A stem-deuterostome origin of the vertebrate pharyngeal transcriptional network.

ABSTRACT: Hemichordate worms possess ciliated gills on their trunk, and the homology of these structures with the pharyngeal gill slits of chordates has long been a topic of debate in the fields of evolutionary biology and comparative anatomy. Here, we show conservation of transcription factor expression between the developing pharyngeal gill pores of the hemichordate Saccoglossus kowalevskii and the pharyngeal gill slit precursors (i.e. pharyngeal endodermal outpockets) of vertebrates. Transcription factors that are expressed in the pharyngeal endoderm, ectoderm and mesenchyme of vertebrates are expressed exclusively in the pharyngeal endoderm of S. kowalevskii. The pharyngeal arches and tongue bars of S. kowalevskii lack Tbx1-expressing mesoderm, and are supported solely by an acellular collagenou

SUBMITTER: Gillis JA 

PROVIDER: S-EPMC3223668 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature