Nucleic Acids of Bovine Lymphosarcoma and Normal Thymus1

Prior work has shown that mild alkaline hydrolysis of nuclei previously extracted with cold dilute acid and with lipid sol vents yielded not only the expected RNA nucleotides but also free adenine and guanine in amounts which varied in versely with the extent of preliminary lipid extraction. The nucleic acid of the nuclei was identified as the source of the free purines. The experiments described here demonstrated that the DNA of the nuclei was the source of the free adenine and probably also of the guanine, and that the conditions to which the nuclei had been subjected were such that significant amounts of purines could not have been removed from isolated DNA. The combined results support the hypothesis that the DNA contains purine deoxyribotides with direct or indirect linkages to lipid which render the deoxyribosidic bonds labile to hy drolysis following extraction with lipid solvents. The lymphosarcoma was found to have a high nuclear ribonucleic acid content when compared with thymus and myo cardium. The cytoplasmic and nuclear ribonucleic acids of the lymphosarcoma were unusual in that each had a high cytidylic acid content. In the analyses of the base content of the DNA, statistically significant differences between lymphosarcoma and thymus were found with respect to adenine and thymine.