Fig. 5

Early embryonic exposure to SB431542 affects axes formation in larvae. Each column contains images from a single L2 larva. The first row shows DIC micrographs. Fluorescent images are merged confocal stacks. b, g, l, q, v depict labeling for nuclei with Hoechst, c, d, h, i, m, n, r, s, w, x show actin filaments with phalloidin, and e, j, o, t, y depict neurons with anti-FMRFamide. Stacks of confocal micrographs of actin labeling are displayed at two different depths in the body to show both muscles and gut cavity organization. a–e are control larvae exposed to 0.2% DMSO during the interval between the 4 cell stage and early gastrula. f–y are larvae resulting from exposure to 20 μM SB431542. f–j are of a larva resulting from exposure during the interval between the 4 and 32 cell stage. k–o are of a larva resulting from exposure during the interval between the 16 and 32 cell stage. p–t are of a larva resulting from exposure during the interval between the 32 cell stage and late cleavage stage embryo. u–y are of a larva resulting from exposure during the interval between the late cleavage and early gastrula stage. Anterior is to the left in all panels. al: abnormal lumen; at: apical tuft attachment point; black arrows: cilia; cc: circumesophageal connective; cbr: cerebral commissure; dor: dorsal; hg: hindgut; mc, main connective; mg: midgut; sc: subesophageal commissure; st: stomodeum; white arrowheads: dorsal longitudinal muscle fibers; white arrows: disorganized muscle fibers; yellow arrows, disorganized neuronal processes