Structure and function of telomerase.

The study of eukaryotic telomeres at the molecular level began with the discovery of short, tandem repeats at Tetrahymena chromosome ends. In the following two decades, major insights about telomere structure and function have come from investigations of telomerase, the DNA polymerase that synthesizes these repeats. In the past year, three areas of telomerase research have been particularly intense: assays of telomerase activity, isolation of telomerase components, and studies of the regulation of telomerase and telomere length in vivo.