Fig. 6. The differentiated pattern elements arising from the O/P lineages following bilateral ablation of the Q lineage differ in H. robusta (Austin) (A-D) and H. robusta (Sacramento) (E-J). (A,E) The presumptive O and P lineages give rise to their normally distinct sets of pattern elements in H. robusta (Austin) (A), but give rise to nearly identical sets of O pattern elements in H. robusta (Sacramento) (E). In both laboratory populations, the presumptive O lineage (red) and the presumptive P lineage (green) are fluorescently labeled. (B,F) Superimposed images of presumptive o bandlet descendants (red), presumptive p bandlet descendants (green), and nuclear staining (blue) in the ventral nerve cord of H. robusta (Austin) (B) and H. robusta, Sacramento (F). (C,G) The presumptive O lineage gives rise to O pattern elements in both laboratory populations. (D,H) The presumptive P lineage gives rise to normal P pattern elements in H. robusta (Austin) (D), but to O pattern elements in H. robusta (Sacramento) (H). (I,J) Following Q lineage ablation in H. robusta (Sacramento), O pattern elements that are represented by single cells in normal embryos are present as duplicate cells. Rhodamine- and fluorescein-labeling of these duplicate pattern elements reflects their derivation from the two different ipsilateral O/P teloblasts. See Fig. 3 for labeling of pattern elements and orientation. Scale bar: 200 µm in A-E; 50 µm in B-D,F-H; 33 µm I,J.