An example of an inverted repeat in B. alternatus genes. A) Structure of inverted repeat (IR) transcripts in a bradykinin-potentiating peptide/C-type natriuretic peptide (BPP/CNP) precursor gene identified in Contig649. The normal gene organization is shown in the upper part of (A), with a normal sequence (NS) of 132 nucleotides located in the 3'-UTR (red arrow, right) between the stop codon and the poly(A) tail. The lower part of (A) shows the location of the inverted repeat (IR; red arrow, left) relative to the NS. The IR occurred as a perfect repeat (palindrome) involving a portion of the CNP coding region. These two sequences were separated from each other by a 183-nucleotide segment referred to as the inter-IR domain. B) Nucleotide and protein sequences of Contig649 (466 bp long) for which 56 transcripts were obtained. The NS is identified by a single underline and the IR by a double underline. The gray box shows the CNP region involved in the IR and the CNP amino acid residues are indicated in red. * = stop codon.