January 23, 1952

Dr. A. H. Doermann

Kerekhoff Laboratories of Biclogy
California Institute of Technology
Pasadena 4, “aiifornia

Dear Gus:

I'll be interested to hear the results of the UV experiment on
lysis-inhibited celis, however it comes *t, ard with dus account
to your reservations. If you're going to Caltech, youtll nrobably
hear no end of iysogenicity discussion.

I doubt very much whether the croble ta of Jinksos in K-12 are
very pertinent to the situation in phage. I have every reason to
suppose that the pecuiiarities wa have found sre not inherent in
the FE. coli genetic system, but are due to throtosom:1 aberrations
in the stocks we have used. Some notion of the hesis of thig idea
wili be sean in print in: Cavalli. 1950 La seseuhlite fed batterd.
sori, £. sieroter. Miian, 29: 1-9; Neweomhe and “Nvhol: 1950 Anomalous
segregation in crosses of FB. coli, Amer. Net., 8/4: 457-455: my abstract
in Genetics, Jan. '50. There is 2 ~ore invelved discussion in the 8SH
iis., but Lim afraid 1 don't hava a cony with all of the tables and
figures that I can send you. It boils down to tha fact thot, by the
criteria of hy 1947 paver, Bl; Mal: Zyl: and Lac cre each Linked to
ay out not in any iinear sequence. Tis "branched" chroacs:me idea has
been somewhat misunderstood: what + have meant fiz the Mikelfhood that
we have a veciprocal translocation between two chromosomes, with 4a
break—point near M. This would give such a genetiv picture. We are
paintuliy building up new stocks, without the use of artififial mitagens,
in hopes of developing a less aberrant picture, I should say that
wothiels nas eae paper in press (Genetics) with a very nice, sound
confirmation of the linear order cf the negment to the "right" of
M with the loci Lac, Vz, T, L. I think that linearity is still the
fundamental system in coli, and each azgregste of fuctors still
behaves all right. Would repetitive mating cause mich trouble in
assessing linear order in phage?

Sincerely,

Joshua Lederberg