A putative RA-like region in the brain of the scale-backed antbird, Willisornis poecilinotus (Furnariides, Suboscines, Passeriformes, Thamnophilidae).
The memorization and production of song in songbirds share important parallels with the process of speech acquisition in humans. In songbirds, these processes are dependent on a group of specialized telencephalic nuclei known as the song system: HVC (used as a proper name), RA (robust nucleus of arcopallium), LMAN (lateral magnocellular nucleus of the nidopallium) and striatal Area X. A recent study suggested that the arcopallium of the Sayornis phoebe, a non vocal learner suboscine species, contains a nucleus with some properties similar to those of songbird RA, suggesting that the song system may have been present in the last common ancestor of these groups. Here we report morphological and gene expression evidence that a region with some properties similar to RA is present in another suboscine, the Amazonian endemic Willisornis poecilinotus. Specifically, a discrete domain with a distinct Nissl staining pattern and that expresses the RA marker RGS4 was found in the arcopallium where the oscine RA is localized. Our findings, combined with the previous report on the S. phoebe, suggest that an arcopallial region with some RA-like properties was present in the ancestor of both Suboscines infraorders Tyranni and Furnarii, and is possibly an ancestral feature of Passeriformes.
Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
Jamily L R
JL
de Lima
Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
Fabricio A
FA
Soares
Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
Ana C S
AC
Remedios
Museu Paraense Emilio Goeldi, Belém, PA, Brazil.
Gregory
G
Thom
Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA.
Morgan
M
Wirthlin
Museu Paraense Emilio Goeldi, Belém, PA, Brazil.
Alexandre
A
Aleixo
Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
Maria Paula C
MP
Schneider
Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA.
Claudio V
CV
Mello
Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
Patricia N
PN
Schneider
RGS4; in situ hybridization; song nuclei; vocal learning