Chromatographic profiles of deoxyribonucleic acid preparations from rat and mouse tissues.

Experiments by Bendich et al. (1, 2) and by Polli and Shooter (3, 4) have suggested that the deoxyribonucleic acids might be tissue specific. Bendich et al. (1) found that the DNA of rat spleen, kidney, brain, and intestine could be distinguished by their chromatographic profiles on diethylaminoethyl-cellulose. The chromatographic differences between rat kidney and brain DNA were particularly pronounced. Polli and Shooter (3) studied the sedimentation coefficient distribution curves at infinite dilution of DNA preparations from normal human leucocytes or spleen, and from human lymphatic leukemia or myeloid leukemia. Differences between the samples were observed and the following hypotheses were suggested to explain the differences: (a) Variations were associated with the average degree of maturity of the cells; (6) variations were due to the presence of different proportions of the types of cells, or (c) specific changes occurred in the deoxyribonucleic acid of all the cells. It is apparent that problems of considerable genetic importance are raised by the above results. However, the differences in the DNA chromatographic profiles of various rat tissues have not been confirmed by Kondo and Osawa (5). The fractionation of DNA on substituted cellulose anion exchangers has also been under study in this laboratory (6-11). Several Ecteola-cellulose’ anion exchangers of varying nitrogen content and exchange capacity have been employed to study the DNA chromatographic profiles of normal tissues and tumors. DNA preparations from the following rodent tissues have been investigated: rat spleen, kidney, and brain, and mouse spleen, kidney, lung, liver, and thymus. In agreement with the results of Kondo and Osawa (5), it was observed that the DNA chromatographic profiles of the various tissues of the same animal were rather similar.