λCM8, a human sequence with putative centromeric function, does not map to the centromere but is present in one to two copies at 9qter

A DNA fragment isolated from a human genomic library,was reported to be present at all human centromeres and present at 16–32 copies per genome. Reintroduction of this DNA into mammalian cells as a concatenated phage clone gave rise to dicentric chromosomes which gave rise to a new, stable, chromosome. Taken together these observations could mean that this DNA is part of a native centromere. We have reexamined the location and copy number of this sequence and find it to be present at 1–2 copies per genome with a single site of in situ hybridisation at 9qter.