Fig. 8. Functional replacement of Neur by D-mib. Shown are dorsal thoraces from adult flies (A-D) or 36-hour APF pupae (E-P) containing ubx-FLP-generated MARCM clones of cells that are simultaneously mutant for neur and express sca-Gal4 and relevant UAS-transgenes (please refer to the Materials and methods for details of the genetics). (A) Clones of the weak allele neur^A101 exhibit a bristle tufting phenotype (asterisk), wherein multiple sensory organs are present at individual positions. (B) The tufting phenotype of neur^A101 clones is completely rescued by expression of UAS-neur. (C) Clones of the stronger allele neur^IF65 are bald (asterisk), due to conversion of outer sensory cell fates into neurons. (D) The balding phenotype of neur^IF65 clones is rescued back to a mild-tufting phenotype (asterisk) by expression of UAS-D-mib. (E-G) neur^IF65 sensory clusters marked by GFP expression (due to MARCM activation of sca-Gal4>UAS-pon-GFP: E, asterisk) fail to express Su(H), a marker of socket cell fate (red, F,G); arrow in F indicates a Su(H)⁺ nucleus. (H-J) neur^IF65 sensory clusters with sensory specific expression of D-mib show rescue of Su(H) expression. Note that small clusters of Su(H)⁺ cells are usually seen, indicating a partial rescue of the strong neur^IF65 lateral inhibition defect. (K-P) X-Z confocal sections through individual neur mutant sensory clusters expressing GFP and stained for ELAV, a neuronal marker. (K,N) A single neuron and the two large cell bodies of the socket and shaft cells are present in wild type. (L,O) A large mass of neurons is found in a neur^IF65 sensory cluster, and large cell bodies indicative of outer cell fates are absent. (M,P) Rescue of the neur^IF65 neurogenic defect and socket/shaft differentiation by ectopic D-mib.