Human centromere repositioning "in progress"

Abstract

Centromere repositioning provides a potentially powerful evolutionary force for reproductive isolation and speciation, but the underlying mechanisms remain ill-defined. An attractive model is through the simultaneous inactivation of a normal centromere and the formation of a new centromere at a hitherto noncentromeric chromosomal location with minimal detrimental effect. We report a two-generation family in which the centromeric activity of one chromosome 4 has been relocated to a euchromatic site at 4q21.3 through the epigenetic formation of a neocentromere in otherwise cytogenetically normal and mitotically stable karyotypes. Strong epigenetic inactivation of the original centromere is sug..