Table 2. Positively selected codons within the extracellular domains of TLRs.
| Species | Origin | Genes | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TLR1 | TLR2 | TLR6 | TLR8 | |||||||||||||
| Codons | ||||||||||||||||
| 117 | 434* | 451 | 559 | 216 | 338* | 183 | 334 | 452 | 459 | 501 | 554 | 560 | 178 | 388 | ||
| S. scrofa (E) | Eurasia | Met | Leu | Ile | Glu | Lys | Ala | Met | Arg | Ile | Ser | Thr | Ser | Glu | Asp | Phe |
| S. scrofa (A) | Met | Leu | Ile | Glu | Lys | Ala | Met | Arg | Ile | Asn | Ile | Gly | Lys | Glu | Phe | |
| S. barbatus | Southeast Asia | Thr | Leu | Val | Glu | Lys | Thr | X | Arg | Ile | Asn | X | Gly | Glu | Asp | Phe |
| S. celebensis | Thr | Leu | Val | Lys | Glu | Thr | Met | Gly | Val | X | Ile | Gly | Glu | Glu | Phe | |
| S. cebifrons | Thr | Leu | X | X | Lys | Thr | Thr | Arg | Val | Asn | Thr | Gly | Glu | Glu | Phe | |
| S. verrucosus | Thr | Met | Ile | X | Glu | Thr | Met | Gly | Ile | X | Ile | Ser | Glu | Glu | Phe | |
| B. babyrussa | Ile | Met | Val | Lys | Glu | Ala | Val | Arg | Val | Ser | Ile | Gly | Lys | Glu | Phe | |
| P. larvatus | Africa | Thr | Met | Val | Glu | Glu | Ala | Val | Arg | Val | Asn | Ile | Gly | Glu | Glu | Leu |
| P. porcus | Thr | Met | Val | Glu | Glu | Lys | Val | Arg | Val | Asn | Ile | Gly | Glu | Glu | Phe | |
| P. africanus | Thr | Met | Val | Lys | Glu | Ala | Val | Arg | Val | Asn | Ile | Gly | Glu | Glu | Val | |
*Codon site 434 in TLR1 is under episodic positive selection and codon site 338 in TLR2 is under both persistent and episodic positive selection. Other codon sites are under persistent positive selection. Amino acid properties: Met, Ile, Leu, Val, Ala are non-polar aliphatic; Thr, Ser, Asn are polar neutral; Lys, Arg are polar positive; Glu, Asp are polar negative; Gly is non-polar neutral; Phe is non-polar aromatic. (E) represents Europe, (A) represents Asia. X represents an undetermined amino acid.