Table 4.
Tests for positive selection among codons of GRAS genes using site-specific model
| Model | lnL | Estimates of parameter a | 2ΔlnL | Positive selection sites b |
|---|---|---|---|---|
| M0(one-ratio) | −82992.756 | ω = 0.12433 | 3508.354 | Not allowed |
| M3(discrete) | −81238.579 | p0 = 0.20058 ω0 = 0.03406 | (M3vsM0)** | None |
| p1 = 0.55607 ω1 = 0.10851 | ||||
| p2 = 0.23655 ω2 = 0.28245 | ||||
| M7(beta) | −81023.838 | p = 0.99909 q = 4.93337 | 0.002 | Not allowed |
| M8(beta & ω) | −81023.839 | p0 = 0.99999 p = 0.99909 | (M8vsM7) | None |
| q = 4.93337 p1 = 0.00001 | ||||
| ω = 1.00000 |
Note: *p < 0.05 and **p < 0.01 (x 2 test).
aω was estimated under model M0,M3,M7, and M8; p and q are the parameters of the beta distribution.
bThe number of amino acid sites estimated to have undergone positive selection.