Aldh5a1 is another duplicated ALDH gene within the zebrafish genome. The duplication aldh5a1.2 resides on the same chromosome as the aldh5a1.1 parent gene, and the two share 100 per cent sequence identity. Aldh5a1.2 encodes a peptide containing an additional 22 amino-terminal and 88 carboxy-terminal residues. It also shares greater sequence identity with the human ALDH5A1 orthologue than Aldh5a1.1 (65.5 per cent versus 51.4 per cent). This suggests that aldh5a1.2 might actually be the parent gene and aldh5a1.1 a slightly truncated version formed as the result of gene duplication.
