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The beginning of a genetic analysis of recombination proficiency
Author(s) -
Clark A. J.
Publication year - 1967
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1040700412
Subject(s) - complementation , genetics , biology , mutant , lysogen , recombination , allele , escherichia coli , strain (injury) , mutation , phenotype , gene , bacteriophage , anatomy
Recombination‐deficient mutants of Escherichia coli have been isolated as members of a class showing reduced ability to mother recombinants when crossed with a given Hfr strain. All those showing less than one‐tenth the ability of their immediate ancestors in mothering merodiploids have been eliminated from consideration, as have those strains of reduced fertility with only one donor strain. The remainder are all more sensitive to ultraviolet light (UV) than were their immediate ancestors; differences in levels of sensitivity are evident. Mutants have been isolated from two distantly related ancestors, and the sets of mutants from each are divisible into three phenotypic groups. The strains in the first group are the least UV‐sensitive (UV s ), and lambda lysogens of these show normal spontaneous induction. The strains in the second and third groups are more UV s than those in Group 1, and lysogens of these show abnormally low spontaneous induction. Groups 2 and 3 are separable by their levels of fertility with the Hfr strain (KL16) found to transfer the rec + allele of some of the strains early in conjugation. The strains more fertile with KL16 are in Group 2, and those less fertile are in Group 3. Two mutants (JC1553 and AB2463) of different parentage but both in phenotypic Group 2 have been analyzed by transduction; and a single mutation probably determines both their mutant UV s and Rec − phenotypes. When the mutants of different parentage are arranged together, a continuous ranking of fertilities is observed. Preliminary complementation tests show no complementation between those mutations carried by strains in Group 2 and Group 3 which have been tested. Complementation has been observed between those mutations carried by strains in Group 1 and those carried by strains in Groups 2 and 3.