Parrots produce stunning plumage colors through unique pigments called psittacofulvins. However, the mechanism underlying their ability to generate a spectrum of vibrant yellows, reds, and greens remains enigmatic. We uncover a unifying chemical basis for a wide range of parrot plumage colors, which result from the selective deposition of red aldehyde- and yellow carboxyl-containing psittacofulvin molecules in developing feathers. Through genetic mapping, biochemical assays, and single-cell genomics, we identified a critical player in this process, the aldehyde dehydrogenase ALDH3A2, which oxidizes aldehyde psittacofulvins into carboxyl forms in late-differentiating keratinocytes during feather development. The simplicity of the underlying molecular mechanism, in which a single enzyme influences the balance of red and yellow pigments, offers an explanation for the exceptional evolutionary lability of parrot coloration.

BIOPOLIS Program in Genomics Biodiversity and Land Planning CIBIO Vairão Portugal

cE3c Center for Ecology Evolution and Environmental Change and CHANGE Departamento de Biologia Animal Faculdade de Ciências Universidade de Lisboa Lisboa Portugal

CIBIO Centro de Investigação em Biodiversidade e Recursos Genéticos InBIO Laboratório Associado Universidade do Porto Vairão Portugal

Departamento de Biologia Faculdade de Ciências da Universidade do Porto Porto Portugal

Department of Food Science Faculty of Agrobiology Food and Natural Resources Czech University of Life Sciences Prague Prague Czech Republic

Department of Genetics Washington University School of Medicine St Louis MO USA

Department of Life Sciences Ben Gurion University of the Negev Beer Sheva 84105 Israel

Department of Pathology and Immunology Washington University School of Medicine St Louis MO USA

Department of Philosophy and History of Science Faculty of Science Charles University Prague Czech Republic

Department of Recent Vertebrates Royal Belgian Institute of Natural Sciences Brussels Belgium

Edison Family Center for Systems Biology and Genome Sciences Washington University School of Medicine St Louis MO USA

Evolution and Optics of Nanostructures Group Biology Department Ghent University Ghent Belgium

Institute of Physics Faculty of Mathematics and Physics Charles University Prague Czech Republic

MHNC UP Natural History and Science Museum of the University of Porto Porto Portugal

School of Biological Sciences The University of Hong Kong Hong Kong

University of Coimbra MARE Marine and Environmental Sciences Centre Department of Life Sciences Coimbra Portugal

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The Role of Two Tyrosinase-Like Glycoenzymes in Defining the Final Hue of Parrot Plumage

Multiple mutations in polyketide synthase led to disruption of Psittacofulvin production across diverse parrot species