Evidence That Purifying Selection Acts on Promoter Sequences [Population and Evolutionary Genetics]

Evidence That Purifying Selection Acts on Promoter Sequences [Population and Evolutionary Genetics]:

We tested whether functionally important sites in bacterial, yeast, and animal promoters are more conserved than their neighbors. We found that substitutions are predominantly seen in less important sites and that those that occurred tended to have less impact on gene expression than possible alternatives. These results suggest that purifying selection operates on promoter sequences.