We are examining the telomere region of the fruitfly, Drosophila melanogaster, as a model for metazoan telomeres. We have shown that in Drosophila, in contrast to yeast, a chromosome from which the terminus has been deleted can be transmitted for many generations. Our structural analysis of the subterminal portion of the telomere region has revealed a complex interspersion of different repetitive sequences. Preliminary results suggest an unexpectedly high frequency of terminal and subterminal length variations. In addition, we have documented a case in which the expression of a gene was repressed when it was transposed to a subterminal site. The termini of eukaryotic chromosomes, called telomeres, are specialized structures thought to be required for chromosome stability. It has recently been shown that a characteristic terminal sequence motif is conserved among unicellular eukaryotes, vertebrates and higher plants. In many eukaryotes the telomere region also encompasses more complex repetitive sequences that are shared among all or a subset or the chromosome tips. Telomeres have been studied most extensively in single-celled eukaryotes and there is little known about the overall sequence organization, functions, or dynamics of the telomere region of multicellular eukaryotes.***
