cis-trans compensation

Barriére A, Gordon KL & Ruvinsky I 2012 Coevolution within and between regulatory loci can preserve promoter function despite evolutionary rate acceleration. PLoS Genet 8:e1002961.

• phenotypes that appear to be conserved could be maintained not only by strong purifying selection on the underlying genetic systems, but also by stabilizing selection acting via compensatory mutations with balanced effects
• coevolution among promoter elements suggests that complex epistatic interactions within cis-regulatory elements may facilitate their divergence
• our results offer a detailed picture of regulatory evolution in which subtle, lineage-specific, and compensatory modifications of interacting cis and trans regulators together maintain conserved gene expression patterns