December 24, 1952
[Second reply to your last,
dated Dec. & '52]
Dear Norton:

First let me send you best wishes for the season and the approaching
new year.

The old one, 1951, does not leave without a minor headache, namely that
¥ grossly underestimated reprint requirements for "enetis exchange in Salmo-
nella". Originsll yf ordered 650 which seemed a sufficient number, and would
have been ordinarily, Of these,éiycu should have received 200 by now. About
two months ago, I realized this would be dnadequate and asked to igcrease the
order, but the type hed already been killed! In order to fill my regular mailing
list, I would need 75 (minimum) to 175 (max.) over the 25 still left dyom
the first mailing. Obviously, I will not be able to fill the postaard requests
ee I had hoped, and «ust forward these to you. On the other hand, many of your
own requests may duplicate my list. Unless you have as many as 400, it would
bs simpier for you to send your list to me than vice verea. If I may make a
suggestion, you might have your secretary make out the address labels for all
the reprints fou planned to send out, but forward these to me for checking.
motto sank. the yaa bned(an ans onl she! pm oy retiirin ctlid dette It hove matie, BO
MAb AOL eh aEMArge to have 2 complete listing made, in fuplicate, for future
reference, My experience has been that if any list is to be keot at all, it
hag to be done this eleborately. I am sorry now aot to have arranged to send
out all the reprints from cone address-~it would have been auch simpler, but
it's too late now. I am going to inquire into the costs of a photo-offset
reprinting, and if these are not prohibitive }, will try to arrange to get several
hundred more. As already mentioned to you, this reprint 4s not included in
mailings to Rockefeller itself [except I notice that McCarty slipped by]. I
hove 1 can rely on a sufficient supply to furnish copies to: Dubos, Goebel,
Hotchkiss, Maramarosch, Braun, Horsfall-~all I can remember off hand. There
will be a comparable situation with the Cell Genetics review, but there waa
no helping this. You should get your kepy over tha weekend.

There are som more interesting things to talk about. I wonder if it ian't
time for us to start thinking about collecting the diverse evidence for the
identification @f FA with phage for publication as a second collaborative paper,
There are a number of approaches to this problem all pointing to the same direc-
tion, but we have to be careful of the rigor of each. The consistency of the
whole story has, I know, tended to make me a bit careless about polishing each
angle of each individual approach. I suggest than that we asart collecting the
detailed evidence so that we can go over it critically and decide what more
needa to be done. One item that does need cleaning up is the identification
of the receptor. One anomaly is 5. paratyphi A: Brace has picked up an O mutant
which can be transinduced by PLT22/2. I can confirm this, but the efficiency
is very low. The rate of adsopption of phage will have to be checked, as well as
the nresumed absence of XIIz. On the other hand, I have an excppticnal paratyphi A
from Kauffmann which does carry XIIs, and it should adsorb PLTZ2,. A second
peculiarity appears s% in Boyd's work. PLT22 Appears to be in his Al group.
Boyd records Al as lysing 5. bovis—morbificahs! I could not confirm this with

any of our b-m (and his Al or PLT22), and Boyd's own strain died out. He is
checking some others to see if this can be confirmed, in his own hands. I should
not be too surprised if he was following a second, rough,phage in this case. I
don't know the status of Sodamckasmuxistftewm S. abortus-bovis anent XIi,, but
will check this at Chamblee. Another approach is to block the receptor (preferably
in extracts) with antibody. Spicer is sétting this up, especially the more amusing
experiment whether anti-IV will block XII of IV-XII complexes (and presumably not
of IX-XII). He ia also trying somatic transductions, has some reconstructions that
make the technique promising, but so far has succeeded mostly in consuming a good
deal of serum.

I will assume that you have nailed down the quantitative equivalence of phage
and FA in filtration, adsorption to bacteria, and inactivag$ion by serum. In a sense
these would show that phage and FA are enclosed in tke same kind of skins, but
whether they are cohorts hinder the skin would still be unsettled. How about the
rates of thermal inactivation and of differential centrifugation to clinch this
end of it?

Let me give a quick rundown on some of our more recent experiments.

First,UV effects. All this is on PLT22 adapted to SW543 atrains (still uncertain
whether thle is a mutative adaptation)-— "Q2B". Heavy doses (20 mins) knowk the
plaque forming ability from ca. 107 to ca. 107/mL. I cahhot demunstrate multiplicity
reactivation of the heavily irradiated phage, perhaps because I can't get away from
it. FA initially ca_103, may rise 2-3 fold, as you found, for low doses, finally
decreases to 10 107 /ink so that one can count plaques and transductions (Gal+, but
Fla also tested) on the game olates. The transducees xxuxmmet remain sensitive to
228. Waiting for your records on 22,

X-ray: 200,000 r (sic) gives about 10% survival of phage, ca. 30% of FA (not
very accurate). There may be a rise with smaller doses, but these experiments are
not very promising in view of the tremendeus duses needed throughout, and the small
effects.

Lwoff effect. LT-22 and LT-2(22) not very promising. SW-543(22B) works reasonably
well (lysates to 1010) This phage behaves in, the pane fashion as 22B grown on sensi-
tive 543 in transductions of Gal+ and Plat H or .

Lysogenization: you have the data in my better of 12/14. Another point: As in
K-12 and lambda, infected LT-2 or 543 give rise to mixed or contaminated colonies.
As far as we can tell now, the transductions are not mixed for lysugenicity. Esther
has done a very clean axperiment with lambda-transduction, with a comparable result.
I would concluds that a transduction is, ordinarily, only that part of a progeny
of an infected cell which has become lysogenic. This makes sense only in terms of
segregation, presumably nuclear. A very useful new tool has just come up. In platings.
of PLT22 on LT2 a clear plagqge was noticed, which, purified gave rise to a new phage
we call 22V¥. 22V lyses LT2 almost completely-~ ca. .1% survival in one expt., mostly
rough, mo lysogenic survivors so far-— but LT2(22) as cox registant. An experi-
ment a la Burnet&Lush worked beautifully. Adding 1lO“PLT-22 to 10’ LT-2, followed
after 15 minuted by excess 22V gave 108 lysogenic survivors. This should make it
possible to detsemmine whether the particles in a prep. of PLT22 which transduce are
the same as those which protect against 22¥ by inducing lysogenicity. 22V itself
transduces to SW-435, but rather poorly. I haven't checked adsorption. It strikes me
with some irony that I spent several weeks in'49 l@oking for such a phage or mutant
for lambda, without success, and here this turns up of its own volition, Your letters
have repeatedly mentioned a lytic variant, but as I have already complained
you kept the details in your own mind, and I had no telepathic access to them.
I&ve gone over the letters, and still can't make out the story. Do you keep
carbon copies? I would appreciate it if you could start from scratch about
xeks your interference exparinsnt, the lytic variant, und ths aulbiplicity
axperiment in your letter of 10/31. I shudder at the possibility that you
may ask me to do likewise, but I will ba glad to if T have {nadvertehtly
left out any essentials. ile have to contend with the fact that unlike former
days, your contexts are now no longer the same as minc, and we cannot communi-
caty without being axnlicit.

On phase variation, I have to wait for some more suitable cultures from
Edwards, to find a suitably stable diphasic I can use to test the role of the
phase of the reciplent cells in the transduction experinents.

Sincerely,

Joahua Lederberg

P.S. Do you want 22V, or do you already have it?