Fig. 8. Genetic interaction between sra-1, kette and wasp. (A-H) Morphology of microchaete on the thorax in different genetic backgrounds. Quantitative analyses are shown in I. (A) Wild-type flies are characterized by an ordered array of microchaete, which are normally thin, straight and have a pointed end. (B) Following expression of one copy of the UAS-Sra-1^Myr transgene in the scabrous pattern, shorter and split bristles develop (arrow). (C) The same phenotype is observed after expression of membrane tethered Kette protein (arrow). (D) Co-expression of both membrane-tethered Sra-1 and Kette leads to a synergistic increase of bristle defects. (E) Same genetic background as in B but lacking one copy of the kette gene. The bristle phenotype evoked by Sra-1^Myr expression is not affected. (F) Same genetic background as in B but lacking one copy of the wasp gene. The bristle phenotype evoked by Sra-1^Myr expression is suppressed. (G) Expression of a UAS-Sra-1C^Myr transgene in the scabrous pattern results in loss of bristles. (H) When flies co-express UAS-Sra-1C^Myr and UAS-Kette^Myr transgenes, the loss of bristle phenotype is suppressed. However, bristles are brushed, which corresponds to the Kette^Myr phenotype. (I) Quantitative analyses of the above-mentioned phenotypes. Threehundred microchaete were counted in each case.