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Repeated structure of chromatin in metaphase nuclei of Physarum
Author(s) -
Vogt Volker M.,
Braun Richard
Publication year - 1976
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(76)80280-3
Subject(s) - citation , library science , metaphase , mathematics , physics , operations research , history , computer science , biology , genetics , chromosome , gene
Several lines of evidence suggest that eucaryotic chromatin is organized in a repetitive structure. Digestion of nuclei with endogenous nuclease [ 11, or with appropriate concentrations of micrococcal nuclease [2] leaves most of the DNA in fragments of about 200 nucleotide pairs, or multiples thereof. Two molecules each of histones F2a, F2b, F3, and F4 appear to condense with each 200 nucleotide pair length of DNA to form one ‘nucleosome’ of chromatin [3,4]. These nucleosomes can be visualized as contiguous beads of approximate diameter 60130 A in the electron microscope [3,5-71. The roles of histone Fl and of other proteins in the organization of chromatin structure are not yet clear. Among the macromolecular changes associated with mitosis are cessation of transcription [8,9] and modifications of histones [ 10-131. In particular, phosphorylation of histone Fl has been implicated in chromatin condensation [ 141. Although the total histone content of mitotic and interphase chromatin is the same, it is not known in these cases whether or not the histones are arranged in the same supramolecular structure. In the experiments presented, we addressed ourselves to the question, are the nucleosomes characteristic of interphase also present at mitosis.