Prdm9 Controls Activation of Mammalian Recombination Hotspots

Homing in on Hotspots The clustering of recombination in the genome, around locations known as hotspots, is associated with specific DNA motifs. Now, using a variety of techniques, three studies implicate a chromatin-modifying protein, the histone-methyltransferase PRDM9, as a major factor involved in human hotspots (see the Perspective by Cheung et al. ). Parvanov et al. (p. 835 , published online 31 December) mapped the locus in mice, and analyzed allelic variation in mice and humans, whereas Myers et al. (p. 876 , published online 31 December) used a comparative analysis between human and chimpanzees to show that the recombination process leads to a self-destructive drive in which the very motifs that…