What is the name of the particular gene in a butterfly which triggers the formation of the eyespot on the butterfly's wing?

Eolena

The Distal-less gene. Source: http://www.sciencemag.org/cgi/content/abstract/265/5168/109 Quoted Text: articles Pattern formation and eyespot determination in butterfly wings SB Carroll, J Gates, DN Keys, SW Paddock, GE Panganiban, JE Selegue, and JA Williams Howard Hughes Medical Institute, Madison, WI. Butterfly wings display pattern elements of many types and colors. To identify the molecular processes underlying the generation of these patterns, several butterfly cognates of Drosophila appendage patterning genes have been cloned and their expression patterns have been analyzed. Butterfly wing patterns are organized by two spatial coordinate systems. One system specifies positional information with respect to the entire wing field and is conserved between fruit flies and butterflies. A second system, superimposed on the general system and involving several of the same genes, operates within each wing subdivision to elaborate discrete pattern elements. Eyespots, which form from discrete developmental organizers, are marked by Distal-less gene expression. These circular pattern elements appear to be generated by a process similar to, and perhaps evolved from, proximodistal pattern formation in insect appendages. Apr 02 07, 3:57 PM