cis versus trans effects
Gordon KL & Ruvinsky I 2012 Tempo and mode in evolution of transcriptional regulation. PLoS Genet 8:e1002432.
- sometimes cis-trans coevolution leads to divergent expression patterns
- in other cases, the gene expression pattern is maintained despite evolution at the level of regulatory interactions in one or both lineages
- this particular type of coevolution is known as Developmental Systems Drift
- an estimated 95% of human expression-QTLs are found in the 20-kb of sequence in cis to the transcription start site of a gene
- the conclusion that cis-regulatory evolution is observed more often than trans-regulatory evolution also agrees with theoretical arguments that cis-regulatory evolution should be common because it can break the pleiotropy of developmentally important genes
- divergence in trans is common, but appears rarely to happen without coevolution in cis
- perhaps because evolutionary changes in cis quickly respond to trans changes
- the dynamics of cis-trans coevolution are not well understood
- it is imperative that they be studied further, particularly with respect to how gene networks respond to single regulatory changes
- a recent simulation and analysis of expression data suggested that cis-trans coevolution may play a larger role than has been previously recognized
- coevolution between cis and trans may constitute a distinct mode of evolution that unfolds with a slower tempo than cis or trans divergence alone
