Development of eyes on a fruit fly leg from ectopic expression of the “eyeless” gene.
The Pax6 gene, known as eyeless in the fruit fly family Drosophilia, is typically considered the “master control” gene for eye development. The gene functions identically, if not highly similarly across animal species - in humans and rats, the amino acid sequences for the gene are 100% identical. More interestingly, the human/mouse version of the gene, while coding for a different sequence, functions normally in Drosophilia.
This gene also yields some unique ectopic results. As photographed in the above image, when the eyeless gene is inserted to a stretch of DNA coding for leg development, eyes develop on the leg of a Drosophilia fruit fly.