Table 1.
Occurrence of AAN codons in some metazoan mitochondrial genomes
| Species | AAT | AAC | AAA | AAG |
|---|---|---|---|---|
| Nematoda | ||||
| Caenorhabditis elegans | 139 | 12 | 95 (K) | 14 |
| Ascaris suum | 107 | 5 | 29 (K) | 65 |
| Annelida | ||||
| Lumbricus terrestris | 70 | 66 | 70 (K) | 22 |
| Mollusca | ||||
| Cepaea nemoralis | 50 | 37 | 36 (K) | 34 |
| Albinaria coerulea | 106 | 32 | 73 (K) | 13 |
| Katharina tunicata | 110 | 51 | 78 (K) | 18 |
| Arthropoda | ||||
| Artemia franciscana | 93 | 31 | 41 (K) | 40 |
| Drosophila yakuba | 193 | 13 | 76 (K) | 9 |
| Locusta migratoria | 141 | 46 | 71 (K) | 29 |
| Vertebrata | ||||
| Petromyzon marinus | 78 | 67 | 90 (K) | 9 |
| Xenopus laevis | 70 | 80 | 77 (K) | 8 |
| Homo sapiens | 33 | 131 | 85 (K) | 10 |
| Echinodermata | ||||
| Paracentrotus lividus | 44 | 50 | 88 (N) | 54 |
| Arbacia lixula | 46 | 44 | 82 (N) | 52 |
| Asterina pectinifera | 41 | 58 | 112 (N) | 48 |
| Hemichordata | ||||
| B. carnosus | 20 | 98 | 0 | 45 |
AAT and AAC code for asparagine (N), AAG for lysine (K), and AAA for either lysine or asparagine, as shown in parentheses.