Alignment of known orthologous peptides from (A) bilaterian NPFF/SIFa (B), chordate QRFP, (C) vertebrate PrRP, and (D) chordate kisspeptin families. The names of deuterostomian and protostomian peptides are shaded in pink and blue, respectively. The C-terminal amide groups are represented by an “a” at the end of aligned sequences. The lamprey sequences are from Ref. (26), other vertebrate and B. floridae sequences are from Ref. (8), the Lottia gigantea sequences are from Ref. (4), and the Capitella teleta sequence is from Ref. (5). For vertebrate sequences, only one peptide from each precursor is shown in the alignment. Genbank (GI) or JGI IDs of all precursor sequences are listed below: (A) alignment of chordate NPFF/SIFa peptides: Hsap_GnIH, Homo sapiens GnIH (GI:11125707); Hsap_NPFF, Homo sapiens NPFF precursor (GI:219878493); Drer_GnIH, Danio rerio GnIH precursor (GI:283825363), Danio rerio NPFF precursor (GI:116078056); Pmar1, Petromyzon marinus NPFF/GnIH precursor 1 (GI:88595366); Pmar2, Petromyzon marinus NPFF/GnIH precursor 2 (GI:374849285); Bflo1, Branchiostoma floridae NPFF/GnIH precursor 1 (GI:260808912); Bflo2_1–7, Branchiostoma floridae NPFF/GnIH precursor 2 (GI:260829186); Lgig1, Lottia gigantea SIFamide precursor 1 (JGI: 176362); Lottia gigantea SIFamide precursor 2 (JGI: 175046); Ctel, Capitella teleta SIFamide precursor (GI:161198869); Tcas, Tribolium castaneum SIFamide precursor (GI:189239683); Dmel_SIFa, Drosophila melanogaster SIFamide precursor (GI:386768581); Dpul, Daphnia pulex SIFamide precursor (JGI: 260818); Cele, Caenorhabditis elegans SIFamide precursor (GI:392894563). (B) Alignment of chordate QRFP peptides: Hsap, Homo sapiens pyroglutamylated RFamide peptide precursor (GI:38016139); Oana Ornithorhynchus anatinus QRFP precursor (GI:620943939); Drer, Danio rerio QRFP precursor (GI:528509692); Bflo1–3, Branchiostoma floridae QRFP precursors (GI:260828082, GI:260828080, and JGI:107075). (C) Alignment of vertebrate PrRP peptides: Hsap, Homo sapiens prolactin-releasing peptide/hormone (GI:7705679); Drer1-2, Danio rerio prolactin-releasing peptide precursors (GI:350539516, GI:528519441); Pmar, Petromyzon marinus prolactin-releasing peptide precursor (Ensembl scaffold: GL490889). (D) Alignment of Kisspeptins: Hsap_Kisspep-14, Homo sapiens KiSS-1 metastasis-suppressor precursor (GI:116829963); Drer1-2, Danio rerio KiSS-1 precursors (GI:157061759, GI:217272819); Pmar, Petromyzon marinus KiSS-1 precursors (GENSCAN00000116455); Bflo1-4, Branchiostoma floridae KiSS-1 precursors (GI:260826607, GI:260793233, GI:260826605, and GI:260827077).