[Structural organization of chromatins from two divisions of rat brain, using micrococcal nuclease]

The cell nuclei of cerebellum and large hemispheres of rat brain were treated with micrococcal nuclease (EC 3.1.4.7); the resulting DNA fragments were separated in 4% polyacrylamide gel. The experimental data are indicative of differences in the structural organization of chromatins from different divisions of the brain: the average value of the repeating DNA sequences of chromatin from the large hemispheres was 184 base pairs against 199 in case of cerebellar chromatin. The DNA fragment incorporated into the nucleosomal nucleus contained 140 base pairs in both chromatin preparations. The dependence of the size of the DNA "bridge" between the vicinal nucleosomal nuclei on the protein composition and template activity of chromatin preparations is discussed.