Zur Herkunft des in der Transduktion durch den Phagen P22 übertragenen Materials

Abstract

The inactivation of the lytic and the transducing activity of phage P 22 was measured by the decay of incorporated P32. if the multiplication of the phage occurs in a radioactive medium and in bacteria previously grown in this medium for several generations, both activities of the phage offspring are inactivated. If only the bacteria are labelled, while the medium used for the multiplication of the phages is non-radioactive, only the transducing ability shows a decrease during the decay of the incorporated radio-phosphorus. This indicates that the material carried over from one bacterium to another in the transduction process was at least in part assimilated by the donor bacteria, before these were infected with the phage. Therefore, this material is probably at least in part original bacterial deoxyribonucleic acid. After one division of the hot bacteria in a cold medium a radioactive and a nonradioactive unit, which can be carried over in transduction, are segregated. The results are interpreted and discussed.