Researchers have modified butterfly genes to change the way their wings look.

Pigments and the fine structure of butterfly wing scales work together to generate a mosaic of colours and patterns that help the insect camouflage or attract mates.

But scientists have found it only takes a few pigment genes to modify both the colour and the morphology of wing scales.

Researchers used CRISPR/Cas9 to tweak wing colours of the squinting bush brown butterfly of East Africa (Bicyclus anynana), and found that it resulted in changes to the scales' surface structure and rigidity, as well as colour.

“Our research indicates that the colour and structure of wing scales are intimately related because pigment molecules also affect the structure of scales,” says senior author Antónia Monteiro, a biologist at the National University of Singapore's Faculty of Science.

“Some end products of the melanin pathway, which produces butterfly wing pigments, play a role in both scale pigmentation and scale morphology.

“Some butterflies can have vivid hues just by having simple thin films of chitin on their scales that interfere with incoming light to create shades known as structural colours without producing corresponding pigments.

“Light beams reflecting off the top and bottom surfaces of the chitin layer can interfere with each other and accentuate specific colours depending on the thickness of the film, so our results might be interesting in this context.”

She said that engineers may one day be able to copy this kind of structure and pigmentation.

“If we understand the developmental genetics of colour, biotech companies of the future might be able to generate vivid, brilliant colours via bioengineering, based on butterfly scales, instead of having to nano-manufacture them using metals, which is currently extremely difficult to do,” Dr Monteiro says.

“These chitin-based colours would be lasting, biodegradable, and environmentally friendly.”

The study is accessible here.