GEPHE SUMMARY Print
Entry Status
Published
GepheID
GP00002039
Main curator
Courtier
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
wild and domesticated canari
Trait State in Taxon B
canari - urucum breed - bright red bills and legs
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Common Name
common canary
Synonyms
Serinus canarius; common canary; canary; Serinus canaria (Linnaeus, 1758)
Rank
species
Lineage
Show more ... ; Tetrapoda; Amniota; Sauropsida; Sauria; Archelosauria; Archosauria; Dinosauria; Saurischia; Theropoda; Coelurosauria; Aves; Neognathae; Passeriformes; Passeroidea; Fringillidae; Carduelinae; Serinus
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Common Name
common canary
Synonyms
Serinus canarius; common canary; canary; Serinus canaria (Linnaeus, 1758)
Rank
species
Lineage
Show more ... ; Tetrapoda; Amniota; Sauropsida; Sauria; Archelosauria; Archosauria; Dinosauria; Saurischia; Theropoda; Coelurosauria; Aves; Neognathae; Passeriformes; Passeroidea; Fringillidae; Carduelinae; Serinus
NCBI Taxonomy ID
is Taxon B an Infraspecies?
Yes
Taxon B Description
urucum canari breed
GENOTYPIC CHANGE
Presumptive Null
Yes
Molecular Type
Aberration Type
SNP
SNP Coding Change
Nonsynonymous
Molecular Details of the Mutation
point mutation at nucleotide position 837,806 that is predicted to be a nonsynonymous mutation in the exon 9 of the BCO2 gene. This variant results in the substitution of a histidine for an arginine at residue 413 of the protein (R413H) . In silico analysis suggests that the R413H could cause structural distortion of the protein and lead to a possible loss of activity. In vitro assays with the urucum BCO2 variant show that the enzyme activity is lost.
Experimental Evidence
Taxon A Taxon B Position
Codon - - -
Amino-acid His Arg 413
Authors
Gazda MA; Toomey MB; Araújo PM; Lopes RJ; Afonso S; Myers CA; Serres K; Kiser PD; et al. ... show more
Abstract
Unlike wild and domestic canaries (Serinus canaria), or any of the three dozen species of finches in genus Serinus, the domestic urucum breed of canaries exhibits bright red bills and legs. This novel trait offers a unique opportunity to understand the mechanisms of bare-part coloration in birds. To identify the mutation producing the colorful phenotype, we resequenced the genome of urucum canaries and performed a range of analyses to search for genotype-to-phenotype associations across the genome. We identified a nonsynonymous mutation in the gene BCO2 (beta-carotene oxygenase 2, also known as BCDO2), an enzyme involved in the cleavage and breakdown of full-length carotenoids into short apocarotenoids. Protein structural models and in vitro functional assays indicate that the urucum mutation abrogates the carotenoid cleavage activity of BCO2. Consistent with the predicted loss of carotenoid cleavage activity, urucum canaries tended to have increased levels of full-length carotenoid pigments in bill tissue and reduced levels of carotenoid cleavage products (apocarotenoids) in retinal tissue compared to other breeds of canaries. We hypothesize that carotenoid-based bare-part coloration might be readily gained, modified, or lost through simple switches in the enzymatic activity or regulation of BCO2 and this gene may be an important mediator in the evolution of bare-part coloration among bird species.

© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Additional References
RELATED GEPHE
Related Genes
Related Haplotypes
No matches found.
EXTERNAL LINKS
COMMENTS
Allele-specific expression in the shared cellular environment of individuals heterozygous for the urucum and wild-type alleles show same expression levels of both alleles, suggesting that there is no cis-regulatory mutations in the urucum breed.
YOUR FEEDBACK is welcome!