Multiple sequence alignment of PoCD9.1 and PoCD9.3 homologues. The percentage number in the bracket following each species name represents the overall sequence identity between PoCD9.1 or PoCD9.3 with other specified species. The consensus residues are in black, and the residues that are ≥ 75% identical among the aligned sequences are in dark blue. The CCG motif and conserved cysteine residues are boxed. The GenBank accession numbers of the aligned sequences are as follows: Paralichthys olivaceus CD9.1 (XP_019934457.1), P. olivaceus CD9.3 (XP_019964847.1), Seriola dumerili (XP_022610189.1), Salmo salar (XP_014003925.1), Oncorhynchus mykiss (XP_021428108.1), Salvelinus alpinus (XP_023827461.1), Cyprinus carpio (KTF92709.1), Nanorana parkeri (XP_018418195.1), Xenopus laevis (NP_001085461.1), and Danio rerio (NP_997784.1).