Intranuclear distribution of satellite DNA from kangaroo rat

Nuclei, nucleoli and three chromatin fractions of varying density were prepared from the livers of kangaroo rats, which have an unusually large content of two satellite DNAs. These components were incubated with sodium dodecyl sulfate and Pronase and were submitted to analytical buoyant density ultracentrifugation in CsCl gradients. The nucleoli and heavy chromatin fractions were markedly enriched in the satellite DNAs. The distribution was similar to that previously reported in the laboratory mouse; however, in the kangaroo rat about 48% of the total cell DNA was present as satellites.