Interspersed repeats are found predominantly in the "old" alpha satellite families.

The biased distribution of dispersed repeat insertions in various types of primate specific alpha satellites (AS) is being discussed in the literature in relation to the modes of AS evolution and their possible roles in maintenance and disruption of functional centromeres. However, such a bias has not been properly documented on a genome-wide scale so far. In this work, using a representative sample of about 100 insertions we show that the "old" AS contains at least 10 times more dispersed repeats than the "new" one.

Alpha-satellite DNA of primates: old and new families.

In this report we review alpha-satellite DNA (AS) sequence data to support the following proposed scenario of AS evolution. Centromeric regions of lower primate chromosomes have solely "old" AS based on type A monomeric units. Type A AS is efficiently homogenized throughout the whole genome and is nearly identical in all chromosomes.

Evidence for selection in evolution of alpha satellite DNA: the central role of CENP-B/pJ alpha binding region.

Conservation of DNA segments performing sequence-related functions is a landmark of selection and functional significance. Phylogenetic variability of alpha satellite and apparent absence of conserved regions calls its functional significance into question, even though sequence-specific alpha satellite-binding proteins pJ alpha and CENP-B have been discovered. Moreover, the function of pJ alpha is obscure and CENP-B binding satellite DNA, which is thought to participate in centromere formation, is found only in few species and not necessarily in all chromosomes.