title: Color phenotypes are under similar genetic control in two distantly related species of Timema stick insect.
abstract: Ecology and genetics are both of general interest to evolutionary biologists as they can influence the phenotypic and genetic response to selection. The stick insects Timema podura and Timema cristinae exhibit a green/melanistic body color polymorphism that is subject to different ecologically based selective regimes in the two species. Here, we describe aspects of the genetics of this color polymorphism in T. podura, and compare this to previous results in T. cristinae. We first show that similar color phenotypes of the two species cluster in phenotypic space. We then use genome-wide association mapping to show that in both species, color is controlled by few loci, dominance relationships between color alleles are the same, and SNPs associated with color phenotypes colocalize to the same linkage group. Regions within this linkage group that harbor genetic variants associated with color exhibit elevated linkage disequilibrium relative to genome wide expectations, but more strongly so in T. cristinae. We use these results to discuss predictions regarding how the genetics of color could influence levels of phenotypic and genetic variation that segregate within and between populations of T. podura and T. cristinae, drawing parallels with other organisms.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom. aacomeault@gmail.com.|Department of Biology, University of North Carolina, Chapel Hill, North Carolina, 27516. aacomeault@gmail.com.
authors.forename: Aaron A
authors.initials: AA
authors.lastname: Comeault
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom.
authors.forename: Clarissa F
authors.initials: CF
authors.lastname: Carvalho
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom.|Eawag, Department of Aquatic Ecology, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
authors.forename: Stuart
authors.initials: S
authors.lastname: Dennis
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom.
authors.forename: Víctor
authors.initials: V
authors.lastname: Soria-Carrasco
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom.
authors.forename: Patrik
authors.initials: P
authors.lastname: Nosil
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003116:Color; D055106:Genome-Wide Association Study; D007313:Insecta / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D010858:Pigmentation; D011110:Polymorphism, Genetic
keywords: Convergence; crypsis; genome-wide association mapping; natural selection; polymorphism