Centromeres from telomeres? The centromeric region of the Y chromosome of Drosophila melanogaster contains a tandem array of telomeric HeT-A- and TART-related sequences.

Cytological and cytogenetic studies have previously defined the region needed for centromeric function in the Y chromosome of Drosophila melanogaster. We have identified a YAC clone that originated from this region. Molecular analysis of the YAC and genomic DNAs has allowed the description of a satellite DNA made of telomeric HeT-A- and TART-derived sequences and the construction of a long-range physical map of the heterochromatic region h18. Sequences within the YAC clone are conserved in the centromeric region of the sibling species Drosophila simulans. That telomere-derived DNA now forms part of the centromeric region of the Y chromosome could indicate a telomeric origin of this centromere. The existence of common determinants for the function of both centromeres and telomeres is discussed.