A PCR product derived from female DNA with regional localization on the Y chromosome

A 154-bp PCR product amplified from human female DNA mapped onto the Y chromosome under high-stringency in situ hybridization conditions. The female DNA sequence revealed an 89% homology with the HSDYZ1 sequence. When the same primers were used to amplify male DNA, a 154-bp DNA fragment was also obtained, showing a 98% homology with HSDYZ1. However, although the HSDYZ1 sequence is widely distributed along the long arm of the Y chromosome, both of these particular PCR products are di-regionally localized within this distal block of constitutive heterochromatin. In situ hybridization under lower stringency showed that these 154-bp sequences map both onto the autosomes and the Y chromosome. Overall, this paper shows (i) a new class of DNA sequences shared by the autosomes and the Y chromosome; and (ii) a substructured organization of some DNA repeats within the DYZ1 family that forms a large part of the constitutive heterochromatin of the Y chromosome.