The centromere specific histone CENP-A is selectively retained in discrete foci in mammalian sperm nuclei

The 17 kDa human autoantigen designated CENP-A is a centromere specific histone. We show here that CENP-A is present in tissue of bovine origin, and that it is quantitatively retained in mature spermatozoa. This result is striking, as a prominent feature of spermatogenesis in mammals is the replacement of most somatic and testes specific histones with protamines. Indirect immunofluorescence studies further show that CENP-A is retained in sperm nuclei in discrete foci, rather than being dispersed throughout the sperm head. These observations suggest that CENP-A is a functionally important component of centromeres, and that pre-existing CENP-A:DNA interactions are likely to be important in organizing the centromeres of the paternal genome during early embryogenesis.