Autoradiographic studies of the replication of satellite DNA in the kangaroo rat. Autoradiographs of satellite DNA

Cells of the Kangaroo rat Dipidomys ordii contain large quantities of satellite DNA (Bostock et al., 1972). Radioactive DNA from such cells has been examined by autoradiography. After a long period of radioactive labeling, long tandem arrays of short radioactive pieces are suddenly observed which are attributed to the replication of satellite DNA. Autoradiograms of DNA isolated by CsCl density centrifugation from such lysates are in agreement with this hypothesis.This material is non-randomly distributed in lysates of single cells. The length of these pieces and their spacings are not remarkably different from DNA made earlier (presumably non-satellite DNA).