KINETICS OF GENETIC RECOMBINATION IN ESCHERICHIA COLI K-12: COMPETITION BETWEEN GENETIC INTEGRATION AND DEGRADATION

Jonathan T. Ou ¹ and Thomas H. Wood ¹

¹ Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104

The effect of shifting zygotes from a rich medium into a poor medium (shift-down) on the frequency of recombination has been examined; our results suggest that protein syntheses other than those required for growth may be involved. Experiments with chloramphenicol support this notion, and further suggest that there is a competition between genetic integration and degradation in the recipient cells. By inhibiting protein synthesis one can shift the competition in favor of either integration or segregation, depending on the physiological state of the zygotes. By calculating the time required for segregation as one generation, we conclude that the recombination chromosome is homozygous at the time of integration.