Comparison of amino acid sequences of (A) vasopressin and (B) oxytocin family hormone precursors in vertebrates. ClustalX was used to generate the alignment. Amino acid residues conserved in all vertebrates are marked with an asterisk. B. japonicus, Bufo japonicus; X. tropicalis, Xenopus tropicalis; and T. scyllium, Triakis scyllium. Accession numbers of sequences used in the alignment: NP_000481.2 (human VP), AAA48556.1 (B. japonicus VT), BAA24026.1 (lungfish VT), O42499 (fugu VT), BAA98140.1 (flounder VT), BAD27476.1 (T. scyllium VT) and BAA06669.1 (lamprey VT), NP_000906.1 (human OT), P08162 (B. japonicus MT), BAA24027.1 (lungfish [Phe2]MT), O42493 (fugu IT), BAA98141.1 (flounder IT), BAD27478.1 (T. scyllium phasitocin) and BAD27477.1 (T. scyllium asvatocin). Sequences for Xenopus tropicalis and coelacanth were generated in this study.