Evolution of a tissue-specific silencer underlies divergence in the expression of pax2 and pax8 paralogues.

Recent studies underscore a role for the differential degeneration of enhancers in the evolutionary diversification of paralogue expression. However, no one has reported evidence for the involvement of innovative cis-regulatory changes. Here we show that silencer innovation diversified expression of the vertebrate paralogues, pax2 and pax8.