Figure 4.

The hypothetical evolution of new centromeres. The ancestral chromosome in this example is submetacentric (the centromere is indicated with red ‘nucleosomes’). The active locus (black dot) carries satellite arrays. Some individual(s) in a population experience the destabilization of the active centromere and formation of a neocentromere, perhaps through the activation of a new TE, resulting in a centric shift (CS). The new centromere is indicated with a black dot, while the latent centromere is indicated with an open circle. The new centromere becomes fixed in a population and eventually gains new satellite arrays (orange), either by interchromosomal seeding from the old centromere (grey) or from the TE itself. Over time, the latent centromere loses its HORs while the new centromere becomes stabilized. In some cases, the ENC can lead to a new species karyotype.