Multivariate heredity of melanin-based coloration,body mass and immunity |
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Authors: | S-Y Kim J A Fargallo P Vergara J Martínez-Padilla |
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Institution: | 1.Departamento de Ecoloxía e
Bioloxía Animal, Universidade de Vigo, Vigo, Spain;2.Departamento de Ecología Evolutiva,
Museo Nacional de Ciencias Naturales-CSIC, José Gutiérrez Abascal 2, Madrid, Spain;3.School of Biological Sciences, University of
Aberdeen, Aberdeen, UK |
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Abstract: | The genetic covariation among different traits may cause the appearance of correlated
response to selection on multivariate phenotypes. Genes responsible for the expression of
melanin-based color traits are also involved in other important physiological functions
such as immunity and metabolism by pleiotropy, suggesting the possibility of multivariate
evolution. However, little is known about the relationship between melanin coloration and
these functions at the additive genetic level in wild vertebrates. From a multivariate
perspective, we simultaneously explored inheritance and selection of melanin coloration,
body mass and phytohemagglutinin (PHA)-mediated immune response by using long-term data
over an 18-year period collected in a wild population of the common kestrel Falco
tinnunculus. Pedigree-based quantitative genetic analyses showed negative genetic
covariance between melanin-based coloration and body mass in male adults and positive
genetic covariance between body mass and PHA-mediated immune response in fledglings as
predicted by pleiotropic effects of melanocortin receptor activity. Multiple selection
analyses showed an increased fitness in male adults with intermediate phenotypic values
for melanin color and body mass. In male fledglings, there was evidence for a disruptive
selection on rump gray color, but a stabilizing selection on PHA-mediated immune response.
Our results provide an insight into the evolution of multivariate traits genetically
related with melanin-based coloration. The differences in multivariate inheritance and
selection between male and female kestrels might have resulted in sexual dimorphism in
size and color. When pleiotropic effects are present, coloration can evolve through a
complex pathway involving correlated response to selection on multivariate traits. |
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Keywords: | animal coloration animal model genetic correlation pleiotropy quantitative genetics selection |
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