natsel_neutral
– a test for selective neutrality#
Note
These docs now use the new_type
core objects via the following setting.
import os
# using new types without requiring an explicit argument
os.environ["COGENT3_NEW_TYPE"] = "1"
We employ codon models to test hypotheses regarding the mode of natural selection that has operated on a gene.
Noting that ω (omega) is the ratio of nonsynonymous substitutions to synonymous substitutions, ω=1 is indicative a gene is evolving neutrally.
Warning
I’m setting optimise_motif_probs=False
to speed up execution of the examples, not because it’s a good idea!
from cogent3 import get_app
loader = get_app("load_aligned", format="fasta", moltype="dna")
aln = loader("data/primate_brca1.fasta")
omega_eq_1 = get_app("natsel_neutral",
"GNC", tree="data/primate_brca1.tree", optimise_motif_probs=False
)
result = omega_eq_1(aln)
type(result)
cogent3.app.result.hypothesis_result
result
LR | df | pvalue |
---|---|---|
4.5034 | 1 | 0.0338 |
hypothesis | key | lnL | nfp | DLC | unique_Q |
---|---|---|---|---|---|
null | 'GNC-null' | -6715.5260 | 22 | True | True |
alt | 'GNC-alt' | -6713.2743 | 23 | True | True |
result.alt.lf
GNC-alt
log-likelihood = -6713.2743
number of free parameters = 23
A>C | A>G | A>T | C>A | C>G | C>T | G>A | G>C | G>T | T>A |
---|---|---|---|---|---|---|---|---|---|
0.8614 | 3.5373 | 0.9792 | 1.6667 | 2.2042 | 6.2565 | 7.9195 | 1.2253 | 0.8014 | 1.2911 |
T>C | omega |
---|---|
3.0723 | 0.8204 |
edge | parent | length |
---|---|---|
Galago | root | 0.5232 |
HowlerMon | root | 0.1338 |
Rhesus | edge.3 | 0.0640 |
Orangutan | edge.2 | 0.0233 |
Gorilla | edge.1 | 0.0075 |
Human | edge.0 | 0.0182 |
Chimpanzee | edge.0 | 0.0085 |
edge.0 | edge.1 | 0.0000 |
edge.1 | edge.2 | 0.0100 |
edge.2 | edge.3 | 0.0366 |
edge.3 | root | 0.0238 |
AAA | AAC | AAG | AAT | ACA | ACC | ACG | ACT | AGA | AGC |
---|---|---|---|---|---|---|---|---|---|
0.0556 | 0.0235 | 0.0344 | 0.0556 | 0.0228 | 0.0046 | 0.0008 | 0.0289 | 0.0231 | 0.0286 |
AGG | AGT | ATA | ATC | ATG | ATT | CAA | CAC | CAG | CAT |
---|---|---|---|---|---|---|---|---|---|
0.0140 | 0.0381 | 0.0186 | 0.0070 | 0.0128 | 0.0192 | 0.0196 | 0.0052 | 0.0238 | 0.0221 |
CCA | CCC | CCG | CCT | CGA | CGC | CGG | CGT | CTA | CTC |
---|---|---|---|---|---|---|---|---|---|
0.0195 | 0.0062 | 0.0006 | 0.0263 | 0.0011 | 0.0009 | 0.0023 | 0.0032 | 0.0137 | 0.0078 |
CTG | CTT | GAA | GAC | GAG | GAT | GCA | GCC | GCG | GCT |
---|---|---|---|---|---|---|---|---|---|
0.0125 | 0.0105 | 0.0755 | 0.0105 | 0.0303 | 0.0315 | 0.0158 | 0.0096 | 0.0014 | 0.0137 |
GGA | GGC | GGG | GGT | GTA | GTC | GTG | GTT | TAC | TAT |
---|---|---|---|---|---|---|---|---|---|
0.0161 | 0.0090 | 0.0067 | 0.0133 | 0.0148 | 0.0070 | 0.0069 | 0.0213 | 0.0023 | 0.0101 |
TCA | TCC | TCG | TCT | TGC | TGG | TGT | TTA | TTC | TTG |
---|---|---|---|---|---|---|---|---|---|
0.0221 | 0.0082 | 0.0015 | 0.0251 | 0.0018 | 0.0040 | 0.0201 | 0.0212 | 0.0078 | 0.0108 |
TTT |
---|
0.0187 |