title: Differential FoxP2 and FoxP1 expression in a vocal learning nucleus of the developing budgerigar.
abstract: The forkhead domain FOXP2 and FOXP1 transcription factors are implicated in several cognitive disorders with language deficits, notably autism, and thus play a central role in learned vocal motor behavior in humans. Although a similar role for FoxP2 and FoxP1 is proposed for other vertebrate species, including songbirds, the neurodevelopmental expression of these genes are unknown in a species with lifelong vocal learning abilities. Like humans, budgerigars (Melopsittacus undulatus) learn new vocalizations throughout their entire lifetime. Like songbirds, budgerigars have distinct brain nuclei for vocal learning, which include the magnocellular nucleus of the medial striatum (MMSt), a basal ganglia region that is considered developmentally and functionally analogous to Area X in songbirds. Here, we used in situ hybridization and immunohistochemistry to investigate FoxP2 and FoxP1 expression in the MMSt of juvenile and adult budgerigars. We found FoxP2 mRNA and protein expression levels in the MMSt that were lower than the surrounding striatum throughout development and adulthood. In contrast, FoxP1 mRNA and protein had an elevated MMSt/striatum expression ratio as birds matured, regardless of their sex. These results show that life-long vocal plasticity in budgerigars is associated with persistent low-level FoxP2 expression in the budgerigar MMSt, and suggests the possibility that FoxP1 plays an organizational role in the neurodevelopment of vocal motor circuitry. Thus, developmental regulation of the FoxP2 and FoxP1 genes in the basal ganglia appears essential for vocal mimicry in a range of species that possess this relatively rare trait.
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces, New Mexico, 88003.
authors.forename: Osceola
authors.initials: O
authors.lastname: Whitney
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces, New Mexico, 88003.
authors.forename: Tawni
authors.initials: T
authors.lastname: Voyles
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces, New Mexico, 88003.
authors.forename: Erina
authors.initials: E
authors.lastname: Hara
authors.affiliation: Interdepartmental Program of Molecular, Cellular, and Integrative Physiology, UCLA, Los Angeles, California, 90095.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Interdepartmental Program of Molecular, Cellular, and Integrative Physiology, UCLA, Los Angeles, California, 90095.|Department of Integrative Biology and Physiology, UCLA, Los Angeles, California, 90095.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: White
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces, New Mexico, 88003.
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Wright
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000378:metabolism*; D001479:Basal Ganglia / Q000254:growth & development* / Q000378:metabolism*; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007858:Learning / Q000502:physiology; D008297:Male; D046408:Melopsittacus / Q000254:growth & development* / Q000378:metabolism*; D018613:Microscopy, Confocal; D012333:RNA, Messenger / Q000378:metabolism; D014828:Vocalization, Animal / Q000502:physiology
chemical_list: D030161:Avian Proteins; D051858:Forkhead Transcription Factors; D012333:RNA, Messenger
keywords: FoxP1; FoxP2; basal ganglia; budgerigar; gene expression; vocal learning