Air Mail

Mbit

YALE UNIVERSITY
OSBORN BOTANICAL LABORATORY
NEW HAVEN, CONNECTICUT

June 9, 1950

Dr. E. L. Tatum
Department of Biology
Stanford University
California

Dear Ed: 4

Could I get a culture of strain 58-278 from you? This is the Coli biotin
phenylalanine strain. . Pete has been using this strain to investigate various
resistance phenomena:.and has found that it behaved in an anomalous fashion. The
most peculiar part of its behavior, however, is the fact that when plated on
complete medium, it gives rise to two types of colonies, large colonies and gall
colonies. The large are biotin-phenylalanineless and the anall colonies require
neither biotin nor phenylalanine but do require norvaline. What this phenomenon
actually is we do not know as yet. However, we relt it might be desirable to get
cultures of this strain from other labs and make sure that this is a mixed culture
typical only of our collection or that it has been a mixed culture from the beginning.

Regarding Beam's thesis--satisfactory arrangements Imve been made and we
will appoint a departmental committee of readers. If the readers all find the
thesis acceptable, there will be no oral defense. It seems a trifle ridiculous
to make Carl take the long trip for a formality; thus rather than do this we decided
to call the examination off. You will not be asked to serve as a reader since the
work has been carried out under your direction and we assume that it has your ap-
proval. However, I would appreciate a short statement from you conceming your
opinion of the work. As for the time of his receiving the degree, Miss Stahl tells
me that no degrees will be awarded now until next June. However, the University
will furnish a letter stating that Carl has fulfilled all the requirements for the
degree and will receive it at the next presentation. I was asked to remind Carl
that in order to receive his degree, he must register for one further term, that
if his thesis is in by June 15th, Miss Stahl suggests that he register for the
fall term of next year. You might tell him of this; I too will do so when next
I write him.

We have been doing a little bit of work with the quadruple requirer 7655.
I think you might be interested in the outcome of the recent genetic work. We
have found in backcrossing that it is possible to isolate strains for simply the
phenylalanine tyrosine requirement and that in such asci the anthranillic and paba
requirements have simply disappeared. This is in agreement with some of our work
with NL5 which suggests that 7655 is actually a phenylalanine tyrosineless mutant
and that the requirement for anthranilic and paba results fim some biochemical
abnormalities occasioned by the phenylalanine block. I thought you might be
interested in this information in connection with the activity of sckemic, acid.

(4p2) .
Dot was here recently and told us that you obtained an allele c83. She.
said that you would be happy to send us a culture of it but I thought it best to
working on the: enzyme at the ‘present time.. We would like, therefore, to mke.a

. On your good nature, we would appreciate very much a culture of your C83 alleles.

 

-..Dr, E. L. Tatum
June 9, 1950:

oe

 
 
   
    

. “mention our request ‘directly. ‘to you since I don't wish to cause hard. feelings’ with
--my interest in this strain. We have been doing some work. with C83 and indeed ene.

. “direct comparison of the two enzymes unless you people wish to do that: yourselves.
-.The other thing, of course, that we would like to do is to test it critically
“as:we have done on the 3416 alleles with the possibility of finding additional . fh.

evidence for our complex Neurospora genes. Dot’ said that she did not know whether feo,

you were planning to play with this mutant or not. If this wouldn't be imposing .

“TT: ‘do not know whether I wrote you or not but Sinnott has officially resign-

8 Ved as chairman of Plant Science and Paul has taken over for this coming year.’
- What. this will finally mean in terms of microbiology, is at present, undecided:
since we now have a Microbiology Department. headed by Pete and a Plant Science .

 

a. Department: with ‘strong microbiological inclinations, Time will tell. the outcome.
Best ‘regards to June, Peggy and Barbara,
As ever,

Bo

David M. Bonner.
Associate Professor of Micro biology

 fewa