& Department of
Medical Genetics

April 7, 1957

Dr. George Klein ~
Institute for Gell Research and Genetics
Karolinkka Institutet

Stockhole 60, Sweden
Dear George:

I have just returned from a trip to Brit&dn to find letter of
March 7. I am delighted to hear #f your result on H2 °/* segregation,
and especially that you are working with precisely known alleles.

What is the ploidy of the changed types? Mitchison has been doing some
reughly comparale experiments, but finds now that the compatibility
change (though it occurs readily only in heterosygous cells) has been
accompanied by hyperploidy, which greatly complicates the interpretation.
(Perhaps this is in your reprint, whioh Crow lmexmestax borrowed from me).

As to the Congresa, of course I will be glad to help you in any way I
can, though the major population of transformists has been pretty well
fixed for a few years. In a tentative way, I would like to tell you that
I would be very happy to participate myself, especially if the Congress can
provide my fare and Esther can can some subsidy elsewhere. However there
are several complications which prevent a fixed commitment now:

1) I will be remarkably busy during the next year, through about the
summer of 1958: a} a 3J-4months trip to Australia on a Fulbright b) the
organization of a new Medical Genetics departasnt here c) the possibility
of moving to Berkeley, which if it happens would probably be about the time
of the Congress or a little later.

2) A symposium on ‘medical genetics! we are having here in Apbil 1958
3) The Genetics Congress, which will be at Montreal in August 1958.

But if I may ask you to make preliminary arrangements on my behalf, es-
pecially in re the travel funds, I will make every effort to arrange to com.
However, it would be impossible for me to mke an irrevocable commitment now.

We will be in Madison until the end of July: if there is any possibility
of your visiting, please do nog dgnore it. With a little time, 1 am sure
ya could also finance your extre travel.

I had heard some talk (mostly Hilary Koprowski's hopes, in the course of
a parallel bid to me) that you might be coming to the States more permanently.
Is this mttled—do you have your professorship and appurtenances of same now?

Sincerely,

i
Pps