title: Genotype × environment interaction is weaker in genitalia than in mating signals and body traits in Enchenopa treehoppers (Hemiptera: Membracidae).
abstract: Theory predicts that selection acting across environments should erode genetic variation in reaction norms; i.e., selection should weaken genotype × environment interaction (G × E). In spite of this expectation, G × E is often detected in fitness-related traits. It thus appears that G × E is at least sometimes sustained under selection, a possibility that highlights the need for theory that can account for variation in the presence and strength of G × E. We tested the hypothesis that trait differences in developmental architecture contribute to variation in the expression of G × E. Specifically, we assessed the influence of canalization (robustness to genetic or environmental perturbations) and condition-dependence (association between trait expression and prior resource acquisition or vital cellular processes). We compared G × E across three trait types expected to differ in canalization and condition-dependence: mating signals, body size-related traits, and genitalia. Because genitalia are expected to show the least condition-dependence and the most canalization, they should express weaker G × E than the other trait types. Our study species was a member of the Enchenopa binotata species complex of treehoppers. We found significant G × E in most traits; G × E was strongest in signals and body traits, and weakest in genitalia. These results support the hypothesis that trait differences in developmental architecture (canalization and condition-dependence) contribute to variation in the expression of G × E. We discuss implications for the dynamics of sexual selection on different trait types.
authors.affiliation: Behavioral and Molecular Ecology Group, Department of Biological Sciences, University of Wisconsin-Milwaukee, Lapham Hall, 3209 N. Maryland Ave., Milwaukee, WI 53201, USA. rafa@uwm.edu
authors.forename: Rafael L
authors.initials: RL
authors.lastname: Rodríguez
authors.forename: Nooria
authors.initials: N
authors.lastname: Al-Wathiqui
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D005075:Biological Evolution; D049628:Body Size; D004777:Environment; D059647:Gene-Environment Interaction; D014644:Genetic Variation / Q000235:genetics*; D005835:Genitalia; D005838:Genotype; D006430:Hemiptera / Q000033:anatomy & histology / Q000235:genetics / Q000502:physiology*; D016014:Linear Models; D008297:Male; D052586:Mating Preference, Animal / Q000502:physiology*; D012098:Reproduction; D027821:Rutaceae / Q000502:physiology; D012641:Selection, Genetic / Q000502:physiology*