group of cells that give rise to group of cells that give rise to (red shows cells expressing ey gene) an adult eye an adult leg Drosophila larva Drosophila adult eye structure formed on leg normal fly fly with ey gene artificially expressed in leg precursor cells (A) (B) 眼分化关键调控基因异位表达使果蝇其他部位分化为眼。 眼分化关键调控基因异位表达使果蝇其他部位分化为眼