Predicted Intron-Exon organization of the Daphnia pulex neurotrophin gene. Exons are represented by boxes and the number of nucleotides included within each exon is indicated above the boxes. Introns figure as a line and their length in number of nucleotides is indicated below. The type of sequence encoded by each exon is shown by initials and colour codes. SP (Dotted fill): Signal Peptide; PP (Grey): ProPeptide; Cys knot (white): CI to CVI stand for the six cysteines of the Cysteine knot. CI to CVI figure on the respective exons encoding them.