Figure 7. reph loss-of-function suggests cell autonomous regulation of Eph expression.

A requirement for reph in optic lobe development was assessed by generating homozygous somatic reph^k8617A clones by the FLP, FRT method. Mutant clones were marked by loss of expression of an arm-lacZ reporter (anti-βgal, red in B, blue in C and D). Overall optic lobe architecture was revealed by anti-HRP staining (green color in all panels, shown alone in A′ and B′). A,A′,A″) A wild type specimen illustrating the normal distribution of Eph expression in the lamina. B,B′,B″) A specimen harboring a homozygous reph^k8617A clone (white or yellow outlines) along the ventral margin of the lamina displayed reduced Eph expression (anti-Eph, blue in B, shown alone in B″) and incomplete LF formation (red arrowhead in B′). To assess potential pleiotrophic effects of reph^k8617A on lamina development, reph^k8617A clones were stained for dachshund, a marker of lamina neurogenesis (anti-Dac, red color in C and D, shown alone in C″ and D″). C,C′,C″) A wild type specimen highlighting Dac expression in the lamina. D,D′,D″) In the specimen shown, a large reph^k8617A clone encompassed most of the ventral lamina (yellow outline) indicated by loss of lac-Z staining (blue). Dac expression was normal within the clone. Dorsal is up and ventral is down in all panels. Abbreviations: lamina (lam), lamina furrow (LF), lobula (lob). Yellow bars in A″–D″ indicate the position of the midline.