Table 1.
TLRs genes in vertebrates and their ligands
| Ligand | Human | X. trop | X. laevis | Bony fish* |
|---|---|---|---|---|
| triacylated lipopeptide | TLR1 | tlr1 | tlr1.L | tlr1 |
| lipopeptides, peptidoglycan, and lipoteichoic acids | TLR2 | tlr2 | tlr2.L, tlr2.S | tlr2 |
| dsRNA molecules | TLR3 | tlr3 | tlr3.L | tlr3 |
| LPS, cd14 | TLR4 | tlr4 | tlr4.S | tlr4** |
| Flagelin | TLR5 | tlr5 | tlr5.L | tlr5 |
| Lipoteichoic acid, MALP2, | TLR6 | tlr6 | tlr6.L | tlr6a |
| ssRNA | TLR7 | tlr7 | tlr7.L | tlr7 |
| GU-rich single-stranded RNA, G-rich oligonucleotides | TLR8 | tlr8 | tlr8.L | tlr8 |
| Unmethylated CpG motifs | TLR9 | tlr9 | tlr9.L | tlr9 |
| Pam3Cys and FSL-1, | TLR10 | Not present | Not present | Not present |
| Uropathogenic bacteria-derived protein (e.g., T. gondii profilin) | Not present | Not present | Not present | tlr11a |
| Apicomplexan profilin | Not present | tlr12 | tlr12.L | Not present |
| 23S rRNA | Not present | tlr13 | tlr13.L | Not present |
| Undefined | tlr14.2, tlr14.3 | tlr14.2.L, tlr14.3.L | tlr14a | |
| CpG oligos in bony fish and chicken only, undefined for the rest | Not present | Not present | Not present | tlr19 |
| CpG oligos in zebrafish only. | Not present | Undefined | Undefined | tlr21 |
| TLR22 (bacterial RNA) | Not present | tlr22 | tlr22.L | tlr22 |
| TLR23 MyD88 and TRIF | Not present | Not present | Not present | Not present |
*
(zebrafish (Danio rerio), fugu (Takifugu rubripes), rainbow trout (Oncorhynchus mykiss), catfish (Ictalurus punctatus).
**
tlr4 is present only in Ictalurus punctutatus and Danio rerio
a
not present in fugu (Takifugu rubripes), rainbow trout (Oncorhynchus mykiss)
→As a general comment here we mention that this Table is subject to changes in the future due to new entries in NCBI gene pages of bony fish.