February 27, 1956

Dr. Herschel Roman
Department of Botany
University of Washington
Seattle, Wash.

Dear Dr. Roman:

One of my graduate stadents, Robert 1. Wright, who was already especially
interested in yeast genetics has been working on some aspects of cytoplasmic
inheritance, particularly transmission of respiratory determinants through
dikaryotic stages (per Powell). But we have been beset by one technical
obstacle after another, particulary the high incidence of petites axong
UV induced auxotrophs, and the accumlation of the cytoplasmic defect in
stocks which purportedly carry the segregational marker only.

It would be quite helpful in fighting out of the morass if we could
hawa as a point of departure a non-petite red-adenineless haploid of either

mating type (preferably both), and I thought you might be the best person
of whom to ask the favor, for which we would be much obliged.

Do you ever find yourself in this part of the country? If so would you
consider paying us a visit— and let us know when you may be, say, near Chica go?

We saw'Hruss'at the symposium at Detroit hn November, where he gave his
usually high standard of exposition ani may have made even some enzymologists
appreciative of morphogenesis. But some of these troubles had not yet arisen
at that time.

Sincerely,

Joshua Lederberg
Professor of Genetics