FIG 3.

Transition graph for the ecological model of S. Tm, group B colicin plasmid and phage based on ordinary differential equations. The S. Tm population was structured into six compartments, according to the presence of prophage (right column), colicin plasmid (middle row) and induction of colicin expression and lysis (red cells, lower row). The S. Tm population is denoted with $s$, the superscript indicates the presence (+) or absence (−) of the prophage, and the subscript indicates the presence (+) or absence (−) of the plasmid. The additional c in the subscript indicates that the bacterium is producing colicin. $s_{-}^{-}$, S. Tm without colicin plasmid and without prophage; $s_{-}^{+}$, S. Tm without colicin plasmid and with prophage; $s_{+}^{-}$, S. Tm with colicin plasmid and without prophage, not producing colicin but immune to colicin; $s_{+}^{+}$, S. Tm with colicin plasmid and with prophage, not producing colicin but immune to colicin; $s_{+c}^{-}$, S. Tm with colicin plasmid and without prophage, producing and immune to colicin, no colicin release; $s_{+c}^{+}$, S. Tm with colicin plasmid and with prophage producing and immune to colicin, colicin release. Furthermore, free phages (Φ), free colicin (C), and a competitor population (e) are shown. See Text S1 in the supplemental material for further details of the model.