Restriction of ectopic eye formation by Drosophila teashirt and tiptop to the developing antenna.

In Drosophila, the retinal determination network comprises a set of nuclear factors whose loss-of-function phenotypes often include the complete or near total elimination of the developing eye. These genes also share the ability of being able to induce ectopic eye formation when forcibly expressed in nonretinal tissues such as the antennae, legs, halteres, wings, and genitals. However, it appears that the ability to redirect and transform tissue fates is limited; not all tissues and cell populations can be forced into adopting an eye fate.