laut

THE UNIVERSITY OF WISCONSIN

MADISON 6
DEPARTMENT OF ZOOLOGY

BIRGE HALL

6/November/1961

Dear Josh,

Please excuse the delay in acknowledging the chloroplast
information. I've just returned from the Chicago Cell Biology
meetings; the turmoil associated with getting two members of my
lab ready to give papers there had taken up most of my energy.

Hans and I have submitted a manuscript on the "DNA"
in Chlamydomonas chloroplasts to the Jour. Biophys. diochem. Cytol.
about two months ago. Presumably it will appear there in due time.
lhe evidence is simply *eulgen and Acridin Orange staining of a
small chloroplast component which is sensitive to DNAase digestion.
Hans adds the presence in presumably identical regions of small
fibrillar elements which resemble, in EM preparations, the fibriilae
seen in the nuclear area of bacteria and blue green algae, as further

evidence for the DNA nature of this plastid component and proceeds

to develop the idea of the chloroplast as the evolved ex-syxubiont. ~
I am still somewhat concerned with the critical identification of =
DONA and will probably try some labeling experiments in Chlamydomonas. o
The Euglena story, however, is even more ripe for a systematic study

of the nucleic acid content of the plastid. The biochemical studies *

of Brawerman, the classical evidence for self-duplication of Lwoff,

and an informal report from a former student of mine that there may

be non-nuelear incorporation of thymidine in this beast all point to

a need for an investigation combining all available tools. I hope to
begin work on this within the next month together with a new and really
first-rate student whom I've managed to trap. It is in this connection
that I am especially interested in the fudr data you so kindly sent me.
We hope to try this drug on bleached “uglena chloroplasts and observe
the effects with cytochemical as well as biochemical methods. Neddless
to say, I shall keep you informed of the results and will also send

a reprint of the Chlamydomonas paper to your student as soon as I

have some. At the moment, I have but one copy of the MS and must retein

this until the proofs are in.
I am including a reprint of a paper given last September
in Paris and mimeo copies of the two lab efforts towards making the

just past Chicago meeting the mediocre mess that it turned out to be.

With best regards to you and Esther and again many thanks for the

chlowplast information,

Yours,