title: Neural FoxP2 and FoxP1 expression in the budgerigar, an avian species with adult vocal learning.
abstract: Vocal learning underlies acquisition of both language in humans and vocal signals in some avian taxa. These bird groups and humans exhibit convergent developmental phases and associated brain pathways for vocal communication. The transcription factor FoxP2 plays critical roles in vocal learning in humans and songbirds. Another member of the forkhead box gene family, FoxP1 also shows high expression in brain areas involved in vocal learning and production. Here, we investigate FoxP2 and FoxP1 mRNA and protein in adult male budgerigars (Melopsittacus undulatus), a parrot species that exhibits vocal learning as both juveniles and adults. To examine these molecules in adult vocal learners, we compared their expression patterns in the budgerigar striatal nucleus involved in vocal learning, magnocellular nucleus of the medial striatum (MMSt), across birds with different vocal states, such as vocalizing to a female (directed), vocalizing alone (undirected), and non-vocalizing. We found that both FoxP2 mRNA and protein expressions were consistently lower in MMSt than in the adjacent striatum regardless of the vocal states, whereas previous work has shown that songbirds exhibit down-regulation in the homologous region, Area X, only after singing alone. In contrast, FoxP1 levels were high in MMSt compared to the adjacent striatum in all groups. Taken together these results strengthen the general hypothesis that FoxP2 and FoxP1 have specialized expression in vocal nuclei across a range of taxa, and suggest that the adult vocal plasticity seen in budgerigars may be a product of persistent down-regulation of FoxP2 in MMSt.
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces, NM 88003, United States. Electronic address: harae@janelia.hhmi.org.
authors.forename: Erina
authors.initials: E
authors.lastname: Hara
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces, NM 88003, United States.
authors.forename: Jemima M
authors.initials: JM
authors.lastname: Perez
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces, NM 88003, United States.
authors.forename: Osceola
authors.initials: O
authors.lastname: Whitney
authors.affiliation: Interdepartment Program of Molecular, Cellular, and Integrative Physiology, UCLA, Los Angeles, CA 90095, United States.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Interdepartment Program of Molecular, Cellular, and Integrative Physiology, UCLA, Los Angeles, CA 90095, United States; Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA 90095, United States.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: White
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces, NM 88003, United States.
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Wright
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000378:metabolism*; D003342:Corpus Striatum / Q000502:physiology*; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007858:Learning / Q000502:physiology; D008297:Male; D046408:Melopsittacus / Q000378:metabolism*; D018613:Microscopy, Confocal; D009474:Neurons / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D012726:Sexual Behavior, Animal / Q000502:physiology; D014828:Vocalization, Animal / Q000502:physiology*
chemical_list: D030161:Avian Proteins; D051858:Forkhead Transcription Factors; D012333:RNA, Messenger
keywords: Budgerigar; FoxP1, FoxP2; Neural gene expression; Open-ended vocal learning; Vocal behavior