Summary
Hfr, F+, and F-prime cells are, unlike F− cells, insensitive to an excess of Hfr donor cells, indicating that there is an F factor mediated immunity to lethal zygosis (Ilz). Results with Flac episomes carrying traJ, traS or various polar mutations in the tra region indicate that this immunity is independent of surface exclusion, of traJ control, and of all known genes within the tra operon. However, analysis of a series of strains with deletions in the F factor, extending from the right into the tra region, suggests that a gene for immunity to lethal zygosis is located within the tra region. We therefore conclude that Ilz is genetically complex, and present a hypothesis to account for these results.
Similar content being viewed by others
References
Achtman, M., Helmuth, R.: The F factor carries an operon of more than 15x106 daltons coding for DNA transfer and surface exclusion. Microbiology 1974 (D. Schlesinger, ed.), pp. 95–103. Washington, D.C.: American Society for Microbiology 1975
Achtman, M., Willetts, N., Clark, A.J.: Beginning a genetic analysis of conjugational transfer determined by the F factor in Escherichia coli by isolation and characterization of transferdeficient mutants. J. Bact. 106, 529–538 (1971)
Achtman, M., Willetts, N., Clark, A.J.: Conjugational complementation analysis of transfer-deficient mutants of Flac in Escherichia coli. J. Bact. 110, 831–842 (1972)
Curtiss, R., Caro, L.G., Allison, D.P., Stallions, D.R.: Early stages of conjugation in Escherichia coli. J. Bact. 100, 1091–1104 (1969)
Daniell, E., Abelson, J.: lac messenger RNA in lacZ gene mutants of Escherichia coli caused by insertion of bactriophage Mu. J. molec. Biol. 76, 319–322 (1973)
Demerec, M., Adelberg, E.A., Clark, A.J., Hartman, P.E.: A proposal for a uniform nomenclature in bacterial genetics. Genetics 54, 61–76 (1966)
Helmuth, R., Achtman, M.: Operon structure of DNA transfer cistrons on the F sex factor. Nature (Lond.) 257, 652–656 (1975)
Ippen-Ihler, K., Achtman, M., Willetts, N.: Deletion map of the Escherichia coli K-12 sex factor: the order of eleven transfer cistrons. J. Bact. 110, 857–863 (1972)
Lederberg, J., Cavalli, L.L., Lederberg, E.M.: Sex compatibility in Escherichia coli. Genetics 37, 720–730 (1952)
Skurray, R.A., Hancock, R.E.W., Reeves, P.: Con− mutants: A class of mutants in Escherichia coli K-12 lacking a major cell wall protein and defective in conjugation and adsorption of a bacteriophage. J. Bact. 119, 726–735 (1974)
Skurray, R.A., Nagaishi, H., Clark, A.J.: Molecular cloning of DNA from the F sex factor of Escherichia coli K-12. Proc. nat. Acad. Sci. (Wash.) 73, 64–68 (1976)
Skurray, R.A., Reeves, P.: Characterization of lethal zygosis associated with conjugation in Escherichia coli K-12. J. Bact. 113, 58–70 (1973a)
Skurray, R.A., Reeves, P.: Physiology of Escherichia coli K-12 during conjugation: altered recipient cell functions associated with lethal zygosis. J. Bact. 114, 11–17 (1973b)
Skurray, R.A., Reeves, P.: F factor-mediated immunity to lethal zygosis in Escherichiia coli K-12. J. Bact. 117, 100–106 (1974)
Taylor, A.L., Trotter, C.D.: Linkage map of Escherichia coli strain K-12. Bact. Rev. 36, 504–524 (1972)
Toussaint, A.: Insertion of phage Mu.1 within prophage λ: a new approach for studying the control of late functions in bacteriophage λ. Molec. gen. Genet. 106, 89–92 (1969)
Willetts, N.: The genetics of transmissible plasmids. Annu. Rev. Genet. 6, 257–268 (1972a)
Willetts, N.S.: Location of the origin of transfer of the sex factor F. J. Bact. 112, 773–778 (1972b)
Willetts, N.: Mapping loci for surface exclusion and incompatibility on the F factor of Escherichia coli K-12. J. Bact. 118, 778–782 (1974)
Willetts, N.S., Finnegan, D.J.: Characteristics of Escherichia coli K-12 strains carrying an F prime and R factor. Genet. Res. 16, 113–122 (1970)
Author information
Authors and Affiliations
Additional information
Communicated by W. Arber
Rights and permissions
About this article
Cite this article
Skurray, R.A., Willetts, N. & Reeves, P. Effect of tra mutations on F factor-specified immunity to lethal zygosis. Molec. Gen. Genet. 146, 161–165 (1976). https://doi.org/10.1007/BF00268084
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00268084