Transcription and intragenic recombination in polar mutants of Escherichia coli.

Mitotic recombination within the beta-galactosidase gene was followed in F' merodiploids grown in the presence and absence of inducer. Inducer inhibited recombination when the two mutations in the merodiploid were nonpolar but had no effect when the mutations were strongly polar. These results are interpreted to mean that transcription inhibits intragenic mitotic recombination and that strongly polar mutations inhibit transcription.