Data from: Candidate gene analysis suggests untapped genetic complexity in melanin-based pigmentation in birds

Studies on melanin-based color variation in a context of natural selection
have provided a wealth of information on the link between phenotypic and
genetic variation. Here, we evaluated associations between melanic plumage
patterns and genetic polymorphism in the Réunion grey white-eye (Zosterops
borbonicus), a species in which mutations on MC1R do not seem to play any
role in explaining melanic variation. This species exhibits five plumage
color variants that can be grouped into three color forms which occupy
discrete geographic regions in the lowlands of Réunion and a fourth form
which comprises two color morphs (grey and brown), occurs at high
elevation, and represents a true color polymorphism. We conducted a
comprehensive survey of sequence variation in 96 individuals at a series
of seven candidate genes other than MC1R that have been previously shown
to influence melanin-based color patterns in vertebrates, including genes
that have rarely been studied in a wild bird species before: POMC, Agouti,
TYR, TYRP1, DCT, Corin and SLC24A5. Of these seven genes, two (Corin and
TYRP1) displayed an interesting shift in allele frequencies between
lowland and highland forms and a departure from mutation-drift equilibrium
consistent with balancing selection in the polymorphic highland form only.
Sequence variation at Agouti, a gene frequently involved in melanin-based
pigmentation patterning, was not associated with color forms or morphs.
Thus, we suggest that functionally important changes in loci other than
those classically studied may beare involved in the color polymorphism
exhibited by the Réunion grey white-eye and possibly many other non-model
species.