THE TRANSFER OF IRRADIATION-ELICITED INDUCTION IN A LYSOGENIC ORGANISM

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Abstract
Results are reported on the transfer of induction from an irradiated lysogenic donor cell (Escherichia coli K12W[center dot]6[center dot]F+) to an unirradiated acceptor cell (E. coli K12W1177[center dot]F-) grown in a medium supporting the growth of the acceptor, i.e., containing leucine, threonine and thiamine, but not the donor, i.e., lacking methionine. After incubation the unlysed cells were removed and the free phage was assayed by plating on the sensitive strain E. coli K12C-600-25. Results indicate that cross-induction is unidirectional, going only from F+ to F-, and that it is dependent on the irradiation of the donor cell, not being merely a form of zygotic induction. Two different mechanisms are proposed. The prophage altered by the irradiation, along with other genetic material of the donor cell, may enter in toto during conjugation into the receptor cell; or some other irradiation-altered molecule may penetrate and initiate induction in the receptor cell as it would in the originally irradiated cell. Two different lines of evidence are offered which support the second mechanism.