Mouse satellite DNA. Further studies on its biological and physical characteristics and its intracellular localization

Application of new principles to cesium chloride density-gradient centrifugation has made it possible to isolate native mouse satellite DNA in sufficient amounts for detailed study. The exclusively intranuclear localization of the satellite DNA has been confirmed. Its metabolic stability has been shown to be equivalent to that of the major band DNA, and there is evidence to suggest that it is randomly distributed throughout the nuclear genome in arrays of about 60,000 base pairs. Some physical characteristics of satellite DNA are evaluated on the basis of melting, buoyant density and renaturing properties of both native and sheared material. Evidence is obtained to support the contentions that strands of satellite DNA are highly homogeneous in base composition, and that its rapid renaturing characteristics are not related to inter-strand cross-linking.