Ostober 23, 1952

Dear Ea:

T was very glad to hear a word from you. The cultures you asked for
are enclosed. You may be interested in some of their history.

W-1310 should be identical with Y-109, having come from sister lygophil
tubes. I hanvened to have %-1310 on an opsn slant, but can provide the
other if this misbehaves. Y~117 is an auxotroph mtant of Y-109. Y-109
is a culture that was represented by Boivin to be the "C2" of his trans-
formation experiments (Cold Spr. Harb. Symposium, 1947), and was brought
over by him in person, Tatum ani @ were interested to look for transforma~
tion of biochemical mutant markers, but nothing ever cams of it. Later we
concluded that the strain had gone comlsetely rough (along with the sister
strain, Cl}, Since Boivin's death, we have not bsen able to locate the
smooth parent cultures, an! his colleagues have, in fact , demanded them
of us. Aa it turna ont, wa have worked out a transducing system in Salmo-
nella-— it should be out in next sonth's J. Bact.

Tn addition to these, IT am also sending K-12 and B strains, in case you
should be interested to pley with them. A variety of auxotrophic atants
should be avallauble, including argininelasa. Ne have sons ourselves, and
know where to look for more. Raplica-plating tethniqus, superimposed
on the penicillin method makes amtant hunting an easy pastine.

Now that I can't just waik acrons the street for a friendly call, I
would especially appreciate the favor of = ramilar exchange of publications,
If this can include the Texas Publications from your lab,so much the
better.

*ith best regardeg
Joshua Lederberg

P.3. That "RNA" matant of Paeudomonas turned out to be satisfied with
pyrimidine + citrulline; another wants Big or methionine.

br. BE. E. Snell
Dept. Chemistry
U. of Texas
Austin 12