Coloured scanning electron micrograph (SEM) of a mutant Fruitfly (Drosophila melanogaster) head. Wildtype (i.e. normal) Fruitflies have two compound eyes (red) – one on either side of the head. Small bristles between the single lenses of the eye make sure it cannot be covered with dust or dirt particles. Genetically manipulated flies can either lack compound eyes completely, or have additional eyes on the antennae, legs and other body parts.
Fruitflies are widely used in genetic experiments, particularly in mutation experiments, because they reproduce rapidly and their genetic systems are well understood. This image visualizes how easily the results of the genetic modification can be observed in the Fruitfly which is one of the main reasons why it is still the most frequently used model organism in genetics despite more than 100 years of experimental research.
Sine oculis-1 (so1) variant which lacks the compound eyes completely. right: Eyeless variant with ectopically expressed compound eyes under dpp-promotor in all imaginal discs.