title: Genomics analysis of potassium channel genes in songbirds reveals molecular specializations of brain circuits for the maintenance and production of learned vocalizations.
abstract: BACKGROUND
  A fundamental question in molecular neurobiology is how genes that determine basic neuronal properties shape the functional organization of brain circuits underlying complex learned behaviors. Given the growing availability of complete vertebrate genomes, comparative genomics represents a promising approach to address this question. Here we used genomics and molecular approaches to study how ion channel genes influence the properties of the brain circuitry that regulates birdsong, a learned vocal behavior with important similarities to human speech acquisition. We focused on potassium (K-)Channels, which are major determinants of neuronal cell excitability.
  
  
  RESULTS
  We identified 107 K-Channel finch genes, including 6 novel genes common to non-mammalian vertebrate lineages. Twenty human genes are absent in songbirds, birds, or sauropsids, or unique to mammals, suggesting K-Channel properties may be lineage-specific. We also identified specific family members with insertions/deletions and/or high dN/dS ratios compared to chicken, a non-vocal learner. In situ hybridization revealed that while most K-Channel genes are broadly expressed in the brain, a subset is selectively expressed in song nuclei, representing molecular specializations of the vocal circuitry.
  
  
  CONCLUSIONS
  Together, these findings shed new light on genes that may regulate biophysical and excitable properties of the song circuitry, identify potential targets for the manipulation of the song system, and reveal genomic specializations that may relate to the emergence of vocal learning and associated brain areas in birds.
authors.forename: Peter V
authors.initials: PV
authors.lastname: Lovell
authors.forename: Julia B
authors.initials: JB
authors.lastname: Carleton
authors.forename: Claudio V
authors.initials: CV
authors.lastname: Mello
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000502:physiology*; D002645:Chickens / Q000235:genetics; D046369:Finches / Q000235:genetics*; D015870:Gene Expression; D006801:Humans; D054643:INDEL Mutation; D007858:Learning; D008297:Male; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000235:genetics*; D012641:Selection, Genetic; D016415:Sequence Alignment; D026801:Synteny; D014828:Vocalization, Animal
chemical_list: D015221:Potassium Channels