Expression of segment polarity genes in brachiopods supports a non-segmental ancestral role of engrailed for bilaterians.

ABSTRACT: The diverse and complex developmental mechanisms of segmentation have been more thoroughly studied in arthropods, vertebrates and annelids-distantly related animals considered to be segmented. Far less is known about the role of "segmentation genes" in organisms that lack a segmented body. Here we investigate the expression of the arthropod segment polarity genes engrailed, wnt1 and hedgehog in the development of brachiopods-marine invertebrates without a subdivided trunk but closely related to the segmented annelids. We found that a stripe of engrailed expression demarcates the ectodermal boundary that delimits the anterior region of Terebratalia transversa and Novocrania anomala embryos. In T. transversa, this engrailed domain is abutted by a stripe of wnt1 expression in a pattern simila

SUBMITTER: Vellutini BC 

PROVIDER: S-EPMC4999882 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature