Fig. 7. Grh is required for maintaining but not initiating the late phase of AbdA expression in neuroblasts. (A) At 96 hours, a neuroblast in an abdominal H99 MARCM clone expresses Grh. (B,C) The abdominal region of a balanced sibling control (B) and grh³⁷⁰ hemizygous CNS (C) at 96 hours, showing that Mira-positive neuroblasts are normally absent by this stage but persist when Grh activity is removed. (D) At 72 hours, a wild-type neuroblast maintains AbdA expression but displays weak and punctate Mira labelling, suggestive of the early stages of apoptosis. (E) At 96 hours, a neuroblast and its last-born progeny in an abdominal H99 MARCM clone maintain AbdA expression. (F,G) At 63 hours, Mira-positive interphase (F) and H3p-positive M-phase (G) neuroblasts in grh³⁷⁰ hemizygotes express AbdA as normal. (H) At 96 hours, a Mira-positive neuroblast from a grh³⁷⁰ hemizygous CNS fails to maintain AbdA expression.