Drosophila Telomeres

Figure WN21.4. Drosophila telomeres consist of long arrays of two non-LTR retrotransposons, HeT-A (dark arrows) and TART (gray arrows). The diagram shows how these are added onto the end of the chromosomes, maintaining the telomere despite its tendency to shorten during replication. These retrotransposons produce a sense-strand transcript with a poly(A) tail, denoted (A)_n. This is transported to the cytoplasm, translated to produce Gag proteins that remain associated with the RNA, transported back to the nucleus, and reverse transcribed to add an extra copy specifically to the end of the telomere. (Adapted from Fig. 3 of Pardue and Debarshye 2003.)