Fig. 2.

IKe-min emerges in passage 41 and spreads to fixation by passage 43 (extinction of IKe-full). Shown is agarose electrophoresis of f1 and IKe genomic preparations from coinfected cells of passages 38–45. Passages are indicated above each lane, and two standards are on the right: IKe-min is a genomic preparation of the minimal IKe phage from passage 50, whereas IKe-full is the IKe used to initiate the experiment. The asterisk indicates the passage in which the minimal IKe genome is first detectable by electrophoresis.