Fig. 6. Genetic mosaic analysis of Echinoid. (A,B) Mosaic analysis of ed^LH23 in third larval instar imaginal discs examined by confocal microscopy. (A) Immunohistological detection of Ase (green) and ß-galactosidase (red) in an ed^LH23 genetic clone in a wing disc. The ed^LH23 homozygous region is marked by the absence of ß-galactosidase and the clone border has been marked by a white line. The arrows indicate cell-autonomous specification of SOPs. The arrowhead labels a pair of adjacent SOPs; one mutant, one wild type. (A') The green channel (Ase). (B) Immunohistological detection of Ed (red) in an ed^LH23 mosaic leg disc. The ed^LH23 homozygous region is marked by the absence of nlsGFP (green), the remainder of the disc is either wild type or heterozygous for ed^LH23. The mutant cells express very little Ed; the wild-type cells at the clone border show a large drop in the amount of Ed on the region of membrane that touches the mutant cells of clone. (B') The red channel (Ed) from B.