Fig. 2

Sequence features and expression patterns of HyWnt3(+) astacin genes. a Multiple sequence alignment of pro-domain and catalytic domain sequences of astacins identified in this study. For comparison, astacin sequences from diverse species outside the cnidarian phylum were included. Gene ID numbers are as follows: Astacin A. astacus (P07584), NAS-35 C. elegans (P98060), ZHE-1 Danio rerio (Q1LW01), HCE-1 O. latipes (P31580), Meprin α H. sapiens (Q16819), Meprin β H. sapiens (Q16820), SPAN S. purpuratus (P98068), HMP1 (NP_001296695.1), HEA-1 Hydractinia echinata astacin 1 (Q2MCX9), HEA-3 Hydractinia echinata astacin 3 (Q2MCX7), HEA-4 Hydractinia echinate astacin 4 (Q2MCX6), HEA-2 Hydractinia echinata astacin 2 (Q2MCX8), HAS-3 (XP_002166229.3), HAS-6 (XP_002157397.2), HAS-5 (XP_002164800.1), HAS-4 (XP_002162738.1), HAS-2 (XP_002162822.1), HAS-8 (XP_002153855.1), HAS-9 (XP_002161766.1), HAS-1 (XP_012565441.1), HAS-11 (XP_012561076.1), HAS-7 (XP_012560086.1), HAS-10 (XP_002159980.2). In red: the aspartate switch residue in the pro-peptide, the zinc-binding motif, and the Met-turn. Orange background: residues forming the S1 ′ sub-site. A red bullet denotes the activation site. b Domain structures of astacins detected in HyWnt3(+) head lysate fractions. S, signal peptide; Pro, pro-domain; ShKT, Stichodactyla toxin domain. c–k WISH experiments using antisense and sense oligonucleotide probes (c–e) or LNAs (f–k) show a collar-like expression pattern marking a transition zone between head and body column for the majority of astacin genes. Representative of 10 hydras examined. Scale bars: HAS-7, 200 μm; HMP-1, 200 μm; HAS-1, 200 μm; HAS-2, 100 μm; HAS-11, 50 μm; HAS-5, 100 μm; HAS-9, 100 μm; HAS-10, 200 μm, control LNA, 200 μm