title: Differential androgen receptor expression and DNA methylation state in striatum song nucleus Area X between wild and domesticated songbird strains.
abstract: In songbirds, a specialized neural system, the song system, is responsible for acquisition and expression of species-specific vocal patterns. We report evidence for differential gene expression between wild and domesticated strains having different learned vocal phenotypes. A domesticated strain of the wild white-rumped munia, the Bengalese finch, has a distinct song pattern with a more complicated syntax than the wild strain. We identified differential androgen receptor (AR) expression in basal ganglia nucleus Area X GABAergic neurons between the two strains, and within different domesticated populations. Differences in AR expression were correlated with the mean coefficient of variation of the inter-syllable duration in the two strains. Differential AR expression in Area X was observed before the initiation of singing, suggesting that inherited and/or early developmental mechanisms may affect expression within and between strains. However, there were no distinct differences in regions upstream of the AR start codon among all the birds in the study. In contrast, an epigenetic modification, DNA methylation state in regions upstream of AR in Area X, was observed to differ between strains and within domesticated populations. These results provide insight into the molecular basis of behavioral evolution through the regulation of hormone-related genes and demonstrate the potential association between epigenetic modifications and behavioral phenotype regulation.
authors.affiliation: Department of Biological Sciences, Hokkaido University, Sapporo, Hokkaido, Japan. wada@sci.hokudai.ac.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Wada
authors.forename: Shin
authors.initials: S
authors.lastname: Hayase
authors.forename: Raimu
authors.initials: R
authors.lastname: Imai
authors.forename: Chihiro
authors.initials: C
authors.lastname: Mori
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Wan-Chun
authors.initials: WC
authors.lastname: Liu
authors.forename: Miki
authors.initials: M
authors.lastname: Takahasi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Okanoya
mesh_terms: D000818:Animals; D000829:Animals, Domestic; D001479:Basal Ganglia / Q000378:metabolism*; D019175:DNA Methylation; D046369:Finches; D059330:GABAergic Neurons / Q000378:metabolism; D049810:Genetic Speciation; D008297:Male; D011944:Receptors, Androgen / Q000235:genetics* / Q000378:metabolism; D014828:Vocalization, Animal / Q000502:physiology*
chemical_list: D011944:Receptors, Androgen
keywords: Bengalese finch; domestication; epigenetics; inter-syllable duration