Fig. 8. Development of a `lone' O/P lineage following ablation of the Q lineages in H. robusta (Austin). (A) In early stage 8, the blast cell clones in the `lone' o/p bandlet express the O-type cleavage pattern. The small o.p nuclei are marked with arrows. Orientation of this panel is the same as Fig. 2. (B,C) Differentiated pattern elements derived from a `lone' O/P lineage in stage 9 embryos. In some embryos the `lone' O/P lineage gives rise to O pattern elements in every segment (B); in other embryos it gives rise to a combination of O pattern elements in more anterior segments and P pattern elements in more posterior segments (C). See Fig. 3 for orientation. Scale bar: 30 µm.