UNIVERSITY OF LONDON

 

“ oP

POSTGRADUATE MEDICAL SCHOOL
OF LONDON ‘ .

POSGRADMED CHISK LONDON , DUCANE ROAD

Telegrams

Telephone
SHEpherds Buh $08 (4 lines) LONDON, W.12
Department of Bacteriology. 12 November,1952.

 

Dear Luca,

This letter is really just to show you that I have
been a good boy and worked hard and that my knowledge of genetics
has increased infinitely - from zero! I hope you are impréssed}
Actually I have for some time been anxious to determine whether UV
treatment of the F+ parent disturbs the segregation ration of F+ X F-
crosses,and thought that,in the process,I could experiment a bit with
Jim's two-chromosome idea. I have therefore carried out an analysis
of 102 prototrophs(as a preliminary run) from each of the crosses:
» 58+161/F- X W-677/F+ on MA + By primarily "B" cross-overs;
58-161/F+ X W-677/F- on MA + Bl = primarily "a" cross-overs ,and
- 58-161/F+ X W-677/F- on WA alotie= all B,+(checked) and involving
"AN & "B" c.o.s it B, is on "B",as seems
likely.
Due to the fact that Ty is technically tedious while "-677 is only
Gals- and gives some growth on MA + Gal which makes things difficult,
I have restricted the analysis to Lac & Az("A") and SM,Mal & By ("BN").
I enclose the analysis,together with a comment on three anomalies
which struck me as being against a simple AB’ theory. You will probably
find these comments very naive but I am still only a "toddler" and
thought you might like to see how the ratios provided quite independent-
ly fitted your own. I am putting up another 100 from crosses 1 & 2
this week,together with a UV series from an aliquot of the same F+
cultures,

(WF
.

Yours,

fi
&