THE GRADUATE SCHOOL

SSE rr rT rT TT == SlCr ere

UNIVERSITY RESEARCH COMMITTEE

REQUEST FOR RESEARCH SUPPORT FOR THE YEAR 1957-58 MUST BE IN THE

GRADUATE SCHOOL OFFICE NOT LATER THAN JANUARY 17, 1957

(Please submit forms in duplicate)

 

 

Name Lederberg doshua Date Jan. 14, 1957
Last First Middle Initial

Department Gere ties

Title of project Genetics of Bacteria

 

—~~detaiis in annual progress reports—

Results to date: l. Phase variation in Salmonella depends on the alternation between
active and inactive'states' of a single gene.

2. Genetic facters of the host bacterina are ‘transduced’ by phage
particles growm on it. The phage itself behaves as another such genetic factor.

3. Galactose-fermentation in F. coli follows the same ensymatic
pathway ae in mn. Mutants affecting different enzymes have been found; some are
homologous with the hereditary disease in aan, ‘galactesemia’. as a rule, mtante
affecting the same enayme show a genetic position-effect with ons another, in accord
with the popular conception of a unitary gene-enzyme relationship; however, some ex-
ceptions have been found and should be analysed further.

4. Penioillin inhibits the synthesis of the becterial cell-@all, resul-
ting in the production of wall-less protoplasts. fhe protoplasts can be cultivated, if
embedded in agar media, to give what had been described as L-colonies.

Procedure — indicete the essential working plans: We plan te contime these studies
along the same lines as now in progress. tional facéés are;

1. The attempted use of pretoplasts as recipients for free DNA. Since they lack ax
rigid external barrier, they might be more amenable to the introduction of free chromo-
some fragamits (i.e., DA~mediated, rather than phage-mediated, transduction).

2. A seareh for mtants which are blocked in the biosynthesis of specific eell~wall
components. One auch mitant 1s already available, faving been found Casually by B. Daris,
and requires diaminopimelic acid. In the absence of this compound, the mtant foras
proteplasts. Such omtants would furnish specific bioassays for wall components like
Gimminopimelic acid,

3. Mr. Richter, who is completing an M.A. thesis on genetio napping in 5. coli, will
work on a collaborative project with Prof. C. Heidelberger on ‘genetic chemistry’.

He will stady the genetic effects of the incorporation of bromouracil ani other
purine-pyrimidine analgnes into bacterial DMA.

Budget - (OVER)
Budget ~
Staff* # are inoushents
Research Assistants (A $1920; Acad Yr $1600) |
A Tetwao Tino 1920

A # Alan &x Richter ("ARF fellow) 1920
A # Robert HE. aright | 1920
A ne 1920
Other
7680
$

*List names only if it is fairly definite the person will be
available; otherwise open positions should be indiceted.

For sicllled undergraduate aasistants coproaching tre
Hour 9 'deT8 of graduate research agsistants, Other fumds are
statle to cover cests ef routine dishwashing.

Supplies and Equipment

3 720

TOTAL REQUEST