Butterflies have always been a favourite topic for researchers as the vibrant and colourful butterflies are known to have evolved from the rather dull and plain moth. For years scientists have been trying to find out the source of the colours and patterns on a butterfly’s wings.

Now, scientists have found that the patterns and colours on butterflies’ wings are the result of suites of genes. The new Crispr- Cas gene-editing technique facilitates the study of the function of each gene by deleting it and seeing what happens.

Two teams of biologists at the Cornell university used the technique to explore the roles of two master genes in the appearance of the butterflies’ wings.

One team led by Linlin Zhang and Robert D Reed found that the gene ‘optix’ had control of all colour of butterflies’ wing. When they deleted optix from the Gulf fritillary’s eggs, the resulting adult butterflies which normally bear a deep brown hue changed to a ghostly black and silver colour.

Another team led by Anyi Mazo-Vargas and Arnaud Martin of George Washington University proved that a gene called ‘WntA’ played a powerful role in the patterning of butterflies’ wings.

Optix and WntA are therefore called paintbrush genes as they can be used to design and colour the butterfles’ wings.