Fig. 5

Chemoreceptors in marine sedentarians (spionids and siboglinids). A Phylogenetic tree of gustatory receptor-like receptors. Motifs were classified using MEME Suite. B Heatmap showing the expression of L. polybranchiata chemoreceptor genes. The prefix GRL denotes gustatory receptor-like receptors; IR, ionotropic receptors. C 3D structure-based tree of candidate IRs from spionids generated using AlphaFold2. Blue molecules indicate the ligand-binding domain of every type, with ligand-binding residues (R, T, D/E) in red. The accession numbers of the reference sequences are in Table S2