Variation in deoxyribonuclease activity in nuclei of splenic lymphocytes

The nuclei of splenic lymphocytes were shown to contain nuclease activity whose action is manifested under optimal conditions for different types of DNases: DNase I, micrococcal nuclease, Ca, Mg-dependent endonuclease, and DNase II. No such variety of nuclease activity was found in liver and kidney nuclei. The presence of high nuclease activity in the lymphocytes is responsible for the more intensive degradation of their chromatin by endonuclease than in liver nuclei. The diversity of nuclease activity and the more advanced degree of chromatin degradation by endonuclease in splenic lymphocyte nuclei may perhaps be connected with the rapid renewal of the lymphocyte pool in lymphoid organs and the need for autolysis of the genome of the dying lymphocytes. They may also lie at the basis of the somatic mutagenic mechanism of the diversity of V-genes and of the union of the V-and C-genes of immunoglobulins.