Neocentromeres structures are fully active in the process of separation of chromatids and their targeting towards the poles of the mitotic spindle during mitosis and meiosis . Centromeric chromatin nucleosomes containing protein CENP -A and its homologues , which are variants of histone H3 and determining the identity of the centromere / neocentromeru . Neocentromeres arise in distant zones niecentromerowych chromosomes and therefore contain different centromeric DNA . The creation of the centromere may be a response to inactivation of endogenous centromere .