HeT DNA is a family of complex repeated sequences in the genome of Drosophila melanogaster. The sequences are entirely confined to the telomeres and the pericentric heterochromatin. One subset of the HeT DNA family consists of the HeT-A elements a novel set of retroposon-like elements that have bee found added onto the ends of the four "healed" telomeres that have been studied in Drosophila or they may be able to organize telomere sequences. We propose to test the putative function of HeT DNA sequences by attempting to construct functional Drosophila mini-chromosomes using these sequences. The mini-chromosomes will be transformed into cultured Drosophila cells and assayed for their ability to be maintained and replicated as linear chromosomes. Such chromosomes would allow a direct test of our conclusions about functions of HeT DNA sequences. If we are successful in constructing mini- chromosomes, they will be a useful tool for other studies on Drosophila.***//
