The Population Genetics of dN/dS
Abstrak
Evolutionary pressures on proteins are often quantified by the ratio of substitution rates at non-synonymous and synonymous sites. The dN/dS ratio was originally developed for application to distantly diverged sequences, the differences among which represent substitutions that have fixed along independent lineages. Nevertheless, the dN/dS measure is often applied to sequences sampled from a single population, the differences among which represent segregating polymorphisms. Here, we study the expected dN/dS ratio for samples drawn from a single population under selection, and we find that in this context, dN/dS is relatively insensitive to the selection coefficient. Moreover, the hallmark signature of positive selection over divergent lineages, dN/dS>1, is violated within a population. For population samples, the relationship between selection and dN/dS does not follow a monotonic function, and so it may be impossible to infer selection pressures from dN/dS. These results have significant implications for the interpretation of dN/dS measurements among population-genetic samples.
Penulis (2)
S. Kryazhimskiy
J. Plotkin
Akses Cepat
- Tahun Terbit
- 2008
- Bahasa
- en
- Total Sitasi
- 906×
- Sumber Database
- Semantic Scholar
- DOI
- 10.1371/journal.pgen.1000304
- Akses
- Open Access ✓