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Fig. 1. (A) Alignment of Spaw and other Nodal-related proteins. Black arrowheads
indicate putative cleavage sites between the prepro and mature ligand domains
(RXRR). Open arrowheads indicate position of a conserved intron. Arrows
indicate peptide stretches where the corresponding nucleotide sequences are
complementary to the morpholinos Spaw-MO1 and Spaw-MO2. Heavy underlining
indicates nodal-specific motifs (NAYRCEG and PTNHAY). The boxed region
highlights the split cysteine pattern (CXXC) that differentiates
the Xnr1/Sqt subclass and Nodal/Cyclops subclass (XXCC). (B) Amino acid
identity (%) between the spaw prepro domain or mature domain and the
corresponding domains of Sqt, Cyclops and Xnr1.