STITT

 

Dear Hayes, so

Thank you for your letter of 8.4.52, and the precdding
one,which I was about to answer. Phenomena similar to the ones yoy
describe have in fact been observed by Lederberg or myself or both
in the past month. I shall be airmailing to you in the next few
days a copy of a paper which the Lederbergs and I are sending join-
tly to Genetics; it is being retyped now for you. This paper®# con-
tains the data in a highly condensed form and is designed for ge-
netical readers, while L. and I thought a more microbiological
paper would be suitable forvGM, It is clear enough that this work
has implications which are more pertinent to genetica,and others
Which have more interest for microbiology,so that a microbiological
and a genetical edition would seem both useful. The paper tor wulu
has only been planned,but should be ready soon - of course ites
content cannot differ much from the genetical one,

To anticipate a few of the matters to be developed in
such papers, and which will answer your questions, there are hints
to a system of "relative sexuality",such as those found in a number
of fungi (e.g., Phycomycetes) . The relatively smaller yield of a
F+ x F+ mating as compared kith F-xF+ matings fits within such a
scheme. But tere ism no such a thing as a theory of self-compati-
bility; all that this word can indicate is,in my views, that there
are strains, like F-,which are self-incompatible, without any pre-
judice as to what may happen fsx as to yield for other crosses.

The different genetical contribution of F+ and F- paren-
ts has certainly made the former,simpler view of a fertilization
between two complete,haploid sets impossible . But from data avai-
lable until now it would seem that slightly more complex,but by
no means “unmendelian" explanations can fit the data . It might be
enough,for instance, if the F- parent were polyploid,using this
term very loosely, to account for the polarity fmx of segregations
as affected by F+ . However, the accurate testing of such theories
will pake a longish time, in view of the number of data necessary
and/fhe complication of fitting to them the relevant theories.

T still believe that $hwst use of the word "gamete" is
unacceptable. It is clear enough that a process of fertilization
goes on, and in such a process there are always two opposite game-
tes. However,the use of such a word should,in my views be strictly
controlled until the details of the fertilization process will be
known.

I shal: be very pleased to read your forthcoming paper$

ee en we shall certainly rechprocate, by feng or TQM were

“f foww af ready.
LOTITUTO

 

Dr. Hayes.

Re the Ber’ strain » &@ subculture of which I am enclosing,
I doubt that it wilt be useful in the sense you mention,i.e.
the recovery of a lambda free strains mimgzz it has no marked
radiation resistance in respect of other K-12 strains, I
send it anyhow, as you may like to test a fact which may in-
terest you in relation to your UV experiments ; that is, that
it seems to give a still higher yield of recombinants after
UV irradiation, than a normal F+ strain. I should like to
mention,however, that this strain is now being the subject
of research,both in L.'s laboratory and mine, with a view
to check older data about it,amdxusgxik test its position
in the system of relative sexuality,and more especially, use
it for a morphological demonstration of the fertilization
process, 1 hope you do not mind if I send the strain and re-
serve its main uses ; it may still be useful to you for xmuux
Brekiagnax some of your problems.

The Symposium #§8xr liicrobial Genetics will be held at Pal-

jana, from the 2nd or 3rd of September to the 6th; you will
shortly receive an invitation for it.

Yours sincerely
Cncn Courrlks >

e/to Lederberg

om Ue Jona, 7 ha jt tryst] o pure on.

§