YALE UNIVERSITY
OSBORN BOTANICAL LABORATORY
NEW HAVEN, CONNECTICUT

 

August 26, 1946.

Dear Dr. Sonneborn,
Thank you for your reprints and for the literature references

you sent earlier. They mve been, need I Say, most interesting.

II

Numarous other recombination types have been found in E coli,
corrobarating the account given at Cold Spring Harbour , and supporting

quite conclusively, I think, the hypothesis of a 'sexual' phase.

Sonneborn mss.
Manuscripts Department, Lilly Library

‘he recombination types are by no means equally prevalent in mixed cultures,
suggesting that there may be some linkages. “esistance to Tl, thiaminless,

and in other crosses, threonineless have, however, segregated sufficiently

 

| tndiane University, Bloomington, Indiana

clearly and independently that there must hed a genic basis to these

characters (andthe others as well undoubtedly).
ve are eontinuing the E. coli work, but are studying other bacteria
now as well, having just begun, in particular with Salmonella. In a dis-—

cussion with Kimball, the analogy of phase variation to the self-differen-

4NLS Matverlas

tiation of mating types in P. bursaria was pointed out. Do you know whether
anything has been done since 1942 on that problem? ‘hat do you think about
it? Finally, has any attempt been made to differentiate nating types on a
serological basis?

Very sincerely yours,

quoted or reproduced without permission

of copyright holder.

Joshua.

 

is covered by copyright and may not be

, for nelerence Use Uniye