Nonrandom segregation of nucleolar organizing chromosomes at mitosis?

The random assortment of non-homologous chromosomes at meiosis is one of the fundamental tenets of genetics, to which few exceptions have been documented. The segregation of mitotic chromatids is believed to be similarly random. We report here that we seem to have discovered a new exception to this rule, in that nucleolar organizing chromosomes remain associated with one another, held in the same lateral orientation, for several mitotic cycles.