Fig. 6

Amino acid sequences of the FRamide preprohormones from T. cystophora, A. alata, and C. fleckeri. Residues and peptide sequences are highlighted as in Fig. 1. The T. cystophora preprohormone produces four copies of a neuropeptide with the sequence CTGQMCWFRamide (named Tcy-FRamide-1), two copies of CKGQMCWFRamide (Tcy-FRamide-2), and one copy of CVGQMCWFRamide (Tcy-FRamide-3). The preprohormone from A. alata produces two copies of a peptide identical to Tcy-FRamide-1, two copies of a peptide identical to Tcy-FRamide-3, one copy of a peptide identical to Tcy-FRamide-2, and one copy of CEGQMCWFRamide (Table 1). The preprohormone fragment from C. fleckeri contains one copy of a peptide identical to Tcy-FRamide-1 and one peptide copy identical to Tcy-FRamide-2 (Table 1). All peptides contained in the three preprohormones are nearly identical in structure and only vary in the second amino acid residue, being either T, K, V, or E