Figure 6

Second quartet micromeres generate foregut and trunk ectoderm. (A-T) Z-stacks of merged, confocal images of late stage 6 larvae 5 days after labeling second quartet micromeres with DiI. The channels are DiI (red), phalloidin (green) and TO-PRO-3 (blue) except for (D), (H), (L) and (T), which are DiI and phalloidin, and (Q) and (S), which are DiI and TO-PRO-3. Panels labeled with an apostrophe (for example, B',D') are single-channel images of DiI that correspond to the multichannel images with the same letter (for example, B, D). A subset of panels are cropped, digitally magnified, z-stacks of confocal images through the foregut (B, F, J, N), prototroch (D, H, L), brain (P), forming ventral nerve cord (Q), body ectoderm (R) and dorsal body ectoderm just posterior to the prototroch (T). In (B, F, J, N) the foregut is outlined with a dashed line. The inset in (D') is an inverted, digitally magnified image of a single DiI-labeled prototroch cell with cilium (arrowhead). In (P) one brain lobe is outlined with a dashed line, and clusters of 2d descendants in the brain (arrow) are indicated. In (P, Q) 2d descendants in the circumesophageal connectives (arrowheads) are indicated. In (R') the boundary between mesoderm and endoderm is indicated with a dashed line. In (T) the arrow points to unlabeled ectodermal cells (arrow). The blastomere labeled with DiI is indicated to the left of each row and the view is indicated in the lower-left corner of each panel (dors = dorsal, vent = ventral, llat = left lateral, rlat = right lateral). Anterior is to the left in all ventral, dorsal and left lateral images, and to the right in all right lateral images. The position of the mouth is indicated with an asterisk. ec = ectoderm, en = endoderm, ms = mesoderm, pt = prototroch, tt = telotroch, vn = ventral nerve cord.