[Properties of rat liver chromatin bound to the nuclear membrane]

The chromatin--nuclear membrane complex was isolated from the interphase nuclei of rat liver. The complex contains all the structures typical for the nuclear membranes in situ, i.e. pores, inner and outer membranes, fibrous layer and chromatin layer made up of nucleomeric granules (phi 20-30 nm) attached to the inner nuclear membrane. The content and molecular weight of DNA in the complex depend on the duration of treatment of the nuclei with DNAase. This DNA does not differ from the total nuclear DNA in terms of its molecular heterogeneity (reassociation kinetics) and frequency of pyrimidine oligonucleotides of different lengths (n = 1-8), but contains by 25% less 5-methylcytosine. The chromatin bound to the nuclear membrane has a far lower amount of histone H1 and is, in all probability, a special fraction of nuclear DNP.