Fig. 3. Additional apoptotic lineages similar to the vmd1a lineage in other embryonic regions. (A-D') Cut-positive md neurons and es organs in the dorsal region of segments A1-A7 (A,B) and in the ventral region of segment A8 (C,D) of wild-type (A,C) and Df(1)H99 (B,D) embryos stained for Cut (red), Elav (blue) and Pros (green). The schematic representations of the Cut-positive md neurons and es organs (A',B',C',D') are as in Fig. 2. Two or three ectopic es organs are observed in the dorsal region of segments A1-A7, as well as five ectopic es organs in the ventral region of segment A8. Arrowheads indicate the ectopic socket and shaft cells. Cells shown into brackets in A',B' are present in 58% of the segments of wild-type embryos (A'; n=33) and in 90% of the segments of Df(1)H99 embryos (B'; n=20). Ectopic cells in B' and D' have a bold outline. (E) Ventral region of segments A7-A8 of a wild-type stage 12 embryo stained for Cut (red) and the sensory organ marker Senseless (Sens; blue (Nolo et al., 2000)). (E') Schematic representation of the Cut-positive and Sens-positive sensory organ precursor cells (yellow) and of the chordotonal (ch) organ precursor cells (blue) which are Cut-negative and Sens-positive. At this stage, six pIIa-pIIb cell clusters are seen in the ventral region of segment A7. In the ventral region of segment A8, five pIIa-pIIb cell clusters are observed at positions corresponding to the vmd1a, vp1, vp2, vp4 and vp4a positions in segment A7.