Letter | Published:

Different ‘Spectra’ of Mutant Types by Extracellular Treatment of Phage Kappa with Differing Mutagens

Naturevolume 199pages932933 (1963) | Download Citation



FOR about twenty years it has been known that the yield of induced mutants has a different type composition in differing mutagenic conditions1. This electiveness of mutagenic action can be either intragenic, intergenie or cell-type specific2. Intragenic electiveness has recently been examined in phage T4 of E. coli especially by Benzer3. This work led to the discovery of sites of high mutability within a gene; the local distribution and the extent of these ‘hot spots’ varies with the mutagenic agent. Since free phage represents extracellular genetic material (DNA) a ‘hot spot’ must be due to the specific nucleotide composition at its site in the DNA which is attacked preferentially by the mutagen. In the case of treatment of cells, mutagenic electiveness could also be an effect of the intracellular environment of the genes but not, or not only, of the DNA-composition differing at different sites within a gene, in different genes or groups of genes. It has been proposed that with forward mutations (for example, auxotrophy) electiveness should not show up as likely as with back-mutations, since the former would be produced by changes at many sites along a gene, while the latter requires a rather specific change at only one or a few points4. No, or only very weak, electiveness should then be expected, especially in forward mutations, if groups of several genes are observed, for example, mutations leading to certain groups of phenotypes.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Knapp, E., and Kaplan, R. W., Z. Vererbl., 80, 501 (1942); Kaplan, R. W., Naturwiss., 33, 348 (1946); Z. Vererbl., 82, 164 (1943/47); Arch. Mikrobiol., 18, 210 (1953); D'Amato and Gustafsson, A., Hereditas, 34, 181 (1948); Kölmark, G., Hereditas, 34, 270 (1953); Demerec, M., Congr. Inertn. Gent., 1, 201 (1955); Glover, S. W., Carn. Inst. Wash. Publ., 612, 121 (1956).

  2. 2

    Kaplan, R. W., in Strahlenbiol., etc., Ergebn., 1952–58, 140 (G. Thieme-Verlag, Stuttgart).

  3. 3

    Benzer, S., and Freese, E., Proc. U.S. Nat. Acad. Sci., 44, 112 (1958); Benzer, S., Proc. U.S. Nat. Acad. Sci., 47, 403 (1961).

  4. 4

    Westergaard, M., Abh. Deutsch. Akad. Wiss. Berlin, E. Baur-Ged.-Vorlesung I, 121 (1960).

  5. 5

    Kaplan, R. W., Winkler, U., and Wolf, H., Nature, 186, 330 (1960).

  6. 6

    Winkler, U., Z. Naturforschg., 18b, 118 (1963).

  7. 7

    Bautz, E., and Freese, E., Proc. U.S. Nat. Acad. Sci., 46, 1585 (1960).

  8. 8

    Lorkiewicz, Z., and Szybalski, W., Biochem. Biophys. Res. Comm., 2, 413 (1960).

  9. 9

    De Serres, F. J., and Osterbind, R. S., Genetics, 47, 793 (1962).

  10. 10

    Crick, F. H. C., Barnett, L., Brenner, S., and Watts-Tobin, R. J., Nature, 192, 1227 (1961).

Download references

Author information


  1. Institute of Microbiology, University of Frankfurt am Main

    • R. W. KAPLAN
    • , H. BECKMANN
    •  & W. RÜGER


  1. Search for R. W. KAPLAN in:

  2. Search for H. BECKMANN in:

  3. Search for W. RÜGER in:

About this article

Publication history

Issue Date



Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.