Tropomyosin expression in Bugula neritina larvae. Expression apical (1), at the pallial epithelium (2), at the equator (3), along the ciliated cleft (4), in the abapical region (5). (A-C) Light micrographs of whole-mounted larvae. Larvae in posterior (A), lateral (B), and abapical view at the equator (C). (D) Light micrograph of semithin section of larva in lateral view showing the expression in coronal cells as well as cells underneath. (E, F) Schematics of BnTropomyosin expression. (E) Larva in posterior/median view, (F) Larva in lateral view. cc, ciliated cleft; co, coronal cells, eb, epidermal blastema; gl, gland cells of pyriform organ; mb, mesodermal blastema; n, neck; pe, pallial epithelium; r, roof; w, wall; yc, yolk inclusions. Scale bars (A) 100 μm, (D) 50 μm.