August 25, 1954

bear M. Renaud:

I have been reading with great interest your remarks
on the dicaryophase of yeast. The most recent of your papers
to which I have had a reference appeared in 1946 (Rev. gen.
Bot., 53); 4f there are later papers on the subject that I
should read, I would appreciate your telling me of then. In-
deed, I would be most grateful to you for any reprints that
may still be available.

tédg¢ There are several aspects of gnetic study that
might clearly benefit from a consideration of the dicaryo-~
phase, and this is in fact the basis of my interest. Do you
know of any heterothallic Saccharomyces that display this
phenomenon to an appreciable degree, or can you suggest
the techngdues that might be likely to provoke the persis~
tence of the dikaryophase? in material already perfected
for genetic study? I am particularly anxious to develop a
method for recovering haploid buds (containing nuclei that
have not undergone karyogamy) but which correspond to a
fusion of the cyteplasm.(i.e. plasmogamy) of the perental
gametes. I would appreciate any advice that you can offer
on the subject, and would be: rdoubly indebted to you for any
yeast strains that would be relevant (e.g. Pouilly # or
Quincy #6, though of course heterothallic types would be
very much preferred. )

My pp ag Ce tt ip
Joshua IL aerberg

( roprs syncerely,
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{ (j Professor of Genetics

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