Deleting a common gene in a breed of butterflies can broadly change their wing patterns, according to a study published recently in the U.S. scientific magazine Proceedings of the National Academy of Sciences.
Arnaud Martin, an evolutionary geneticist at George Washington University and one of the authors of the study, said they used butterfly wing patterns as a proxy to understand fundamental rules about the function of genes.
Butterfly wings vary in color and shape and have different functions. Some butterflies have brightly colored wings to warn predators that they are poisonous. Some have dull camouflage wings, enabling them to pass off as leaves or barks.
The scientists chose butterfly wings for genetic tests for two reasons. First, butterflies and moths have nearly 200,000 species, providing an adequate research source. Second, genetic changes can be discerned in wing patterns.
Martin and his colleagues used CRISPR, a bacterial system that has been likened to cellular cut-and-paste, to delete a gene called WntA in a broad breed of butterflies, The Washington Post reported Tuesday.
The small modification led to big changes. For example, in Heliconius butterflies, a species with dramatic colors, a large red spill appeared on the wings of the mutant ones.
Other noted changes included color splotches and different tints along the edge of the wings.
"It's extraordinary that it works so broadly," said Owen McMillan, a staff scientist at the Smithsonian Tropical Research Institute and a co-author of the study.
The researchers knew WntA is important for wing patterns. However, they were surprised that its removal could lead to changes in so many different forms.
The study highlights the flexibility of the evolution regulation. Carolina Concha, a biogenomics researcher at the Smithsonian and another author of the study, called it "extraordinary".