Conserved expression without conserved regulatory sequence: the more things change, the more they stay the same

摘要: Regulatory regions with similar transcriptional output often have little overt sequence similarity, both within and between genomes. Although cis - trans -regulatory changes can contribute to divergence without dramatically altering gene expression outputs, heterologous DNA functions similarly in organisms that share regulatory similarities (e.g. human fish), indicating mechanisms tend diverge more slowly accommodate a variety of configurations. This capacity ‘tinker' probably relates the complexity, robustness evolvability systems, but cause-and-effect relationships among evolutionary processes properties systems remain topic debate. The challenge understanding concrete underlying evolution – including conservation function general. Currently, we are largely unable recognize functionally DNA.