TELOMERES AND DOUBLE-STRAND BREAKS - TRYING TO MAKE ENDS MEET

Eukaryotic cells encounter two types of DNA ends: telomeres, the natur al ends of linear chromosomes, and double-strand breaks, resulting fro m DNA damage or normal chromosomal processes such as meiotic or V(D)J recombination. These two termini have long been seen as functionally d istinct, based on whether they are resistant to fusion with other ends or instead are acted upon by the DNA-repair machinery. However, a ser ies of recent papers has shown that members of a set of proteins that are crucial for the rejoining of DNA strand breaks are also required f or normal telomere function, raising new questions about how these two types of termini maintain their functional distinction.