National Institute of Genetics
Yata 1111, Misima, Sizuoka-ken
Japan

Jan. 12, 195)

Dr. Joshva Lederberg

Genetics Department

University of Wisconsin

Madison, Wisconsin

U. S. A. : -

Dear Dr. Lederberg:

I am very grateful to you for your kind information and advise
on the comretition for a research assistantship. I will send you a
formal aprlication with letters of reference as soon as possible
when I shall receive it. I shall be very glad if they were considered
for the competition.

My chief interest is in the biochemical] mechanism cf mtation,
and I am using the biochemical mitants of Ustilago for neither
biochemical analysis of some metabolic processes nor genetical ana-
lysis of Ustilago bvt studying the nature of the mutational processes.
The interesting information in this field may be obtained from the
researches on the relations between induced mtation and chemical
mutagen. I have studied mainly alomg this direction since; but the
actions of the mutagens are always none-specific and indirect, and
such research seems always a gap between chemical action and genetic
change in spite of many skilful work by Dr. Demerec and others.

When I have read your parers on transduction I have thought thet this
phenomenon may be vseful for supplying the gap mentioned above,
because it has been proved on the more common heritable characters
than transformation and, as thovgh it is regarded as a sort of
recombination rather than directed induced mutation, it points out
that there are more srecific and direct relations between trans-
missible agent and genetic change than the case of chemical mutagen
and induced mutation. I have interested on the phenomenon since,

and I think that I shal? be very happy if I can study in your labo-
ratories svch problems as the genetical signification of transerction,
for example the mechanism of the action of transmissible agent or

the comparison among recombination unit, transduction unit and
mutation unit. I also think that the learning of the special teécl:-
nigqves in bacterial] genetics which developed in your laboratory, e.g.
recombination analysis, screening of mutant, single cell isolation
and others, are very useful for my research in future, because they
are indispensable for the detailed research on bacterial mutation
and may be applied to the genetical study of the single-cell
organisms other than bacteria.

T am going to aprly for the Fulbright travelling grant in the
spring competition, and I shall be very glad if you wovld kindly
tell me the time when the result of the competition for the research
assistantship is informed. ,

Thanking you heartily,
Yours sincerely