January 17, 1957

Dr. P. R. Edwards
Box 185
Chamblee, Ga.

Dear Phil:

I hoped you would realize we had a standing invitation for you, and
the red carpet ready to roll out. We are simply delighted that you can
finally get around the silly obstagles and come to visit us. We hope you
can manage to take two or three days for us, as there are two or three
independent programs here that could benefit from your counsel. The very
least time that you could manage to compressaall that in would be a day
and a half.

We can undertake to pay your excess transportation costs by air, Detroit
to Madison and return, or if you are not being subsidized for the SAB al-
ready, all the way from Atlanta and retum. We are also in a position to
offer a reasonable ‘consultation fee' in addition, but I understand that
you might not be permitted to accept such. If that situation has altered
also, please do let me know, either now, ar during your visit.

The major costs of this are being borne through a project supervised by
Prof. J. B. Wilson at Bacteriology. We would be delighted if you would use
the occasion to give a seminar lecture on Salmonella, or the work of your
laboratory, or any other related topic, so that our students and colleagues
can see something of you. However, this is not obligatory on you, and we
will be more than repaid, and very well pleased, by the chance at some leddurely
discussion of current problems. As you may imagine, a considerable number
of Madisonians will be going to Detroit too (probably not the Lederbergs—we're
travelling too much this year, having been in California over New Years, and
going to England and back in March, then to Melbourne June through September).
I assum you will want to embark fpp the SAB on S&éurday night or Sunday
morning(Apr 27-28)—— NWAirlines has a number of connections. If you would
be interested to talk, wold you let me know if Fri afternoon would be all
right, and your title? I would like, if possible, to fix all the arrangements
before we leave for England (about March 1); however, Professor Wilson will
be here for any last-minute adjustments. So just let us know your schedule.

Your new bug sounds very much like the S. salinatis story. We never have
gotten round to a transductional analysis of that, and though we might in
due course, why don't you go after it. Salinatis might be better, because the
group B~D phage (PLT22) works so nicely, but I don't remember whether the
stock salinatis ie susceptible to it (and therefore usable as a donor in
transduction).
#X On the other hand your new bug has the advangfage of no crogs-rx
between ths a, enx phases. I don't remember whether you have a group F
phage usable in transduction or not.

My hunch is that these cases represent a duplication of the Hy locus,

basically similar to CDC~-137 and its derivatives. In addition, the normal
mechanism of phase~alternation t= has broken down, perhaps because of the
duplication, and the d antigen therefore shows up in both phases. Then S.
salinatis would have ths genotype:
d ,, oh ,, enx
q Hy He .
At least some tests of this hypothesis are possible by transduction.

For example (with, say, typhimurium as the other parent) we might expect
the following:

Donor Recipient Selective serum Exrs cted progeny
1. 4:1.2 ~——X. d,eh:d,enx Brae d,i: d,enx Qe
d,eh: d,1.2 b.

i,eh: 1,1.2 Ce

2. d,eh: d,enx -x 1:1.2 451.2 d:1.2 O-:d,1. 2m od.
eh:1.2 8.
d,eh:d,1.2 f.
iienx g-

not i:d,enx or d,i:d,enx h.

Now, c.is fairly critical, for it shows that the 'd! of each phase is siml1taneously
replaced by Hj“. But at might coms out f,eh:1.2 twit instead.

d. shows that the #,° of salinatis is homologous with H,+ of typhimurium. It is hard

1
to guess whether it would be expressed in both phases of the progeny or not.
d
£. could occur if the i were closely linked to its duplicate, Ho.

8. shows that the enx is genetically injepemient of the d.

I would not expect the h.classes, as they would mean that the H,° was linked wibk

H °™. this could be true, but has no precedent. At any rate, you should not get

2
beth the h. and the f. result, and neither is most probable, Do you think you will
get ,anto this? We cam discuss it better here.

I have all the data collected for that 'H duplication! paper, but just haven't

had time to write it up. If possible, I hpe to have a draft that you can look at
here.

Phil-- can you help us again with some serological typing? Ino has picked up
some cultures in the course of studies with SW-1062 (the 2 monophasig) that have
been rather perplexing. My hunch is they're carrying an ‘artificial phase' mtant
S

he

of 1.2, —- "8 or 9"? but they give a dubious reaction with anti- b, and
this is causing us som trouble. We are sending, under separate cover,
SW-1161 and SW-1162 and would appreciate your remarks on them. Now SW-1161
has a nonmotile phase, and might revert to give a motile-i for that phase,

corresp@nding to BW-1162. (See sashes shipping ticket.) If you're too
busy, please chuck them and let us Enow.

Iino was also interested in Joan Taylor's culture, Col 52955, r,is lw, that

you had sent us last year, But he wasn't able to find anything but rsiw in it.
Have you any suggestion about that? Did you study this culture at all yourself?
Has she written anything up on it?

The Zrskevs have been a pleasure to have here; I had a chance to meet the elder
Grskov wiso earlier this week. Frits and Ida will be writing you soon about their

hopeful plans to travel a little, and I know they want to visit you and BLll
Ewine.

Sincerelys
Joshua Lederberg

Ene.s S/T SW-}}6}; L162