INDUCTION OF CROWN-GALL - PARTIAL HOMOLOGY BETWEEN TUMOR-CELL DNA BACTERIAL DNA AND G+C-RICH DNA OF STRESSED NORMAL CELLS

The mechanism of Crown-gall tumor inception has been studied by DNA-DNA hybridizations: 1o) there are common sequences between bacterial DNA and the transformed (bacteria free) cell DNA, while no detectable homology occurs with normal cell DNA; 2°) homology is shown to exist also between bacterial DNA and the Nuclear heavy satellite DNA appearing in normal stressed cells; this raises the question of the origin of the integrated new sequences. These results confirm on molecular grounds the hypothesis of a Tumor Inducing Principle and of active sites provided by the wounded host. Formation of a duplex between bacterial DNA and the Nh satellite DNA synthetized during wounding is proposed to be an obligatory step before the true integration of genetic material, provided by the bacteria and/or the host itself. © 1969.