Figure 11

Cell death in walking leg neuromere 1 of Pseudopallene sp. (late ES3 – late ES 4). Horizontal optical sections of tubulin- and PH3-labelled embryos with nuclear counterstain. Sections are at sub-apical to basal level. Dashed vertical lines mark the VMR. Dashed outlines indicate extensions of the hemi-neuromeres. Note increase of pycnotic bodies (arrows) in the VMR from late ES 3 (A) over ES 4 (B) to late ES 4 (C). To a lesser extent cell death occurs also within the developing hemi-neuromeres and at their lateral margins (B,C). Virtually no cell divisions are found in the basally displaced cells of the hemi-neuromeres, the mitoses labelled in (C) are positioned apically in the downwards bent lateral ectoderm of this specimen.