Skip to main content
. 2020 Sep 16;9:e61820. doi: 10.7554/eLife.61820

Figure 1. Writing and reading histone modifications that initiate the exchange of genes during meiosis.

Figure 1.

(Top) Inside cells, DNA (blue line) is stored in repeated units called nucleosomes, which consist of segments of DNA wrapped around a core of eight histone proteins (orange and grey spheres). (Middle) When an enzyme called PRDM9 binds to specific sites in the genome, it modifies the nucleosomes adjacent to it by adding a methyl group to two residues (lysine 4 and lysine 36) on one of the histones (histone 3). These histone modifications are represented as pink and yellow dots, and may be on the same or different proteins, and on one or both PRDM9-flanking nucleosomes. (Bottom) A protein called ZCWPW1 contains two domains that can recognize the modifications deposited by PRDM9. During meiosis, double stranded breaks (DSBs) in DNA form at or around PRDM9 binding sites and are repaired by homologous recombination. ZCWPW1 binding promotes efficient DSB repair via an unknown mechanism.