Thermosensitive Mutants of E. coli Affected in the Processes of DNA Synthesis and Cellular Division

The division cycle of a bacterium involves a complex series of events. In a cell, which contains one or two nuclei, the DNA is replicated so that two or four nuclei are formed; the cell elongates and the DNA replicas progressively separate from each other; a septum is then formed near the equatorial plane of the cell so that two cells, each one containing half the DNA content of the mother cell, are formed and separate from each other (Robinow, 1944).