This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The fluorescence lifetime imaging technique (FLIM) was applied for lifetime imaging of the cell DNA. Nuclear DNA of 3T3 fibroblasts was stained by YOYO-1 dye which exhibits different lifetimes when bound to AT and GC base-pairs. The experiment allowed to monitor distribution of AT and GC-rich regions of the nuclear DNA as a function of the cell cycle without being biased by a nonuniform DNA concentration in the nucleus. Topological reconfigurations and proximity of the AT and GC-rich regions were also studied by a fluorescence resonance energy transfer (FRET) using AT-specific dye Hoechst 33258 as a donor and GC-specific acceptor 7-Aminoactinomycine D. Experiments all three dyes were performed on an ensemble of 50-100 cells and results were statistically analyzed by a texture analysis. Results reveal existence of spatially well-separated AT and GC-rich DNA domains the size and number of which changes during the cell cycle.
Showing the most recent 10 out of 44 publications
