Figure 7

Late-stage Buddenbrockia plumatellae worm from Plumatella sp. (A) Whole mount, light micrograph. (B) through (H) Confocal images. (B), (D) and (G) Maximum-intensity projections of whole three-dimensional image stacks. (C), (F) and (H) Optical median horizontal section. (E) Optical cross section. Details of proximal tip (B) and (C); middle-body region (D), (E) and (F); and distal tip (G) and (H). Scale bar as in (G). (I) Horizontal optical section through muscle block showing distribution of muscle cell nuclei. (J) Detail of (I), maximum-intensity projection of muscle block. (K) Horizontal optical section through row of connecting cells. (L) Horizontal section through distal tip of mature worm showing porelike opening (arrowhead). F-actin (green); nuclei (red); cc, connecting cell; dt, distal tip; ecm, extracellular matrix; ep, epidermis; mb, muscle block; mc, myocyte; mr, myocyte row; nu, nucleus; pt, proximal tip; sp, spore.