WASHINGTON (Eh UNIVERSITY

 

SCHOOL OF MEDICINE
SAINT LOUIS

DEPARTMENT OF BACTERIOLOGY
EUCLID AVENUE AND KINGSHIGHWAY June 14 1946
3

Mr. J. Lederberg

Yale University

Osborn Botanical Laboratory
New Haven, Connecticut

Dear Josh:

I am sending off today a copy of our pombe culture. With
reference to the cerevisiae haploids, we are testing whatever
stocks we have available for viability. Unfortunately, we do
not use these in our work and so they are not very well taken
eare of. If you should fail to get haploids from me within the
next two weeks, I suggest you write to Lindegren who I am sure
has a large collection easily available. It seems to me that in
the long-run such haploid stocks from cerevisiae would be your
best bet, since it can be kept haploid indefinitely. So far as I
know, according to our experience with pombe there is differentia-
tion into mating types so that one single spore cultures were ob-
tained they would remain haploid indefinitely. You were probably
thinking of octosporous when you thought that heavy illegitimate
diploidization occured.

Sincerely yours,

s

S. Spiegelman

SS:mm