May 20, 1948.

Dr. Orvillé, Wyss,
Dept. Eucterlology,
University of Texas,
Austin,

Dear Dr. Wyss,

It was a pleasure to make the acquaintance of your wife and yourself at the
Minnezpolis meetings. I hope thet we my have an cnportunity sovetime to discuss
at greater loisure than is possible at ao hactic a gathering sone of the many
problems in which we seen to share an’ interest.

“ith respect to two or three of these, may I ask your help now?

Firstly, I sheuld be plaesed to ses the K.A. thesis (which you mentioned at
the meeting) which contains data relevant to recczbination in Staphylcecus. One
of my colleagues in the Brucella abortus program here is making an attempt to use
drug-resistance factors for a recombination test in this crganisan,

Also, when you are ready, Could you advise me as to ycur procedures and results .
in your study of the influence of ultra-violet irradiation on factor exchange in
Fe edli X-12 mtants. If there are any additional stocks that would be useful to
you, plesse let me know. Have you considered the possibility of recombination of
idethal factors in this study? If these plzyed a role, one might expect sone distar—
bance in the linkugo relationships, perhaps a solective recovery of mltiple crossover
typea, although I have not vet worked out the expectations conse-uent to 4 random
placement of lethal mutations, ,

Finally, I should of course be anxious to hear of your results on transformations .
especiaily in E, coli. As I may have told you at Minneapolis, Tatur and i have been
unable to find anything of the sort in Boivin's coli strains, in which he had repor=
ted a transformation of antigenio type. However, there is coneidersble suestion
&3 to the true idontity of the strains in our possession, and our inmiries to
Beivin have not as yet been answered,

with best regards to Ms, Wyss and to Prof. Stone,

Yours sincerely,

Joshua Lederberg
Assistant Professor of Genstics.