title: Genes located in a chromosomal inversion are correlated with territorial song in white-throated sparrows.
abstract: The genome of the white-throated sparrow (Zonotrichia albicollis) contains an inversion polymorphism on chromosome 2 that is linked to predictable variation in a suite of phenotypic traits including plumage color, aggression and parental behavior. Differences in gene expression between the two color morphs, which represent the two common inversion genotypes (ZAL2/ZAL2 and ZAL2/ZAL2(m) ), may therefore advance our understanding of the molecular underpinnings of these phenotypes. To identify genes that are differentially expressed between the two morphs and correlated with behavior, we quantified gene expression and terrirorial aggression, including song, in a population of free-living white-throated sparrows. We analyzed gene expression in two brain regions, the medial amygdala (MeA) and hypothalamus. Both regions are part of a 'social behavior network', which is rich in steroid hormone receptors and previously linked with territorial behavior. Using weighted gene co-expression network analyses, we identified modules of genes that were correlated with both morph and singing behavior. The majority of these genes were located within the inversion, showing the profound effect of the inversion on the expression of genes captured by the rearrangement. These modules were enriched with genes related to retinoic acid signaling and basic cellular functioning. In the MeA, the most prominent pathways were those related to steroid hormone receptor activity. Within these pathways, the only gene encoding such a receptor was ESR1 (estrogen receptor 1), a gene previously shown to predict song rate in this species. The set of candidate genes we identified may mediate the effects of a chromosomal inversion on territorial behavior.
authors.affiliation: Department of Psychology, Emory University, Atlanta, GA.
authors.forename: W M
authors.initials: WM
authors.lastname: Zinzow-Kramer
authors.affiliation: Department of Psychology, Emory University, Atlanta, GA.
authors.forename: B M
authors.initials: BM
authors.lastname: Horton
authors.affiliation: Department of Psychology, Emory University, Atlanta, GA.
authors.forename: C D
authors.initials: CD
authors.lastname: McKee
authors.affiliation: Department of Psychology, Emory University, Atlanta, GA.
authors.forename: J M
authors.initials: JM
authors.lastname: Michaud
authors.affiliation: Yerkes Nonhuman Primate Genomics Core, Emory University, Atlanta, GA.
authors.forename: G K
authors.initials: GK
authors.lastname: Tharp
authors.affiliation: NIH Intramural Sequencing Center, National Human Genome Research Institute, NIH, Rockville, MD.
authors.forename: J W
authors.initials: JW
authors.lastname: Thomas
authors.affiliation: Department of Biology, Indiana State University, Terre Haute, IN.|The Center for Genomic Advocacy, Indiana State University, Terre Haute, IN.
authors.forename: E M
authors.initials: EM
authors.lastname: Tuttle
authors.affiliation: School of Biology, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yi
authors.affiliation: Department of Psychology, Emory University, Atlanta, GA.
authors.forename: D L
authors.initials: DL
authors.lastname: Maney
mesh_terms: D000374:Aggression; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D007446:Chromosome Inversion; D047628:Estrogen Receptor alpha / Q000235:genetics; D005260:Female; D056726:Genetic Association Studies; D016678:Genome; D008297:Male; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012919:Social Behavior; D046370:Sparrows / Q000235:genetics*; D059467:Transcriptome; D014828:Vocalization, Animal / Q000502:physiology*
chemical_list: D047628:Estrogen Receptor alpha
keywords: Behavioral polymorphism; RNA-seq; WGCNA; estrogen receptor alpha; social behavior