Expression of the receptor, FGFRb at the oral and aboral poles. NvFGFRb is not expressed during gastrulation (a), but transcripts are first visible in the developing pharynx of the planula (b). During later planula development, expression can also be visualized in a few cells in the endoderm below the apical tuft (arrow). Later, during polyp formation, NvFGFRb is expressed in the endoderm of the growing tentacles (d, f). Expression is also visible in discrete cells forming a symmetric pattern in the intra-tentacle endoderm (e, f). The asterisk denotes the blastopore and future oral pole (ph pharynx; at apical tuft; ten tentacle; int inter-tentacular endoderm). All embryo views are lateral except (f), which is an oral view