealis, cellulose-producing fields are located over and under the mouth (left and middle images), and in the dorsal projection over the esophagus (right image). D Cell organization (left image) and cellulose “mask” (middle image) in the lip organ in F. haplostoma. E High magnification of a dorsal oikoplastic row of cells in fluorescence-stained F. haplostoma and bright-field illumination showing the opaque organelles (E’). Cyan, DAPI; green, GFP-CBM; magenta, phalloidin-AF488; adf, anterior dorsal oikoplastic field; avf, anterior ventral oikoplastic field; br, brain; ce, cellulose fibrils; cf, ciliary funnel; ch, house chamber; dp, dorsal projection over the esophagus; dor, dorsal oikoplastic row of cells; en, endostyle; laf, lateral oikoplastic field; li, lip; lic, lip cell; oe, esophagus; pa, palps; pdf, posterior dorsal oikoplastic field; ph, pharynx; sp, spiracle; sy, statocyst; vgc, ventral giant cell. Scale bar, 20 microns