Unravelling the X in Sex

New cytological techniques combined with genome-wide expression studies and ChIP-on-chip have revealed that random X-inactivation is not a simple one-step process that occurs uniformly across the entire chromosome, but a complex series of events with clear links to both the epigenetic silencing of autosomal genes and the imprinted X-inactivation that occurs in male meiosis. It appears to be less bizarre, as the French love to say, and as such an even better model of epigenetic gene silencing, than previously thought.