title: Spatial distribution analysis of AT- and GC-rich regions in nuclei using corrected fluorescence resonance energy transfer.
abstract: We employed microscopic intensity-based fluorescence resonance energy transfer (FRET) images with correction by donor and acceptor concentrations to obtain unbiased maps of spatial distribution of the AT- and GC-rich DNA regions in nuclei. FRET images of 137 bovine aortic endothelial cells stained by the AT-specific donor Hoechst 33258 and the GC-specific acceptor 7-aminoactinomycin D were acquired and corrected for the donor and acceptor concentrations by the Gordon's method based on the three fluorescence filter sets. The corrected FRET images were quantitatively analyzed by texture analysis to correlate the spatial distribution of the AT- and GC-rich DNA regions with different phases of the cell cycle. Both visual observation and quantitative texture analysis revealed an increased number and size of the low FRET efficiency centers for cells in the G(2)/M-phases, compared to the G(1)-phase cells. We have detected cell cycle-dependent changes of the spatial organization and separation of the AT- and GC-rich DNA regions. Using the corrected FRET (cFRET) technique, we were able to detect early DNA separation stages in late interphase nuclei.
authors.affiliation: Department of Pathology, University of Yamanashi School of Medicine, 1110 Shimokato, Tamaho-cho Nakakoma-gun, Yamanishi, Japan 409-3898. smurata@res.yamanashi-med.ac.jp
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Murata
authors.forename: Petr
authors.initials: P
authors.lastname: Herman
authors.forename: Kunio
authors.initials: K
authors.lastname: Mochizuki
authors.forename: Tadao
authors.initials: T
authors.lastname: Nakazawa
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kondo
authors.forename: Nobuki
authors.initials: N
authors.lastname: Nakamura
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Lakowicz
authors.forename: Ryohei
authors.initials: R
authors.lastname: Katoh
mesh_terms: D020856:AT Rich Sequence; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D002417:Cattle; D002453:Cell Cycle; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D002478:Cells, Cultured; D004247:DNA / Q000032:analysis; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D031541:Fluorescence Resonance Energy Transfer; D020862:GC Rich Sequence
chemical_list: D004247:DNA