Chromatin structure and function in proliferating cells.

The conclusions that we would like to draw from this review are the following: (a) Chromatin structure and function are exceedingly sensitive to changes in the proliferative state of a cell. Differences can be detected between cells in mitosis, G1 and S, and even between G0 and G1 cells. (b)These differences are very unlikely to be artifactual, since similar changes can also be demonstrated in intact nuclei. (c) Some of these differences can be abolished by extraction of chromatins with low concentrations of salt. (d) Differences between chromatins of normal and neoplastic cells can also be detected, but they are largely related to differences in the extent of cell proliferation. (e) A number of laboratories have been very busy in trying to elucidate chromatin structure with different technologies. Sometimes a change in a macromolecule cause by a physiological stimulus can tell us as much about its structure as a thousand instruments. The changes occuring in chromatin of proliferating cells could perhaps be profitably used to know more about chromatin structure.