June 1, 1950
REPORT ON RESEARCH PROJECTS

for the
FISCAL YEAR 1949-50

I. Name hederhorg, Joshua Dept. Genetias Proj. No.__gas3ou
Title. Baeterial Ganatica
II. Personnel: (Micg) Ethelyn Lively, Res. Ass't

 

III. Statement of other financial support, if any:

Rockefeller Foundation, $7500/3 years, mainly for supplies
Rational Iastitutes of Health, $3500 idenotics of Salmonella)

IV, Brief statement of specific progress made during the year:

a, A method was developed and verified for detecting genetic recoidination
by the use of "drug"-resistance markers in Beeheriohis goll.

b, Cytological study of haploid and diploid eultures of &. golf ase shom that
pher nuslear patterns are distinguishable, supporting the concept of the nucleus
n bacteria.

c, Additional mtations affecting the formation of the enzyme galcctosidase have
been isolated, ineluding one which establishes the constitutive, rather than adap-
tive, formation of this enzyme, The substrate-spesificitios of galuctosidese and
of the adaptive mechaniss have been shown to be qualitatively distinct, showing
that pre-existent ensyme is probably not the intracellular component with which
substrate reacts in provoking adaptetion.

V. Publications that have appeared in print during the present fiscal year:
Lederberg, J., Bacterial Variation. ann. Rev. Mieroblol.3: 1-22, 1949

Lederberg, J., The Selection of Genetic Recombinations With Bacterial
Growth Inhibitors, d. Bact. $9: 211-215, 1950 (Febr.)

VI. Manuscripts accepted for publication but not yet printed:

Lederverg, J., Teolation and Characterization of Biochemical Nuetants of
Bacteria. Methods of Medical Research, In Press.

The pink copy should be returned to the Graduate School Office on or before
July 1, 1950. The blue copy is for your file.