The goal of this experiment was to determine if lower temperatures could serve to induce runaway replication for the expression of the lacZ gene in Vibrio species B-18 carrying a different runaway replication vector, pJM9487. One experiment compares β-galactosidase activity in cells incubated at 35, 37, and 39°C while the second experiment examines the enzyme levels for cells incubated at either a low temperature or a high temperature in the presence and absence of the chemical inducer used for the promoter (ptrp) that controls the expression of the lacZ gene on this plasmid.