MAD Inc i BS

INSTITUTUM SEP j ¢ 1962

SERO-BACTERIOLOGICUM
UNIVERSITATIS

59-1 179a/19

HELSINKI Helsinkg September 12th 1962

Dr. J. Lederberg

Genetics Department

Stanford University Medical School
Palo Alto, California

Dear Josh,

This is the manuscript that I promised to send soon, The
writing took again more time than I hoped, although it is mostly
based on old data. However, I still hope that you would be kind
enough to go through it inanear future. If the first paper is
(or was?) accepted in Genetics I think that this should go in
the same journal,

Meanwhile, I have obtained rather nice linkage data on the
Hy locus: 70 to 80 per cent linkage to the "arom" locus for

7 and : : cuz, Hr Hi Sos" Sweet .
the synthesis of phenylalanine and tyrosine: gt 50% Lex
@ 5/5 ? Vai
Re the Salmonella - Serratia hybrid for density gradient "A oc,

you wrote about. In my opinion the possibilities of obtaining bag
it are rather poor. However, with the purpose being excellent,

I have done the following: immunized a rabbit with Serratia

SM 6-11S (of Baron), to get an immobilising antiserum. Crossed
several of my best 5S, abony Hfr’s with SM 6-11 in a number of Lite, of
soft NA+ Sm + antiserum, or soft minimal agar + antiserum

(you can’t use gelatin with Serratia). So far no swarms have

been produced,

Iino wrote me about Salmonella hybrids alternating between
bienx:i:1.2. He apparently has had better luck than I - I feel
that his selection of recipient was the thing. It will be most
exciting to hear of his results with these hybrids.

We enjoyed Gan’s visit here a lot. He also gave a very good
talk on his work which seems to be a very good and beautifully
done bit of work, We have also seen a number of other people,
the Canns stopped here on their Scandinavian tour - they are
apparently happily settled down in Milan - and the Mitchisons
spent most of their vacation with us,

Yours

Mele