fig3

Figure 3. Bottlenecking effect. Only a small number of the initial recipient population become transconjugants, and only a small number of this population undergo chromosomal insertion or homologous recombination. (A) With CTns and suicide plasmids, the reduction in population is compounded during serial steps. (B) With autonomously replicating plasmids, the population can be recovered between conjugation and chromosomal insertion/homologous recombination. Initial wild-type population (yellow), transconjugants (grey) and chromosomal insertion generating desired mutants (green).