PERIODIC INDUCTION OF DEOXYRIBONUCLEASE ACTIVITY IN RELATION TO THE MITOTIC CYCLE.

The behavior of developing anthers has been studied with respect to deoxyribonuclease. This enzyme, in contrast to related hydrolytic ones, is sharply periodic in its activity. Whenever a pool of deoxyribosides appears in situ, it is preceded by the appearance of deoxyribonuclease. The duration of pool or enzyme does not exceed and is generally less than 12 hours, even though the life span of the cells concerned is of the order of 25 to 30 days. The significance of periodic enzyme induction is discussed in relation to cell morphogenesis.