The three dimensional (3D) structure of chromatin fibers in sections of nuclei has been
determined using electron tomography. Low temperature embedding and nucleic acid …

The predominant view of chromatin structure is that the beaded chain of nucleosomes is
folded into a symmetrical helical fibre. Recently, however, direct evidence from cryoelectron …

The" 30-nm" chromatin fibers, as observed in eukaryotic nuclei, are considered a discrete
level in a hierarchy of DNA folding. At present, there is considerable debate as to how the …

Chromatin structure plays a fundamental role in the regulation of nuclear processes such as
DNA transcription, replication, recombination, and repair. Despite considerable efforts …

Both intact and nuclease-isolated chromatin fibers have been examined at different degrees
of salt-induced compaction, using a variety of preparation techniques. The results suggest …

The last years have witnessed rapid progress in our understanding of chromatin structure at
the nucleosome or beads-on-a-string level (Elgin and Weintraub 1975; Kornberg 1977) …

The DNA helix is coiled in the nucleohistone fiber in a nonrandom, precise manner. At one
end of the coiling spectrum we have the nucleosome and at the other end the metaphase …

The architecture of the chromatin fiber, which determines DNA accessibility for transcription
and other template-directed biological processes, remains unknown. Here we investigate …

The in situ three-dimensional organization of chromatin at the nucleosome and
oligonucleosome levels is unknown. Here we use cryo-electron tomography to determine …

The basic structural elements of chromatin and chromosomes are reviewed. Then a model
involving only three architectural motifs, nucleosomes, chromatin loops and transcription …