Bkm sequences are polymorphic in humans and are clustered in pericentric regions of various acrocentric chromosomes including the Y.

Probes of uncloned Bkm satellite DNA and a Drosophila clone 2 (8), consisting mainly of GATA repeats related to a major sequence component in Bkm, have been used to probe Southern blots of human male and female DNAs obtained from a Caucasian and an Australian aboriginal population and to human chromosomes in situ. Hybridization was observed to a distinct and an indistinct series of bands against a smeared background. The same distinct bands are identified in the DNA samples with both probes, but are most readily detected using the uncloned Bkm probe. Most restriction bands are common to both populations and some are polymorphic. However, certain bands appear to be characteristic of the Australian aboriginal samples. There are no distinct sex-linked patterns. However all of the small acrocentric human chromosomes, including the Y chromosome show hybridization to uncloned Bkm in situ.