Fig. 4. Synergistic activation of the DC5(8x) enhancer in vivo. (A) Cell culture co-transfection assays in Schneider 2 cells. Wild-type and mutant DC5 enhancers were tested for activation by exogenous Drosophila Pax6, Pax2 and Sox2 homologues. The structure of the reporter and effector plasmids is shown (A1). ß-gal activity of the reporter vector co-transfected with the empty effector vector was taken as 1 (column C). (B) Ectopic activation in Drosophila tissue. Wild-type DC5(8x) enhancer was tested for activation in the wing imaginal disc by ectopic expression of Drosophila Pax6, Pax2 and Sox2 homologues.