Pattern formation

Pattern formation

The colorful patterns on many butterfly wings tell potential predators that they are toxic. Hence, the genetic basis of wing pattern formation can illuminate both the evolution of butterflies as well as their developmental biology. The color of butterfly wings is derived from tiny structures called scales, each of which have their own pigments. In Heliconius butterflies, there are three types of scales: yellow/white, black, and red/orange/brown scales. Some mechanism of wing pattern formation are now being solved using genetic techniques. For instance, a gene called cortex determines the color of scales: deleting cortex turned black and red scales yellow. Mutations, e.g. transposon insertions of the non-coding DNA around the cortex gene can turn a black-winged butterfly into a butterfly with a yellow wing band.^[57]