Genetic Mapping and Biochemical Basis of Yellow Feather Pigmentation in Budgerigars

Thomas F Cooke; Curt R Fischer; Ping Wu; Ting-Xin Jiang; Kathleen T Xie; James Kuo; Elizabeth Doctorov; Ashley Zehnder; Chaitan Khosla; Cheng-Ming Chuong; Carlos D Bustamante

doi:10.1016/j.cell.2017.08.016

Genetic Mapping and Biochemical Basis of Yellow Feather Pigmentation in Budgerigars

Cell. 2017 Oct 5;171(2):427-439.e21. doi: 10.1016/j.cell.2017.08.016.

Authors

Affiliations

¹ Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA.
² ChEM-H, Stanford University, Stanford, CA 94305, USA; Stanford Genome Technology Center, Stanford University, Stanford, CA 94305, USA.
³ Department of Pathology, University of Southern California, Los Angeles, CA 90033, USA.
⁴ Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA.
⁵ Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA.
⁶ Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA 94305, USA.
⁷ ChEM-H, Stanford University, Stanford, CA 94305, USA; Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA; Departments of Chemistry, Stanford University, Stanford, CA 94305, USA.
⁸ Department of Pathology, University of Southern California, Los Angeles, CA 90033, USA; Integrative Stem Cell Center, China Medical University, Taichung 404, Taiwan; Center for the Integrative and Evolutionary Galliformes Genomics, National Chung Hsing University, Taichung 402, Taiwan.
⁹ Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA 94305, USA. Electronic address: [email protected].

Abstract

Parrot feathers contain red, orange, and yellow polyene pigments called psittacofulvins. Budgerigars are parrots that have been extensively bred for plumage traits during the last century, but the underlying genes are unknown. Here we use genome-wide association mapping and gene-expression analysis to map the Mendelian blue locus, which abolishes yellow pigmentation in the budgerigar. We find that the blue trait maps to a single amino acid substitution (R644W) in an uncharacterized polyketide synthase (MuPKS). When we expressed MuPKS heterologously in yeast, yellow pigments accumulated. Mass spectrometry confirmed that these yellow pigments match those found in feathers. The R644W substitution abolished MuPKS activity. Furthermore, gene-expression data from feathers of different bird species suggest that parrots acquired their colors through regulatory changes that drive high expression of MuPKS in feather epithelia. Our data also help formulate biochemical models that may explain natural color variation in parrots. VIDEO ABSTRACT.

Keywords: Hi-C; Parrot; artificial selection; budgerigar; feather color; mendelian; pigmentation; polyene; polyketide synthase; psittacofulvin; specialized metabolism; trait mapping.

MeSH terms

Amino Acid Sequence
Animals
Avian Proteins / genetics*
Avian Proteins / metabolism
Feathers / anatomy & histology
Feathers / chemistry
Feathers / physiology*
Gene Expression
Genome
Genome-Wide Association Study
Melopsittacus / anatomy & histology
Melopsittacus / genetics*
Melopsittacus / physiology
Pigmentation
Pigments, Biological / biosynthesis*
Polyenes / metabolism*
Polyketide Synthases / genetics*
Polyketide Synthases / metabolism
Polymorphism, Single Nucleotide
Regeneration
Sequence Alignment

Substances

Avian Proteins
Pigments, Biological
Polyenes
Polyketide Synthases

Abstract

MeSH terms

Substances

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