Summary
Lambda virC mutant, presumably an operator mutant for the operon including x, y, CII and O genes (Fig. 1), produce clearish plaque on a λ sensitive bacteria.
Four revertants producing turbid plaques were isolated from λvirC and the mutational sites of which were studied. One (tw 1) is located very close to and on the left side of virC34, and another (tw 32) is at the almost same site of virC34. The others (tx 6 and tx 53) are located on the right side of virC34. λtx recombinants have been isolated and characterized. These recombinants produce very turbid plaques and the rate of the repressor formation in the presence of CIts repressor is somewhat higher than that of λ wild type. λtx develops very poorly after infection to λ sensitive cells but λCItx develops normally. λtx lysogens synthesize two to three times more λ exonuclease than the wild type λ lysogen. On a function of x region for the repressor formation and on a presence of a possible anti-repressor were discussed. The mutant tw 1 might be a promotor mutation of the CI-rex operon.
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Communicated by H. Ozeki
This material has been published as an abstract in Jap. J. Genetics 45, 474 (1970).
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Fujii, S., Horiuchi, T. Studies on lambda virulent mutants. Molec. gen. Genet. 118, 287–294 (1972). https://doi.org/10.1007/BF00333465
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DOI: https://doi.org/10.1007/BF00333465