DNA polymerase activity of lymphocyte nuclei of cattle lymph in the normal state and in lympholeukemia.

A comparative study wad made of the DNA polymerase activity of lymphocyte nuclei of cattle lymph in the normal state and in lympholeukemia. No significant differences were found in the specific DNA polymerase activity of the nuclei of normal and leukemic lymphocytes, both in the absence and in the presence of exogenous "activated" DNAs. The DNA polymerase activity of both types of nuclei was a maximum at pH 7.8 and a Mg2+ concentration of 4--6 mM. The DNA polymerase activities of lymphocyte nuclei of the lymph of healthy and leukemic animals did not differ in sensitivity to the inhibiting action of actinomycin D and in thermal stability. It was concluded that in cattle lympholeukemia, there are no significant changes in the DNA polymerase system of lymph lymphocyte nuclei.