4.

dys July 4, 1954

Dr. W. Be Cherry
Box 185, Chamblee, Gas

Dear BALI:

I am greatly indebted to you for the preview on your very interesting
work on Baolllus. It looks like much more promising material than IT had
thought when I first saw the Manninger~Tomoesik capers some years ago.

I realize that this ma. is not quite in final form, but as you asked
for my critical comment, I had to bring up points most of which you probably
have already had in mind. First of all, I doubt you need make anyy reference
at all to Jel. unpubl., as the citatione are all covered by Zinder & Lederberg
152, Al&o, pele, this, rather than Stocker Z & L is the primary reference for
transduction by phage.

Let me olear up terminology firet. Traneduction means the transmission of
a fragment, by phage or any other vector (DNA or what have you.) Strictly, one
should not talk about a transduced o¢1] (though we have erred on this ourselves);
I would leave £t+ to you whether to continue this imvreciaion, or to substitute
transinduced or transformed to describe the cell that has been altered when a
genetic fragment wae transduced to it.

Some of my comments relate to my personal judgment on form for publication
(as in J. Bacte) rather than material sorment. They are numbered per marginal
marke in penei!.

1. Is this right-- or fe it anthracis sells plus mesentericus extracts?

2. 9e0 above

3 This whole paragraph could prwebably be omitted in favor of a reference .
to some review (Austrian 1952, Bact. Rev.)among others. I think Groman distinguis’ <<‘
his case at least he does now.

5. Confer/transduce. The latter term would presunpose your conclusions, and
probably should not be used too freely in describing the experimente.

6. Thie ie too oritical to be passed over by “variable results". Can you
present a table?

7. "traneduced” see above. This is not entirely convincing evidéance for
lyaogenickty (vs. admixture of phage + bacteria) unless the cultures were
reisolated repeatedly from sing’e colokies.

8. How were sterility tests made? How long kept? Since the other genetic
markers (except posaibly pathogenicity) are not s0 éistinctivey this becomes
eritical.
9. I assume the motile varients were repurified before further tests.

10. Since this experiment was repeadéd with purified DNAse, it probably should ie
reduced to a lime, and the experimental emphasis put on the latter. The cenclusion
is more important than the historical sequence.

ll. In view of all thie, had you not better sey lysate rather than phage in describing
the active materialj throughout the paper?

12. Your sumaary puts thie better. There Le no evidence the phage playe any role
except perhaps to extract the DNA from the source bacteria.

5. Z&L '52. Best review on pneucoseccal INA Le Modarty '46, Bact Rev.
14. What dees unmesicing mean? Is 4% dietincs fron any other mode of varfationt

13. I am confused on the evidence that thia is tranaduction, 4.6., that a genetic
factor must be present in the donor bacterfa to result in “tranamotilization”.
It would be necessary to compare felated strains for such e comparison. Can the
Chio strain be motilized? Does it then become itself « competent donor for the
tranemotilizetion ef the aon-notile Obie? As things stand now (sea 6.) your systen
might be a wore direct result of lysogenization itsel?, with sexe confusion grom
hoet~-cange wodificetions or the lLke.

16. The comparison is not quite valdd. In Salmonella, about 1/106 phage particles
ie competent, and a bacterLum oan effectively adsorb only about 10-100 phages.
You have not measured the bacterial competence, as table 6 showd about 10° bacteria
in,each experiment. If phage has anything to do with} it, the competence of about
10“ phage/notilization suggests thet, could you get cffective cdsorption at such
low densities, you might get 1-10% of your bacteria transformed with a sufficient
exoess of phage. Your 1072 per phage le very much higher than our 10-6, but is
not necessarily a fundamental distinction in mechanian. (We have a cold transduction
now with an efficiency per phage of 10-1 or betters, but this is an exceptiona’
wace).(Gan't you just spin eut your phage at high speed end see whether the
supernates is still active?)

17+ Den't you wish you had seme distinctive -arkera in your etrains, though! Something
like streptomyoin-resistance should be easy onough, and would disqualify this
conceiwuble source of error altogether. One might imagine that damaged spores
would only germinate under special conditiona.

18. Have you ever observed a spontaneous motile reversion? This would be ideal for
the comparison suggested at 15.

19. Ry undersbanding is that the agent ie present in lysates of phage+ sensitive
bacteria. Can you get it from lysogenics directly?

20. If this 4s a euphemiem for O.C. it is hardly secure.
In sum, I think this is an extremely provocative and competent bit of work. If there

ie any possibility of it, however, I think publication should be deferred until a
few crucial pointe are cleared up:
A. Are any bacilld (in a competent system) lysogenized without being mot4 lized?

(I note here the two stages: the first ia presumably induced by the phage, the
second might conceivably also be induced, but more probably is selected, judging
from comparable experiences with Salmonella. What happens when you plant a
repurified, first atage isclate on motility agar? I think thia stage corresponds

to the "flares" that Stocker et al. noted, and not the trails. :

B. Pobnt 15-6-18 abovee

C. Perhaps some further attempt to remove the phage and leave acthvity. (Can I help
in any way on this?} and

D. Point 17.

C and D are not so essential aa A and Be I would hate to see the same kind of
confusion and misunderstanding come out of this story as there was with diphtheria,
and if a little patience can give a well-rounded account, why no&® wait a short
while longer.

it

If you have an extra copy of your final version, could you let me have (and
requote it alsop if you would)?

Yours thuly,

Joshua Lederberg
Professor of Genetics