title: Genetic Correlates of Individual Differences in Sleep Behavior of Free-Living Great Tits (Parus major).
abstract: Within populations, free-living birds display considerable variation in observable sleep behaviors, reflecting dynamic interactions between individuals and their environment. Genes are expected to contribute to repeatable between-individual differences in sleep behaviors, which may be associated with individual fitness. We identified and genotyped polymorphisms in nine candidate genes for sleep, and measured five repeatable sleep behaviors in free-living great tits (Parus major), partly replicating a previous study in blue tits (Cyanistes caeruleus). Microsatellites in the CLOCK and NPAS2 clock genes exhibited an association with sleep duration relative to night length, and morning latency to exit the nest box, respectively. Furthermore, microsatellites in the NPSR1 and PCSK2 genes associated with relative sleep duration and proportion of time spent awake at night, respectively. Given the detection rate of associations in the same models run with random markers instead of candidate genes, we expected two associations to arise by chance. The detection of four associations between candidate genes and sleep, however, suggests that clock genes, a clock-related gene, or a gene involved in the melanocortin system, could play key roles in maintaining phenotypic variation in sleep behavior in avian populations. Knowledge of the genetic architecture underlying sleep behavior in the wild is important because it will enable ecologists to assess the evolution of sleep in response to selection.
authors.affiliation: Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen, Germany efstuber@gmail.com.
authors.forename: Erica F
authors.initials: EF
authors.lastname: Stuber
authors.affiliation: Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Baumgartner
authors.affiliation: Evolutionary Ecology of Variation Research Group, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany Department of Biology II, Behavioural Ecology, Ludwig-Maximilians University of Munich, 82152 Germany.
authors.forename: Niels J
authors.initials: NJ
authors.lastname: Dingemanse
authors.affiliation: Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen, Germany.
authors.forename: Bart
authors.initials: B
authors.lastname: Kempenaers
authors.affiliation: Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen, Germany.
authors.forename: Jakob C
authors.initials: JC
authors.lastname: Mueller
mesh_terms: D000483:Alleles; D000818:Animals; D001522:Behavior, Animal; D002940:Circadian Rhythm / Q000235:genetics; D005787:Gene Frequency; D056726:Genetic Association Studies; D005828:Genetics, Population; D005838:Genotype; D018895:Microsatellite Repeats; D046109:Passeriformes / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D012890:Sleep / Q000235:genetics*
keywords: candidate gene; circadian rhythm; genotype-phenotype association; repeatability; sleep