Some of these effects are probably caused by oestrogen and/or testosterone synthesized within the brain itself rather than just in the gonads 14. Sex steroid hormones also contribute to songbird neural plasticity, in part by influencing the survival of new neurons 13. Analysis of the underlying cellular mechanisms of plasticity led to the unexpected discovery of neurogenesis in adult songbirds and life-long replacement of neurons 12. In the zebra finch, these nuclei develop more fully in the male than in the female (who does not sing), and they change markedly in size and organization during the juvenile period when the male learns to sing 11.
Neurophysiological studies in these nuclei during singing have yielded some of the most illuminating examples of how vocalizations are encoded in the motor system of a vertebrate brain 9, 10.
SONGBIRD SONG APRIL SEATTLE SERIES
These results indicate an active involvement of the genome in neural processes underlying vocal communication and identify potential genetic substrates for the evolution and regulation of this behaviour.Īs in all songbirds, singing in the zebra finch is under the control of a discrete neural circuit that includes several dedicated centres in the forebrain termed the ‘song control nuclei’ (for an extensive series of reviews see ref. We also show evidence for rapid molecular evolution in the songbird lineage of genes that are regulated during song experience. We show that song behaviour engages gene regulatory networks in the zebra finch brain, altering the expression of long non-coding RNAs, microRNAs, transcription factors and their targets. We find that the overall structures of the genomes are similar in zebra finch and chicken, but they differ in many intrachromosomal rearrangements, lineage-specific gene family expansions, the number of long-terminal-repeat-based retrotransposons, and mechanisms of sex chromosome dosage compensation. Here we present a structural, functional and comparative analysis of the genome sequence of the zebra finch ( Taeniopygia guttata), which is a songbird belonging to the large avian order Passeriformes 7. Like other songbirds, the zebra finch communicates through learned vocalizations, an ability otherwise documented only in humans and a few other animals and lacking in the chicken 5-the only bird with a sequenced genome until now 6. The zebra finch is an important model organism in several fields 1, 2 with unique relevance to human neuroscience 3, 4. Nature volume 464, pages 757–762 ( 2010) Cite this article
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