Molecular characterization of the apical organ of the anthozoan Nematostella vectensis.
Bottom Line: In bilaterians they are characterised by a tuft of long cilia and receptor cells and they are associated with groups of neurons, but their relatively low morphological complexity and dispersed phylogenetic distribution have left their evolutionary relationship unresolved.To provide a foundation for a better understanding of this structure we have characterised the molecular composition of the apical organ of the sea anemone Nematostella vectensis.Our study provides a molecular characterization of the apical organ of Nematostella and represents an informative tool for future studies addressing the development, function and evolutionary history of apical organ cells.
Affiliation: Sars Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt 55, 5008 Bergen, Norway.Show MeSH
Mentions: Regarding the characterized genes, the non-ciliary dataset contained two genes related to the Wnt signalling pathway, which determines the site of gastrulation in bilaterians and cnidarians and is involved in the patterning of the anterior–posterior axis of bilaterians. Both the Wnt receptor NvFrizzled5/8 (ao97) and the putative Wnt antagonist secreted Frizzled-Related protein (NvSFRP1, ao63) are expressed in a broad aboral domain at gastrulation and at highest levels in the apical organ of the planula larvae (Fig. 3A–D), and (Kumburegama et al., 2011)). While the function of the two Fibroblast growth factor genes NvFGFa1 and NvFGFa2 in apical organ development has been described (Rentzsch et al., 2008; Sinigaglia et al., 2013), there are 11 Nematostella FGFs for which expression data are not yet available. We identified NvFGF1e (ao190) (Matus et al., 2007) as an additional apical organ related FGF. NvFGF1e is expressed at the aboral pole from gastrula stage on and its expression at planula stage is restricted to a subset of apical organ cells (Fig. 3E and F).
Affiliation: Sars Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt 55, 5008 Bergen, Norway.