An international team led by CIBIO-BIOPOLIS at the University of Porto has found that genes involved in melanin production control the organisation of the microscopic structures that create feather iridescence, the sheen that changes colour with the viewing angle.
The researchers analysed eight colour varieties of the Indian peafowl and identified eight genes linked to changes in iridescence. Small mutations alter the shape, composition or quantity of melanin granules, and that is enough to turn metallic blue-green into dull beige or grey plumage. In wild birds such as the emerald dove and the mallard, these genes were far more active in iridescent areas than in non-iridescent ones.
The study, with Soraia Barbosa as first author and Miguel Carneiro as principal investigator, made the cover of PNAS. It helps explain how small DNA changes produce the huge diversity of bird colours.
