Figure 1.

During telophase/early G1, newly synthesized CENP-A is loaded onto centromeric nucleosomes. During S phase and DNA replication, CENP-A is redistributed to sister chromosomes through either a replacement or a dilution process (indicated by ‘?') before entering G2. After mitosis, new CENP-A loading is likely facilitated by a priming mechanism, which may prepare the centromeric nucleosome for the replacement of H3 with CENP-A, although the actual mechanism of CENP-A/H3 replacement is currently unknown (indicated by a ‘?'). Key is shown in inset at bottom.