GEPHE SUMMARY Print
Gephebase Gene
Entry Status
Published
GepheID
GP00001355
Main curator
Prigent
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Arctic skua ; nonmelanic (pale)
Trait State in Taxon B
Arctic skua ; melanic (intermediate and dark)
Ancestral State
Unknown
Taxonomic Status
Taxon A
Common Name
-
Synonyms
-
Rank
species
Lineage
Show more ... notetrapodomorpha; Tetrapoda; Amniota; Sauropsida; Sauria; Archelosauria; Archosauria; Dinosauria; Saurischia; Theropoda; Coelurosauria; Aves; Neognathae; Charadriiformes; Stercorariidae; Stercorarius
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Common Name
-
Synonyms
-
Rank
species
Lineage
Show more ... notetrapodomorpha; Tetrapoda; Amniota; Sauropsida; Sauria; Archelosauria; Archosauria; Dinosauria; Saurischia; Theropoda; Coelurosauria; Aves; Neognathae; Charadriiformes; Stercorariidae; Stercorarius
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Presumptive Null
No
Molecular Type
Aberration Type
SNP
SNP Coding Change
Nonsynonymous
Molecular Details of the Mutation
Melanic and nonmelanic haplotypes in the Arctic skua are defined by three amino acid changes: nonmelanic: His8-Glu12-Arg230; melanic: Arg8-Lys12-His230. The effect of each single amino acid change has not been tested
Experimental Evidence
Taxon A Taxon B Position
Codon - - -
Amino-acid - - -
Authors
Janssen K; Mundy NI
Abstract
The Arctic skua (Stercorarius parasiticus) is a classic example of an avian plumage polymorphism, with variation in melanin-based ventral plumage coloration defining pale, intermediate and dark morphs in adults of both sexes. However, despite several decades of field research, there is an incomplete understanding of how the polymorphism in ventral plumage colour is maintained and the selective forces involved. Here, we investigate selection on a locus (MC1R) that is strongly associated with plumage colour variation in Arctic skuas using patterns of nucleotide variation and comparison to neutral loci (nuclear introns and mtDNA). We find that three linked nonsynonymous mutations in MC1R, including the single mutation described previously, are associated with plumage colour in the Arctic skua. The position of nonsynonymous mutations on a MC1R haplotype network implies that divergent selection drove the initial evolution of the colour morphs. Comparisons of F(ST)s of MC1R vs. nuclear introns among five skua populations differing in proportion of dark morphs along an approximate north-south cline reveal a signature of divergent selection on MC1R. In contrast, we find limited evidence for balancing selection on MC1R within populations, although the power is low. Our results provide strong evidence for both past and ongoing selection on MC1R, and, by implication, plumage colour in Arctic skuas. The results suggest that a fruitful avenue for future ecological studies will be analysis of selection on morphs in colonies at the extremes along the morph ratio cline.

© 2013 John Wiley & Sons Ltd.
Additional References
RELATED GEPHE
Related Genes
No matches found.
Related Haplotypes
1
COMMENTS
@SeveralCandidateMutations @BalancingSelection - Heterozygous are intermediate (melanic)
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