Fig. 4.

Amino acid sequences of the RAamide preprohormones from T. cystophora, A. alata, C. xaymacana, C. quadrumanus, and C. fleckeri. Residues and peptide sequences are highlighted as in Fig. 1. In T. cystophora, the preprohormone (named Tcy-RAamide) can be processed into 13 peptide copies with the C-terminal sequence RPRAamide, (named Tcy-RAamide-1), three copies with the sequence pQPRSamide (named Tcy-RSamide-1), and one copy with the sequence pQVLTRPRGamide (named Tcy-RGamide; see Table 1). In A. alata, the preprohormone (named Aal-RAamide) contains 14 peptide copies with the RPRAamide C-terminus, and three copies of pQPRGamide (Table 1). In C. xaymacana, we identified a small preprohormone fragment (named Cxa-RAamide) that contained two peptide copies with the RPRAamide C-terminal sequence, and one copy with the VPRAamide C-terminal sequence (Table 1). In the C. quadrumanus transcriptome we identified two small preprohormone fragments (probably part of one preprohormone named Cqu-RAamide) that contained two copies of a RPRAamide peptide and one peptide with the sequence pQPRSamide (Table 1). In C. fleckeri we identified a small preprohormone fragment (named Cfl-RAamide) that contained three copies of a peptide with the C-terminal sequence RPRAamide (Table 1)