Fig. 3

Neuropeptides identified as candidate ligands for kisspeptin-type receptors in echinoderms aligned with chordate kisspeptins. A Sequences of the A. rubens kisspeptin-type precursors ArKPP1 and ArKPP2 and SALMFamide-type precursors ArL-SALMFaP and ArF-SALMFaP. N-terminal signal peptide is shown in blue, neuropeptides predicted or shown to be derived from these proteins are shown in red (with C-terminal glycine that is a substrate for amidation shown in orange) and monobasic or dibasic cleavage sites are shown in green. Neuropeptides (red) are named in accordance with the precursor they are derived from and their relative position in the precursor, which explains the nomenclature used in B–D. Likewise, annotated precursor sequences for other neuropeptides included in B and C are shown in Additional file 13. B Alignment of ArKP1.1, ArKP1.2, and KP1-type neuropeptides from other echinoderms (blue) with chordate kisspeptin-type neuropeptides (yellow). C Alignment ArKP2.1, ArKP2.2, and KP2-type neuropeptides from other echinoderms (blue) with chordate kisspeptin-type neuropeptides (yellow). D Alignment of L-type SALMFamide precursor-derived peptides from A. rubens (ArS1.1, ArS1.3, ArS1.4, and S1.7) and other echinoderms (blue) with chordate kisspeptin-type neuropeptides (yellow). E Alignment of F-type SALMFamide precursor-derived peptides from A. rubens (ArS2.2, ArS2.3, and S2.8) and other echinoderms (blue) with chordate kisspeptin-type neuropeptides (yellow). Conserved residues are highlighted in black or gray. Abbreviations: Ar, Asterias rubens; Sp, Strongylocentrotus purpuratus; Aj, Apostichopus japonicus, Hs, Homo sapiens, Lo, Lepisosteus oculatus, Bf, Branchiostoma floridae. The accession numbers for the precursor sequences used for this figure are in Additional file 13