November 5, 1951

Professor Paul R. Burkholder
Osborn Botanical Laboratory
Yale University

New Haven, Connecticut,

Bear Dr. Burkholder:

Ever since I was at OBL, I have wondered whether a2 genetic analysis of
actinomycetes might not yield reaulte as fruitful «as on B. coli and other
bacteria. I am sure that this thought is not unique, but an act aware that
anyone else has been doing anything about it. Klienberger-Nobel's morpho-
logical swidy of some streptomyoetes has seemed as good a starting point
as any, although her account of a sexual stage in the formation of the
aerial mycelium is not entirely convinoing, and seems to be virtually ig-
nored by some actinpmycetologists. A little while ago, I decided to try
my hand at a genetic atudy with limited objectives; a) to confirm or refute
Kifensberger{s interpretation cf the aerlel aye’btum as diploid, and potentially
heterozygous, and b) less ambitiously, to determine whether (following
Carvajal) hyphak anastomoses occur, resulting in heterokaryosis. All we
need, of course, ard some good markers, but IT don't know at all whether
the mathods worked out for eubacteria will be successful.

I am vritdag, essentially, to ask if you have any thoughts on this mat-
ter-- in particular whether you might not yourself have contemplated or
executed auch a study. Perhaps you could also suggest a species that gight
be especially favorable from the point of view of rapid growth on minimal
media, disparsibility of spores, and so om. Barring that, I had planned,
of course, to work with S. griseus, but if you have any suggestions, and
can provide a culture accordingly, I would anoreciate Sftvery much.

With best regards, gin ay
cerely yours,

Joshua Lederberg
Associate Professor of Genetics