Pairs | | Bur | Zeb | Bri | Nye | Til |
---|
| Bur | 2 | 9 | 0 | 11 | 0 |
| Zeb | | 0 | 0 | 10 | 0 |
| Bri | | | 0 | 1 | 0 |
| Nye | | | | 0 | 0 |
| Til | | | | | 7 |
Triplets
| Bur | Zeb | Nye | 37 | | |
| Bur | Bur | Nye | 1 | | |
| Til | Til | Til | 1 | | |
Quadruplets
| Bur | Zeb | Nye | Bri | 2 | |
| Bur | Zeb | Nye | Til | 1 | |
| Til | Til | Til | Til | 1 | |
- Olfactory receptors sharing 99% of AA identity were identified from the phylogenetic tree. The greatest numbers of pairs or triplets were found between H. burtoni, M. zebra and P. nyererei, in agreement with their closer phylogenetic relatedness. In O. niloticus 7 pairs, 1 triplet and 2 quadruplets of paralogous genes were identified consistent with this repertoire having undergone a higher level of duplication. The list of genes is shown in Additional file 5.