Super-resolution optical microscopy study of telomere structure.
Chromosome ends are shielded from exonucleolytic attack and inappropriate end-joining by terminal structures called telomeres; these structures are potential targets for anticancer drugs. Telomeres are composed of a simple DNA sequence (5?-TTAGGG-3? in humans) repeated more than a thousand times, a short 3? single-stranded overhang, and numerous proteins. Electron microscopy has shown that the 3? overhang pairs with the complementary strand at an internal site creating a small displacement loop and a large double-stranded “t-loop.” Our goal is to determine whether all telomeres adopt the t-loop configuration, or whether there are two or more distinct configurations. Progress in optimizing super-resolution (SR) microscopy for this ongoing investigation is reported here. Results suggest that under certain conditions sample preparation procedures may disrupt chromatin by causing loss of nucleosomes. This finding may limit the use of SR microscopy in telomere studies.
Los Alamos National Laboratory, Center for Integrated Nanotechnologies, P.O. Box 1663, Bikini Atoll Road, SM-30, Los Alamos, New Mexico 84545, United States.
Mary Lisa
ML
Phipps
Los Alamos National Laboratory, Center for Integrated Nanotechnologies, P.O. Box 1663, Bikini Atoll Road, SM-30, Los Alamos, New Mexico 84545, United States.
Peter M
PM
Goodwin
Los Alamos National Laboratory, Center for Integrated Nanotechnologies, P.O. Box 1663, Bikini Atoll Road, SM-30, Los Alamos, New Mexico 84545, United StatesbLos Alamos National Laboratory, Institute for Materials Science, P.O. Box 1663, Bikini Atoll Road, SM-30, Los Alamos, New Mexico 84545, United States.
Jennifer S
JS
Martinez
The New Mexico Consortium, 100 Entrada Drive, Los Alamos, New Mexico 87544, United States.
Edwin H
EH
Goodwin