SOUTHERN ILLINOIS UNIVERSITY

c A R 8 o N DB A ft E 1 t L 1 N fo] t s

December 30, 1974

Dear David:

I remember visiting Malloch and talking with him about
Tetrasperma. I do not know if he worked with Dodge in New York
as I did, but he looked at the problem in mich the same way as
Dodge did, Both of them were impressed by Tetrasperma. I did a
little work on Tetrasperma at Dodge's insistance, but soon gave it
up for crassa. All of Dodge's genetical work was done on sitophila,
but I think my crassa cultures sporulated a little better so I chose
it. Malloch and I never exchanged cultures either way.

I inbred the mutant Neurospora stocks, as you will see in
my earlier papers, for ten or eleven gererations. I never outcrossed
it into other stocks so it was extremely homozygous and highly inbred,

In 1941 when wa were at Washington Universityiin St. Louis,
Beadle wrote requesting.cultures. He said that he was interested in
starting work on the sugject. I sent him the cultures marked for the
genes in the first chromosome, pale, gap, crisp —- and -. Although
I had started working on yeast, Jerry still maintained the Neurospora
stock and had done a few crosses. We had just finished spending a
year with Lew Stadler demonstrating the use of microconidia in U. V.
and X-ray mutation experiments.

The Neurospora stocks were, as I said, highly inbred and gave
no evidence of high, second-disision Segregation of sites of affinity,
although a German worker Studying, I think, smuts found 90 percent
sactdnd division segregation in smut and I think his name was Bauch.

The Saccharomyces stock that we use was produced from a highly
cross bred cultures; sites of affinity abound in this stock. I suggest
you look for second division Segregation not due to crossing over in
your cultures. I made some earlier studies of hybrids between sitophila
and crassa as well as between Sitophila and tetrasperma with the most
unusual results, I could not understand them. I think pertinent to my
current interest in sites that this would be an interesting field.

With warm regards

Sincerely [}

UGK
Carl c. Lindegren