Data from: Centromere innovations within a mouse species

<p class="MsoNormal">Mammalian centromeres direct faithful genetic inheritance and are typically characterized by regions of highly repetitive and rapidly evolving DNA. We focused on a mouse species, <em>Mus pahari, </em>that we found has evolved to house centromere-specifying CENP-A nucleosomes at the nexus of a satellite repeat that we identified and term p-satellite (p-sat), a small number of recruitment sites for CENP-B, and short stretches of perfect telomere repeats. One <em>M. pahari</em> chromosome, however, houses a radically divergent centromere harboring ~6 Mbp of a homogenized p-sat-related repeat, p-sat^B, that contains &gt;20,000 functional CENP-B boxes. There, CENP-B abundance drives accumulation of microtubule-binding components of the kinetochore, as well as a microtubule-destabilizing kinesin of the inner centromere. The balance of pro- and anti-microtubule-binding by the new centromere permits it to segregate during cell division with high fidelity alongside the older ones whose sequence creates a markedly different molecular composition.</p>