| Abstract: | ABSTRACT. The role of bacterial endosymbionts in the acquisition of new phenotypic characters was studied by transplanting nuclei from an uninfected strain of Amoeba proteus into the enucleated cytoplasm of a symbiont-carrying strain. After 1–10 cell cycles, the nuclei were tested for two characters: compatibility with uninfected and infected cytoplasm, and their lethal effect against amoebae of the uninfected parent strain. A significant number of transplanted nuclei displayed both of the new phenotypic traits after a few divisions in the infected cytoplasm. Thus the influence of these endosymbionts on the nucleus of A. proteus was virtually instantaneous. |
